Tinker A, Jan Y N, Jan L Y
Howard Hughes Medical Institute, Department of Physiology, University of California, San Francisco 94143-0724, USA.
Cell. 1996 Nov 29;87(5):857-68. doi: 10.1016/s0092-8674(00)81993-5.
Inwardly rectifying potassium channels have an important role in determining the resting potential of the cell. They are tetrameric proteins with two transmembrane segments (M1 and M2), a pore-forming loop (H5), a cytoplasmic N-terminal, and longer C-terminal domain. We have used biochemical and electrophysiological methods to identify regions required for homotypic interactions and those responsible for the incompatibility between IRK1 and two other members of the same subfamily (IRK2 and IRK3) and two members from other subfamilies (ROMK1 and 6.1 uK(ATP)). The data indicate that, in contrast to the voltage-gated class of potassium channel, the proximal C-terminus and the transmembrane segment M2 determine homo-and heteromultimerization and that heteromultimerization between members of the same or different subfamilies is case specific.
内向整流钾通道在决定细胞静息电位方面发挥着重要作用。它们是四聚体蛋白，具有两个跨膜片段（M1和M2）、一个形成孔道的环（H5）、一个胞质N端和较长的C端结构域。我们运用生化和电生理方法来确定同型相互作用所需的区域，以及导致IRK1与同一亚家族的其他两个成员（IRK2和IRK3）以及来自其他亚家族的两个成员（ROMK1和6.1 uK(ATP)）之间不相容性的区域。数据表明，与电压门控型钾通道不同，近端C端和跨膜片段M2决定了同型和异型多聚化，并且同一亚家族或不同亚家族成员之间的异型多聚化具有个案特异性。
