A downstream AP-1 element regulates in vitro lung transcription from the human pulmonary surfactant protein B promoter.
We have used the human lung surfactant protein B (SP-B) gene as a template for in vitro transcription studies. Transcription factors were provided by nuclear extracts from a cultured line of human lung (type II-like) cells. Elements upstream of -50 had essentially no effect on the efficiency of the SP-B promoter in vitro. However, a deletion of the region from +8 to +8 reduced in vitro transcription by a factor of 10. The only factor whose binding was detected between +1 and +100 by footprinting, and between +12 and +38 by electrophoretic mobility shift analysis (EMSA), was a member of the AP-1 family. Mutation of 4 of 7 bases of the AP-1 site reduced transcription two-fold and ablated the AP-1 EMSA binding complex observed on the SP-B downstream region (+12 to +38). Competition with unlabeled AP-1 consensus oligonucleotide abolished the downstream footprint over the AP-1 site. Thus, the SP-B promoter is one of a very small class of RNA polymerase II promoters that are strongly dependent in vitro on sequence elements downstream of the transcription start site, and, in this case, the AP-1 consensus element and surrounding sequences.
McWhinney
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Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, OH 45267, USA.
D001483:Base Sequence; D002474:Cell-Free System; D002478:Cells, Cultured; D018983:DNA Footprinting; D004252:DNA Mutational Analysis; D006801:Humans; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011510:Proteolipids / Q000235:genetics*; D011663:Pulmonary Surfactants / Q000235:genetics*; D012045:Regulatory Sequences, Nucleic Acid; D012689:Sequence Homology, Nucleic Acid; D013045:Species Specificity; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014158:Transcription, Genetic
D011510:Proteolipids; D011663:Pulmonary Surfactants; D018808:Transcription Factor AP-1