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        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCV 100
Cdd:cd18384     1 IRINVGGFRRRLSASALLRFPGTRLGRLLACHSEEAILELCDDYDVAAREFYFDRNPGFFLYVLHFYRTGKLHVMDELCV 80

                          90       100
                  ....*....|....*....|....*.
gi 1907135701 101 FAFGQEADYWGLGENALATCCRARYL 126
Cdd:cd18384    81 FSFSQEIEYWGINEFFLDSCCSYRYH 106

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 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCV 100
Cdd:cd18384     1 IRINVGGFRRRLSASALLRFPGTRLGRLLACHSEEAILELCDDYDVAAREFYFDRNPGFFLYVLHFYRTGKLHVMDELCV 80

                          90       100
                  ....*....|....*....|....*.
gi 1907135701 101 FAFGQEADYWGLGENALATCCRARYL 126
Cdd:cd18384    81 FSFSQEIEYWGINEFFLDSCCSYRYH 106

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 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGRLQaaaseeqaRRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRT-GHLHVLDELC 99
Cdd:pfam02214   1 VKLNVGGTRFETLKSTLTRFPDTRLGRLL--------ELECDDYDDDTNEYFFDRSPKHFETILNFYRTgGKLHRPEEVC 72

                          90       100
                  ....*....|....*....|.
gi 1907135701 100 VFAFGQEADYWGLGENALATC 120
Cdd:pfam02214  73 LDEFLEEAEFYGLDELALELC 93

voltage-gated potassium channel protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907135701 348 VGILLLYlavgvSVFsGVAYTAEEENEGFHTIPACWWWGTVSMTTVGYGDVVPETVGGKLAASGCILGGILVVALPITII 427
Cdd:PRK10537  144 ITSLLFY-----STF-GALYLGDGFSPPIESLSTAFYFSIVTMSTVGYGDIVPVSESARLFTISVIILGITVFATSISAI 217

                  .
gi 1907135701 428 F 428
Cdd:PRK10537  218 F 218

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 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCV 100
Cdd:cd18384     1 IRINVGGFRRRLSASALLRFPGTRLGRLLACHSEEAILELCDDYDVAAREFYFDRNPGFFLYVLHFYRTGKLHVMDELCV 80

                          90       100
                  ....*....|....*....|....*.
gi 1907135701 101 FAFGQEADYWGLGENALATCCRARYL 126
Cdd:cd18384    81 FSFSQEIEYWGINEFFLDSCCSYRYH 106

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily S member 1 (KCNS1); KCNS1, also called delayed-rectifier K(+) channel alpha subunit 1 or voltage-gated potassium channel subunit Kv9.1, is a modulatory alpha subunit of voltage-gated potassium channel that mediates neuropathic pain following nerve injury. It 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. KCNS1 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 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCV 100
Cdd:cd18426     1 ININVGGLKRRLSSSTLSKFPDTRLGRLLSCDSEESILQICDDYDVSAKEFYFDRNPGLFPYVLHFYQTGKLHIMEELCV 80

                          90       100
                  ....*....|....*....|....*
gi 1907135701 101 FAFGQEADYWGLGENALATCCRARY 125
Cdd:cd18426    81 FSFSQEIEYWGINEFFLDSCCSYRY 105

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 1907135701  22 RVNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCVF 101
Cdd:cd18378     5 LLNVGGVRHEVLWRTLDRLPRTRLGRLRECNTHESLLELCDDYDLEDNEYFFDRHPGAFTSILNFYRTGKLHMPEEMCVL 84

                          90       100
                  ....*....|....*....|....
gi 1907135701 102 AFGQEADYWGLGENALATCCRARY 125
Cdd:cd18378    85 SFSQELEYWGIDEIYLESCCQHRY 108

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 1907135701   6 PGPGSRVPWRPRDEALRVNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLH 85
Cdd:cd18412     4 PEPVEIIRSKACSRRVKINVGGLNHEVLWRTLDRLPRTRLGKLRDCNTHESLLEVCDDYNLNENEYFFDRHPGAFTSILN 83

