Characterization of the rat pulmonary surfactant protein A promoter.
The expression of the pulmonary surfactant protein A (SP-A) is developmentally regulated and controlled by several hormones. In an attempt to characterize cis-acting elements involved in the regulation of SP-A expression, we have cloned the 5' flanking sequence of the rat SP-A gene. The promoter region contains a TATA box but no CAAT box. The transcription start site has been identified by anchored polymerase chain reaction and S1 nuclease mapping of the mature and precursor transcripts. S1 mapping of precursor transcripts has confirmed the stimulating effect of glucocorticoids on SP-A rat gene transcription in vivo. This hormonal effect may be mediated by a putative glucocorticoid responsive element located 140 bp upstream from the initiation site and protected against DNase 1 digestion in footprinting experiments. In vitro transcription of a G-free reporter cassette linked to the 212-bp 5' flanking DNA fragment has established that this putative promoter region is functional. Efficient transcription of the G-free reporter cassette was obtained with cell-free fetal lung extracts, whereas no transcript was detectable with cell-free liver extracts. Comparative analysis of the human and rat 5' flanking sequences shows the presence of strongly conserved motifs, unrelated to previously known consensus sequences. Some of these motifs, specifically protected in DNase 1 footprinting studies, could therefore be involved in the regulation of SP-A gene expression.
Lacaze-Masmonteil
T
T
Unité de Recherches en Génétique et Pathologie Moléculaires, Institut National de la Santé et de la Recherche Médicale U. 129, Paris France.
Fraslon
C
C
Bourbon
J
J
Raymondjean
M
M
Kahn
A
A
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D003850:Deoxyribonuclease I; D003907:Dexamethasone / Q000494:pharmacology; D005786:Gene Expression Regulation; D008168:Lung / Q000737:chemistry / Q000196:embryology; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011401:Promoter Regions, Genetic / Q000235:genetics*; D011510:Proteolipids / Q000235:genetics*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000235:genetics*; D051381:Rats; D011919:Rats, Inbred Strains; D012045:Regulatory Sequences, Nucleic Acid; D015719:Single-Strand Specific DNA and RNA Endonucleases; D014158:Transcription, Genetic / Q000187:drug effects
D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants; D003907:Dexamethasone; D003850:Deoxyribonuclease I; D015719:Single-Strand Specific DNA and RNA Endonucleases