Recruitment of Cbl-b to B Cell Antigen Receptor Couples Antigen Recognition to Toll-Like Receptor 9 Activation in Late Endosomes

Recruitment of Cbl-b to B Cell Antigen Receptor Couples Antigen Recognition to Toll-Like Receptor 9 Activation in Late Endosomes

Casitas B-lineage lymphoma-b (Cbl-b) is a ubiquitin ligase (E3) that modulates signaling by tagging molecules for degradation. It is a complex protein with multiple domains and binding partners that are not involved in ubiquitinating substrates. Herein, we demonstrate that Cbl-b, but not c-Cbl, is recruited to the clustered B cell antigen receptor (BCR) and that Cbl-b is required for entry of e...

Processing in Murine B Cells in B Cell Receptor-Mediated Antigen Involvement of MIIC-Like Late Endosomes

Kidins220/ARMS binds to the B cell antigen receptor and regulates B cell development and activation

B cell antigen receptor (BCR) signaling is critical for B cell development and activation. Using mass spectrometry, we identified a protein kinase D-interacting substrate of 220 kD (Kidins220)/ankyrin repeat-rich membrane-spanning protein (ARMS) as a novel interaction partner of resting and stimulated BCR. Upon BCR stimulation, the interaction increases in a Src kinase-independent manner. By kn...

Autoantigen-B cell antigen receptor interactions that regulate expression of B cell antigen receptor Loci.

Levels of AgR (BCR) expression are regulated during B cell development, activation, and induction of tolerance. The mechanisms responsible for and consequences of this regulation are poorly understood. We have described a class of DNA-based autoantigen-reactive B cell that down-regulates BCR expression during development to mature follicular phenotype. In this study, we show that at immature st...

Delivery of B Cell Receptor–internalized Antigen to Endosomes and Class II Vesicles

B cell receptor (BCR)-mediated antigen processing is a mechanism that allows class II-restricted presentation of specific antigen by B cells at relatively low antigen concentrations. Although BCR-mediated antigen processing and class II peptide loading may occur within one or more endocytic compartments, the functions of these compartments and their relationships to endosomes and lysosomes rema...