Yamanashi Y, Fukui Y, Wongsasant B, Kinoshita Y, Ichimori Y, Toyoshima K, Yamamoto T
Department of Oncology, University of Tokyo, Japan.
Proc Natl Acad Sci U S A. 1992 Feb 1;89(3):1118-22. doi: 10.1073/pnas.89.3.1118.
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.
作为B细胞抗原受体的膜结合免疫球蛋白的交联会导致B细胞增殖和分化或抑制其生长。受体介导的信号传导涉及细胞蛋白的酪氨酸磷酸化。Src样蛋白酪氨酸激酶Lyn优先在B细胞中表达，是B细胞抗原受体复合物的胞质内成分。膜结合免疫球蛋白M与抗体的交联导致Lyn和Lyn相关磷脂酰肌醇3激酶的激酶活性迅速增加。B细胞抗原受体的交联还诱导Lyn与磷脂酰肌醇3激酶的85 kDa非催化亚基结合。因此，Lyn在功能上与膜结合免疫球蛋白M相关，似乎可能参与B细胞抗原受体介导的信号传导。
