Skip to main page content
Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
Comparative Study
, 10 (4), 885-92

Identification of the Regulatory Phosphorylation Sites in pp42/mitogen-activated Protein Kinase (MAP Kinase)

Affiliations
Comparative Study

Identification of the Regulatory Phosphorylation Sites in pp42/mitogen-activated Protein Kinase (MAP Kinase)

D M Payne et al. EMBO J.

Abstract

Mitogen-activated protein kinase (MAP kinase) is a 42 kd serine/threonine protein kinase whose enzymatic activity requires phosphorylation of both tyrosyl and threonyl residues. As a step in elucidating the mechanism(s) for activation of this enzyme, we have determined the sites of regulatory phosphorylation. Following proteolytic digestion of 32P-labeled pp42/MAP kinase with trypsin, only a single phosphopeptide was detected by two-dimensional peptide mapping, and this peptide contained both phosphotyrosine and phosphothreonine. The amino acid sequence of the peptide, including the phosphorylation sites, was determined using a combination of Fourier transform mass spectrometry and collision-activated dissociation tandem mass spectrometry with electrospray ionization. The sequence for the pp42/MAP kinase tryptic phosphopeptide is similar (but not identical) to a sequence present in the ERK1- and KSS1-encoded kinases. The two phosphorylation sites are separated by only a single residue. The regulation of activity by dual phosphorylations at closely spaced threonyl and tyrosyl residues has a functional correlate in p34cdc2, and may be characteristic of a family of protein kinases regulating cell cycle transitions.

Similar articles

See all similar articles

Cited by 249 PubMed Central articles

See all "Cited by" articles

References

    1. Cancer Res. 1987 Jul 15;47(14):3868-72 - PubMed
    1. J Biol Chem. 1988 Sep 5;263(25):12721-7 - PubMed
    1. Science. 1988 Jul 1;241(4861):42-52 - PubMed
    1. Proc Natl Acad Sci U S A. 1988 Jun;85(11):3753-7 - PubMed
    1. Cell. 1989 Jul 14;58(1):193-203 - PubMed

Publication types

LinkOut - more resources

Feedback