Rabbit surfactant protein b (sp-b) gene: structure and functional
characterization of the promoter.
Margana, Ramgopal K., and Vijayakumar Boggaram.
Department of Molecular Biology, The University of Texas Health
Science Center at Tyler, P. O. Box 2003, Tyler, Texas 75710
APStracts 2:0214L, 1995.
Surfactant protein B (SP-B) is essential for physiological function of
pulmonary surfactant. In the present investigation, we isolated
rabbit SP-B gene and determined its nucleotide sequence,
transcription start site and exon/intron organization. The coding
region of rabbit SP-B gene is comprised of 6.8 kb of sequence and is
organized into 10 introns and 11 exons. By deletion analysis we
determined that a region of SP-B gene extending from -236 to +39
nucleotides is sufficient for high level expression of CAT reporter
gene in a cell type-specific manner in the pulmonary adenocarcinoma
cell line NCI-H441. Deletion of 5' flanking sequence to -140 and -71
nucleotides significantly reduced SP-B promoter activity suggesting
that -236 to +39 region contains cis-DNA elements required for cell
type-specific expression. The proximal promoter region of SP-B gene
contained DNA sequence motifs for binding thyroid transcription
factor 1 (TTF-1) (-113 to -97) and hepatocyte nuclear factor 3 (HNF
-3) (-91 to -81). Although SP-B gene sequence -140 to +39 did not
support high level expression of CAT gene in NCI-H441 cells it was
capable of activation by TTF-1 in HeLa cells suggesting that the -236
to -140 sequence plays an important role in cell type-specific
activation of SP-B promoter.
Received 15 May 1995; accepted in final form 6 November 1995.
APS Manuscript Number L147-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95