Transcriptional activation of C/EBPbeta gene by c-Jun and ATF2.
C/EBPbeta is one of the key transcription factors responsible for the induction of a wide array of genes. Like many proto-oncogenes and transcription factors, transcription of C/EBPbeta gene can be induced by multiple extracellular signals. Using nuclear extracts from lipopolysaccharide (LPS)-stimulated mouse liver, five trans-acting factor-binding motifs, URE1 (-376 to -352), URE2 (-253 to -223), URE3 (-220 to -190), URE4 (-123 to -103), and URE5 (-72 to -45) were identified by DNAse I footprinting assays. Competition and supershift analysis of the complexes formed at the URE2 and URE4 indicated that they contain CREB/ATF and AP-1 family factors. Furthermore, recombinant ATF2 and c-Jun proteins from mammalian and bacterial cells can bind to URE2 and URE4 but not URE1. Cotransfection experiments showed that ATF2 and c-Jun activate the C/EBPbeta gene expression cooperatively through URE2 and URE4, and this activation was greatly increased under the treatment of low concentration of anisomycin. During acute phase response, the phosphorylation of c-Jun and ATF2 was found to correlate with C/EBPbeta gene expression. Taken together, our results provide the evidences that both c-Jun and ATF2 are the regulators of C/EBPbeta gene.
Lin
Wei-Chin
WC
Institute of Biological Chemistry, Academia Sinica, Taipei, Taiwan.
Shen
Bin-Jon
BJ
Tsay
Yeou-Guang
YG
Yen
Hsueh-Chi
HC
Lee
Sheng-Chung
SC
Chang
Ching-Jin
CJ
D051698:Activating Transcription Factor 2; D000210:Acute-Phase Reaction / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D022782:CCAAT-Enhancer-Binding Protein-beta / Q000096:biosynthesis / Q000235:genetics*; D002460:Cell Line; D017362:Cyclic AMP Response Element-Binding Protein / Q000502:physiology*; D006801:Humans; D008099:Liver / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D016755:Proto-Oncogene Proteins c-jun / Q000502:physiology*; D020218:Response Elements; D014157:Transcription Factors / Q000502:physiology*; D015533:Transcriptional Activation
C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; C497106:Atf2 protein, mouse; D022782:CCAAT-Enhancer-Binding Protein-beta; D017362:Cyclic AMP Response Element-Binding Protein; D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors