Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

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.


Journal article



Publication Date





635 - 645


Animals, Antigens, CD19, B-Lymphocytes, Calcium, Cell Cycle Proteins, Cells, Cultured, Enzyme Activation, Guanine Nucleotide Exchange Factors, Humans, JNK Mitogen-Activated Protein Kinases, MAP Kinase Kinase 4, Mice, Mitogen-Activated Protein Kinase Kinases, Phosphorylation, Phosphotransferases (Alcohol Group Acceptor), Protein Binding, Protein Kinases, Proteins, Proto-Oncogene Proteins, Proto-Oncogene Proteins c-vav, Rats, Tyrosine