Angiotensinogen gene-inducible enhancer-binding protein 1, a member of a new family of large nuclear proteins that recognize nuclear factor kappa B-binding sites through a zinc finger motif.
Transcriptional activation of the rat angiotensinogen gene during the acute-phase response is dependent on a previously characterized acute-phase response element (APRE) that binds at least two types of nuclear proteins: a cytokine-inducible activity indistinguishable from nuclear factor kappa-B (NF kappa B) and a family of C/EBP-like proteins. We screened a rat liver cDNA expression library with a labeled APRE DNA probe and isolated a single clone that encodes a sequence-specific APRE-binding protein. This new protein, the angiotensinogen gene-inducible enhancer-binding protein 1 (AGIE-BP1), is encoded by a large continuous open reading frame and contains a zinc finger motif virtually identical to the DNA-binding domain of a recently described human protein, MBP-1/PRDII-BF1, and a homologous mouse protein, alpha A-CRYBP1. Outside the binding domain, the sequences diverged considerably. Southern blot analysis indicated that AGIE-BP1 and alpha A-CRYBP1 are encoded by separate genes, thus defining a new family of DNA-binding proteins. Electrophoretic mobility shift assays, methylation interference, and DNase I footprint protection assays with the bacterially expressed DNA-binding domain of AGIE-BP1 demonstrated a binding specificity indistinguishable from that of purified NF kappa B. Antiserum raised against the bacterially expressed DNA-binding domain of AGIE-BP1 detected on immunoblots of cellular proteins a large (greater than 250-kDa) nuclear protein. Northern (RNA) blot analysis of RNAs from different rat tissues and cell lines indicated different levels of expression of the large (greater than 10-kb) AGIE-BP1 transcript in different tissues. The potential role of AGIE-BP1 in the regulation of gene expression is discussed.
Ron
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Laboratory of Molecular Endocrinology, Massachusetts General Hospital, Boston.
Brasier
A R
AR
Habener
J F
JF
D000595:Amino Acid Sequence; D000808:Angiotensinogen / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D003001:Cloning, Molecular; D004268:DNA-Binding Proteins / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D005810:Multigene Family; D016328:NF-kappa B / Q000378:metabolism*; D009687:Nuclear Proteins / Q000235:genetics* / Q000378:metabolism; D015345:Oligonucleotide Probes; D009928:Organ Specificity; D051381:Rats; D012689:Sequence Homology, Nucleic Acid; D014158:Transcription, Genetic; D016335:Zinc Fingers / Q000235:genetics*
D004268:DNA-Binding Proteins; D016328:NF-kappa B; D009687:Nuclear Proteins; D015345:Oligonucleotide Probes; C068401:angiotensinogen gene-inducible enhancer-protein 1; D000808:Angiotensinogen