Activation of Src-like protein-tyrosine kinase Lyn and its association with phosphatidylinositol 3-kinase upon B-cell antigen receptor-mediated signaling.
Crosslinking of membrane-bound immunoglobulins, which are B-cell antigen receptors, causes proliferation and differentiation of B cells or the inhibition of their growth. The receptor-mediated signaling involves tyrosine phosphorylation of cellular proteins. The Src-like protein-tyrosine kinase Lyn is expressed preferentially in B cells and is an intracytoplasmic constituent of the B-cell antigen receptor complex. Crosslinking of membrane-bound immunoglobulin M with antibody induced rapid increases in the kinase activities of Lyn and Lyn-associated phosphatidylinositol 3-kinase. Crosslinking of B-cell antigen receptor also induced association of Lyn with an 85-kDa noncatalytic subunit of phosphatidylinositol 3-kinase. Thus, Lyn is functionally associated with membrane-bound immunoglobulin M and seems likely to participate in B-cell antigen receptor-mediated signaling.
Department of Oncology, University of Tokyo, Japan.
Y
Y
Yamanashi
Y
Y
Fukui
B
B
Wongsasant
Y
Y
Kinoshita
Y
Y
Ichimori
K
K
Toyoshima
T
T
Yamamoto
D001402:B-Lymphocytes / Q000502:physiology*; D004789:Enzyme Activation; D006801:Humans; D007075:Immunoglobulin M / Q000502:physiology; D066298:In Vitro Techniques; D019869:Phosphatidylinositol 3-Kinases; D010750:Phosphoproteins / Q000378:metabolism; D010770:Phosphotransferases / Q000378:metabolism*; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000502:physiology*; D011940:Receptor Aggregation; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism* / Q000502:physiology; D015398:Signal Transduction; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000031:analogs & derivatives / Q000378:metabolism; D015854:Up-Regulation; D019061:src-Family Kinases
D007075:Immunoglobulin M; D010750:Phosphoproteins; D011947:Receptors, Antigen, B-Cell; D019000:Phosphotyrosine; D014443:Tyrosine; D010770:Phosphotransferases; D019869:Phosphatidylinositol 3-Kinases; D011505:Protein-Tyrosine Kinases; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases