BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, and similar proteins; This subfamily includes potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, all of which function as adaptors of Cullin3 based ubiquitin E3 ubiquitin ligases. KCTD2 suppresses gliomagenesis by destabilizing c-Myc. KCTD5 is a negative regulator of the AKT pathway, a key signaling cascade frequently deregulated in cancer. KCTD5 does not impact the operation of Kv4.2, Kv3.4, Kv2.1, or Kv1.2 channels. KCTD17 polyubiquitylates trichoplein, a protein involved in ciliogenesis down-regulation. It is a positive regulator of ciliogenesis, playing a crucial role in the initial steps of axoneme extension. A missense mutation in KCTD17 causes autosomal dominant myoclonus-dystonia (M-D). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. KCTD5 and KCTD17 BTB domains form pentamer structures.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  23 WVKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVLD-GVSEEGVLE 101
Cdd:cd18362    1 WVKLNVGGTYFLTTRTTLCRDPKSFLCRLCQEDPDLPSDKDETGAYLIDRDPTYFGPILNYLRHGKLIIDkDLAEEGVLE 80

                 ....*
gi 665389148 102 EAEFY 106
Cdd:cd18362   81 EAEFY 85

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, and similar proteins; This subfamily includes potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, all of which function as adaptors of Cullin3 based ubiquitin E3 ubiquitin ligases. KCTD2 suppresses gliomagenesis by destabilizing c-Myc. KCTD5 is a negative regulator of the AKT pathway, a key signaling cascade frequently deregulated in cancer. KCTD5 does not impact the operation of Kv4.2, Kv3.4, Kv2.1, or Kv1.2 channels. KCTD17 polyubiquitylates trichoplein, a protein involved in ciliogenesis down-regulation. It is a positive regulator of ciliogenesis, playing a crucial role in the initial steps of axoneme extension. A missense mutation in KCTD17 causes autosomal dominant myoclonus-dystonia (M-D). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. KCTD5 and KCTD17 BTB domains form pentamer structures.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  23 WVKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVLD-GVSEEGVLE 101
Cdd:cd18362    1 WVKLNVGGTYFLTTRTTLCRDPKSFLCRLCQEDPDLPSDKDETGAYLIDRDPTYFGPILNYLRHGKLIIDkDLAEEGVLE 80

                 ....*
gi 665389148 102 EAEFY 106
Cdd:cd18362   81 EAEFY 85

Broad-Complex, Tramtrack and Bric a brac; Domain in Broad-Complex, Tramtrack and Bric a brac. Also known as POZ (poxvirus and zinc finger) domain. Known to be a protein-protein interaction motif found at the N-termini of several C2H2-type transcription factors as well as Shaw-type potassium channels. Known structure reveals a tightly intertwined dimer formed via interactions between N-terminal strand and helix structures. However in a subset of BTB/POZ domains, these two secondary structures appear to be missing. Be aware SMART predicts BTB/POZ domains without the beta1- and alpha1-secondary structures.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148    23 WVKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDlisdRDETGAYLIDRDPKYFAPVLNYLRHGKLVLDGVSEEGVLEE 102
Cdd:smart00225   1 DVTLVVGGKKFHAHKAVLAAHSPYFKALFSSDFKE----SDKSEIYLDDVSPEDFRALLNFLYTGKLDLPEENVEELLEL 76

                           90       100
                   ....*....|....*....|
gi 665389148   103 AEFYNVTQLIALLKECILHR 122
Cdd:smart00225  77 ADYLQIPGLVELCEEFLLKL 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, and similar proteins; This subfamily includes potassium channel tetramerization domain-containing proteins KCTD2, KCTD5, and KCTD17, all of which function as adaptors of Cullin3 based ubiquitin E3 ubiquitin ligases. KCTD2 suppresses gliomagenesis by destabilizing c-Myc. KCTD5 is a negative regulator of the AKT pathway, a key signaling cascade frequently deregulated in cancer. KCTD5 does not impact the operation of Kv4.2, Kv3.4, Kv2.1, or Kv1.2 channels. KCTD17 polyubiquitylates trichoplein, a protein involved in ciliogenesis down-regulation. It is a positive regulator of ciliogenesis, playing a crucial role in the initial steps of axoneme extension. A missense mutation in KCTD17 causes autosomal dominant myoclonus-dystonia (M-D). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. KCTD5 and KCTD17 BTB domains form pentamer structures.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  23 WVKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVLD-GVSEEGVLE 101
Cdd:cd18362    1 WVKLNVGGTYFLTTRTTLCRDPKSFLCRLCQEDPDLPSDKDETGAYLIDRDPTYFGPILNYLRHGKLIIDkDLAEEGVLE 80

