NF-κB1 p50 is required for BLyS attenuation of apoptosis but dispensable for processing of NF-κB2 p100 to p52 in quiescent mature B cells Academic Article Article uri icon


MeSH Major

  • Diffusion Magnetic Resonance Imaging


  • B lymphocyte stimulator (BLyS), a TNF family protein essential for peripheral B cell development, functions primarily through attenuation of B cell apoptosis. In this study, we show that BLyS activates NF-κB through both classical and alternative pathways with distinct kinetics in quiescent mature B cells. It rapidly and transiently enhances the p50/p65 DNA binding activity and induces phosphorylation of IκBα characteristic of the classical NF-κB pathway, albeit maintaining IκBα at a constant level through ongoing protein synthesis and proteasome-mediated destruction. With delayed kinetics, BLyS promotes the processing of p100 to p52 and sustained formation of p52/RelB complexes via the alternative NF-κB pathway. p50 is dispensable for p100 processing. However, it is required to mediate the initial BLyS survival signals and concomitant activation of Bcl-xL in quiescent mature B cells ex vivo. Although also a target of BLyS activation, at least one of the A1 genes, A1-a, is dispensable for the BLyS survival function. These results suggest that BLyS mediates its survival signals in metabolically restricted quiescent B cells, at least in part, through coordinated activation of both NF-κB pathways and selective downstream antiapoptotic genes.

publication date

  • July 15, 2003



  • Academic Article


PubMed ID

  • 12847243

Additional Document Info

start page

  • 761

end page

  • 768


  • 171


  • 2