Coupling of vesicle tethering and Rab binding is required for in vivo functionality of the golgin GMAP-210.
Coupling of vesicle tethering and Rab binding is required for in vivo functionality of the golgin GMAP-210.
复制标题
GOLGIN GMAP-210的体内功能需要囊泡绑定和RAB结合的耦合。
DOI：
10.1091/mbc.e14-10-1450
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发表时间：
2015-02-01
影响因子：
3.3
通讯作者：
Lowe M
中科院分区：
文献类型：
--
作者：
Sato K;Roboti P;Mironov AA;Lowe M
GMAP-210介导的囊泡拴系是维持高尔基体结构所必需的。GMAP-210的拴系完全由Alps基序介导，与Rab2的结合和GMAP-210的长度虽然本身并不是拴系所必需的，但对于它在高尔基体的功能作用也是至关重要的。高尔基体是一种延伸的卷曲卷曲蛋白，据信参与高尔基体的膜系留活动。然而，高尔金介导的系链的重要性仍然没有明确的定义，高尔夫球的替代功能已经被提出。此外，虽然高尔根蛋白与Rab GTP酶结合，但Rab结合的功能意义尚未确定。在这项研究中，我们表明，GMAP-210的耗尽会导致高尔基池的丧失和大量囊泡的积累。GMAP-210在体内的功能依赖于其连接膜的能力，这一能力完全由氨基末端的Alps基序介导。与Rab2的结合对GMAP-210的功能也很重要，尽管它对于拴系本身是必要的。GMAP-210的长度在体内也具有重要的功能。综上所述，我们的结果表明GMAP-210介导的膜系留在维持高尔基体结构中起关键作用，并支持Rab2结合在连接高尔基体的下游对接和融合事件中的作用。
Vesicle tethering mediated by the golgin GMAP-210 is required to maintain the structure of the Golgi apparatus. Tethering by GMAP-210 is mediated solely by the ALPS motif, and binding to Rab2 and the length of GMAP-210, although not required for tethering per se, are also critical for its functional role at the Golgi apparatus. Golgins are extended coiled-coil proteins believed to participate in membrane-tethering events at the Golgi apparatus. However, the importance of golgin-mediated tethering remains poorly defined, and alternative functions for golgins have been proposed. Moreover, although golgins bind to Rab GTPases, the functional significance of Rab binding has yet to be determined. In this study, we show that depletion of the golgin GMAP-210 causes a loss of Golgi cisternae and accumulation of numerous vesicles. GMAP-210 function in vivo is dependent upon its ability to tether membranes, which is mediated exclusively by the amino-terminal ALPS motif. Binding to Rab2 is also important for GMAP-210 function, although it is dispensable for tethering per se. GMAP-210 length is also functionally important in vivo. Together our results indicate a key role for GMAP-210–mediated membrane tethering in maintaining Golgi structure and support a role for Rab2 binding in linking tethering with downstream docking and fusion events at the Golgi apparatus.