                 ....*
gi 665389148 102 EAEFY 106
Cdd:cd18362   81 EAEFY 85

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 2 (KCTD2); KCTD2 is a BTB/POZ domain-containing protein that functions as an adaptor of Cullin3 E3 ubiquitin ligase. It suppresses gliomagenesis by destabilizing c-Myc. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. KCTD5 and KCTD17 BTB domain, highly similar to KCTD2, form pentamer structures.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  22 QWVKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVLDG-VSEEGVL 100
Cdd:cd18389    1 KWVRLNVGGTYFVSTKQTLCRDPKSFLYRLCQEDPDLDSDKDETGAYLIDRDPTYFGPILNYLRHGKLIINKeLAEEGVL 80

                         90       100
                 ....*....|....*....|....*
gi 665389148 101 EEAEFYNVTQLIALLKECILHRDQR 125
Cdd:cd18389   81 EEAEFYNIASLVRLVKERIRDNENR 105

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 9 (KCTD9); KCTD9 is a BTB/POZ domain-containing protein that contributes to liver injury through NK cell activation during hepatitis B virus-induced acute-on-chronic liver failure. It functions as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex, which mediates the ubiquitination of target proteins, leading to their degradation by the proteasome. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD9 BTB domain forms a pentameric structure.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  22 QWVKLNVGGTYFLTTKTTL-SRDPNSFLSRLIQEDCDLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVLD-GVSEEGV 99
Cdd:cd18368    1 DWIKLNVGGRIFTTTRSTLvKKEPDSMLARMFSDDSTWPSSRDENGAYLIDRSPEYFEPILNYLRHGQLILNdGLNPLGV 80

                         90       100
                 ....*....|....*....|
gi 665389148 100 LEEAEFYNVTQLIALLKECI 119
Cdd:cd18368   81 LEEAKFFGIQSLIEILEQLI 100

BTB/POZ domain; In voltage-gated K+ channels this domain is responsible for subfamily-specific assembly of alpha-subunits into functional tetrameric channels. In KCTD1 this domain functions as a transcriptional repressor. It also mediates homomultimerization of KCTD1 and interaction of KCTD1 with the transcription factor AP-2-alpha.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148   24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDliSDRDETGAYLIDRDPKYFAPVLNYLRH-GKL-VLDGVSEEGVLE 101
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRFPDTRLGRLLELECD--DYDDDTNEYFFDRSPKHFETILNFYRTgGKLhRPEEVCLDEFLE 78

                          90
                  ....*....|....*..
gi 665389148  102 EAEFYNVTQLIalLKEC 118
Cdd:pfam02214  79 EAEFYGLDELA--LELC 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 3 (KCTD3); KCTD3, also called renal carcinoma antigen NY-REN-45, is a BTB/POZ domain-containing protein that is an accessory subunit of potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), upregulating its cell-surface expression and current density without affecting its voltage dependence and kinetics. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDcdLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVLDGVSEEGVLEEA 103
Cdd:cd18392    4 IQLNVGGTRFSTSRQTLMWIPDSFFSSLLSGR--ISSLKDETGAIFIDRDPTAFVPILNFLRTKELDLRGVNINVLRHEA 81

