Bipolar assembly of caveolae in retinal pigment epithelium. Academic Article uri icon

Overview

abstract

  • Caveolae and their associated structural proteins, the caveolins, are specialized plasmalemmal microdomains involved in endocytosis and compartmentalization of cell signaling. We examined the expression and distribution of caveolae and caveolins in retinal pigment epithelium (RPE), which plays key roles in retinal support, visual cycle, and acts as the main barrier between blood and retina. Electron microscopic observation of rat RPE, in situ primary cultures of rat and human RPE and a rat RPE cell line (RPE-J) demonstrated in all cases the presence of caveolae in both apical and basolateral domains of the plasma membrane. Caveolae were rare in RPE in situ but were frequent in primary RPE cultures and in RPE-J cells, which correlated with increased levels in the expression of caveolin-1 and -2. The bipolar distribution of caveolae in RPE is striking, as all other epithelial cells examined to date (liver, kidney, thyroid, and intestinal) assemble caveolae only at the basolateral side. This might be related to the nonpolar distribution of both caveolin-1 and 2 in RPE because caveolin-2 is basolateral and caveolin-1 nonpolar in other epithelial cells. The bipolar localization of plasmalemmal caveolae in RPE cells may reflect specialized roles in signaling and trafficking important for visual function.

publication date

  • October 26, 2005

Research

keywords

  • Caveolae
  • Pigment Epithelium of Eye

Identity

Scopus Document Identifier

  • 33645461657

Digital Object Identifier (DOI)

  • 10.1152/ajpcell.00405.2005

PubMed ID

  • 16251472

Additional Document Info

volume

  • 290

issue

  • 3