Rodriguez-Gabin A G, Cammer M, Almazan G, Charron M, Larocca J N
Department of Neurology/Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Ave., Bronx, NY 10461, USA.
J Neurosci Res. 2001 Dec 15;66(6):1149-60. doi: 10.1002/jnr.1253.
Intracellular membrane trafficking plays an essential role in the biogenesis and maintenance of myelin. Members of the Rab protein family are important components of the systems that regulate intracellular vesicle transport. We examine the function of rRab22b, a novel rat Rab protein cloned from an oligodendrocyte cDNA library, by visualizing and identifying in living Hela cells the organelles that contain rRab22b. Our results show that rRab22b is present in the trans Golgi/TGN and endocytic compartments. Trafficking of membranes from trans Golgi to endocytic compartments takes place via small tubulo vesicular organelles containing rRab22b. The formation of vesicles in the trans Golgi also appears to be regulated by rRab22b. Additionally, our results suggest that rRab22b controls the transport of vesicles from the trans Golgi to endocytic compartments that localize in oligodendrocyte processes. That rRab22b is involved in the transport of certain proteins from trans Golgi to myelin is suggested by the evidence that certain proteins being targeted to the plasma membrane are first transported from trans Golgi to endocytic compartments.
细胞内膜运输在髓鞘的生物发生和维持中起着至关重要的作用。Rab蛋白家族成员是调节细胞内囊泡运输系统的重要组成部分。我们通过在活的Hela细胞中可视化和鉴定含有rRab22b的细胞器，来研究从少突胶质细胞cDNA文库中克隆出的一种新型大鼠Rab蛋白rRab22b的功能。我们的结果表明，rRab22b存在于反式高尔基体/反式高尔基体网络（TGN）和内吞区室中。从反式高尔基体到内吞区室的膜运输是通过含有rRab22b的小管状囊泡细胞器进行的。反式高尔基体中囊泡的形成似乎也受rRab22b调控。此外，我们的结果表明，rRab22b控制着囊泡从反式高尔基体到位于少突胶质细胞突起中的内吞区室的运输。某些靶向质膜的蛋白质首先从反式高尔基体运输到内吞区室，这一证据表明rRab22b参与了某些蛋白质从反式高尔基体到髓鞘的运输。