                          90       100       110       120
                  ....*....|....*....|....*....|....*....|....
gi 1907135701  86 FYRTGHLHVLDELCVFAFGQEADYWGLGENALATCCRARYLERR 129
Cdd:cd18412    84 FYRTGKLHMMEEMCALSFGQELDYWGIDEIYLESCCQARYHQKK 127

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in Drosophila melanogaster potassium voltage-gated channel protein Shab and similar proteins; Shab is a slow delayed rectifier 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. Shab 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 1907135701  23 VNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCVFA 102
Cdd:cd18413     6 INVGGVKHEVLWRTLDRMPHTRLGKLRDSNTHEAIVELCDDYSLADNEYFFDRHPRSFASILNFYRTGKLHLVEEMCVLA 85

                          90       100
                  ....*....|....*....|...
gi 1907135701 103 FGQEADYWGLGENALATCCRARY 125
Cdd:cd18413    86 FSDDLEYWGVDELYLESCCQHKY 108

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily B member 1 (KCNB1); KCNB1, also called delayed rectifier potassium channel 1 (DRK1) or voltage-gated potassium channel subunit Kv2.1, mediates transmembrane potassium transport in excitable membranes, primarily in the brain, but also in the pancreas and cardiovascular system. 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. KCNB1 is involved in the regulation of the action potential (AP) repolarization, duration and frequency of repetitive AP firing in neurons, muscle cells and endocrine cells and plays a role in homeostatic attenuation of electrical excitability throughout 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. KCNB1 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 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCV 100
Cdd:cd18411    12 VKLNVGGLAHEVLWRTLDRLPRTRLGKLRDCNTHESLMEICDDYNLEENEYFFDRHPGAFTSILNFYRTGKLHMMEEMCA 91

                          90       100
                  ....*....|....*....|....*
gi 1907135701 101 FAFGQEADYWGLGENALATCCRARY 125
Cdd:cd18411    92 LSFSQELDYWGIDEIYLESCCQARY 116

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily G members, KCNG1 and KCNG2; KCNG1, also called voltage-gated potassium channel subunit Kv6.1 or kH2, functions as a regulatory alpha-subunit of voltage-gated potassium channel that 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. KCNG2, also called cardiac potassium channel subunit or voltage-gated potassium channel subunit Kv6.2, is a new gamma-subunit of voltage-gated potassium channels that can form functional heterodimeric channels with KCNB1, and further modulates channel activity by shifting the threshold and the half-maximal activation to more negative values. 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. KCNG1 and KCNG2 are regulatory alpha subunits and do not form homomultimers. They form heteromultimers (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 1907135701  17 RDEALRVNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLD 96
Cdd:cd18421     2 RTRHVIINVGGIKYRIPWTTLEEFPLTRLGQLKSCNNFDEIMDICDDYDVTCNEFFFDRNPCAFRTILTFLRAGKLRLLR 81

                          90       100       110
                  ....*....|....*....|....*....|..
gi 1907135701  97 ELCVFAFGQEADYWGLGENALATCCRARYLER 128
Cdd:cd18421    82 EMCALSFQEELLYWGIEEENLEWCCRRRLLQK 113

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNC/Kv3 subfamily of Shaw-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 four alpha subunit members, Kv3.1 (KCNC1), Kv3.2 (KCNC2), Kv3.3 (KCNC3), and Kv3.4 (KCNC4), which are orthologs of the Shaw gene in Drosophila. Unlike other Kv subfamilies, Kv3 channels typically open only at positive potentials and both, activation and deactivation, in response to changes in voltage are very rapid. They are uniquely associated with the ability of certain neurons to fire action potentials and to release neurotransmitter at high rates of up to 1,000 Hz. Kv3/KCNC 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 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGRLqaaaSEEQARRLcdDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCV 100
Cdd:cd18379     1 IVINVGGVRHETYKSTLRNLPDTRLAWL----TETEASAF--DYDPVTGEFFFDRHPGVFAQILNYYRTGKLHCPADVCG 74

                          90       100       110
                  ....*....|....*....|....*....|.
gi 1907135701 101 FAFGQEADYWGLGENALATCCRARYLERRVA 131
Cdd:cd18379    75 PLFEEELAFWGIDETQIEPCCWMTYRQHRDA 105

