USP9x-mediated deubiquitination of EFA6 regulates de novo tight junction assembly.

ABSTRACT: In epithelial cells, the tight junction (TJ) functions as a permeability barrier and is involved in cellular differentiation and proliferation. Although many TJ proteins have been characterized, little is known about the sequence of events and temporal regulation of TJ assembly in response to adhesion cues. We report here that the deubiquitinating enzyme USP9x has a critical function in TJ biogenesis by controlling the levels of the exchange factor for Arf6 (EFA6), a protein shown to facilitate TJ formation, during a narrow temporal window preceding the establishment of cell polarity. At steady state, EFA6 is constitutively ubiquitinated and turned over by the proteasome. However, at newly forming contacts, USP9x-mediated deubiquitination protects EFA6 from proteasomal degradation, leading

SUBMITTER: Theard D 

PROVIDER: S-EPMC2876957 | biostudies-literature | 2010 May

REPOSITORIES: biostudies-literature