The lectin concanavalin A stimulates a protein-tyrosine kinase p72syk in peripheral blood lymphocytes.
We report that the activation of porcine peripheral blood lymphocytes (PBL) by lectin concanavalin A (Con A) led to the increase in tyrosine phosphorylation on 84-, 72-, 55-, 40-, and 33-kDa proteins. A non-receptor protein-tyrosine kinase (PTK), p72syk (Taniguchi et al. (1991) J. Biol. Chem. 266, 15790-15796), was detected in PBL around 0.1% of total protein and distributed in both particulate and cytosolic fractions. Furthermore, Con A induced a rapid activation of p72syk within 1 min in a manner similar to the time course of Con A-induced protein-tyrosine phosphorylation. These results suggest that p72syk plays a certain role in the activation of PBL and that p72syk may be one of the major non-receptor PTKs in T cells as well as in B cells.
Takeuchi
F
F
Department of Biochemistry, Fukui Medical School, Japan.
Taniguchi
T
T
Maeda
H
H
Fujii
C
C
Takeuchi
N
N
Yamamura
H
H
D000818:Animals; D003208:Concanavalin A / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D004789:Enzyme Activation; D004792:Enzyme Precursors / Q000378:metabolism*; D015151:Immunoblotting; D047908:Intracellular Signaling Peptides and Proteins; D008214:Lymphocytes / Q000201:enzymology*; D008970:Molecular Weight; D010750:Phosphoproteins / Q000302:isolation & purification / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000378:metabolism*; D013552:Swine; D000072377:Syk Kinase; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis
D004792:Enzyme Precursors; D047908:Intracellular Signaling Peptides and Proteins; D010750:Phosphoproteins; D003208:Concanavalin A; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase