DNA binding proteins that amplify surfactant protein B gene expression: isolation and characterization.
We identified and characterized two proteins that bind the promoter of surfactant protein B (SP-B) and affect its expression. Proteins A2 and B were identified and their cDNAs cloned and sequenced. Both were novel. They bound a 212-bp functional promoter region at an NF1 site, located between -184 and -198. Effects of these DNAbp on SP-B promoter activity were studied by contransfecting a reporter construct of this 212-bp sequence + luciferase, together with expression constructs for A2 and B into H441 cells. Alone, A2 and B expression elicited modest but statistically significant increases in SP-B promoter activity. When dexamethasone was added, B further increased SP-B promoter activity. For SP-B, basal expression and glucocorticoid responsiveness may involve a number of hitherto unknown gene activators.
Luzi
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Department of Pathology and Cell Biology, Jefferson Medical College, Philadelphia, Pennsylvania 19107.
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D000328:Adult; D000595:Amino Acid Sequence; D000818:Animals; D002460:Cell Line; D003001:Cloning, Molecular; D018076:DNA, Complementary; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D005784:Gene Amplification; D015870:Gene Expression; D015723:Gene Library; D006801:Humans; D008168:Lung / Q000378:metabolism*; D008969:Molecular Sequence Data; D016366:Open Reading Frames; D011401:Promoter Regions, Genetic; D011510:Proteolipids / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000096:biosynthesis* / Q000737:chemistry / Q000235:genetics; D011817:Rabbits; D011956:Receptors, Cell Surface / Q000737:chemistry; D015183:Restriction Mapping; D017386:Sequence Homology, Amino Acid
D018076:DNA, Complementary; D004268:DNA-Binding Proteins; D011510:Proteolipids; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D011956:Receptors, Cell Surface