                 ....*.
gi 665389148 104 EFYNVT 109
Cdd:cd18392   82 EFYGIT 87

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 3 (KCTD3) and SH3KBP1-binding protein 1 (SHKBP1); The group of KCTD proteins includes KCTD3 and SHKBP1. KCTD3, also called renal carcinoma antigen NY-REN-45, is a BTB/POZ domain-containing protein that is an accessory subunit of potassium/sodium hyperpolarization-activated cyclic nucleotide-gated channel 3 (HCN3), upregulating its cell-surface expression and current density without affecting its voltage dependence and kinetics. SHKBP1, also called SETA-binding protein 1, interacts with cathepsin B and participates in tumor necrosis factor (TNF)-induced apoptosis in ovarian cancer cells. It can promote epidermal growth factor receptor (EGFR) signaling by interrupting c-Cbl-CIN85 complex and inhibiting EGFR degradation. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIqeDCDLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVLDGVSEEGVLEEA 103
Cdd:cd18363    4 INLNVGGKRFSTSRQTLTWIPDSFFTSLL--SGRISSLKDETGAIFIDRDPKLFSIILNYLRTKEIDLRNVDISSLRHEA 81

                 ....*
gi 665389148 104 EFYNV 108
Cdd:cd18363   82 EFYGI 86

Broad-Complex, Tramtrack and Bric a brac; Domain in Broad-Complex, Tramtrack and Bric a brac. Also known as POZ (poxvirus and zinc finger) domain. Known to be a protein-protein interaction motif found at the N-termini of several C2H2-type transcription factors as well as Shaw-type potassium channels. Known structure reveals a tightly intertwined dimer formed via interactions between N-terminal strand and helix structures. However in a subset of BTB/POZ domains, these two secondary structures appear to be missing. Be aware SMART predicts BTB/POZ domains without the beta1- and alpha1-secondary structures.

                           10        20        30        40        50        60        70        80
                   ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148    23 WVKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDlisdRDETGAYLIDRDPKYFAPVLNYLRHGKLVLDGVSEEGVLEE 102
Cdd:smart00225   1 DVTLVVGGKKFHAHKAVLAAHSPYFKALFSSDFKE----SDKSEIYLDDVSPEDFRALLNFLYTGKLDLPEENVEELLEL 76

                           90       100
                   ....*....|....*....|
gi 665389148   103 AEFYNVTQLIALLKECILHR 122
Cdd:smart00225  77 ADYLQIPGLVELCEEFLLKL 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in voltage-gated potassium (Kv) channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. This family includes several groups of alpha subunits such as KCNA/Kv1 family of Shaker-type Kv channels, KCNB/Kv2 family of Shab-type Kv channels, KCNC/Kv3 family of Shaw-type Kv channels, KCND/Kv4 family of Shal-type Kv channels, KCNF/Kv5 subfamily of Kv channels, KCNG/Kv6 subfamily of Kv channels, KCNV/Kv8 subfamily of Kv channels, and KCNS/Kv9 subfamily of Kv channels. Kv alpha subunits form functional homo- or hetero-tetrameric channels (typically with other alpha subunits from the same subfamily) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. KCNQ/Kv7 channels are not included in this family, since they do not contain a BTB/POZ domain.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDEtgaYLIDRDPKYFAPVLNYLRHGKL-VLDGVSEEGVLEE 102
Cdd:cd18317    1 VVLNVGGTRFELSRSTLLRFPDTRLGKLAKESHAYDESTNE---YFFDRNPEVFEAILDYYRTGELhLPSNVCPASFKEE 77

                 ....
gi 665389148 103 AEFY 106
Cdd:cd18317   78 LEFW 81

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 7 (KCTD7); KCTD7 is a BTB/POZ domain-containing protein that has an impact on K+ fluxes, neurotransmitter synthesis, and neuronal function. It functions as a regulator of potassium conductance in neurons, and is involved in the control of excitability of cortical neurons. Mutations in KCTD7 may cause progressive myoclonus epilepsy (PME). The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLisDRDETGAYLIDRDPKYFAPVLNYLRHGKLVLDGVSEEgVLEEA 103
Cdd:cd18366    6 VPLNVGGMHFTTRLSTLRKYEDSMLAAMFSGRHHI--PKDSEGRYFIDRDGSYFGYILNFLRDGDLPPRERARA-VYKEA 82

