Synergistic activation of PKD by the B cell antigen receptor and CD19 requires PI3K, Vav1 and PLCgamma.
Antigens coated with complement fragments coligate the B cell receptor (BCR) with the CD21/CD19 complex which results in synergistic activation of B cells. Previous studies identified PI3K, Vav proteins and PLCgamma as important components of this synergy. We now show that protein kinase D (also known as PKCmu) is also a point of convergence of these signalling pathways. We found that PKD activation upon BCR engagement or coligation of the BCR with CD19 is entirely dependent on PI3K and PLCgamma but differ in the requirement for Vav proteins. Whereas PKD activation is Vav1 and Vav2 dependent in response to BCR cross-linking, PKD activation is sensitive to the lack of Vav1 under synergistic stimulation of BCR and CD19. These findings show that Vav proteins and PI3K regulation of PLCgamma contributes to the activation of PKD in response to BCR and or CD19 cross-linking.
Vigorito
Elena
E
Laboratory of Lymphocyte Signaling and Development, The Babraham Institute, Babraham Research Campus, Cambridge CB2 4AT, UK. elena.vigorito@bbsrc.ac.uk
Kovesdi
Dorottya
D
Turner
Martin
M
D000818:Animals; D018941:Antigens, CD19 / Q000378:metabolism*; D001402:B-Lymphocytes / Q000378:metabolism; D004789:Enzyme Activation; D051379:Mice; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D051966:Phospholipase C gamma / Q000235:genetics / Q000378:metabolism*; D011493:Protein Kinase C / Q000378:metabolism*; D051567:Proto-Oncogene Proteins c-vav / Q000235:genetics / Q000378:metabolism*; D011947:Receptors, Antigen, B-Cell / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
D018941:Antigens, CD19; D051567:Proto-Oncogene Proteins c-vav; D011947:Receptors, Antigen, B-Cell; C496619:Vav1 protein, mouse; C490565:Vav2 protein, mouse; D019869:Phosphatidylinositol 3-Kinases; C089212:protein kinase D; D011493:Protein Kinase C; D051966:Phospholipase C gamma