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A Nerve Growth Factor‐Sensitive S6 Kinase in Cell‐Free Extracts from PC 12 Cells
Author(s) -
Matsuda Yuzuru,
Nakanishi Nobuo,
Dickens Geneva,
Guroff Gordon
Publication year - 1986
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.1471-4159.1986.tb13081.x
Subject(s) - protein kinase a , mitogen activated protein kinase kinase , nerve growth factor , kinase , ribosomal protein s6 , cyclin dependent kinase 2 , microbiology and biotechnology , cgmp dependent protein kinase , map2k7 , cyclin dependent kinase 9 , biology , biochemistry , phosphorylation , chemistry , protein kinase r , protein phosphorylation , receptor
Soluble extracts from nerve growth factor (NGF)‐stimulated PC 12 cells prepared by alkaline lysis show a two‐to 10‐fold greater ability to phosphorylate the 40S ribosomal protein S6 than do extracts from control cells. The alkaline lysis method yields a preparation of much higher specific activity than does sonication. Half‐maximal incorporation of 32 P from [ 32 P]ATP into S6 occurred after 4–7 min of NGF treatment. The partially purified NGF‐sensitive S6 kinase has a molecular weight of 45,000. It is not inhibited by NaCl, chlorpromazine, or the specific inhibitor of cyclic AMP (cAMP)‐dependent protein kinase, nor is it activated by addition of diolein plus phosphatidylserine. Trypsin treatment of either crude extracts or partially purified S6 kinase from control or NGF‐treated cells was without effect. These data suggest that the S6 kinase stimulated by NGF is neither cAMP‐dependent protein kinase or protein kinase C nor the result of tryptic activation of an inactive proenzyme. Treatment of intact cells with dibutyryl cAMP or 5′‐ N ‐ethylcarboxamideadenosine also increases the subsequent cell‐free phosphorylation of S6. This observation suggests that cAMP‐dependent protein kinase may be involved in the phosphorylation of S6 kinase.