Receptor-specific induction of NF-kappaB components in primary B cells.
The NF-kappaB transcription factor complex plays a key role in the expression of genes involved in immune responses. Nuclear NF-kappaB is induced in B lymphocytes by engagement of either the antigen receptor (sIg) or the CD40 receptor for a T cell activation antigen, although different intracellular pathways appear to be involved. In the present study the protein composition of NF-kappaB complexes triggered by sIg and CD40 was probed by electrophoretic mobility shift, supershift, shift-Western, and Western blot analyses. At the time of peak NF-kappaB induction (2 h), the NF-kappaB components detected in the complexes induced through sIg and through CD40 were the same. However, with continued stimulation RelB completely disappeared from anti-Ig-stimulated kappaB binding material, but remained a component of CD40L-induced NF-kappaB. The loss of DNA-binding RelB from anti-Ig-induced NF-kappaB did not result from depletion of RelB from B cell nuclei, suggesting specific regulation of RelB function which is not directly attributed to IkappaB function. These results indicate that NF-kappaB complexes may undergo protein-specific alterations in a time- and receptor-dependent fashion that may be associated with differences in the outcomes of B cell stimulation through sIg and CD40.
Francis
D A
DA
Department of Pathology, Boston University Medical Center, MA 02118, USA.
Sen
R
R
Rice
N
N
Rothstein
T L
TL
D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D019013:CD40 Antigens / Q000502:physiology*; D023201:CD40 Ligand; D002478:Cells, Cultured; D008297:Male; D008562:Membrane Glycoproteins / Q000502:physiology; D051379:Mice; D008807:Mice, Inbred BALB C; D016328:NF-kappa B / Q000096:biosynthesis*; D011518:Proto-Oncogene Proteins; D011947:Receptors, Antigen, B-Cell / Q000502:physiology*; D013997:Time Factors; D051841:Transcription Factor RelB; D014157:Transcription Factors / Q000502:physiology
D019013:CD40 Antigens; D008562:Membrane Glycoproteins; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D011947:Receptors, Antigen, B-Cell; C497594:Relb protein, mouse; D014157:Transcription Factors; D023201:CD40 Ligand; D051841:Transcription Factor RelB