                         90
                 ....*....|
gi 665389148 104 EFYNVTQLIA 113
Cdd:cd18366   83 QYYGIGPLIE 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 14 (KCTD14); KCTD14 is a BTB/POZ domain-containing protein with unknown biological function. KCTD proteins play crucial roles in a variety of fundamental biological processes, such as protein ubiquitination and degradation, suppression of proliferation or transcription, cytoskeleton regulation, tetramerization and gating of ion channels and others. Some KCTD proteins are involved in protein ubiquitination as part of the CRL (Cullin RING Ligase) E3 ligases. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  22 QWVKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDetGAYLIDRDPKYFAPVLNYLRHGKLVLDGVSEegVLE 101
Cdd:cd18371    2 QVVSLNVGGHIYTTTLSTLRKFPGSKLAELFNGQPKLRTDSE--GRYFIDRDGTYFRYILEYLRTNQVPTQHIQE--VYK 77

                         90
                 ....*....|....*.
gi 665389148 102 EAEFYNVTQLIALLKE 117
Cdd:cd18371   78 EALFYDIEPLVKLLEE 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein KCTD11; KCTD11 may function as an antagonist of the Hedgehog pathway of cell proliferation and differentiation by affecting the nuclear transfer of transcription factor GLI1, thus maintaining cerebellar granule cells in the undifferentiated state. It is a probable substrate-specific adapter for a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex towards HDAC1. It contains a BTB/POZ domain; in some cases the domain may be truncated. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. Variants of the human/mouse KCTD11 appear to contain truncated BTB/POZ domains.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLI--SDRDETGAYLIDRDPKYFAPVLNYLRHGKLVL-DGVSEEGVL 100
Cdd:cd18370    1 VTLNVGGTLYSTTLETLTRFPDSMLGAMFRAGTPIPpnLNMQGGGHYFIDRDGKAFRHILNFLRLGRLDLpRGYGETALL 80

                 ....*..
gi 665389148 101 E-EAEFY 106
Cdd:cd18370   81 RaEADFY 87

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 21 (KCTD21); KCTD21, also calledz KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 2 (KCASH2), is a BTB/POZ domain-containing protein that functions as a substrate-specific adaptor of cullin-3, promoting the ubiquitination and degradation of histone deacetylase HDAC1, thereby inhibiting the deacetylation-mediated transcriptional activation of the Hedgehog effectors Gli1 and Gli2. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDcdLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVL-DGVSEEGVLE- 101
Cdd:cd18395    3 ITLNVGGKLYTTSLATLTRYPDSMLGAMFSGK--FPTKKDSQGNCFIDRDGKIFRYILNFLRTSHLDLpEDFQEMGLLKr 80

                         90
                 ....*....|....*.
gi 665389148 102 EAEFYNVTQLIALLKE 117
Cdd:cd18395   81 EADFYQIQPLIEALQE 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD10 (BACURD3), KCTD13 (BACURD1), and TNFAIP1 (BACURD2); This subfamily of KCTD proteins, also called the BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein (BACURD) subfamily, includes KCTD10 (BACURD3), KCTD13 (BACURD1), and TNFAIP1 (BACURD2). KCTD10 is a BTB/POZ domain-containing protein that interacts with proliferating cell nuclear antigen (PCNA) and polymerase delta, and participates in DNA repair, DNA replication, and cell-cycle control. Its down-regulation could inhibit cell proliferation. KCTD10 also plays crucial roles in embryonic angiogenesis and heart development in mammals by negatively regulating the Notch signaling pathway. KCTD13 is a BTB/POZ domain-containing protein that may function as a substrate-specific adaptor of a BCR (BTB-CUL3-RBX1) E3 ubiquitin-protein ligase complex that mediates the ubiquitination of RhoA, leading to its degradation by the proteasome, thereby regulating the actin cytoskeleton and cell migration. TNFAIP1, also called protein B12, is a BTB/POZ domain-containing protein that is involved in DNA replication, DNA damage repair, cell apoptosis, and is implicated in human diseases including cancer, Alzheimer's disease (AD) and type 2 diabetic nephropathy. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. KCTD10 and KCTD13 BTB domains form a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNsFLSRLIQEDCDLISDRDetGAYLIDRDPKYFAPVLNYLRHGKLVL-DGVSE-EGVLE 101
Cdd:cd18369    1 VKLNVGGSLHYTTIGTLTKQDT-MLRAMFSGRMEVLTDSE--GWILIDRCGKHFGTILNYLRDGSVPLpESRRElAELLA 77

