Ioannou Maria S, Girard Martine, McPherson Peter S
From the Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada.
From the Department of Neurology and Neurosurgery, Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 2B4, Canada
J Biol Chem. 2016 May 13;291(20):10726-35. doi: 10.1074/jbc.M116.722298. Epub 2016 Mar 11.
Rab GTPases are critical regulators of membrane trafficking. The canonical view is that Rabs are soluble in their inactive GDP-bound form, and only upon activation and conversion to their GTP-bound state are they anchored to membranes through membrane insertion of a C-terminal prenyl group. Here we demonstrate that C-terminal prenylation is not required for Rab13 to associate with and traffic on vesicles. Instead, inactive Rab13 appears to associate with vesicles via protein-protein interactions. Only following activation does Rab13 associate with the plasma membrane, presumably with insertion of the C-terminal prenyl group into the membrane.
Rab GTP酶是膜运输的关键调节因子。传统观点认为，Rabs在其无活性的GDP结合形式下是可溶的，只有在激活并转化为GTP结合状态后，它们才通过C末端异戊二烯基插入膜中而锚定在膜上。在这里，我们证明Rab13与囊泡结合并在囊泡上运输不需要C末端异戊二烯化。相反，无活性的Rab13似乎通过蛋白质-蛋白质相互作用与囊泡结合。只有在激活后，Rab13才与质膜结合，推测是C末端异戊二烯基插入膜中。
