Publication Date:
1992-02-14
Description:
T cell signaling via the CD4 surface antigen is mediated by the associated tyrosyl protein kinase p56lck. The 42-kilodalton mitogen-activated protein (MAP) kinase (p42mapk) was tyrosyl-phosphorylated and activated after treatment of the murine T lymphoma cell line 171CD4+, which expresses CD4, with antibody to CD3. Treatment of the CD4-deficient cell line 171 with the same antibody did not result in phosphorylation or activation of p42mapk. Purified p56lck both tyrosyl-phosphorylated and stimulated the seryl-threonyl phosphotransferase activity of purified p44mpk, a MAP kinase isoform from sea star oocytes. A synthetic peptide modeled after the putative regulatory phosphorylation site in murine p42mapk (Tyr185) was phosphorylated by p56lck with a similar Vmax, but a fivefold lower Michaelis constant (Km) than a peptide containing the Tyr394 autophosphorylation site from p56lck. MAP kinases may participate in protein kinase cascades that link Src family protein-tyrosyl kinases to seryl-threonyl kinases such as those encoded by rsk and raf, which are putative substrates of MAP kinases.〈br /〉〈span class="detail_caption"〉Notes: 〈/span〉Ettehadieh, E -- Sanghera, J S -- Pelech, S L -- Hess-Bienz, D -- Watts, J -- Shastri, N -- Aebersold, R -- R126604/PHS HHS/ -- New York, N.Y. -- Science. 1992 Feb 14;255(5046):853-5.〈br /〉〈span class="detail_caption"〉Author address: 〈/span〉Biomedical Research Centre, University of British Columbia, Vancouver, Canada.〈br /〉〈span class="detail_caption"〉Record origin:〈/span〉 〈a href="http://www.ncbi.nlm.nih.gov/pubmed/1311128" target="_blank"〉PubMed〈/a〉
Keywords:
Amino Acid Sequence
;
Animals
;
Antigens, CD3
;
Antigens, Differentiation, T-Lymphocyte/physiology
;
Calcium-Calmodulin-Dependent Protein Kinases
;
Cell Line
;
Glycogen Synthase Kinase 3
;
In Vitro Techniques
;
Lymphocyte Specific Protein Tyrosine Kinase p56(lck)
;
Lymphoma, T-Cell
;
Mice
;
Molecular Sequence Data
;
Oncogene Proteins, Viral/*physiology
;
Phosphorylation
;
Protein Kinases/*physiology
;
Protein-Tyrosine Kinases/*physiology
;
Receptors, Antigen, T-Cell/physiology
;
Signal Transduction/*physiology
;
T-Lymphocytes/physiology
Print ISSN:
0036-8075
Electronic ISSN:
1095-9203
Topics:
Biology
,
Chemistry and Pharmacology
,
Computer Science
,
Medicine
,
Natural Sciences in General
,
Physics
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