Nucleic acid helix destabilizing proteins (HDP) promote conformational change in DNA resulting in the unwinding of the double helical structure of DNA. This change is believed to facilitate replication as well as transcription. The current study was undertaken to investigate genes whose expression was altered during fetal rat lung development. Using differential display (DD) method, we found that mRNA levels of an initially unknown transcript were higher at day 18 of gestation and decreased thereafter as maturation increased (day 22). Maternal administration of dexamethasone (known to accelerate lung maturity), 24 hours prior to sacrifice, also decreased the mRNA levels of this transcript in fetal (day 18) lung. We excised and cloned the band from DD, sequenced it and used it as probe in RNA blot analysis of mRNAs from fetal lung tissues of day 18,20, 22, and adult.with and without maternal dexamethasone treatment and confirmed the findings from DD method. We also used it as probe to obtain a full length cDNA. The sequence analysis indicated that this cDNA encoded HDP, a protein of 320 residues. Sequence comparison between the lung HDP cDNA and the brain HDP cDNA (J. Biol. Chem. 261:3536-3543,1986.) revealed several differences in the 3' untranslated region. The higher expression of HDP at day 18 of gestation and its gradual decrease as lung maturation increases suggests that HDP plays a role in fetal lung development. Supported by NIH, ROI HL38288.
|Published - Dec 1 1996
All Science Journal Classification (ASJC) codes
- Molecular Biology