Src regulates distinct pathways for cell volume control through Vav and phospholipase Cgamma.
Cell volume recovery in response to swelling requires reorganization of the cytoskeleton and fluid efflux. We have previously shown that electrolyte and fluid efflux via K+ and Cl- channels is controlled by swelling-induced activation of phospholipase Cgamma (PLCgamma). Recently, integrin engagement has been suggested to trigger responses to swelling through activation of Rho family GTPases and Src kinases. Because both PLCgamma and Rho GTPases can be regulated by Src during integrin-mediated cytoskeletal reorganization, we sought to identify swelling-induced Src effectors. Upon hypotonic challenge, Src was rapidly activated in transient plasma membrane protrusions, where it colocalized with Vav, an activator of Rho GTPases. Inhibition of Src with PP2 attenuated phosphorylation of Vav. PP2 also attenuated phosphorylation of PLCgamma, and inhibited swelling-mediated activation of K+ and Cl- channels and cell volume recovery. These findings suggest that swelling-induced Src regulates cytoskeletal dynamics, through Vav, and fluid efflux, through PLCgamma, and thus can coordinate structural reorganization with fluid balance to maintain cellular integrity.
Barfod
Elisabeth T
ET
Department of Medicine, University of Vermont, Burlington, Vermont 05405, USA.
Moore
Ann L
AL
Melnick
Richard F
RF
Lidofsky
Steven D
SD
D008841:Actin Cytoskeleton / Q000378:metabolism; D000818:Animals; D006528:Carcinoma, Hepatocellular; D018797:Cell Cycle Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D048430:Cell Shape; D048429:Cell Size; D018118:Chloride Channels / Q000502:physiology; D004789:Enzyme Activation / Q000502:physiology; D022001:Focal Adhesions / Q000378:metabolism; D007038:Hypotonic Solutions / Q000494:pharmacology; D008113:Liver Neoplasms; D008564:Membrane Potentials / Q000502:physiology; D015513:Oncogene Proteins / Q000378:metabolism; D018408:Patch-Clamp Techniques; D051966:Phospholipase C gamma; D015221:Potassium Channels / Q000502:physiology; D011518:Proto-Oncogene Proteins / Q000378:metabolism*; D051567:Proto-Oncogene Proteins c-vav; D051381:Rats; D010738:Type C Phospholipases / Q000378:metabolism*; D014882:Water-Electrolyte Balance / Q000502:physiology*; D019061:src-Family Kinases / Q000378:metabolism*
D018797:Cell Cycle Proteins; D018118:Chloride Channels; D007038:Hypotonic Solutions; D015513:Oncogene Proteins; D015221:Potassium Channels; D011518:Proto-Oncogene Proteins; D051567:Proto-Oncogene Proteins c-vav; C496620:Vav1 protein, rat; C490564:Vav2 protein, rat; D019061:src-Family Kinases; D010738:Type C Phospholipases; D051966:Phospholipase C gamma