Runnels Loren W, Yue Lixia, Clapham David E
Howard Hughes Medical Institute, Children's Hospital, Harvard Medical School, Enders 1309, 320 Longwood Avenue, Boston, MA 02115, USA.
Nat Cell Biol. 2002 May;4(5):329-36. doi: 10.1038/ncb781.
TRPM7 (ChaK1, TRP-PLIK, LTRPC7) is a ubiquitous, calcium-permeant ion channel that is unique in being both an ion channel and a serine/threonine kinase. The kinase domain of TRPM7 directly associates with the C2 domain of phospholipase C (PLC). Here, we show that in native cardiac cells and heterologous expression systems, G alpha q-linked receptors or tyrosine kinase receptors that activate PLC potently inhibit channel activity. Numerous experimental approaches demonstrated that phosphatidylinositol 4,5-bisphosphate (PIP(2)), the substrate of PLC, is a key regulator of TRPM7. We conclude that receptor-mediated activation of PLC results in the hydrolysis of localized PIP(2), leading to inactivation of the TRPM7 channel.
瞬时受体电位阳离子通道亚家族M成员7(ChaK1、TRP-PLIK、LTRPC7)是一种广泛存在的、钙通透离子通道,其独特之处在于它既是一个离子通道,又是一种丝氨酸/苏氨酸激酶。TRPM7的激酶结构域直接与磷脂酶C(PLC)的C2结构域结合。在此,我们表明,在天然心肌细胞和异源表达系统中,激活PLC的Gαq偶联受体或酪氨酸激酶受体可有效抑制通道活性。众多实验方法表明,PLC的底物磷脂酰肌醇-4,5-二磷酸(PIP₂)是TRPM7的关键调节因子。我们得出结论,受体介导的PLC激活导致局部PIP₂水解,从而使TRPM7通道失活。