AMP-activated protein kinase induces actin cytoskeleton reorganization in epithelial cells.
AMP-activated protein kinase (AMPK), a known regulator of cellular and systemic energy balance, is now recognized to control cell division, cell polarity and cell migration, all of which depend on the actin cytoskeleton. Here we report the effects of A769662, a pharmacological activator of AMPK, on cytoskeletal organization and signalling in epithelial Madin-Darby canine kidney (MDCK) cells. We show that AMPK activation induced shortening or radiation of stress fibers, uncoupling from paxillin and predominance of cortical F-actin. In parallel, Rho-kinase downstream targets, namely myosin regulatory light chain and cofilin, were phosphorylated. These effects resembled the morphological changes in MDCK cells exposed to hyperosmotic shock, which led to Ca(2+)-dependent AMPK activation via calmodulin-dependent protein kinase kinase-beta(CaMKKbeta), a known upstream kinase of AMPK. Indeed, hypertonicity-induced AMPK activation was markedly reduced by the STO-609 CaMKKbeta inhibitor, as was the increase in MLC and cofilin phosphorylation. We suggest that AMPK links osmotic stress to the reorganization of the actin cytoskeleton.
Miranda
Lisa
L
de Duve Institute, Université catholique de Louvain, Avenue Hippocrate, B-1200 Brussels, Belgium.
Carpentier
Sarah
S
Platek
Anna
A
Hussain
Nusrat
N
Gueuning
Marie-Agnès
MA
Vertommen
Didier
D
Ozkan
Yurda
Y
Sid
Brice
B
Hue
Louis
L
Courtoy
Pierre J
PJ
Rider
Mark H
MH
Horman
Sandrine
S
D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D051339:Actin Depolymerizing Factors / Q000378:metabolism; D000199:Actins / Q000378:metabolism* / Q000648:ultrastructure; D000620:Aminoimidazole Carboxamide / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology; D001713:Biphenyl Compounds; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase / Q000037:antagonists & inhibitors / Q000378:metabolism; D002460:Cell Line; D003599:Cytoskeleton / Q000378:metabolism* / Q000648:ultrastructure; D004285:Dogs; D004847:Epithelial Cells / Q000378:metabolism* / Q000648:ultrastructure; D053644:Naphthalimides / Q000494:pharmacology; D009997:Osmotic Pressure; D051419:Paxillin / Q000378:metabolism; D010766:Phosphorylation; D011753:Pyrones / Q000494:pharmacology; D012265:Ribonucleotides / Q000494:pharmacology; D012462:Saline Solution, Hypertonic / Q000494:pharmacology; D013876:Thiophenes / Q000494:pharmacology; D054460:rho-Associated Kinases / Q000378:metabolism
D051339:Actin Depolymerizing Factors; D000199:Actins; D001562:Benzimidazoles; D001713:Biphenyl Compounds; D053644:Naphthalimides; D051419:Paxillin; D011753:Pyrones; D012265:Ribonucleotides; C458525:STO 609; D012462:Saline Solution, Hypertonic; D013876:Thiophenes; D000620:Aminoimidazole Carboxamide; D054460:rho-Associated Kinases; D054737:Calcium-Calmodulin-Dependent Protein Kinase Kinase; D055372:AMP-Activated Protein Kinases; C031143:AICA ribonucleotide; C512408:4-hydroxy-3-(4-(2-hydroxyphenyl)phenyl)-6-oxo-7H-thieno(2,3-b)pyridine-5-carbonitrile