                         90
                 ....*....|.
gi 665389148 102 EAEFYNVTQLI 112
Cdd:cd18369   78 EAKYYLVQGLV 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 12 (KCTD12); KCTD12, also called predominantly fetal expressed T1 domain (Pfetin), is a BTB/POZ domain-containing protein that is an auxiliary subunit of GABAB receptors associated with mood disorders. It regulates agonist potency and kinetics of GABAB receptor signaling. It promotes tumorigenesis by facilitating CDC25B/CDK1/Aurora A-dependent G2/M transition. It also regulates colorectal cancer cell stemness through the ERK pathway. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVL-DGVSEEGVLE- 101
Cdd:cd18397    5 VELNVGGQVYVTRHTTLVSVPDSLLWHMFSQQKPGELARDSKGRFFLDRDGFLFRYILDYLRDLQLVLpDYFPERSRLQr 84

                         90
                 ....*....|....
gi 665389148 102 EAEFYNVTQLIALL 115
Cdd:cd18397   85 EAEFFQLPELVKRL 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein KCTD8; KCTD8, a BTB/POZ domain-containing protein, is an auxiliary subunit of GABA-B receptors that determine the pharmacology and kinetics of the receptor response. It interacts as a tetramer with GABRB1 and GABRB2. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDETGAYLIDRDPKYFAPVLNYLRHGKLVL-DGVSE-EGVLE 101
Cdd:cd18396    6 VELNVGGQVYVTKHSTLLSVPDSTLASMFSRRAARELPRDNRGRFFIDRDGFLFRYVLDYLRDKQLALpDHFPEkERLLR 85

                         90
                 ....*....|....*
gi 665389148 102 EAEFYNVTQLIALLK 116
Cdd:cd18396   86 EAEYFQLGDLVKLLT 100

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCND/Kv4 subfamily of Shal-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv4, also known as subfamily D, contains three alpha subunit members, Kv4.1 (KCND1), Kv4.2 (KCND2), and Kv4.3 (KCND3), which are orthologs of the Shal gene in Drosophila. They are A-type potassium channels that mediate the native, fast inactivating (A-type) K+ current (IA) described both in the nervous system (A currents) and the heart (transient outward current). Kv4/KCND subfamily alpha subunits form functional homo- or hetero-tetrameric channels through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. They are modulated by cytoplasmic KChIPs/KCNIPs (Kv-channel interacting proteins), which are small calcium binding proteins with EF-hand-like domains.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSrliQEDCDLISDrDETGAYLIDRDPKYFAPVLNYLRHGKL 89
Cdd:cd18380    2 IVINVSGRRFETWKNTLEKYPDTLLG---STEKEFFYD-DDTKEYFFDRDPEIFRHILNFYRTGKL 63

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNB/Kv2 subfamily of Shab-type voltage-dependent potassium channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv3, also known as subfamily C, contains two alpha subunit members, Kv2.1 (KCNB1) and Kv2.2 (KCNB2), which are orthologs of the Shab gene in Drosophila. They are delayed-rectifier potassium currents in various neurons, although their physiological roles often remain elusive. Kv2/KCNB subfamily alpha subunits form functional homo- or hetero-tetrameric channels (with other alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRL--------IQEDCDLIS-DRDEtgaYLIDRDPKYFAPVLNYLRHGKL-VLDG 93
Cdd:cd18378    4 VLLNVGGVRHEVLWRTLDRLPRTRLGRLrecnthesLLELCDDYDlEDNE---YFFDRHPGAFTSILNFYRTGKLhMPEE 80

