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Updated: Jun 11, 2026

Overlapping Peptide Library to Map Qa-1 Epitopes in a Protein
Published on: December 20, 2017
G alpha q-containing G proteins regulate B cell selection and survival and are required to prevent B cell-dependent
Ravi S Misra1, Guixiu Shi, Miguel E Moreno-Garcia
1Department of Medicine, Division of Allergy, Immunology, and Rheumatology, University of Rochester, Rochester, NY 14642, USA.
Abstract:
Survival of mature B cells is regulated by B cell receptor and BAFFR-dependent signals. We show that B cells from mice lacking the G(alphaq) subunit of trimeric G proteins (Gnaq(-/-) mice) have an intrinsic survival advantage over normal B cells, even in the absence of BAFF. Gnaq(-/-) B cells develop normally in the bone marrow but inappropriately survive peripheral tolerance checkpoints, leading to the accumulation of transitional, marginal zone, and follicular B cells, many of which are autoreactive. Gnaq(-/-) chimeric mice rapidly develop arthritis as well as other manifestations of systemic autoimmune disease. Importantly, we demonstrate that the development of the autoreactive B cell compartment is the result of an intrinsic defect in Gnaq(-/-) B cells, resulting in the aberrant activation of the prosurvival factor Akt. Together, these data show for the first time that signaling through trimeric G proteins is critically important for maintaining control of peripheral B cell tolerance induction and repressing autoimmunity.
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