Induction of the nuclear IkappaB protein IkappaB-zeta upon stimulation of B cell antigen receptor.
The nuclear IkappaB protein IkappaB-zeta is barely detectable in resting cells and is induced in macrophages and fibroblasts following stimulation of innate immunity via Toll-like receptors. The induced IkappaB-zeta associates with nuclear factor (NF)-kappaB in the nucleus and plays crucial roles in its transcriptional regulation. Here, we examined the induction of IkappaB-zeta in B lymphocytes, one of the major players in adaptive immunity. Upon crosslinking of the surface immunoglobulin complex, IkappaB-zeta mRNA was robustly induced in murine B-lymphoma cell line A20 cells. While the crosslinking activated NF-kappaB and induced its target gene, IkappaB-alpha, co-crosslinking of Fcgamma receptor IIB to the surface immunoglobulin complex inhibited NF-kappaB activation and the induction of IkappaB-zeta and IkappaB-alpha, suggesting critical roles for NF-kappaB in the induction. These results indicate that IkappaB-zeta is also induced by stimulation of B cell antigen receptor, suggesting that IkappaB-zeta is involved in the regulation of adaptive immune responses.
Hijioka
Kuniaki
K
Department of Molecular and Cellular Biochemistry, Graduate School of Medical Sciences, Kyushu University, Fukuoka 812-8582, Japan.
Matsuo
Susumu
S
Eto-Kimura
Akiko
A
Takeshige
Koichiro
K
Muta
Tatsushi
T
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism*; D003432:Cross-Linking Reagents; D020672:I-kappa B Proteins / Q000378:metabolism; D051379:Mice; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism; D009687:Nuclear Proteins / Q000096:biosynthesis* / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D017452:Receptors, IgG / Q000378:metabolism / Q000502:physiology*
D048868:Adaptor Proteins, Signal Transducing; D003432:Cross-Linking Reagents; C499172:Fcgr2b protein, mouse; D020672:I-kappa B Proteins; D016328:NF-kappa B; C000606205:Nfkbia protein, mouse; C485947:Nfkbiz protein, mouse; D009687:Nuclear Proteins; D012333:RNA, Messenger; D011947:Receptors, Antigen, B-Cell; D017452:Receptors, IgG; D000072000:NF-KappaB Inhibitor alpha