Woodman Philip G, Futter Clare E
Faculty of Life Sciences, University of Manchester, Oxford Road, Manchester M13 9PT, United Kingdom.
Curr Opin Cell Biol. 2008 Aug;20(4):408-14. doi: 10.1016/j.ceb.2008.04.001. Epub 2008 May 24.
Multivesicular endosomes/bodies (MVBs) sort endocytosed proteins to different destinations. Many lysosomally directed membrane proteins are sorted onto intralumenal vesicles, whilst recycling proteins remain on the perimeter membrane from where they are removed via tubular extensions. MVBs move to the cell centre during this maturation process and, when all recycling proteins have been removed, fuse with lysosomes. Recent advances have identified endosomal-sorting complex required for transport (ESCRT)-dependent and ESCRT-independent pathways in intralumenal vesicle formation and mechanisms for sorting recycling cargo into tubules. Cytoskeletal motors, through interactions with these machineries and by regulating MVB movement, help to co-ordinate events leading to a mature, fusion-competent MVB.
多囊泡内体/小体（MVBs）将内吞的蛋白质分选至不同的目的地。许多靶向溶酶体的膜蛋白被分选到腔内小泡上，而循环利用的蛋白质则保留在周边膜上，随后通过管状延伸从该膜上被移除。在这个成熟过程中，MVBs向细胞中心移动，当所有循环利用的蛋白质都被移除后，它们会与溶酶体融合。最近的进展已经确定了腔内小泡形成过程中依赖转运所需内体分选复合物（ESCRT）和不依赖ESCRT的途径，以及将循环利用货物分选到小管中的机制。细胞骨架马达通过与这些机制相互作用并调节MVB的移动，有助于协调导致形成成熟的、具有融合能力的MVB的一系列事件。