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in KCNF/Kv5 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 Kv5, also known as subfamily F, only contains KCNF1 (also known as Kv5.1 or kH1), which functions as a regulatory alpha-subunit of voltage-gated potassium channel that when coassembled with Kv2.1 can modulate gating in a physiologically relevant manner. It forms 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 1907135701  23 VNVGGVRRLLSARALARFPGTRLGRL--QAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCV 100
Cdd:cd18381     5 VNVGGVRQVLYGDVLNRYPETRLAELlnCLSGGYDAIFSLCDDYDPGKREFYFDRDPDAFKCIIEVYYYGEIHMKKGICP 84

                          90       100
                  ....*....|....*....|....*....
gi 1907135701 101 FAFGQEADYWGLGENALATCCRARYLERR 129
Cdd:cd18381    85 ICFKNEMDFWRVDLDFLDECCKCHLSEKR 113

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        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907135701  18 DEALRVNVGGVRRLLSARALARFPGTRLGRLQAAASeeqarrlcdDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDE 97
Cdd:cd18416     1 ENRVVLNVGGIRHETYKATLKKIPATRLSRLTEALA---------NYDPVLNEYFFDRHPGVFAQILNYYRTGKLHYPTD 71

                          90       100       110
                  ....*....|....*....|....*....|..
gi 1907135701  98 LCVFAFGQEADYWGLGENALATCCRARYLERR 129
Cdd:cd18416    72 VCGPLFEEELEFWGLDANQVEPCCWMTYTAHR 103

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily G member 3 (KCNG3); KCNG3, also called voltage-gated potassium channel subunit Kv6.3 or voltage-gated potassium channel subunit Kv10.1, is an electrically silent modulatory subunit that can form functional heterotetrameric channels with KCNB1 (also known as Kv2.1), and further promotes a reduction in the rate of activation and inactivation of the delayed rectifier voltage-gated potassium channel 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. KCNG3 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 1907135701  23 VNVGGVRRLLSARALARFPGTRLGRLQAAASEEQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCVFA 102
Cdd:cd18422     3 LNVGGTRYSFSREVIKDFPLRRVSRLHGCLSEQDVLEVCDDYDRERNEYFFDRHSEAFGFIMLYVKYGKLRFVPQMCELS 82

                          90       100
                  ....*....|....*....|....*.
gi 1907135701 103 FGQEADYWGLGENALATCCRARYLER 128
Cdd:cd18422    83 FYNEMIYWGLERSHLEYCCQRRLDDR 108

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        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGrlqaaASEEQARrlcddYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCV 100
Cdd:cd18380     2 IVINVSGRRFETWKNTLEKYPDTLLG-----STEKEFF-----YDDDTKEYFFDRDPEIFRHILNFYRTGKLHYPRHECI 71

                          90       100
                  ....*....|....*....|....*....
gi 1907135701 101 FAFGQEADYWGLGENALATCCRARYLERR 129
Cdd:cd18380    72 SAYDDELAFFGILPEIIGDCCYEDYRDRK 100

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily D member 3 (KCND3); KCND3, also called voltage-gated potassium channel subunit Kv4.3, is a pore-forming subunit of voltage-gated rapidly inactivating A-type potassium channels. Mutations in KCND3 cause spinocerebellar ataxia. 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. KCND3 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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907135701  15 RPRDEALRVNVGGvRRLLSAR-ALARFPGTRLGRlqaaaSEEQARrlcddYDAAAHEFYFDRHPGFFLGLLHFYRTGHLH 93
Cdd:cd18419    31 KRQDELIVLNVSG-RRFQTWRtTLERYPDTLLGS-----TEKEFF-----FNEDTKEYFFDRDPEVFRCVLNFYRTGKLH 99

                          90       100       110
                  ....*....|....*....|....*....|....*.
gi 1907135701  94 VLDELCVFAFGQEADYWGLGENALATCCRARYLERR 129
Cdd:cd18419   100 YPRYECISAYDEELAFYGILPEIIGDCCYEEYKDRK 135

