Genesis of polarity in renal tubular cells.

Overview

Using enveloped RNA viruses as probes to study the biogenesis of surface polarity in epithelial cell lines, evidence has been obtained that, as shown for secretion in exocrine cells, the delivery of plasma membrane proteins to the cell surface is polarized. Divergence between the pathways of apical and basolateral plasma membrane proteins occurs at the level of the distal Golgi apparatus. Presumably, carrier vesicles with affinity for specific receptors in the apical or in the basolateral regions of the plasmalemma participate in the transport between the Golgi apparatus and the cell surface. Agents which disrupt actin filaments and microtubules do not alter significantly this process of vectorial exocytosis.