In vitro analysis of rat surfactant protein a (sp-a) gene
expression.
Stuempfle, Kristin J., Michael Koptides, Patrick G. Quinn, and Joanna
Floros.
Department of Cellular and Molecular Physiology, The Pennsylvania
State University College of Medicine, Hershey, Pennsylvania 17033
APStracts 2:0188L, 1995.
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.
Received 26 May 1995; accepted in final form 28 September 1995.
APS Manuscript Number L171-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95