Isolation and characterization of a novel member of the gene family encoding the cAMP response element-binding protein CRE-BP1.
Among multiple CRE (cyclic AMP response element)-binding proteins, CRE-BP1 (also designated ATF-2) has two unique characteristics: it mediates the adenovirus E1A-induced trans-activation and forms a heterodimer with c-Jun. Two structures, a putative metal finger and a leucine zipper, in CRE-BP1 are responsible for these capacities. As a new member of a CRE-BP1 family that has similar metal finger and leucine zipper structures, we have isolated cDNA clones of CRE-BPa by cross-hybridization with CRE-BP1 cDNA. CRE-BPa protein consists of 508 amino acids and has a molecular weight of 56,840. CRE-BPa protein is highly homologous with CRE-BP1 in four regions: two of them are the regions containing the putative metal finger or the DNA-binding domain consisting of the basic amino acid cluster and the leucine zipper. Like CRE-BP1, CRE-BPa binds to CRE with higher affinity than to the 12-O-tetradecanoylphorbol-13-acetate response element as a homodimer or a CRE-BPa/c-Jun or CRE-BPa/CRE-BP1 heterodimer. However, using the c-Myb-CRE-BPa fusion protein, it was show that CRE-BPa could not mediate the E1A-induced trans-activation. Expression of CRE-BPa mRNA was found in a limited number of cell lines, and multiple sizes of CRE-BPa mRNA species were detected in some cell lines and tissues. CRE-BPa will be useful to clarify the mechanism of CRE-mediated transcriptional activation by E1A or c-Jun.
Nomura
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Laboratory of Molecular Biology, Nippon Medical School, Kanagawa, Japan.
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Maekawa
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Tabata
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Akiyama
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Ishii
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D051698:Activating Transcription Factor 2; D017500:Adenovirus E1A Proteins / Q000378:metabolism; D000595:Amino Acid Sequence; D001483:Base Sequence; D003001:Cloning, Molecular; D017362:Cyclic AMP Response Element-Binding Protein / Q000235:genetics* / Q000378:metabolism; D051699:Cyclic AMP Response Element-Binding Protein A; D004247:DNA / Q000378:metabolism; D004926:Escherichia coli; D016356:Gene Products, tax / Q000378:metabolism; D006801:Humans; D016350:Leucine Zippers / Q000235:genetics; D008969:Molecular Sequence Data; D005810:Multigene Family; D011485:Protein Binding; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D012045:Regulatory Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D014157:Transcription Factors; D015533:Transcriptional Activation
C497105:ATF2 protein, human; D051698:Activating Transcription Factor 2; D017500:Adenovirus E1A Proteins; C497102:CREB5 protein, human; D017362:Cyclic AMP Response Element-Binding Protein; D051699:Cyclic AMP Response Element-Binding Protein A; D016356:Gene Products, tax; D016755:Proto-Oncogene Proteins c-jun; D012333:RNA, Messenger; D014157:Transcription Factors; D004247:DNA