期刊
MOLECULAR AND CELLULAR BIOLOGY
卷 22, 期 15, 页码 5518-5526出版社
AMER SOC MICROBIOLOGY
DOI: 10.1128/MCB.22.15.5518-5526.2002
关键词
-
The molecular mechanism for the regulated exocytosis of dense-core granules in endocrine cells remains relatively uncharacterized compared to that of synaptic vesicles in neurons. A novel set of Rab and its effector, Rab27a/granuphilin, which is localized on insulin granules in pancreatic beta cells, was recently identified. Here we demonstrate that granuphilin directly binds to syntaxin la on the plasma membrane, and this interaction is regulated by Rab27a. Granuphilin shows affinity to syntaxin la with a closed conformation but not to mutant syntaxin 1a, which adopts an open conformation constitutively. Overexpression of granuphilin significantly enhances basal insulin secretion but profoundly inhibits high K+-induced insulin secretion. The effect of granuphilin on insulin secretion was impaired by its mutation that disrupts the binding to either Rab27a or syntaxin la. Thus, granuphilin is the first regulator in the exocytotic pathway that functions by directly connecting two critical vesicle transport proteins, Rab and SNARE.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据