These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.
Pubmed for Handhelds
PUBMED FOR HANDHELDS
Search MEDLINE/PubMed
Title: Characterization of a third transforming growth factor beta 1 transcript in rat tracheal epithelial cells. Author: Ostrowski LE, Gray TE, Randell SH, Nettesheim P. Journal: Cell Growth Differ; 1993 Dec; 4(12):985-91. PubMed ID: 8117625. Abstract: It has been previously reported (R. W. Steigerwalt et al., Mol. Carcinog., 5:32-40, 1992) that primary cultures of rat tracheal epithelial (RTE) cells and immortalized RTE cell lines produce three mRNA transcripts [2.5, 1.9, 1.4 kilobases (kb)] which hybridize to a murine transforming growth factor beta 1 (TGF-beta 1) complementary DNA probe. In this report, we show that the 1.9- and 1.4-kb transcripts are not detectable by Northern analysis of resting adult trachea but are induced in regenerating tracheal grafts and tumors formed from transformed RTE cells. Northern analysis of the TGF-beta 1 transcripts with subclones of the murine complementary DNA demonstrate that the 1.4-kb transcript lacks much of the 5' untranslated region (UTR). RNase protection analysis was used to map the transcriptional start site of the 1.4-kb transcript to within 30-40 base pairs of the first ATG codon. No differences in the coding or 3' UTR were detected between the 1.4-kb and the 2.5-kb transcripts. Although RTE cells produce a 1.9-kb TGF-beta 1 mRNA, we were unable to detect a previously reported unique 3' UTR, which we found to be almost identical to a rat mitochondrial ATPase sequence. Because the 1.4-kb transcript is missing most of the long GC-rich 5' UTR, it may be translated at a different rate than the 2.5- and 1.9-kb transcripts, or it may code for an intracellular form of TGF-beta 1. The 1.4-kb transcript has been observed under several conditions of injury or stress and, therefore, may be an important component of the TGF-beta 1 response to these conditions.[Abstract] [Full Text] [Related] [New Search]