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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907135701  23 VNVGGVRRLLSARALARFPGTRLGrlqaaASEEQARrlcddYDAAAHEFYFDRHPGFFLGLLHFYRTGHLHVLDELCVFA 102
Cdd:cd18418     4 LNVSGTRFQTWRNTLERYPDTLLG-----SSERDFF-----YHEETQEYFFDRDPDIFRHILNFYRTGKLHYPRHECISA 73

                          90       100
                  ....*....|....*....|....*..
gi 1907135701 103 FGQEADYWGLGENALATCCRARYLERR 129
Cdd:cd18418    74 YDEELAFFGIIPEIIGDCCYEEYKDRR 100

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 7 (KCNA7); KCNA7, also called voltage-gated potassium channel subunit Kv1.7, 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. KCNA7 plays an important role in the repolarization of cell membranes. 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. KCNA7 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA 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 1907135701  19 EALRVNVGGVRRLLSARALARFPGTRLGrlqaaaseeQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRT-GHLHVLDE 97
Cdd:cd18408     6 ERVVLNVAGLRFETRARTLGRFPDTLLG---------DPARRGRFYDDRRREYFFDRHRPSFDAVLYYYQSgGRLRRPAH 76

                          90       100
                  ....*....|....*....|.
gi 1907135701  98 LCVFAFGQEADYWGLGENALA 118
Cdd:cd18408    77 VPLDVFLEEVAFYGLGAAALA 97

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins; This family includes two protein groups: voltage-gated potassium (Kv) channels and potassium channel tetramerization domain-containing (KCTD) proteins. Kv channels are membrane proteins with fundamental physiological roles. They are responsible for a variety of electrical phenomena, such as the repolarization of the action potential, spike frequency adaptation, synaptic repolarization, and smooth muscle contraction. 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. All family members contain the 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        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGRLqaaasEEQARRLCDDYDAAahEFYFDRHPGFFLGLLHFYRTGHLHVLDELCV 100
Cdd:cd18187     1 VVLNVSGTRFVTNRQTLTRHPDTLLGRM-----FKPGREFTFPNETG--EYFIDRDPTVFRTILNYYRTGKLNCPDGISI 73

                          90
                  ....*....|
gi 1907135701 101 FAFGQEADYW 110
Cdd:cd18187    74 PDLREECDFY 83

voltage-gated potassium channel protein;

                          10        20        30        40        50        60        70        80
                  ....*....|....*....|....*....|....*....|....*....|....*....|....*....|....*....|
gi 1907135701 348 VGILLLYlavgvSVFsGVAYTAEEENEGFHTIPACWWWGTVSMTTVGYGDVVPETVGGKLAASGCILGGILVVALPITII 427
Cdd:PRK10537  144 ITSLLFY-----STF-GALYLGDGFSPPIESLSTAFYFSIVTMSTVGYGDIVPVSESARLFTISVIILGITVFATSISAI 217

                  .
gi 1907135701 428 F 428
Cdd:PRK10537  218 F 218

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A members 2 (KCNA2) and 3 (KCNA3); KCNA2 is also called NGK1, voltage-gated K(+) channel HuKIV, voltage-gated potassium channel HBK5, or voltage-gated potassium channel subunit Kv1.2. KCNA3 is also called HGK5, HLK3, HPCN3, voltage-gated K(+) channel HuKIII, or voltage-gated potassium channel subunit Kv1.3. KCNA2 and KCNA3 mediate 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. KCNA2 primarily functions in the brain and the central nervous system, but also in the cardiovascular system. It prevents aberrant action potential firing and regulates neuronal output. 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. KCNA2 and KCNA3 are alpha subunits that form functional homo- or hetero-tetrameric channels (with other Kv1/KCNA 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 1907135701  19 EALRVNVGGVRRLLSARALARFPGTRLGrlqaaaseeQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRT-GHLHVLDE 97
Cdd:cd18403     1 ERVVINISGLRFETQLKTLAQFPETLLG---------DPKKRMRYFDPLRNEYFFDRNRPSFDAILYYYQSgGRLRRPVN 71