                         90       100
                 ....*....|....*....|....*....
gi 665389148  94 VSEEGVLEEAEFYNVTQLiaLLKECILHR 122
Cdd:cd18378   81 MCVLSFSQELEYWGIDEI--YLESCCQHR 107

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 2 (KCND2); KCND2, also called voltage-gated potassium channel subunit Kv4.2, is a major pore-forming subunit in somatodendritic subthreshold A-type potassium current I(SA) channels. It mediates transmembrane potassium transport in excitable membranes, primarily in the brain. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCND2 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv4/KCND alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif. It is modulated by cytoplasmic KChIPs/KCNIPs (Kv-channel interacting proteins), which are small calcium binding proteins with EF-hand-like domains.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|.
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRliqedcdliSDRD-----ETGAYLIDRDPKYFAPVLNYLRHGKL 89
Cdd:cd18418    2 IVLNVSGTRFQTWRNTLERYPDTLLGS---------SERDffyheETQEYFFDRDPDIFRHILNFYRTGKL 63

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel protein Shaw; Shaw, also called Shaw2, is a voltage-gated potassium channel in Drosophila. It mediates transmembrane potassium transport in excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. Shaw is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....
gi 665389148  21 DQWVKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDEtgaYLIDRDPKYFAPVLNYLRHGKL 89
Cdd:cd18416    1 ENRVVLNVGGIRHETYKATLKKIPATRLSRLTEALANYDPVLNE---YFFDRHPGVFAQILNYYRTGKL 66

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in tumor necrosis factor, alpha-induced protein 1, endothelial (TNFAIP1); TNFAIP1, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 2 (BACURD2), or protein B12, is a BTB/POZ domain-containing protein that is involved in DNA replication, DNA damage repair and cell apoptosis, and is implicated in human diseases including cancer, Alzheimer's disease (AD) and type 2 diabetic nephropathy. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The BTB domains of other BACURD subfamily members, KCTD10 and KCTD13, form a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  21 DQWVKLNVGGTYFLTTKTTLSRDpNSFLSRLIQEDCDLISDRDetGAYLIDRDPKYFAPVLNYLRHGKLVLDGVSEE--G 98
Cdd:cd18401    2 NKYVRLNVGGSLYYTTVQVLTRH-DTMLKAMFSGRMEVLTDKE--GWILIDRCGKHFGTILNYLRDDTVALPKSRQEikE 78

                         90
                 ....*....|....
gi 665389148  99 VLEEAEFYNVTQLI 112
Cdd:cd18401   79 LMAEAKYYLIQGLV 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 15 (KCTD15); KCTD15 is a BTB/POZ domain-containing protein that plays a role in the regulation of neural crest (NC) formation and other steps in embryonic development. It inhibits AP2 transcriptional activity by interaction with its activation domain. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization. The KCTD1 BTB domains, closely related to KCTD15, form pentamers.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRDETgAYLIDRDPKYFAPVLNYLRHGKLVL-DGVSEEGVL-E 101
Cdd:cd18388    4 VHIDVGGHMYTSSLATLTKYPDSRISRLFNGTEPIVLDSLKQ-HYFIDRDGEIFRYILSFLRTSKLLLpEDFKDFNLLyE 82

                         90
                 ....*....|....*.
gi 665389148 102 EAEFYnvtQLIALLKE 117
Cdd:cd18388   83 EAKYY---QLQPMVKE 95

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily C members KCNC1 and KCNC3; KCNC1 (also called NGK2, voltage-gated potassium channel subunit Kv3.1, or voltage-gated potassium channel subunit Kv4) and KCNC3 (also called KSHIIID or voltage-gated potassium channel subunit Kv3.3) play important roles in the rapid repolarization of fast-firing brain neurons. Assuming opened or closed conformations in response to the voltage difference across the membrane, the proteins form tetrameric potassium-selective channels through which potassium ions may pass in accordance with their electrochemical gradient. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNC1 and KCNC3 are alpha subunit that form functional homo- or hetero-tetrameric channels (with other alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQEDCDLISDRD-ETGAYLIDRDPKYFAPVLNYLRHGKL 89
Cdd:cd18414    5 IVINVGGTRHETYRSTLRTLPGTRLAWLAEPDAHSNFDYDpRADEFFFDRHPGVFAHILNYYRTGKL 71

