title: Vasopressin-induced intracellular redistribution of protein kinase D in intestinal epithelial cells.
abstract: The spatio-temporal changes of signaling molecules in response to G protein-coupled receptors (GPCR) stimulation is a poorly understood process in intestinal epithelial cells. Here we investigate the dynamic mechanisms associated with GPCR signaling in living rat intestinal epithelial cells by characterizing the intracellular translocation of protein kinase D (PKD), a serine/threonine protein kinase involved in mitogenic signaling in intestinal epithelial cells. Analysis of the intracellular steady-state distribution of green fluorescent protein (GFP)-tagged PKD indicated that in non-stimulated IEC-18 cells, GFP-PKD is predominantly cytoplasmic. However, cell stimulation with the GPCR agonist vasopressin induces a rapid translocation of GFP-PKD from the cytosol to the plasma membrane that is accompanied by its activation via protein kinase C (PKC)-mediated process and posterior plasma membrane dissociation. Subsequently, active PKD is imported into the nuclei where it transiently accumulates before being exported into the cytosol by a mechanism that requires a competent Crm1 nuclear export pathway. These findings provide evidence for a mechanism by which PKC coordinates in intestinal epithelial cells the translocation and activation of PKD in response to vasopressin-induced GPCR activation.
authors.affiliation: Division of Digestive Diseases, Department of Medicine, UCLA-CURE Digestive Diseases Research Center and Molecular Biology Institute, David Geffen School of Medicine, University of California at Los Angeles, California, USA.
authors.forename: Osvaldo
authors.initials: O
authors.lastname: Rey
authors.forename: Elena
authors.initials: E
authors.lastname: Zhukova
authors.forename: James
authors.initials: J
authors.lastname: Sinnett-Smith
authors.forename: Enrique
authors.initials: E
authors.lastname: Rozengurt
mesh_terms: D000818:Animals; D002460:Cell Line; D002462:Cell Membrane / Q000378:metabolism; D002467:Cell Nucleus / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D020962:Heterotrimeric GTP-Binding Proteins / Q000378:metabolism; D007413:Intestinal Mucosa / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011956:Receptors, Cell Surface / Q000819:agonists / Q000378:metabolism; D015398:Signal Transduction; D014667:Vasopressins / Q000494:pharmacology*
chemical_list: D011956:Receptors, Cell Surface; D014667:Vasopressins; C089212:protein kinase D; D011493:Protein Kinase C; D020962:Heterotrimeric GTP-Binding Proteins