BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain superfamily; Proteins in this superfamily are characterized by the presence of a common protein-protein interaction motif of about 100 amino acids, known as the BTB/POZ domain. Members include transcription factors, oncogenic proteins, ion channel proteins, and potassium channel tetramerization domain (KCTD) proteins. They have been identified in poxviruses and many eukaryotes, and have diverse functions, such as transcriptional regulation, chromatin remodeling, protein degradation and cytoskeletal regulation. Many BTB/POZ proteins contain one or two additional domains, such as kelch repeats, zinc-finger domains, FYVE (Fab1, YOTB, Vac1, and EEA1) fingers, or ankyrin repeats, among others. These special additional domains or interaction partners provide unique characteristics and functions to BTB/POZ proteins. In ion channel proteins and KCTD proteins, the BTB/POZ domain is also called the tetramerization (T1) domain.

                         10        20        30        40        50        60
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 157819025   1 MLGAMFRADTLMPANLNPQGDGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQ 65
Cdd:cd18370   24 MLGAMFRAGTPIPPNLNMQGGGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLRAEADFYQ 88

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 157819025   1 MLGAMFRADTLMPANLNPQGDGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQ 65
Cdd:cd18370   24 MLGAMFRAGTPIPPNLNMQGGGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLRAEADFYQ 88

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
                  ....*....|....*....|....*....|....*....|....*....|.
gi 157819025   21 DGHYFIDRDGKAFRHILNFLRLGrLDLPRGYGETAL-LKAEADFYQIRPLL 70
Cdd:pfam02214  40 TNEYFFDRSPKHFETILNFYRTG-GKLHRPEEVCLDeFLEEAEFYGLDELA 89

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*
gi 157819025   1 MLGAMFRADTLMPANLNPQGDGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQ 65
Cdd:cd18370   24 MLGAMFRAGTPIPPNLNMQGGGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLRAEADFYQ 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD6, KCTD21 and similar proteins; KCTD6, also called KCASH3 (KCTD containing, Cullin3 adaptor, suppressor of Hedgehog 3), is a substrate-specific adaptor of cullin-3, effectively regulating protein levels of the muscle small ankyrin-1 isoform 5 (sAnk1.5). KCTD21, also called KCASH2, 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 157819025   1 MLGAMFRADtlMPANLNPQGDghYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQIRPLLDAL 73
Cdd:cd18365   26 MLGAMFSGS--MPTTRDDQGN--YFIDRDGTLFRYILNFLRSSQLSLPEDFKEYDLLLREADFYQIEPLIEAL 94

BTB/POZ domain-containing protein KCTD11/21 C-terminus; This family represents the C-terminal region of BTB/POZ domain-containing protein KCTD11 (known as REN: EGF-, NGF- and retinoic acid-responsive gene) and one homolog, a member of KCTD containing, Cullin3 adaptor, suppressor of Hedgehog (KCASH) family, KCASH2-KCTD21 protein. They share high similarity and a BTB domain responsible for oligomerization and formation of a Cullin3 ubiquitin ligase complex, specific expression in brain and cerebellum where they have a role in neuronal differentiation, and suppressor activity on acetylation-dependent Hedgehog/Gli signalling through ubiquitination and degradation of histone deacetylase 1. These proteins have been described as tumor suppressors that inhibit medulloblastoma growth by antagonizing Hedgehog signalling.

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 157819025   88 ALLHADVDVSPRLVHFSARRGPHHYELSSVQVDTFRANLFCTDPECLAAMRNR-FGVASGDRA------EGGPHFRLEWA 160
Cdd:pfam19329   4 AMLNISLDQKMQTVHFTVREAPQIYSLSSSTMEVFNANIFCTSGLFLKLLGSQlCYFFNGNLSpicselEDQNHLTLQWV 83

                          90       100       110       120       130       140       150
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|..
gi 157819025  161 SRPQELPEVEYQRLGLQPLWTggPEDRREVVNTPTFLEEVLRVALEHGFRLDSVFPDPEDLLNSRSLRFVRH 232
Cdd:pfam19329  84 AAVEGLPEEEYTLQNLKRLWV--FPANKQINSFQAFVEEVLKIAMNDGFCMDSSHPSSLDFMNNKIIRLIRY 153

