InterPro domain: IPR003131

This domain can be found at the N terminus of voltage-gated potassium channel proteins, where represents a cytoplasmic tetramerisation domain (T1) involved in assembly of alpha-subunits into functional tetrameric channels [ 1 ]. This domain can also be found in proteins that are not potassium channels, like KCTD1 (potassium channel tetramerisation domain-containing protein 1). KCTD1 is though to be a nuclear protein that functions as a transcriptional repressor. In KCTD1, the T1-type BTB domain mediates homomeric protein-protein interactions [ 2 , 3 ].

1. Zn2+-binding and molecular determinants of tetramerization in voltage-gated K+ channels. Nat. Struct. Biol. 6, 38-43
2. Characterization and expression of a human KCTD1 gene containing the BTB domain, which mediates transcriptional repression and homomeric interactions. DNA Cell Biol. 27, 257-65
3. The interaction of KCTD1 with transcription factor AP-2alpha inhibits its transactivation. J. Cell. Biochem. 106, 285-95