A possible role for α-dystrobrevin in the reorganization of tight junctions in epithelial cells
(English)Manuscript (preprint) (Other academic)
Alpha-dystrobrevin (α -DB) has been described primarily as a cytoplasmic component of the dystrophin-glycoprotein complex (DGC) in skeletal muscle cells. Isoforms of α -DB show different localization in cells and tissues; at basolateral membranes in epithelial cells, dystrobrevins mediate contact with the extracellular matrix, peripheral and transmembrane proteins and the filamentous actin cytoskeleton. Beside their structural role, α -DBs are assumed to be important in cell signalling and cell differentiation. We have assessed the role of a-DB in two epithelial cell lines (MDCK I and HT 29) that are in different developmental stages and exhibit distinct permeability characteristics. Using a polyclonal anti-α-DB antibody, we have investigated its localization and association with tight junction (TJ)-associated proteins before and after protein kinase C (PKC) activation with phorbol myristate acetate (PMA). In both cell lines, there was submembranous localization of α -DB both apically and basolaterally, as assessed with confocal imaging. PKC caused a reorganization of TJ, which was parallel with increased localization of α -DB to TJ areas, especially in MDCK I cells. Moreover, the TJ-associated protein Z0-1 co-immunoprecipitated with α -DB, as displayed with SDS-PAGE and immunoblotting. Thus, α -DBs not only take part in the regulation of the contact between intra- and extracellular proteins at basolateral membranes, but possibly also in the regulation of tight junctions via ZO-1 and PKC-activation.
dystrobrevin, tight junction, protein kinase C, epithelium, dystrophin-glycoprotein complex
Medical and Health Sciences
IdentifiersURN: urn:nbn:se:liu:diva-97568OAI: oai:DiVA.org:liu-97568DiVA: diva2:648858