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins, KCTD1 and KCTD15; This subfamily of KCTD proteins includes KCTD1 and KCTD15. KCTD1 is a nuclear BTB/POZ domain-containing protein that acts as a transcriptional repressor and mediates protein-protein interactions through a BTB domain. It represses the transcriptional activity of AP-2 family members, including TFAP2A, TFAP2B and TFAP2C. It also functions as a novel inhibitor of the Wnt signaling pathway. Mutations in KCTD1 cause scalp-ear-nipple (SEN) syndrome. 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 form pentamers.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|.
gi 157819025  23 HYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQIRPLLDAL 73
Cdd:cd18361   43 HYFIDRDGKMFRHILNFLRTSKLLLPDDFTEFDLLYEEARYYELQPMVKQL 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Arabidopsis thaliana FH protein interacting protein FIP2 and similar proteins; FIP2 may act as a substrate-specific adaptor of an E3 ubiquitin-protein ligase complex (CUL3-RBX1-BTB) which mediates the ubiquitination and subsequent proteasomal degradation of target proteins. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                         10        20        30        40        50        60        70
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 157819025   1 MLGAMFRADTLMPanlnPQGDGHYFIDRDGKAFRHILNFLRLGRLDLP----RGYGEtalLKAEADFYQIRPL 69
Cdd:cd18376   24 MLAAMFSGRHSLK----KDEDGSYFIDRDGTHFRHILNYLRDGEVKIPtedrSVLKE---LLEEAEYYQLRGL 89

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel regulatory protein (KCNRG); KCNRG, also called potassium channel regulator or protein CLLD4, is an endoplasmic reticulum (ER)-associated tumor suppressor that regulates Kv1 family potassium channel proteins by retaining a fraction of the channels in endomembranes. It contains a BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|...
gi 157819025  21 DGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQIRPLLDAL 73
Cdd:cd18375   42 NGQFFVDRDGSLFSYILDYLRTGQLTLPTEFSDYNRLAREAEFYGLYSLADLL 94

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
                 ....*....|....*....|....*....|....*....|....*....|....*
gi 157819025  23 HYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQIRPLldaLRELE 77
Cdd:cd18388   46 HYFIDRDGEIFRYILSFLRTSKLLLPEDFKDFNLLYEEAKYYQLQPM---VKELE 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 1 (KCTD1); KCTD1 is a nuclear BTB/POZ domain-containing protein that acts as a transcriptional repressor and mediates protein-protein interactions through a BTB domain. It represses the transcriptional activity of AP-2 family members, including TFAP2A, TFAP2B and TFAP2C to various extent. It also functions as a novel inhibitor of the Wnt signaling pathway. Mutations in KCTD1 cause scalp-ear-nipple (SEN) syndrome. 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 form pentamers.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 157819025  23 HYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQIRPLLDALRELEASR 80
Cdd:cd18387   47 HYFIDRDGQMFRYILNFLRTSKLLIPDDFKDYSLLYEEAKYFQLQPMLLELERWKQDR 104

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 16 (KCTD16); KCTD16 is a BTB/POZ domain-containing protein that is an auxiliary subunit of GABAB receptors associated with mood disorders. It interacts with amyloid beta precursor protein (APP), a type I transmembrane protein involved in a variety of cellular processes such as cell adhesion and axon guidance. 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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|...
gi 157819025   1 MLGAMFRADTLMPANLNPQGDGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQIRPLLDAL 73
Cdd:cd18398   28 LLWKMFSPKRDTANDLAKDSKGRFFIDRDGFLFRYILDYLRDRQVVLPDHFPEKGRLKREAEYFQLPDLVKLL 100

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*..
gi 157819025   1 MLGAMFRADTLMPANLNPQGdgHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLkAEADFYQIRPLLDALRELE 77
Cdd:cd18368   27 MLARMFSDDSTWPSSRDENG--AYLIDRSPEYFEPILNYLRHGQLILNDGLNPLGVL-EEAKFFGIQSLIEILEQLI 100

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
                 ....*....|....*....|....*....|....*....|....*....|....*....|....*.
gi 157819025  13 PANLNPQGDGHYFIDRDGKAFRHILNFLRLGrlDLPrgygeTALLK---AEADFYQIRPLLDALRE 75
Cdd:cd18371   35 QPKLRTDSEGRYFIDRDGTYFRYILEYLRTN--QVP-----TQHIQevyKEALFYDIEPLVKLLEE 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 17 (KCTD17); KCTD17 is a BTB/POZ domain-containing protein that functions as a substrate-adaptor for cullin3-RING ubiquitin ligases that 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. The KCTD17 BTB domains form pentamers.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....
gi 157819025  22 GHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKaEADFYQIRPLLDALRE 75
Cdd:cd18391   44 GAYLIDRDPTYFGPILNFLRHGKLVLDKDMAEEGVLE-EAEFYNIGPLIRIIKD 96

