FXYD5: Na(+)/K(+)-ATPase Regulator in Health and Disease.

Irina Lubarski Gotliv

doi:10.3389/fcell.2016.00026

Abstract

FXYD5 (Dysadherin, RIC) is a single span type I membrane protein that plays multiple roles in regulation of cellular functions. It is expressed in a variety of epithelial tissues and acts as an auxiliary subunit of the Na+/K+-ATPase. During the past decade, a correlation between enhanced expression of FXYD5 and tumor progression has been established for various tumor types. In this review, current knowledge on FXYD5 is discussed, including experimental data on the functional effects of FXYD5 on the Na+/K+-ATPase. FXYD5 modulates cellular junctions, influences chemokine production, and affects cell adhesion. The accumulated data may provide a basis for understanding the molecular mechanisms underlying FXYD5 mediated phenotypes.

Highlights

FXYD5 (Dysadherin, RIC) is a single span type I membrane protein that plays multiple roles in regulation of cellular functions
Its role has been well characterized in epithelial tissues, probably due to the high abundance of FXYD5 in these cells and its up-regulation in several carcinomas, which originated from epithelial cells
FXYD5 expression could be compartmentalized to endothelial cells, which are a part of the vascular supply to muscle bundle

Summary

Introduction

FXYD5 (Dysadherin, RIC) is a single span type I membrane protein that plays multiple roles in regulation of cellular functions. The specific interaction of FXYD5 with Na+/K+-ATPase was demonstrated by co-immunoprecipitation in several expression systems (Lubarski et al, 2005, 2007, 2011; Miller and Davis, 2008b). A series of experiments, using point mutations, identified three trans-membrane residues as important for the FXYD5/Na+/K+-ATPase interaction (Lubarski et al, 2007).

Results

Conclusion