GIT1 phosphorylation on serine 46 by PKD3 regulates paxillin trafficking and cellular protrusive activity.
The continuous assembly and disassembly of focal adhesions is required for efficient cell spreading and migration. The G-protein-coupled receptor kinase-interacting protein 1 (GIT1) is a multidomain protein whose dynamic localization to sites of cytoskeletal remodeling is critically involved in the regulation of these processes. Here we provide evidence that the subcellular localization of GIT1 is regulated by protein kinase D3 (PKD3) through direct phosphorylation on serine 46. GIT1 phosphorylation on serine 46 was abrograted by PKD3 depletion, thereby identifying GIT1 as the first specific substrate for this kinase. A GIT1 S46D phosphomimetic mutant localized to motile, paxillin-positive cytoplasmic complexes, whereas the phosphorylation-deficient GIT1 S46A was enriched in focal adhesions. We propose that phosphorylation of GIT1 on serine 46 by PKD3 represents a molecular switch by which GIT1 localization, paxillin trafficking, and cellular protrusive activity are regulated.
Institute of Cell Biology and Immunology, University of Stuttgart, Allmandring 31, 70569 Stuttgart, Germany.
Bettina
B
Huck
Ralf
R
Kemkemer
Mirita
M
Franz-Wachtel
Boris
B
Macek
Angelika
A
Hausser
Monilola A
MA
Olayioye
D048868:Adaptor Proteins, Signal Transducing / Q000235:genetics / Q000378:metabolism*; D019943:Amino Acid Substitution; D018797:Cell Cycle Proteins / Q000235:genetics / Q000378:metabolism*; D045744:Cell Line, Tumor; D002465:Cell Movement / Q000502:physiology*; D003599:Cytoskeleton / Q000235:genetics / Q000378:metabolism*; D057809:HEK293 Cells; D006801:Humans; D020125:Mutation, Missense; D051419:Paxillin / Q000235:genetics / Q000378:metabolism*; D010766:Phosphorylation / Q000502:physiology; D017346:Protein Serine-Threonine Kinases / Q000235:genetics / Q000378:metabolism*; D021381:Protein Transport / Q000502:physiology; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D012694:Serine / Q000235:genetics / Q000378:metabolism
D048868:Adaptor Proteins, Signal Transducing; D018797:Cell Cycle Proteins; C485647:GIT1 protein, human; C496061:PXN protein, human; D051419:Paxillin; D000081382:Pyruvate Dehydrogenase Acetyl-Transferring Kinase; D012694:Serine; D017346:Protein Serine-Threonine Kinases