Swiatecka-Urban Agnieszka
Department of Nephrology, Children's Hospital of Pittsburgh, Pittsburgh, PA, USA; Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
Front Pediatr. 2017 Feb 24;5:32. doi: 10.3389/fped.2017.00032. eCollection 2017.
Endocytic trafficking couples cell signaling with the cytoskeletal dynamics by organizing a crosstalk between protein networks in different subcellular compartments. Proteins residing in the plasma membrane are internalized and transported as cargo in endocytic vesicles (i.e., endocytosis). Subsequently, cargo proteins can be delivered to lysosomes for degradation or recycled back to the plasma membrane. The slit diaphragm is a modified tight junction connecting foot processes of the glomerular epithelial cells, podocytes. Signaling at the slit diaphragm plays a critical role in the kidney while its dysfunction leads to glomerular protein loss (proteinuria), manifesting as nephrotic syndrome, a rare condition with an estimated incidence of 2-4 new cases per 100,000 each year. Relatively little is known about the role of endocytic trafficking in podocyte signaling and maintenance of the slit diaphragm integrity. This review will focus on the role of endocytic trafficking at the mature podocyte slit diaphragm.
内吞运输通过在不同亚细胞区室的蛋白质网络之间组织串扰，将细胞信号传导与细胞骨架动力学联系起来。位于质膜上的蛋白质被内化并作为货物运输到内吞小泡中（即内吞作用）。随后，货物蛋白可以被递送到溶酶体进行降解，或者再循环回到质膜。裂孔隔膜是一种修饰的紧密连接，连接肾小球上皮细胞（足细胞）的足突。裂孔隔膜处的信号传导在肾脏中起关键作用，而其功能障碍会导致肾小球蛋白丢失（蛋白尿），表现为肾病综合征，这是一种罕见疾病，估计每年每10万人中有2 - 4例新发病例。关于内吞运输在足细胞信号传导和裂孔隔膜完整性维持中的作用，人们了解相对较少。本综述将聚焦于内吞运输在成熟足细胞裂孔隔膜中的作用。
