Transcription of human zinc finger ZNF268 gene requires an intragenic promoter element.
Human ZNF268 gene is a typical Krüppel-associated box/C2H2 zinc finger gene whose homolog has been found only in higher mammals and not in lower mammals such as mouse. Its expression profiles have suggested that it plays a role in the differentiation of blood cells during early human embryonic development and the pathogenesis of leukemia. To gain additional insight into the molecular mechanisms controlling the expression of the ZNF268 gene and to provide the necessary tools for further genetic studies of leukemia, we have mapped the 5'-end of the human ZNF268 mRNA by reverse transcription-PCR and primer extension assays. We then cloned the 5'-flanking genomic DNA containing the putative ZNF268 gene promoter and analyzed its function in several different human and mouse tissue culture cell lines. Interestingly, our studies show that the ZNF268 gene lacks a typical eukaryotic promoter that is present upstream of the transcription start site and directs a basal level of transcription. Instead, the functional promoter requires an essential element that is located within the first exon of the gene. Deletion and mutational analysis reveals the requirement for a cAMP response-element-binding protein (CREB)-binding site within this element for promoter function. Gel mobility shift and chromatin immunoprecipitation assays confirm that CREB-2 binds to the site in vitro and in vivo. Furthermore, overexpression of CREB-2 enhances the promoter activity. These results demonstrate that the human ZNF268 gene promoter is atypical and requires an intragenic element located within the first exon that mediates the effect of CREB for its activity.
Guo
Ming-Xiong
MX
State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan 430072, China.
Wang
Di
D
Shao
Huan-Jie
HJ
Qiu
Hong-Ling
HL
Xue
Lu
L
Zhao
Zhou-Zhou
ZZ
Zhu
Chen-Gang
CG
Shi
Yun-Bo
YB
Li
Wen-Xin
WX
D024506:5' Flanking Region; D051701:Activating Transcription Factor 4 / Q000235:genetics / Q000378:metabolism; D000818:Animals; D001483:Base Sequence; D001665:Binding Sites; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D015973:Gene Expression Regulation, Leukemic; D006801:Humans; D007938:Leukemia / Q000235:genetics; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism; D016415:Sequence Alignment; D017421:Sequence Analysis; D014158:Transcription, Genetic; D016335:Zinc Fingers
C497109:ATF4 protein, human; D004268:DNA-Binding Proteins; D012097:Repressor Proteins; C482295:ZNF268 protein, human; D051701:Activating Transcription Factor 4