Departments of Cellular & Molecular Physiology and Cell Biology, Yale University School of Medicine, New Haven, Connecticut.
Departments of Cellular & Molecular Physiology and Cell Biology, Yale University School of Medicine, New Haven, Connecticut
J Am Soc Nephrol. 2014 Jul;25(7):1375-86. doi: 10.1681/ASN.2013080883. Epub 2014 Mar 20.
Renal epithelial cells must maintain distinct protein compositions in their apical and basolateral membranes in order to perform their transport functions. The creation of these polarized protein distributions depends on sorting signals that designate the trafficking route and site of ultimate functional residence for each protein. Segregation of newly synthesized apical and basolateral proteins into distinct carrier vesicles can occur at the trans-Golgi network, recycling endosomes, or a growing assortment of stations along the cellular trafficking pathway. The nature of the specific sorting signal and the mechanism through which it is interpreted can influence the route a protein takes through the cell. Cell type-specific variations in the targeting motifs of a protein, as are evident for Na,K-ATPase, demonstrate a remarkable capacity to adapt sorting pathways to different developmental states or physiologic requirements. This review summarizes our current understanding of apical and basolateral trafficking routes in polarized epithelial cells.
为了执行其转运功能，肾上皮细胞必须在其顶膜和基底外侧膜中保持独特的蛋白质组成。这些极化蛋白分布的创建取决于分拣信号，这些信号指定了每种蛋白质的运输途径和最终功能位置。新合成的顶膜和基底外侧蛋白可以在反式高尔基体网络、再循环内体或沿着细胞运输途径的不断增加的一系列站点中分离成不同的载体小泡。特定分拣信号的性质以及其被解释的机制可以影响蛋白质在细胞中的运输途径。蛋白质的靶向基序在细胞类型上存在差异，如 Na,K-ATPase 所示，这表明其分拣途径具有显著的适应不同发育状态或生理需求的能力。这篇综述总结了我们目前对极化上皮细胞中顶膜和基底外侧转运途径的理解。
