Association of B cell antigen receptor with protein tyrosine kinase Lyn.
Antigen is thought to cross-link membrane-bound immunoglobulins (Igs) of B cells, causing proliferation and differentiation or the inhibition of growth. Protein tyrosine kinases are probably involved in signal transduction for cell proliferation and differentiation. The Src-like protein tyrosine kinase Lyn is expressed preferentially in B cells. The Lyn protein and its kinase activity could be coimmunoprecipitated with IgM from detergent lysates. Cross-linking of membrane-bound IgM induced a rapid increase in tyrosine phosphorylation of at least ten distinct proteins of B cells. Thus, Lyn is physically associated with membrane-bound IgM, and is suggested to participate in antigen-mediated signal transduction.
Department of Oncology, University of Tokyo, Japan.
Y
Y
Yamanashi
T
T
Kakiuchi
J
J
Mizuguchi
T
T
Yamamoto
K
K
Toyoshima
D000818:Animals; D001402:B-Lymphocytes / Q000276:immunology; D002460:Cell Line; D003902:Detergents; D004591:Electrophoresis, Polyacrylamide Gel; D015151:Immunoblotting; D007075:Immunoglobulin M / Q000378:metabolism; D007163:Immunosorbent Techniques; D051379:Mice; D008970:Molecular Weight; D010750:Phosphoproteins / Q000378:metabolism; D010766:Phosphorylation; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000235:genetics / Q000378:metabolism*; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D015398:Signal Transduction; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D019061:src-Family Kinases
D003902:Detergents; D007075:Immunoglobulin M; D010750:Phosphoproteins; D011947:Receptors, Antigen, B-Cell; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases