title: Laminin stimulates protein tyrosine dephosphorylation in PC12 cells.
abstract: Laminin stimulates neurite outgrowth in rat pheochromocytoma cells (PC12 cells). Here, we investigated laminin signal transduction mechanisms by adding the tyrosine kinase/phosphatase modulators, genistein, quercetin, aurin tricarboxylic acid (ATA), and vanadate to PC12 cells. At 10 microM both genistein and quercetin enhanced laminin-mediated neurite outgrowth by 1.7- and 2.3-fold, respectively, while at 10 microM, ATA inhibited laminin-mediated neurite outgrowth by 92%. Vanadate inhibited neurite outgrowth by 63% at 10 microM. Immunoblot analysis revealed four proteins of approximately 240, 22, 110, and 35 kDa, which were dephosphorylated on tyrosine residues in laminin-treated PC12 cells, but not in NIH 3T3 cells. These results demonstrate that laminin-mediated neurite outgrowth involves protein tyrosine dephosphorylation and suggests that this mechanism may have specificity to neuronal cells.
authors.affiliation: Department of Biology, Adelphi University, Garden City, New York, 11530, USA.
authors.forename: B S
authors.initials: BS
authors.lastname: Weeks
authors.forename: P J
authors.initials: PJ
authors.lastname: Wilson
authors.forename: C C
authors.initials: CC
authors.lastname: Heffernan
authors.forename: V A
authors.initials: VA
authors.lastname: Gorra
authors.forename: L E
authors.initials: LE
authors.lastname: White
authors.forename: A
authors.initials: A
authors.lastname: Ahmad
mesh_terms: D000818:Animals; D001312:Aurintricarboxylic Acid / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D019833:Genistein / Q000494:pharmacology; D007700:Kinetics; D007797:Laminin / Q000494:pharmacology*; D016716:PC12 Cells; D010636:Phenols / Q000494:pharmacology; D010750:Phosphoproteins / Q000378:metabolism*; D019000:Phosphotyrosine / Q000378:metabolism*; D017027:Protein Tyrosine Phosphatases / Q000378:metabolism; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011794:Quercetin / Q000494:pharmacology; D051381:Rats; D015398:Signal Transduction; D014638:Vanadates
chemical_list: D004791:Enzyme Inhibitors; D007797:Laminin; D010636:Phenols; D010750:Phosphoproteins; D019000:Phosphotyrosine; D014638:Vanadates; C062898:lavendustin A; D001312:Aurintricarboxylic Acid; D011794:Quercetin; D019833:Genistein; D011505:Protein-Tyrosine Kinases; D017027:Protein Tyrosine Phosphatases