Regulation of Amphiphysin1 by Mitogen-activated Protein Kinase
Regulation of Amphiphysin1 by Mitogen-activated Protein Kinase
复制标题
DOI：
10.1074/jbc.m404527200
复制
发表时间：
2004-09
影响因子：
4.8
通讯作者：
W. Shang;Y. Adachi;A. Nakamura;T. Copeland;S. R. Kim;T. Kamata
中科院分区：
文献类型：
--
作者：
W. Shang;Y. Adachi;A. Nakamura;T. Copeland;S. R. Kim;T. Kamata
Amphiphyn1 可以同时与 dynamin1 和网格蛋白接头 AP-2 结合，对于受体介导的内吞作用期间 dynamin1 的募集至关重要，但对其调节机制知之甚少。在这里，我们从猪脑中纯化了一种 120 kDa 丝裂原激活蛋白激酶 (MAPK) 底物蛋白，并鉴定该蛋白为两栖蛋白 1。 PC12 细胞中神经生长因子 (NGF) 快速诱导两性蛋白 1 的丝氨酸磷酸化，并且这种诱导被 MAPK 抑制剂阻断。此外，当在体外被 MAPK 磷酸化或在体内被 NGF 处理磷酸化时，amphiphyn1 无法与 AP-2 结合，但其与 dynamin1 的结合不受影响。与此一致的是，共有 MAPK 磷酸化位点的突变增加了两栖蛋白 1 与 AP-2 的结合及其细胞内共定位。因此，我们提出，amphiphyn1 的 MAPK 磷酸化通过终止 amphiphyn1-AP-2 相互作用来控制 NGF 受体/TrkA 介导的内吞作用。这可能有助于调节两性蛋白 1-动力蛋白 1 复合物与内吞囊泡结合的可用性。
Amphiphysin1, which can simultaneously bind to dynamin1 and the clathrin adaptor AP-2, is essential for dynamin1 recruitment during receptor-mediated endocytosis, but little is known about its regulatory mechanism. Here, we purified a 120-kDa mitogen-activated protein kinase (MAPK) substrate protein from porcine brains and identified the protein as amphiphysin1. Serine phosphorylation of amphiphysin1 was rapidly induced by nerve growth factor (NGF) in PC12 cells, and the induction was blocked by a MAPK inhibitor. Furthermore, when phosphorylated by MAPK in vitro or by NGF treatment in vivo, amphiphysin1 failed to bind to AP-2, but its association with dynamin1 was unaffected. Consistent with this, mutation of consensus MAPK phosphorylation sites increased amphiphysin1 binding to AP-2 and their intracellular colocalization. Thus, we propose that MAPK phosphorylation of amphiphysin1 controls NGF receptor/TrkA-mediated endocytosis by terminating the amphiphysin1-AP-2 interaction. This perhaps helps to regulate the availability of amphiphysin1-dynamin1 complexes for binding to the endocytic vesicle.