Identification of a tight junction-associated guanine nucleotide exchange factor that activates Rho and regulates paracellular permeability.

ABSTRACT: Rho family GTPases are important regulators of epithelial tight junctions (TJs); however, little is known about how the GTPases themselves are controlled during TJ assembly and function. We have identified and cloned a canine guanine nucleotide exchange factor (GEF) of the Dbl family of proto-oncogenes that activates Rho and associates with TJs. Based on sequence similarity searches and immunological and functional data, this protein is the canine homologue of human GEF-H1 and mouse Lfc, two previously identified Rho-specific exchange factors known to associate with microtubules in nonpolarized cells. In agreement with these observations, immunofluorescence of proliferating MDCK cells revealed that the endogenous canine GEF-H1/Lfc associates with mitotic spindles. Functional analysis based

SUBMITTER: Benais-Pont G 

PROVIDER: S-EPMC2173357 | biostudies-literature | 2003 Mar

REPOSITORIES: biostudies-literature