Phospholipase C-gamma2 and Vav cooperate within signaling microclusters to propagate B cell spreading in response to membrane-bound antigen.
B cell receptor (BCR) recognition of membrane-bound antigen initiates a spreading and contraction response, the extent of which is controlled through the formation of signaling-active BCR-antigen microclusters and ultimately affects the outcome of B cell activation. We followed a genetic approach to define the molecular requirements of BCR-induced spreading and microcluster formation. We identify a key role for phospholipase C-gamma2 (PLCgamma2), Vav, B cell linker, and Bruton's tyrosine kinase in the formation of highly coordinated "microsignalosomes," the efficient assembly of which is absolutely dependent on Lyn and Syk. Using total internal reflection fluorescence microscopy, we examine at high resolution the recruitment of PLCgamma2 and Vav to microsignalosomes, establishing a novel synergistic relationship between the two. Thus, we demonstrate the importance of cooperation between components of the microsignalosome in the amplification of signaling and propagation of B cell spreading, which is critical for appropriate B cell activation.
Weber
Michele
M
Lymphocyte Interaction Laboratory, London Research Institute, Cancer Research UK, London WC2A 3PX, England, UK.
Treanor
Bebhinn
B
Depoil
David
D
Shinohara
Hisaaki
H
Harwood
Naomi E
NE
Hikida
Masaki
M
Kurosaki
Tomohiro
T
Batista
Facundo D
FD
D000818:Animals; D000941:Antigens / Q000378:metabolism*; D001402:B-Lymphocytes / Q000166:cytology* / Q000201:enzymology*; D002462:Cell Membrane / Q000378:metabolism*; D002465:Cell Movement; D002645:Chickens; D053496:Inositol 1,4,5-Trisphosphate Receptors / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D051966:Phospholipase C gamma / Q000378:metabolism*; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D051567:Proto-Oncogene Proteins c-vav / Q000378:metabolism*; D051381:Rats; D015398:Signal Transduction; D000072377:Syk Kinase; D019061:src-Family Kinases / Q000378:metabolism
D000941:Antigens; D053496:Inositol 1,4,5-Trisphosphate Receptors; D047908:Intracellular Signaling Peptides and Proteins; D051567:Proto-Oncogene Proteins c-vav; D011505:Protein-Tyrosine Kinases; D000072377:Syk Kinase; C000606897:Syk protein, mouse; C000606898:Syk protein, rat; C060902:lyn protein-tyrosine kinase; D019061:src-Family Kinases; D051966:Phospholipase C gamma