Protein phosphatase-2A modulates the serine and tyrosine phosphorylation of paxillin in Lewis lung carcinoma tumor variants.
Cellular adhesion and motility, processes regulated by focal adhesion assembly and disassembly, can influence a tumor cell's ability to metastasize. Focal adhesion dynamics are, in turn, influenced by the serine and tyrosine phosphorylation state of paxillin. Using Lewis lung carcinoma (LLC) tumor variants, this study shows the importance of the serine/threonine protein phosphatase-2A (PP-2A) in maintaining adherence and restricting tumor cell motility, and modulating the serine and tyrosine phosphorylation of paxillin. Treating non-metastatic LLC-C8 tumor variants with okadaic acid to inhibit PP-2A activity resulted in cell rounding and increased motility. These effects on motility and adherence were accompanied by increased serine and decreased tyrosine phosphorylation of paxillin. These results suggest PP-2A regulation of paxillin phosphorylation may have a role in controlling tumor cell adherence and motility.
Departments of Cell Biology, Neurobiology and Anatomy, Loyola University Chicago-Stritch School of Medicine, Maywood, Illinois, USA.
Jodi L
JL
Jackson
M Rita I
MR
Young
D000818:Animals; D018827:Carcinoma, Lewis Lung / Q000201:enzymology* / Q000473:pathology; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D004791:Enzyme Inhibitors / Q000494:pharmacology; D022001:Focal Adhesions / Q000187:drug effects / Q000502:physiology; D051379:Mice; D009363:Neoplasm Proteins / Q000378:metabolism*; D019319:Okadaic Acid / Q000494:pharmacology; D051419:Paxillin; D010749:Phosphoprotein Phosphatases / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010750:Phosphoproteins / Q000378:metabolism*; D010766:Phosphorylation; D010768:Phosphoserine / Q000378:metabolism; D019000:Phosphotyrosine / Q000378:metabolism; D054648:Protein Phosphatase 2; D011499:Protein Processing, Post-Translational
D003598:Cytoskeletal Proteins; D004791:Enzyme Inhibitors; D009363:Neoplasm Proteins; D051419:Paxillin; D010750:Phosphoproteins; C496062:Pxn protein, mouse; D010768:Phosphoserine; D019319:Okadaic Acid; D019000:Phosphotyrosine; D010749:Phosphoprotein Phosphatases; D054648:Protein Phosphatase 2