Intracellular trafficking of tyrosine kinases and their differential functions

酪氨酸激酶的细胞内运输及其差异功能

基本信息

批准号：
17590053
负责人：
YAMAGUCHI Naoto
金额：
$ 2.24万
依托单位：
Chiba University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

项目摘要

Src-family tyrosine kinases are cytosolic enzymes, and lipid modification at their N-termini leads to their localization to endomembranes as well as the plasma membrane. In this study, we examined intracellular trafficking, localization and function of Src-family tyrosine kinases and their negative regulator Chk tyrosine kinase. Our findings are described as follows.1. Stimulation of cells with H_2O_2 induces tyrosine phosphorylation of annexin 11 by Lyn that is present on the Golgi apparatus, leading to the translocation of annexin 11 from the Golgi to the endoplasmic reticulum.2. Lyn kinase domain, which is important for Lyn trafficking, associates with two proteins that are identified by mass spectrometry.3. Nuclear localization of Chk induces dynamic multi-lobulation of the nucleus and prolonged S phase of the cell cycle. The N-terminal domain of Chk associates with the nucleus and the nuclear matrix, and nuclear tyrosine phosphorylation induced by Chk contributes to inhibition of cell proliferation.4. c-Src, unlike Lyn, c-Yes and Fyn, associates with macropinosomes via its N-terminus continuously from their generation at membrane ruffles, through their centripetal trafficking, to fusion with late endosomes and lysosomes. c-Src is rapidly recruited to macropinosomal membranes from the plasma membrane and intracellular organelles.5. Src signaling regulates the terminal step in cytokinesis called abscission in HeLa cells. Completion of abscission requires Src-mediated tyrosine phosphorylation during early stages of mitosis (before cleavage furrow formation), which is subsequently delivered to the midbody through Rab11-driven vesicle transport. Src kinase activity during the early mitosis mediates ERK activation in late cytokinesis. Recruitment of activated ERK, which is phosphorylated by MEK downstream of Src kinases, to the midbody plays an important role in completion of abscission.

Src 家族酪氨酸激酶是胞质酶，其 N 末端的脂质修饰导致其定位于内膜和质膜。在这项研究中，我们检查了 Src 家族酪氨酸激酶及其负调节因子 Chk 酪氨酸激酶的细胞内运输、定位和功能。我们的研究结果描述如下： 1． H_2O_2刺激细胞，诱导高尔基体上的Lyn对膜联蛋白11进行酪氨酸磷酸化，导致膜联蛋白11从高尔基体易位至内质网。2． Lyn 激酶结构域对于 Lyn 运输很重要，与质谱鉴定的两种蛋白质相关。 3． Chk 的核定位诱导细胞核动态多分叶并延长细胞周期的 S 期。 Chk的N端结构域与细胞核和核基质结合，Chk诱导的核酪氨酸磷酸化有助于抑制细胞增殖。4．与 Lyn、c-Yes 和 Fyn 不同，c-Src 通过其 N 末端与巨胞质体持续结合，从膜皱褶处的生成，通过向心运输，到与晚期内体和溶酶体融合。 c-Src从质膜和细胞内细胞器迅速募集到巨脂质体膜上。5． Src 信号传导调节 HeLa 细胞胞质分裂的最终步骤（称为脱落）。脱落的完成需要在有丝分裂的早期阶段（卵裂沟形成之前）进行 Src 介导的酪氨酸磷酸化，随后通过 Rab11 驱动的囊泡运输将其递送至中体。有丝分裂早期的 Src 激酶活性介导胞质分裂晚期的 ERK 激活。活化的 ERK 被 Src 激酶下游的 MEK 磷酸化，募集到中体在脱落的完成中起着重要作用。