Hasson Tama
Division of Biological Sciences, Section of Cell and Developmental Biology, University of California at San Diego, 2129 Bonner Hall, MC 0368, 9500 Gilman Drive, La Jolla, CA 92093-0368, USA.
J Cell Sci. 2003 Sep 1;116(Pt 17):3453-61. doi: 10.1242/jcs.00669.
Actin is found at the cortex of the cell where endocytosis occurs, but does it play a role in this essential process? Recent studies on the unconventional myosin, myosin VI, an actin-based molecular motor, provide compelling evidence that this myosin and therefore actin is involved in two distinct steps of endocytosis in higher eukaryotes: the formation of clathrin-coated vesicles and the movement of nascent uncoated vesicles from the actin-rich cell periphery to the early endosome. Three distinct adapter proteins--GIPC, Dab2 and SAP97--that associate with the cargo-binding tail domain of myosin VI have been identified. These proteins may recruit myosin VI to its sites of action.
肌动蛋白存在于发生内吞作用的细胞皮层,但它在这个重要过程中起作用吗?最近对非常规肌球蛋白——肌球蛋白VI(一种基于肌动蛋白的分子马达)的研究提供了令人信服的证据,表明这种肌球蛋白以及肌动蛋白参与了高等真核生物内吞作用的两个不同步骤:网格蛋白包被小泡的形成以及新生的无包被小泡从富含肌动蛋白的细胞周边向早期内体的移动。已经鉴定出三种与肌球蛋白VI的货物结合尾域相关的不同衔接蛋白——GIPC、Dab2和SAP97。这些蛋白质可能会将肌球蛋白VI招募到其作用位点。