Ubiquitination of IgG1 cytoplasmic tail modulates B-cell signalling and activation

Upon antigen stimulation, IgG+ B cells rapidly proliferate and differentiate into plasma cells, which has been attributed to the characteristics of membrane-bound IgG (mIgG), but the underlying molecular mechanisms remain elusive. We have found that a part of mouse mIgG1 is ubiquitinated through the two responsible lysine residues (K378 and K386) in its cytoplasmic tail and this ubiquitination is augmented upon antigen stimulation. The...