Identical M sub r 70,000 S6 kinase is activated biphasically by epidermal growth factor: A phosphopeptide that characterizes the late phase

Journal Article · Sat Sep 01 04:00:00 EDT 1990 · Proceedings of the National Academy of Sciences of the United States of America; (United States)

DOI:https://doi.org/10.1073/pnas.87.18.7040· OSTI ID:5323784

Susa, M; Thomas, G ^[1]

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1. Friedrich Miescher Inst., Basel (Switzerland)

Mitogenic stimulation of quiescent mouse 3T3 cells with epidermal growth factor leads to biphasic S6 kinase activation. The kinases present in both phases of the response have been purified from {sup 32}P-labeled cells and shown to contain a phosphoprotein of equivalent M{sub r} 70,000. Chromatographic analysis of the purified S6 kinases on a Mono Q column reveals that (1) all {sup 32}P-labeled protein coelutes with S6 kinase activity, (2) only those fractions containing S6 kinase autophosphorylate, (3) autophosphorylation is restricted to a single M{sub r} 70,000 protein, and (4) the extent of autophosphorylation directly parallels the degree of S6 kinase activation. Analysis of the two autophosphorylated S6 kinases by two-dimensional tryptic phosphopeptide mapping indicates that they are the same protein. Both in vivo {sup 32}P-labeled S6 kinase contain phosphoserine and phosphothreonine but no detectable phosphotyrosine. Two-dimensional tryptic peptide maps of the in vivo {sup 32}P-labeled S6 kinases are essentially identical, except for a single qualitative change in the late-phase S6 kinase.

• OSTI ID: 5323784
• Journal Information: Proceedings of the National Academy of Sciences of the United States of America; (United States), Journal Name: Proceedings of the National Academy of Sciences of the United States of America; (United States) Vol. 87:18; ISSN PNASA; ISSN 0027-8424
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
AMINO ACIDS
ANIMAL CELLS
ANIMALS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
BIOLOGICAL EFFECTS
CARBOXYLIC ACIDS
CHEMICAL ACTIVATION
CONNECTIVE TISSUE CELLS
DAYS LIVING RADIOISOTOPES
ENZYME ACTIVITY
ENZYMES
FIBROBLASTS
GROWTH FACTORS
HYDROXY ACIDS
ISOTOPES
LIGHT NUCLEI
MAMMALS
MICE
MITOGENS
NUCLEI
ODD-ODD NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
PHOSPHOPROTEINS
PHOSPHORUS 32
PHOSPHORUS ISOTOPES
PHOSPHORUS-GROUP TRANSFERASES
PHOSPHOTRANSFERASES
PROTEINS
RADIOISOTOPES
RODENTS
SERINE
SOMATIC CELLS
THREONINE
TRANSFERASES
VERTEBRATES