Transcriptional regulation of lung cytidylyltransferase in developing transgenic mice.
Lung development is associated with a surge in surfactant phosphatidylcholine (PC) production to prepare the newborn for extrauterine breathing. This process is associated with a marked increase in the activity of the rate-regulatory surfactant enzyme, CTP:phosphocholine cytidylyltransferase (CCTalpha). To investigate the molecular basis for developmental activation of CCTalpha, we analyzed expression of endogenous CCTalpha and a reporter gene, beta-galactosidase, in fetal, newborn, and adult promoter-reporter transgenic mice. Transgenics harboring approximately 2 kb of the CCTalpha promoter linked upstream of a beta-galactosidase reporter gene displayed relatively high expression in distal lung epithelia. Endogenous lung CCTalpha and beta-galactosidase activities, protein content, and transcript levels displayed maximal expression within the newborn period. CCTalpha and beta-galactosidase activities and enzyme levels increased with time in cultured fetal lung explants isolated from transgenics. Transfectional analysis using CCTalpha promoter-reporter constructs in developing rat type II cells revealed that a region encompassing -169/+71 contained the DNA elements required for perinatal activation. The studies demonstrate that developmental induction of surfactant phospholipid is due, at least in part, to transcriptional activation of the CCTalpha gene.
McCoy
Diann M
DM
Department of Internal Medicine, University of Iowa Carver College of Medicine, Iowa City, Iowa 52242, USA.
Fisher
Kurt
K
Robichaud
John
J
Ryan
Alan J
AJ
Mallampalli
Rama K
RK
D000818:Animals; D002478:Cells, Cultured; D019916:Choline-Phosphate Cytidylyltransferase / Q000235:genetics*; D018507:Gene Expression Regulation, Developmental / Q000235:genetics*; D015971:Gene Expression Regulation, Enzymologic / Q000235:genetics*; D017930:Genes, Reporter; D008168:Lung / Q000166:cytology / Q000201:enzymology / Q000254:growth & development*; D051379:Mice; D008822:Mice, Transgenic; D010743:Phospholipids / Q000378:metabolism; D011401:Promoter Regions, Genetic; D011650:Pulmonary Alveoli / Q000166:cytology / Q000201:enzymology; D011663:Pulmonary Surfactants / Q000378:metabolism; D051381:Rats; D014158:Transcription, Genetic; D014162:Transfection; D001616:beta-Galactosidase / Q000032:analysis / Q000235:genetics
D010743:Phospholipids; D011663:Pulmonary Surfactants; D019916:Choline-Phosphate Cytidylyltransferase; D001616:beta-Galactosidase