Mapping of phosphomonoester and apparent phosphodiester bonds of the oncogene product p53 from simian virus 40-transformed 3T3 cells
The oncogene product p53, isolated from SV3T3 cells where it forms a complex with simian virus 40 large tumor antigen (T antigen) in the nucleus, has been found to be phosphorylated at least four distinct sites on the 390 amino acid protein. Separation of tryptic phosphopeptides has permitted identificatio of two sites as Ser-312 and Ser-389, and permitted analysis of the types of phosphate bonds. The peptide containing Ser-312 separates electrophoretically into three charged forms; two are resistant to dephosphorylation by both alkaline phosphatase and alkaline hydrolysis, suggesting a phosphodiester. The carboxyl-terminal phosphopeptide containing Ser-389 was alkaline phosphatase-resistant and liberated four ribonucleoside monophosphates upon base or RNase hydrolysis, suggesting that Ser-389 may be covalently linked to RNA. Phosphorylation of Ser-389 decreased markedly at the nonpermissive temperature in simian virus 40 tsA58-transformed cells, indicating a dependence on native T antigen function and a possible role in transformation by T antigen. Two additional phosphorylation sites, one involving serine and one involving threonine, probably reside in the amino-terminal segment of p53 and appear to be peptide-phosphate monoesters.
- Research Organization:
- New York Univ. Medical School, NY
- OSTI ID:
- 6358535
- Journal Information:
- Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 83:4; ISSN PNASA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
AMINO ACID SEQUENCE
ANIMAL CELLS
BETA DECAY RADIOISOTOPES
BETA-MINUS DECAY RADIOISOTOPES
CELL TRANSFORMATIONS
CHEMICAL ANALYSIS
CHEMICAL BONDS
CHEMICAL REACTIONS
CONNECTIVE TISSUE CELLS
COUNTING TECHNIQUES
DAYS LIVING RADIOISOTOPES
ENZYMES
ESTERASES
FIBROBLASTS
GENES
HYDROLASES
ISOTOPES
LIGHT NUCLEI
MICROORGANISMS
MOLECULAR STRUCTURE
NUCLEI
ODD-ODD NUCLEI
ONCOGENES
ONCOGENIC TRANSFORMATIONS
OXYGEN COMPOUNDS
PARASITES
PHOSPHATES
PHOSPHODIESTERASES
PHOSPHORUS 32
PHOSPHORUS COMPOUNDS
PHOSPHORUS ISOTOPES
PHOSPHORYLATION
PROTEIN STRUCTURE
QUANTITATIVE CHEMICAL ANALYSIS
RADIOCHEMICAL ANALYSIS
RADIOISOTOPES
SCINTILLATION COUNTING
SIMIAN VIRUS
SOMATIC CELLS
TRANSCRIPTION
VIRUSES