Structural and functional divergences of the columbid annexin I-encoding cp37 and cp35 genes.
Annexin-I proteins in the pigeon are encoded by two genes. One encodes a constitutively expressed cp37 protein, and the other encodes a major prolactin (PRL)-regulated protein (cp35). As one goal in understanding the differential regulation of these genes, we have determined a 10.8-kb genomic sequence of the cp37 gene containing 1.3 kb of 5'-flanking region and the first six exons. The promoters of cp37 and cp35 are 84% identical over the first 210 bp upstream from the transcription start point (tsp). Cell-free transcription demonstrated that this -210 region of cp37 contained an active promoter. Two nuclear protein-binding sites, which may be involved in the constitutive expression of cp37, were localized between -205 and -106 bp. PRL-dependent transcription factors bind to the -73 to -8 region of cp35, but not cp37. The sequences of these regions contain six single-base differences, which may be responsible for the genes' divergent transcriptional regulation. The 5'-flanking regions of cp37 and cp35 were cloned into a reporter plasmid and transfected into T-47D cells. Transient transfection analysis revealed that the constructs containing cp35 5'-flanking regions were inactive, whereas the cp37 promoter was constitutively active and contained both positive and negative cis-acting sequences.
Gao
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Y
Department of Physiology and Biophysics, University of Cincinnati College of Medicine, OH 45267-0576.
Horseman
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ND
D000595:Amino Acid Sequence; D000818:Animals; D017305:Annexin A1 / Q000235:genetics*; D001483:Base Sequence; D002135:Calcium-Binding Proteins / Q000235:genetics; D015500:Chloramphenicol O-Acetyltransferase / Q000235:genetics; D010856:Columbidae / Q000235:genetics*; D004268:DNA-Binding Proteins / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000378:metabolism; D011401:Promoter Regions, Genetic; D015183:Restriction Mapping; D012689:Sequence Homology, Nucleic Acid; D014407:Tumor Cells, Cultured
D017305:Annexin A1; D002135:Calcium-Binding Proteins; D004268:DNA-Binding Proteins; D009687:Nuclear Proteins; C060529:cp35 protein, Columba livia; D015500:Chloramphenicol O-Acetyltransferase