title: c-Myc gene single-strand binding protein-1, MSSP-1, suppresses transcription of alpha-smooth muscle actin gene in chicken visceral smooth muscle cells.
abstract: The expression of alpha-smooth muscle actin is coordinately regulated by positive and negative cis- elements in the promoter region. Although cis -elements and trans -acting factors involved in the positive regulation of the alpha-smooth muscle (alpha-SM) actin gene have been well characterized, details of negative regulation remain unclear. In functional analyses using cultured gizzard smooth muscle cells, we identified a sequence ranging from -238 to -219 in the promoter region as a novel negative element. Mutation and deletion analyses further revealed that a sequence, TATCTTA (-228 to -222), is essential for negative regulation. Gel shift assay and Southwestern blotting indicated that a nuclear protein factor specifically interacts with single- or double-strand DNA including this sequence, and the protein factor displays a highly potent binding to the sense strand DNA. cDNA cloning and gel shift analysis using anti-MSSP-1 antibodies revealed that this protein factor is a chicken homolog of human MSSP-1 (c- myc gene single-strand binding protein-1). In fact, overexpression of MSSP-1 in cultured smooth muscle cells suppresses the promoter activity. These results suggest a novel function of MSSP-1 regarding the transcriptional regulation of alpha-sm actin gene.
authors.affiliation: Department of Neurochemistry and Neuropharmacology, Biomedical Research Center, Osaka University Medical School, 2-2 Yamadaoka, Suita, Osaka 565, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Kimura
authors.forename: H
authors.initials: H
authors.lastname: Saga
authors.forename: K
authors.initials: K
authors.lastname: Hayashi
authors.forename: H
authors.initials: H
authors.lastname: Obata
authors.forename: Y
authors.initials: Y
authors.lastname: Chimori
authors.forename: H
authors.initials: H
authors.lastname: Ariga
authors.forename: K
authors.initials: K
authors.lastname: Sobue
mesh_terms: D000199:Actins / Q000235:genetics*; D000818:Animals; D002457:Cell Extracts; D002467:Cell Nucleus; D002478:Cells, Cultured; D002642:Chick Embryo; D003001:Cloning, Molecular; D004247:DNA / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000235:genetics; D005895:Gizzard, Avian; D008969:Molecular Sequence Data; D009130:Muscle, Smooth / Q000166:cytology / Q000378:metabolism*; D009154:Mutation; D011401:Promoter Regions, Genetic / Q000235:genetics*; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D014158:Transcription, Genetic / Q000235:genetics*
chemical_list: D000199:Actins; D002457:Cell Extracts; D004268:DNA-Binding Proteins; C086384:RBMS1 protein, human; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D004247:DNA