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily C members KCNC2 and KCNC4; KCNC2, also called Shaw-like potassium channel or voltage-gated potassium channel Kv3.2, is a delayed rectifier voltage-gated potassium channel that mediates transmembrane potassium transport in excitable membranes, primarily in the brain. It contributes to the regulation of the fast action potential repolarization and in sustained high-frequency firing in neurons of the central nervous system. KCNC4, also called KSHIIIC or voltage-gated potassium channel subunit Kv3.4, is a novel high-voltage-activating, tetraethylammonium (TEA)-sensitive, type-A potassium channel that mediates the voltage-dependent potassium ion permeability of excitable membranes. It plays a pivotal role in oxidative stress-related neural cell damage as an oxidation-sensitive channel. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNC2 and KCNC4 are alpha subunit that form functional homo- or hetero-tetrameric channels (with other alpha subunits) through their BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*...
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLI----QEDC-----DLISDRDETGA---YLIDRDPKYFAPVLNYLRHGKL 89
Cdd:cd18415    4 IILNVGGTRHETYRSTLKTLPGTRLALLAssdpQGDCltqcsQVGGSDGSPGGgneFFFDRHPGVFAYVLNYYRTGKL 81

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily V member 2 (KCNV2); KCNV2, also called voltage-gated potassium channel subunit Kv8.2, is a modulatory voltage-gated potassium channel alpha subunit that modulates channel activity by shifting the threshold and the half-maximal activation to more negative values. KCNV2 is essential for visual function and cone survival. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNV2 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  26 LNVGGTYFLTTKTTLSRDPNSFLSRLI-----QEDCDLISDRDE-TGAYLIDRDPKYFAPVLNYLRHGKL-VLDGVSEEG 98
Cdd:cd18425    3 INVGGTSYQISYRVAASYPKTRIGRLAtytdrSRKLDLCDDYNVqNDEYFFDRDPAVFHHIYNFYRTGVLwVKDELCPRN 82

                         90
                 ....*....|
gi 665389148  99 VLEEAEFYNV 108
Cdd:cd18425   83 FLEEINYWGV 92

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNS/Kv9 subfamily of potassium voltage-gated channels; Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. The potassium voltage-gated channel subfamily Kv9, also known as subfamily S, includes KCNS1 (Kv9.1), KCNS2 (Kv9.2) and KCNS3 (Kv9.3). They are regulatory alpha subunits that cannot form functional homo-tetrameric channels. Both KCNS1 and KCNS2 are delayed-rectifier K(+) channel alpha subunits that can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 and KCNB2. KCNS3 is a delayed-rectifier K(+) channel alpha subunit linked to tissue oxygenation responses. It can form functional heterotetrameric channels with KCNB1, and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRL--------IQEDCDLISDRDETgaYLIDRDPKYFAPVLNYLRHGKL-VLDGV 94
Cdd:cd18384    1 IRINVGGFRRRLSASALLRFPGTRLGRLlachseeaILELCDDYDVAARE--FYFDRNPGFFLYVLHFYRTGKLhVMDEL 78

                         90
                 ....*....|....*..
gi 665389148  95 SEEGVLEEAEFYNVTQL 111
Cdd:cd18384   79 CVFSFSQEIEYWGINEF 95

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 3 (KCNS3); KCNS3, also called delayed-rectifier K(+) channel alpha subunit 3 or voltage-gated potassium channel subunit Kv9.3, is an alpha subunit of voltage-gated potassium channel linked to tissue oxygenation responses. It can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS3 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRL--------IQEDCDLISDRDETgaYLIDRDPKYFAPVLNYLRHGKL-VLDGV 94
Cdd:cd18428    3 INLNVGGFKQSVDQSTLLRFPHTRLGKLlnchseeaILELCDDYSVADKE--YYFDRNPSLFRYVLNFYYTGKLhVMEEL 80

