title: Src-mediated caveolin-1 phosphorylation regulates intestinal epithelial restitution by altering Ca(2+) influx after wounding.
abstract: Early mucosal restitution occurs as a consequence of intestinal epithelial cell (IEC) migration to reseal superficial wounds, but its exact mechanism remains largely unknown. Caveolin-1 (Cav1), a major component associated with caveolar lipid rafts in the plasma membrane, is implicated in many aspects of cellular functions. This study determined if c-Src kinase (Src)-induced Cav1 phosphorylation promotes intestinal epithelial restitution after wounding by activating Cav1-mediated Ca(2+) signaling. Src directly interacted with Cav1, formed Cav1-Src complexes, and phosphorylated Cav1 in IECs. Inhibition of Src activity by its chemical inhibitor PP2 or suppression of the functional caveolin scaffolding domain by caveolin-scaffolding domain peptides prevented Cav1-Src interaction, reduced Cav1 phosphorylation, decreased Ca(2+) influx, and inhibited cell migration after wounding. Disruption of caveolar lipid raft microdomains by methyl-β-cyclodextrin reduced Cav1-mediated Ca(2+) influx and repressed epithelial restitution. Moreover, Src silencing prevented subcellular redistribution of phosphorylated Cav1 in migrating IECs. These results indicate that Src-induced Cav1 phosphorylation stimulates epithelial restitution by increasing Cav1-mediated Ca(2+) signaling after wounding, thus contributing to the maintenance of gut mucosal integrity under various pathological conditions.
authors.affiliation: Department of Surgery, Cell Biology Group, University of Maryland School of Medicine, Baltimore, Maryland;
authors.forename: Navneeta
authors.initials: N
authors.lastname: Rathor
authors.forename: Ran
authors.initials: R
authors.lastname: Zhuang
authors.forename: Jian-Ying
authors.initials: JY
authors.lastname: Wang
authors.forename: James M
authors.initials: JM
authors.lastname: Donahue
authors.forename: Douglas J
authors.initials: DJ
authors.lastname: Turner
authors.forename: Jaladanki N
authors.initials: JN
authors.lastname: Rao
mesh_terms: D000081247:CSK Tyrosine-Protein Kinase; D002118:Calcium / Q000378:metabolism*; D051242:Caveolin 1 / Q000378:metabolism*; D002465:Cell Movement / Q000502:physiology; D002478:Cells, Cultured; D006801:Humans; D007413:Intestinal Mucosa / Q000293:injuries / Q000378:metabolism; D015398:Signal Transduction; D014945:Wound Healing / Q000502:physiology; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: D051242:Caveolin 1; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C000631346:CSK protein, human; D002118:Calcium
keywords: IEC-6 cells; Src activity; calcium influx; caveolin-1 scaffolding domain peptide; cell migration; cyclopiazonic acid; intracellular calcium