                          90       100
                  ....*....|....*....|
gi 1907135701  98 LCVFAFGQEADYWGLGENAL 117
Cdd:cd18403    72 VPLDIFSEEIRFYELGEEAM 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 1 (KCNA1); KCNA1 is also called voltage-gated K(+) channel HuKI, voltage-gated potassium channel HBK1, or voltage-gated potassium channel subunit Kv1.1. It mediates transmembrane potassium transport in excitable membranes, primarily in the brain and the central nervous system, but also in the kidney. It is involved in the regulation of the membrane potential and nerve signaling, and prevents neuronal hyperexcitability. 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. KCNA1 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA 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 1907135701  19 EALRVNVGGVRRLLSARALARFPGTRLGrlqaaaseeQARRLCDDYDAAAHEFYFDRHPGFFLGLLHFYRT-GHLHVLDE 97
Cdd:cd18402     9 ERVVINIAGLRFETQLKTLAQFPNTLLG---------NPKKRMRYFDPLRNEYFFDRNRPSFDAILYYYQSgGRLRRPVN 79

                          90
                  ....*....|....*....
gi 1907135701  98 LCVFAFGQEADYWGLGENA 116
Cdd:cd18402    80 VPLDMFSEEIKFYELGEEA 98

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 5 (KCNA5); KCNA5, also called HPCN1, voltage-gated potassium channel HK2, or voltage-gated potassium channel subunit Kv1.5, 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. KCNA5 may play a role in regulating the secretion of insulin in normal pancreatic islets. 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. KCNA5 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA 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 1907135701  19 EALRVNVGGVRRLLSARALARFPGTRLGrlqaaaseEQARRLcDDYDAAAHEFYFDRHPGFFLGLLHFYRT-GHLHVLDE 97
Cdd:cd18406     1 ERVIINIAGLRFETQLGTLNQFPDTLLG--------DPDKRM-RYFDPLRNEYFFDRNRPSFDGILYFYQSgGKIRRPVN 71

                          90       100
                  ....*....|....*....|
gi 1907135701  98 LCVFAFGQEADYWGLGENAL 117
Cdd:cd18406    72 VSIDVFADEIRFYQLGEEAM 91

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium voltage-gated channel subfamily A member 6 (KCNA6); KCNA6, also called voltage-gated potassium channel HBK2 or voltage-gated potassium channel subunit Kv1.6, 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. KCNA6 is distributed primarily in neurons of central and peripheral nervous systems. 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. KCNA6 is an alpha subunit that forms functional homo- or hetero-tetrameric channels (with other Kv1/KCNA 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 1907135701  19 EALRVNVGGVRRLLSARALARFPGTRLGrlqaaaseEQARRLcDDYDAAAHEFYFDRHPGFFLGLLHFYRT-GHLHVLDE 97
Cdd:cd18407     1 ERLVINISGLRFETQLRTLSIFPDTLLG--------DPSRRV-RYFDPLRNEYFFDRNRPSFDAILYYYQSgGRLRRPVH 71

                          90       100
                  ....*....|....*....|..
gi 1907135701  98 LCVFAFGQEADYWGLGENALAT 119
Cdd:cd18407    72 VPLDIFLEEIRFYQLGQEAIET 93

BTB (Broad-Complex, Tramtrack and Bric a brac)/POZ (poxvirus and zinc finger) domain found in potassium channel tetramerization domain-containing proteins; The potassium channel tetramerization domain (KCTD) family proteins contain the BTB/POZ domain, also known as tetramerization (T1) domain, which is a versatile protein-protein interaction motif that facilitates homodimerization or heterodimerization. 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. Some others show Cullin-independent functions including binding and regulation of GABA (gamma-aminobutyric acid) receptors (KCTD8, KCTD12 and KCTD16) and inhibition of AP-2 function (KCTD15). 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 1907135701  21 LRVNVGGVRRLLSARALARFPGTRLGRLqaaasEEQARRLCDDYDAAaheFYFDRHPGFFLGLLHFYRTGHLHV------ 94
Cdd:cd18316     1 VKLNVGGTLFTTSRSTLLKDPDSLLAAL-----FSGRWPLPRDEDGS---IFIDRDPELFRHILNFLRTGKLPLpsdfve 72

                          90
                  ....*....|....*.
gi 1907135701  95 LDELCvfafgQEADYW 110
Cdd:cd18316    73 LEELL-----AEAEFY 83