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Phosphorylation of Endogenous Proteins by Adenosine 3′:5′‐Monophosphate‐Dependent Protein Kinase in Mouse Neuroblastoma Cells
Author(s) -
Prashad Nagindra,
Evetts Curtis,
Wischmeyer Betsy
Publication year - 1980
Publication title -
journal of neurochemistry
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.75
H-Index - 229
eISSN - 1471-4159
pISSN - 0022-3042
DOI - 10.1111/j.1471-4159.1980.tb12487.x
Subject(s) - protein kinase a , phosphorylation , protein phosphorylation , phosphotransferase , kinase , biology , biochemistry , map2k7 , cgmp dependent protein kinase , cyclin dependent kinase 2 , mitogen activated protein kinase kinase , mapk14 , protein kinase r , microbiology and biotechnology
Increased intracellular adenosine 3′:5′‐monophosphate (cAMP) levels and activation of cAMP‐dependent protein kinases (ATP:protein phosphotransferase, EC 2.7.1.37) in vivo were correlated in mouse neuroblastoma cells grown in the presence of 1 mM‐ 6 N.O 2 ‐dibutyryl 3′:5′‐monophosphate (Bt 2 cAMP). The time course for activation showed that cAMP‐dependent protein kinases were activated by 30 min. A heat‐stable inhibitor protein inhibited a majority of activated cAMP‐dependent protein kinase. Activation of cAMP—dependent protein kinase caused additional phosphorylation of proteins when compared with untreated control cells, as demonstrated by endogenous phosphorylation of proteins in vitro using [γ‐ 32 P]ATP and analysis by two—dimensional polyacrylamide gel electrophoresis. The phosphorylation data show selective phosphorylation of specific proteins by cAMP‐independent and cAMP‐dependent protein kinase. Among the proteins in the postmitochondrial supernatant fraction phosphorylated by cAMP‐dependent protein kinases, two proteins with a molecular weight of 43,000 were heavily phosphorylated. It is suggested that phosphorylation of cellular proteins by cAMP‐dependent protein kinases might be involved in the cAMP‐modulated biochemical changes in neuroblastoma cells.