Authors:
LM O'Rourke, R Tooze, M Turner, DM Sandoval, RH Carter, VL Tybulewicz, DT Fearon
Journal name: 
Immunity
Citation info: 
8(5):635-645
Abstract: 
CD19 is a coreceptor that amplifies signaling by membrane immunoglobulin (mIg) to promote responses of the B lymphocyte to T-dependent antigens. Vav is a guanine nucleotide exchange factor for the Rho, Rac, Cdc42 family of small GTPases. We found that coligating mIg and CD19 causes a synergistic increase in the tyrosine phosphorylation of CD19. Phosphorylated tyrosine-391 of CD19 binds Vav to mediate a sustained increase in intracellular Ca2+ concentration. This response correlates with activation by the CD19-Vav complex of phosphatidylinositol 4-phosphate 5-kinase for the synthesis of phosphatidylinositol 4,5-bisphosphate. Interaction of CD19 with Vav also mediates the synergistic activation of the mitogen-activated protein kinase JNK. Therefore, CD19 is a membrane adaptor protein that recruits Vav for the activation of lipid and protein kinases.
DOI: 
http://doi.org/10.1016/s1074-7613(00)80568-3
E-pub date: 
01 May 1998
Users with this publication listed: 
Doug Fearon