                         90       100       110
                 ....*....|....*....|....*....|
gi 665389148  95 SEEGVLEEAEFYNVTQLiaLLKECILHRDQ 124
Cdd:cd18428   81 CVFSFCQEIEYWGINEL--FIDSCCSNRYQ 108

first BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 19 (KCTD19); KCTD19 is a BTB/POZ domain-containing protein with unclear biological function. It may be a host factor involved in Nef-induced downregulation of MHC-I. Nef is a HIV-1-encoded protein that plays a key role in the development of AIDS. KCTD19 contains two BTB domains. This model corresponds to the first domain. The BTB/POZ domain, also known as tetramerization (T1) domain, is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. KCTD family BTB domains can adopt a wide range of oligomerization geometries, including homodimerization, tetramerization, and pentamerization.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  27 NVGGTYFLTTKTTLSRDPNSFLSRliqEDCDLisDRDETGAYLIDRDPKYFAPVLNYLRHGKLVLDGVSEEGVL-EEAEF 105
Cdd:cd18373    4 NVGGWIFSVPKSKLAQFPDSLLWK---EASSL--SESENTRLFIDRDGFTFRHVHYYLQTSKLSSSSCSELNLLyEQAAG 78

                         90
                 ....*....|
gi 665389148 106 YNVTQLIALL 115
Cdd:cd18373   79 LQLTSLLQAL 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 2 (KCNS2); KCNS2, also called delayed-rectifier K(+) channel alpha subunit 2 or voltage-gated potassium channel subunit Kv9.2, is a modulatory alpha subunit of voltage-gated potassium channel that can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1) and KCNB2 (also known as Kv2.2), and further modulates the delayed rectifier voltage-gated potassium channel activation and deactivation rates of KCNB1 and KCNB2. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNS2 is a regulatory alpha subunit that cannot form a functional homo-tetrameric channel. It forms hetero-tetrameric channels (with other functional alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  24 VKLNVGGTYFLTTKTTLSRDPNSFLSRLIQedC-------DLISDRDET-GAYLIDRDPKYFAPVLNYLRHGKL-VLDGV 94
Cdd:cd18427    2 ISINVGGFKKRLRSHTLLRFPETRLGRLLS--CrskesilELCDDYDDTkNEFYFDRNPELFPYVLHFYNTGKLhVMGEL 79

                         90
                 ....*....|....*..
gi 665389148  95 SEEGVLEEAEFYNVTQL 111
Cdd:cd18427   80 CVFSFSQEIEYWGINEF 96

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily B member 2 (KCNB2); KCNB2, also called voltage-gated potassium channel subunit Kv2.2, mediates transmembrane potassium transport in excitable membranes, primarily in the brain and smooth muscle cells. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a tetrameric potassium-selective channel through which potassium ions may pass in accordance with their electrochemical gradient. KCNB2 contributes to the delayed-rectifier voltage-gated potassium current in cortical pyramidal neurons and smooth muscle cells. Voltage-gated potassium (Kv) channels are composed of alpha subunits, which form the actual conductance pore, and cytoplasmic beta subunits, which are auxiliary proteins that associate with alpha subunits to modulate the activity of the Kv channel. KCNB2 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other alpha subunits) through its BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif.

                         10        20        30        40        50        60        70        80
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 665389148  13 NVLKKQGTDQWVKLNVGGTYFLTTKTTLSRDPNSFLSRL--------IQEDCDLISDRDETgaYLIDRDPKYFAPVLNYL 84
Cdd:cd18412    8 EIIRSKACSRRVKINVGGLNHEVLWRTLDRLPRTRLGKLrdcnthesLLEVCDDYNLNENE--YFFDRHPGAFTSILNFY 85

                 ....*
gi 665389148  85 RHGKL 89
Cdd:cd18412   86 RTGKL 90