Growth factor-induced activation of a kinase activity which causes regulatory phosphorylation of p42/microtubule-associated protein kinase.
p42/microtubule-associated protein kinase (p42mapk) is activated by tyrosine and threonine phosphorylation, and its regulatory phosphorylation is likely to be important in signalling pathways involved in growth control, secretion, and differentiation. Here we show that treatment of quiescent 3T3 cells with diverse agonists results in the appearance of an activity capable of causing the in vitro phosphorylation of p42mapk on the regulatory tyrosine and to a lesser extent on the regulatory threonine, resulting in enzymatic activation of the p42mapk. This p42mapk-activating activity is capable of phosphorylating a kinase-defective p42mapk mutant, thus confirming its activity as a kinase.
L'Allemain
G
G
Department of Microbiology, University of Virginia, Charlottesville 22908.
Her
J H
JH
Wu
J
J
Sturgill
T W
TW
Weber
M J
MJ
D016475:3T3 Cells; D000595:Amino Acid Sequence; D000596:Amino Acids / Q000032:analysis; D000818:Animals; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D003600:Cytosol / Q000201:enzymology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D006801:Humans; D007700:Kinetics; D051379:Mice; D016297:Mutagenesis, Site-Directed; D010766:Phosphorylation; D010982:Platelet-Derived Growth Factor / Q000494:pharmacology*; D011494:Protein Kinases / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D011994:Recombinant Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology; D013912:Threonine; D014443:Tyrosine
D000596:Amino Acids; D010982:Platelet-Derived Growth Factor; D011994:Recombinant Proteins; D013912:Threonine; D014443:Tyrosine; D004815:Epidermal Growth Factor; D011494:Protein Kinases; D011505:Protein-Tyrosine Kinases; D017871:Calcium-Calmodulin-Dependent Protein Kinases