The constant region of the membrane immunoglobulin mediates B cell-receptor clustering and signaling in response to membrane antigens.

ABSTRACT: B cells are activated in vivo after the B cell receptors (BCRs) bind to antigens captured on the surfaces of antigen-presenting cells. Antigen binding results in BCR microclustering and signaling; however, the molecular nature of the signaling-active BCR clusters is not well understood. Using single-molecule imaging techniques, we provide evidence that within microclusters, the binding of monovalent membrane antigens results in the assembly of immobile signaling-active BCR oligomers. The oligomerization depends on interactions between the membrane-proximal Cmicro4 domains of the membrane immunoglobulin that are both necessary and sufficient for assembly. Antigen-bound BCRs that lacked the Cmicro4 domain failed to cluster and signal, and conversely, Cmicro4 domains alone clustered spontaneo

SUBMITTER: Tolar P 

PROVIDER: S-EPMC2656684 | biostudies-literature | 2009 Jan

REPOSITORIES: biostudies-literature