Differential regulation of baboon SP-A1 and SP-A2 genes: Structural and functional analysis of 5'-flanking dna

Jinxing Li, Erwei Gao, Steven R. Seidner, Carole R. Mendelson

Research output: Contribution to journalArticlepeer-review

6 Scopus citations

Abstract

Surfactant protein (SP) A gene transcription is developmentally regulated and stimulated by hormones and factors that increase intracellular cAMP. The baboon (b) genome contains two highly similar SP-A genes, bSP-A1 and bSP-A2. With the use of a ribonuclease protection assay with gene- specific probes, the two bSP-A genes were found to be differentially regulated during baboon fetal lung development in that expression of the bSP- A2 gene appeared to be induced to a high level at a later time in gestation than that of the bSP-A1 gene. Both the bSP-A1 and bSP-A2 genes were found to be highly responsive to the inductive effects of cAMP in baboon fetal lung explants in culture. By DNase I footprinting and electrophoretic mobility shift assays with bacterially expressed thyroid transcription factor-1 (TTF- 1) and type II cell nuclear extracts, three TTF-1 binding elements were identified within the 255-bp region flanking the 5'-end of each bSP-A gene; however, these differed in position and spacing for the two bSP-A genes. To functionally define the genomic regions that are required for cAMP regulation of bSP-A gene expression in type II cells, fusion genes composed of various amounts of 5'-flanking DNA from the bSP-A1 and bSP-A2 genes linked to the human growth hormone structural gene as a reporter were transfected into type II cells in primary culture. We found that 255 bp of 5'-flanking DNA, which contain three TTF-1 binding elements, from bSP-A1 and bSP-A2 genes were sufficient to mediate high basal and cAMP-inducible expression in type II cells. We also observed that there were no obvious differences in the magnitude of the responses of these fusion genes to cAMP treatment.

Original languageEnglish (US)
Pages (from-to)L1078-L1088
JournalAmerican Journal of Physiology - Lung Cellular and Molecular Physiology
Volume275
Issue number6 19-6
DOIs
StatePublished - 1998

Keywords

  • Deoxyribonucleic acid
  • Fetal lung
  • Ribonuclease protection assay
  • Surfactant protein A
  • Thyroid transcription factor-1

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Physiology (medical)
  • Cell Biology

Fingerprint Dive into the research topics of 'Differential regulation of baboon SP-A1 and SP-A2 genes: Structural and functional analysis of 5'-flanking dna'. Together they form a unique fingerprint.

Cite this