TY - JOUR
T1 - T and B lymphocytes express distinct tyrosine protein kinases
AU - Harrison, M. L.
AU - Low, P. S.
AU - Geahlen, R. L.
PY - 1984
Y1 - 1984
N2 - Murine B and T lymphocytes each contain a protein kinase activity that catalyzes the phosphorylation of both endogenous and exogenous substrates on tyrosine residues. In B lymphocytes, endogenous substrates of 56,000 and 60,000 daltons are found in the particulate fraction. Peptide mapping experiments indicate that these two substrates are closely related but are distinct from the major 58,000-dalton tyrosine protein kinase substrate found in T lymphocytes. To determine if the same kinase is active in both B and T lymphocytes, their substrate specificities were compared using two exogenously added substrates: angiotensin I and the cytoplasmic domain of the erythrocyte band 3 protein. LSTRA, a lymphoma cell line that expresses elevated levels of the T lymphocyte kinase (Casnellie, J.E., Harrison, M.L., Hellstrom, K.E., and Krebs, E.G. (1983) J. Biol. Chem. 258, 10738-10742), was used as a source of this enzyme. Kinetic analyses indicate that angiotensin I serves as a better substrate for the LSTRA kinase than for the B cell enzyme. Band 3, however, is preferentially phosphorylated by the B cell kinase. These results indicate that B and T lymphocytes express distinct tyrosine protein kinases.
AB - Murine B and T lymphocytes each contain a protein kinase activity that catalyzes the phosphorylation of both endogenous and exogenous substrates on tyrosine residues. In B lymphocytes, endogenous substrates of 56,000 and 60,000 daltons are found in the particulate fraction. Peptide mapping experiments indicate that these two substrates are closely related but are distinct from the major 58,000-dalton tyrosine protein kinase substrate found in T lymphocytes. To determine if the same kinase is active in both B and T lymphocytes, their substrate specificities were compared using two exogenously added substrates: angiotensin I and the cytoplasmic domain of the erythrocyte band 3 protein. LSTRA, a lymphoma cell line that expresses elevated levels of the T lymphocyte kinase (Casnellie, J.E., Harrison, M.L., Hellstrom, K.E., and Krebs, E.G. (1983) J. Biol. Chem. 258, 10738-10742), was used as a source of this enzyme. Kinetic analyses indicate that angiotensin I serves as a better substrate for the LSTRA kinase than for the B cell enzyme. Band 3, however, is preferentially phosphorylated by the B cell kinase. These results indicate that B and T lymphocytes express distinct tyrosine protein kinases.
UR - http://www.scopus.com/inward/record.url?scp=0021185906&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0021185906&partnerID=8YFLogxK
M3 - Article
C2 - 6378908
AN - SCOPUS:0021185906
VL - 259
SP - 9348
EP - 9350
JO - The Journal of biological chemistry
JF - The Journal of biological chemistry
SN - 0021-9258
IS - 15
ER -