B cell signaling is regulated by induced palmitoylation of CD81.
Signaling through the B cell antigen receptor (BCR) is amplified and prolonged by coligation of the BCR to the CD19/CD21/CD81 coreceptor complex. Coligation is induced during immune responses by the simultaneous binding of complement-tagged antigens to the complement receptor, CD21, and to the BCR. Enhanced signaling is due in part to the ability of the CD19/CD21/CD81 complex to stabilize the BCR in sphingolipid- and cholesterol-rich membrane microdomains termed lipid rafts. The tetraspanin CD81 is essential for the raft-stabilizing function of the coreceptor. Here we show that coligation of the BCR and the CD19/CD21/CD81 complex leads to selective, rapid, and reversible palmitoylation of CD81 and that palmitoylation is necessary for the raft stabilizing function of the CD19/CD21/CD81 complex. Inducible palmitoylation may represent a novel mechanism by which tetraspanins function to facilitate lipid raft-dependent receptor signaling.
Cherukuri
Anu
A
Laboratory of Immunogenetics, NIAID, National Institutes of Health, Rockville, Maryland 20852, USA.
Carter
Robert H
RH
Brooks
Stephen
S
Bornmann
William
W
Finn
Ronald
R
Dowd
Cynthia S
CS
Pierce
Susan K
SK
D000911:Antibodies, Monoclonal; D015703:Antigens, CD / Q000737:chemistry* / Q000378:metabolism*; D018941:Antigens, CD19 / Q000737:chemistry / Q000378:metabolism; D001402:B-Lymphocytes / Q000276:immunology* / Q000378:metabolism; D002460:Cell Line; D002784:Cholesterol / Q000378:metabolism; D003432:Cross-Linking Reagents; D006801:Humans; D046911:Macromolecular Substances; D021962:Membrane Microdomains / Q000276:immunology / Q000378:metabolism; D019308:Palmitic Acid / Q000378:metabolism*; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism; D017464:Receptors, Complement 3d / Q000737:chemistry / Q000378:metabolism; D015398:Signal Transduction; D060225:Tetraspanin 28
D000911:Antibodies, Monoclonal; D015703:Antigens, CD; D018941:Antigens, CD19; C554798:CD81 protein, human; D003432:Cross-Linking Reagents; D046911:Macromolecular Substances; D011947:Receptors, Antigen, B-Cell; D017464:Receptors, Complement 3d; D060225:Tetraspanin 28; D019308:Palmitic Acid; D002784:Cholesterol