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
                 ....*....|....*....|....*....|....*....|....*
gi 157819025  22 GHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETalLKAEADFYQI 66
Cdd:cd18363   44 GAIFIDRDPKLFSIILNYLRTKEIDLRNVDISS--LRHEAEFYGI 86

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 1 (KCND1); KCND1, also called voltage-gated potassium channel subunit Kv4.1, is a pore-forming subunit of voltage-gated rapidly inactivating A-type potassium channels. It may contribute to I (To) current in heart and I (Sa) current in neurons. Its properties are modulated by interactions with other alpha subunits and with regulatory subunits. 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. KCND1 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
                 ....*....|....*....|....*....|....*....|....*....|
gi 157819025  19 QGDGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETAlLKAEADFYQIRP 68
Cdd:cd18417   72 EDTQEYFFDRDPEMFRHILNFYRTGRLHYPRHECIQA-FDEELSFYGIIP 120

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
                 ....*....|....*....|....*....|....*....|....*....|..
gi 157819025  22 GHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQIRPLLDAL 73
Cdd:cd18396   48 GRFFIDRDGFLFRYVLDYLRDKQLALPDHFPEKERLLREAEYFQLGDLVKLL 99

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
                 ....*....|....*....|....*....|....*....|....*..
gi 157819025  22 GHYFIDRDGKAFRHILNFLRLGRLDLpRGYgETALLKAEADFYQIRP 68
Cdd:cd18392   44 GAIFIDRDPTAFVPILNFLRTKELDL-RGV-NINVLRHEAEFYGITP 88

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 5 (KCTD5); KCTD5 is a BTB/POZ domain-containing protein that functions as a substrate adaptor for cullin3 based ubiquitin E3 ligases. It 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. 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 forms pentamers mediated by its BTB domain.

                         10        20        30        40        50
                 ....*....|....*....|....*....|....*....|....*....|....*...
gi 157819025  22 GHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKaEADFYQIRPLL----DALRE 75
Cdd:cd18390   49 GAYLIDRDPTYFGPVLNYLRHGKLVINKDLAEEGVLE-EAEFYNITSLIklvkDKIRE 105

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 13 (KCTD13); KCTD13, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 1 (BACURD1), or TNFAIP1-like protein, 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. 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 KCTD13 BTB domain forms 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 157819025   1 MLGAMFRADTlmpaNLNPQGDGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQIRPLL-DALRELEAS 79
Cdd:cd18400   26 MLKAMFSGRV----EVLTDSEGWVLIDRSGRHFGTILNYLRDGSVPLPESTRELEELLGEARYYLVQGLVeDCQLALQQK 101

                 .
gi 157819025  80 R 80
Cdd:cd18400  102 R 102

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
                 ....*....|....*....|....*....|....*....|...
gi 157819025  22 GHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLkAEADFY 64
Cdd:cd18362   44 GAYLIDRDPTYFGPILNYLRHGKLIIDKDLAEEGVL-EEAEFY 85

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing protein 10 (KCTD10); KCTD10, also called BTB/POZ domain-containing adapter for CUL3-mediated RhoA degradation protein 3 (BACURD3), 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. Furthermore, KCTD10 may function 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 KCTD10 BTB domain forms a novel two-fold symmetric tetramer that is distinct from the tetramer formed by voltage-gated potassium (Kv) channels.

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gi 157819025   1 MLGAMF--RADTLMPAnlnpqgDGHYFIDRDGKAFRHILNFLRLGRLDLPRGYGETALLKAEADFYQIRPLLD 71
Cdd:cd18399   31 MLKAMFsgRMEVLTDS------EGWILIDRCGKHFGTILNYLRDGAVPLPESRREIEELLAEAKYYLVQGLVE 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shal and similar proteins; Drosophila melanogaster Shal, also called Shaker cognate l or Shal2, is a transient potassium current (I(A)) channel, which is required for maintaining excitability during repetitive firing and normal locomotion in Drosophila. It may play a role in the nervous system and in the regulation of beating frequency in pacemaker cells. Shal mediates the voltage-dependent potassium ion permeability of excitable membranes. Assuming opened or closed conformations in response to the voltage difference across the membrane, the protein forms a 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. Shal 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.

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gi 157819025  24 YFIDRDGKAFRHILNFLRLGRLDLPRGYGETAlLKAEADFYQIRP 68
Cdd:cd18420   78 YFFDRDPDIFRHILNYYRTGKLHYPKHECLTA-YDEELAFFGIMP 121

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.

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gi 157819025  21 DGHYFIDRDGKAFRHILNFLRLGRLDLPR 49
Cdd:cd18378   51 DNEYFFDRHPGAFTSILNFYRTGKLHMPE 79