Phosphorylation of murine mammary tumor virus precursor polypeptides

Janis Racevskis, N. H. Sarkar

Research output: Contribution to journalArticle

8 Citations (Scopus)

Abstract

Phosphorylation of the murine mammary tumor virus (MuMTV) structural proteins was studied in an MuMTV-infected epithelial cell line derived from a BALB/cf C3H mouse mammary tumor. Immunoprecipitation of 32P-labeled cell extracts with monospecific anti-p27 serum revealed that phosphorylation occurred at the stage of the core-protein polyprotein precursor prp 75. Two forms of phosphorylated prp75 were found: one migrating with an apparent molecular weight of 80,000, and the other with a molecular weight of 76,000. The 80,000-molecular-weight species was found to be the most heavily phosphorylated. In addition, a relatively stable phosphorylated processing intermediate of 34,000 molecular weight was observed as well. Tryptic peptide mapping analysis of the 32P-labeled viral proteins indicated a precursor product relationship between the intracellular phosphorylated, high-molecular-weight peptides and the mature MuMTV phosphoproteins p23 and p27. Phosphopeptide analysis also suggested that phosphorylation of the viral proteins occurred in discrete steps and that the attached phosphate groups were conserved throughout the processing steps.

Original languageEnglish (US)
Pages (from-to)241-247
Number of pages7
JournalJournal of Virology
Volume30
Issue number1
StatePublished - 1979
Externally publishedYes

Fingerprint

Gammaretrovirus
mammary neoplasms (animal)
polypeptides
phosphorylation
Molecular Weight
Phosphorylation
Breast Neoplasms
molecular weight
viruses
Peptides
mice
viral proteins
Viral Proteins
Viral Structural Proteins
peptide mapping
Polyproteins
Phosphopeptides
phosphoproteins
Peptide Mapping
Protein Precursors

ASJC Scopus subject areas

  • Immunology

Cite this

Phosphorylation of murine mammary tumor virus precursor polypeptides. / Racevskis, Janis; Sarkar, N. H.

In: Journal of Virology, Vol. 30, No. 1, 1979, p. 241-247.

Research output: Contribution to journalArticle

@article{1a9930b0bc38406087ec6c41bc1f5e77,
title = "Phosphorylation of murine mammary tumor virus precursor polypeptides",
abstract = "Phosphorylation of the murine mammary tumor virus (MuMTV) structural proteins was studied in an MuMTV-infected epithelial cell line derived from a BALB/cf C3H mouse mammary tumor. Immunoprecipitation of 32P-labeled cell extracts with monospecific anti-p27 serum revealed that phosphorylation occurred at the stage of the core-protein polyprotein precursor prp 75. Two forms of phosphorylated prp75 were found: one migrating with an apparent molecular weight of 80,000, and the other with a molecular weight of 76,000. The 80,000-molecular-weight species was found to be the most heavily phosphorylated. In addition, a relatively stable phosphorylated processing intermediate of 34,000 molecular weight was observed as well. Tryptic peptide mapping analysis of the 32P-labeled viral proteins indicated a precursor product relationship between the intracellular phosphorylated, high-molecular-weight peptides and the mature MuMTV phosphoproteins p23 and p27. Phosphopeptide analysis also suggested that phosphorylation of the viral proteins occurred in discrete steps and that the attached phosphate groups were conserved throughout the processing steps.",
author = "Janis Racevskis and Sarkar, {N. H.}",
year = "1979",
language = "English (US)",
volume = "30",
pages = "241--247",
journal = "Journal of Virology",
issn = "0022-538X",
publisher = "American Society for Microbiology",
number = "1",

}

TY - JOUR

T1 - Phosphorylation of murine mammary tumor virus precursor polypeptides

AU - Racevskis, Janis

AU - Sarkar, N. H.

PY - 1979

Y1 - 1979

N2 - Phosphorylation of the murine mammary tumor virus (MuMTV) structural proteins was studied in an MuMTV-infected epithelial cell line derived from a BALB/cf C3H mouse mammary tumor. Immunoprecipitation of 32P-labeled cell extracts with monospecific anti-p27 serum revealed that phosphorylation occurred at the stage of the core-protein polyprotein precursor prp 75. Two forms of phosphorylated prp75 were found: one migrating with an apparent molecular weight of 80,000, and the other with a molecular weight of 76,000. The 80,000-molecular-weight species was found to be the most heavily phosphorylated. In addition, a relatively stable phosphorylated processing intermediate of 34,000 molecular weight was observed as well. Tryptic peptide mapping analysis of the 32P-labeled viral proteins indicated a precursor product relationship between the intracellular phosphorylated, high-molecular-weight peptides and the mature MuMTV phosphoproteins p23 and p27. Phosphopeptide analysis also suggested that phosphorylation of the viral proteins occurred in discrete steps and that the attached phosphate groups were conserved throughout the processing steps.

AB - Phosphorylation of the murine mammary tumor virus (MuMTV) structural proteins was studied in an MuMTV-infected epithelial cell line derived from a BALB/cf C3H mouse mammary tumor. Immunoprecipitation of 32P-labeled cell extracts with monospecific anti-p27 serum revealed that phosphorylation occurred at the stage of the core-protein polyprotein precursor prp 75. Two forms of phosphorylated prp75 were found: one migrating with an apparent molecular weight of 80,000, and the other with a molecular weight of 76,000. The 80,000-molecular-weight species was found to be the most heavily phosphorylated. In addition, a relatively stable phosphorylated processing intermediate of 34,000 molecular weight was observed as well. Tryptic peptide mapping analysis of the 32P-labeled viral proteins indicated a precursor product relationship between the intracellular phosphorylated, high-molecular-weight peptides and the mature MuMTV phosphoproteins p23 and p27. Phosphopeptide analysis also suggested that phosphorylation of the viral proteins occurred in discrete steps and that the attached phosphate groups were conserved throughout the processing steps.

UR - http://www.scopus.com/inward/record.url?scp=0018742679&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0018742679&partnerID=8YFLogxK

M3 - Article

C2 - 225520

AN - SCOPUS:0018742679

VL - 30

SP - 241

EP - 247

JO - Journal of Virology

JF - Journal of Virology

SN - 0022-538X

IS - 1

ER -