Transcription factor NF-kappaB regulates inducible Oct-2 gene expression in precursor B lymphocytes.
The POU transcription factors Oct-1 and Oct-2 regulate the activity of octamer-dependent promoters, including those that direct transcription from rearranged immunoglobulin genes. Unlike Oct-1, which is constitutively expressed in many cell types, Oct-2 expression is restricted primarily to B lymphocytes and can be induced in precursor B cells by stimulation with bacterial lipopolysaccharide (LPS). However, the precise factors that mediate this induction mechanism remain unknown. In the present study, we monitored Oct-2 expression in cells arrested for the activation of NF-kappaB, an LPS-responsive member of the Rel transcription factor family. Despite stimulation with LPS, disruption of the NF-kappaB signaling pathway in precursor B cells led to the loss of inducible Oct-2 DNA binding activity in vitro and the suppression of Oct-2-directed transcription in vivo. This biochemical defect correlated with a specific block to Oct-2 gene expression at the level of transcription, whereas the expression of Oct-1 was unaffected. The finding that Oct-2 is under NF-kappaB control highlights an important cross-talk mechanism involving two distinct transcription factor families that regulate B lymphocyte function.
Bendall
H H
HH
Department of Microbiology and Immunology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232, USA.
Scherer
D C
DC
Edson
C R
CR
Ballard
D W
DW
Oltz
E M
EM
D001402:B-Lymphocytes / Q000378:metabolism*; D002461:Cell Line, Transformed; D002467:Cell Nucleus / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000235:genetics*; D006801:Humans; D016328:NF-kappa B / Q000378:metabolism*; D050813:Octamer Transcription Factor-2; D015398:Signal Transduction; D014157:Transcription Factors; D015533:Transcriptional Activation
D004268:DNA-Binding Proteins; D016328:NF-kappa B; D050813:Octamer Transcription Factor-2; C058435:POU2F2 protein, human; D014157:Transcription Factors