Walther K, Krauss M, Diril M K, Lemke S, Ricotta D, Honing S, Kaiser S, Haucke V
Zentrum Biochemie und Molekulare Zellbiologie, University of Göttingen, Humboldtallee 23, D-37073 Göttingen, Germany.
EMBO Rep. 2001 Jul;2(7):634-40. doi: 10.1093/embo-reports/kve134. Epub 2001 Jul 3.
Synaptic vesicle biogenesis involves the recycling of synaptic vesicle components by clathrin-mediated endocytosis from the presynaptic membrane. stoned B, a protein encoded by the stoned locus in Drosophila melanogaster has been shown to regulate vesicle recycling by interacting with synaptotagmin. We report here the identification and characterization of a human homolog of stoned B (hStnB). Human stoned B is a brain-specific protein which co-enriches with other endocytic proteins such as AP-2 in a crude synaptic vesicle fraction and at nerve terminals. A domain with homology to the medium chain of adaptor complexes binds directly to both AP-2 and synaptotagmin and competes with AP-2 for the same binding site within synaptotagmin. Finally we show that the mu 2 homology domain of hStnB stimulates the uncoating of both clathrin and AP-2 adaptors from clathrin-coated vesicles. We hypothesize that hStnB regulates synaptic vesicle recycling by facilitating vesicle uncoating.
突触小泡的生物发生涉及通过网格蛋白介导的内吞作用从突触前膜回收突触小泡成分。stoned B是果蝇中stoned基因座编码的一种蛋白质，已被证明可通过与突触结合蛋白相互作用来调节小泡回收。我们在此报告stoned B的人类同源物（hStnB）的鉴定和特性。人类stoned B是一种脑特异性蛋白，在粗制突触小泡组分和神经末梢中与其他内吞蛋白（如AP-2）共同富集。一个与衔接蛋白复合物中链具有同源性的结构域直接与AP-2和突触结合蛋白结合，并与AP-2竞争突触结合蛋白内的相同结合位点。最后，我们表明hStnB的μ2同源结构域可刺激网格蛋白和AP-2衔接蛋白从网格蛋白包被小泡上脱衣。我们推测hStnB通过促进小泡脱衣来调节突触小泡回收。
