In vitro analysis of rat surfactant protein A gene expression.
Previous findings suggest that the rat proximal promoter segment (rPPS) of the SP-A gene is important in the regulation of the lung-specific expression of the gene. In this report, two regions within the rPPS containing thyroid transcription factor-1 (TTF-1) binding sites are identified that form strong lung- and thyroid- specific DNA-protein complexes. These regions bind nuclear polypeptides with similar apparent molecular mass to TTF-1, suggesting that TTF-1 binds to these regions. Two regions within the rPPS that form weaker lung-specific DNA-protein complexes are also identified. The transcription start site is mapped, and a functional analysis shows that the sequences of the 5' flanking region are sufficient to support in vitro transcription but are not sufficient to reproduce tissue-specific expression. Together, these results show that lung- and thyroid-specific, as well as lung-specific, DNA-protein interactions occur within the rPPS but are not sufficient for the lung-specific expression of the rat SP-A gene to be duplicated in vitro.
Stuempfle
K J
KJ
Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey 17033, USA.
Koptides
M
M
Quinn
P G
PG
Floros
J
J
D000818:Animals; D001483:Base Sequence; D002874:Chromosome Mapping; D015870:Gene Expression; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011510:Proteolipids / Q000235:genetics*; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants / Q000235:genetics*; D051381:Rats; D013237:Stereoisomerism; D014158:Transcription, Genetic
D015335:Molecular Probes; D011510:Proteolipids; D037662:Pulmonary Surfactant-Associated Protein A; D037661:Pulmonary Surfactant-Associated Proteins; D011663:Pulmonary Surfactants