title: Calyculin A-induced actin phosphorylation and depolymerization in renal epithelial cells.
abstract: This study reports actin phosphorylation and coincident actin cytoskeleton alterations in renal epithelial cell line, LLC-PK1. Serine phosphorylation of actin was first observed in vitro after the cell lysate was incubated with phosphatase inhibitors and ATP. Both the phosphorylated actin and actin kinase activities were found in the cytoskeletal fraction. Actin phosphorylation was later detected in living LLC-PK1 cells after incubation with the phosphatase inhibitor calyculin A. Calyculin A-induced actin phosphorylation was associated with reorganization of the actin cytoskeleton, including net actin depolymerization, loss of cell-cell junction and stress fiber F-actin filaments, and redistribution of F-actin filaments in the periphery of the rounded cells. Actin phosphorylation was abolished by 3-h ATP depletion but not by the non-specific kinase inhibitor staurosporine. These results demonstrate that renal epithelial cells contain kinase/phosphatase activities and actin can be phosphorylated in LLC-PK1 cells. Actin phosphorylation may play an important role in regulating the organization of the actin cytoskeleton in renal epithelium.
authors.affiliation: Department of Life Sciences, Indiana State University, Terre Haute, IN 47809, USA.
authors.forename: Luo
authors.initials: L
authors.lastname: Gu
authors.forename: Hui
authors.initials: H
authors.lastname: Zhang
authors.forename: Qi
authors.initials: Q
authors.lastname: Chen
authors.forename: Jing
authors.initials: J
authors.lastname: Chen
mesh_terms: D008841:Actin Cytoskeleton / Q000187:drug effects / Q000378:metabolism*; D000255:Adenosine Triphosphate / Q000172:deficiency; D000818:Animals; D002460:Cell Line; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D004847:Epithelial Cells / Q000187:drug effects / Q000378:metabolism*; D007687:Kidney Tubules, Proximal / Q000187:drug effects / Q000378:metabolism*; D008387:Marine Toxins; D010080:Oxazoles / Q000494:pharmacology*; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011108:Polymers / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000187:drug effects / Q000378:metabolism; D012694:Serine / Q000378:metabolism; D019311:Staurosporine / Q000494:pharmacology
chemical_list: D004791:Enzyme Inhibitors; D008387:Marine Toxins; D010080:Oxazoles; D011108:Polymers; D012694:Serine; C059041:calyculin A; D000255:Adenosine Triphosphate; C074377:actin kinase; D017346:Protein Serine-Threonine Kinases; D010749:Phosphoprotein Phosphatases; D019311:Staurosporine