Multiple transcription start sites and 5' alternate splicing of murine IL-3 receptor beta-chain transcripts
Norga, K.; Pless, M.; Stanulla, M.; TePas, E.C.; Mathey-Prevot, B.
Biochemical and Biophysical Research Communications 205(1): 886-892
1994
ISSN/ISBN: 0006-291X PMID: 7999127 Document Number: 426035
The murine interleukin-3 receptor beta-chain genes, IL-3R-beta-IL-3 and IL-3R-beta-C, encode the signal transducing chains of the high affinity receptors for IL-3 and IL-3, GM-CSF and IL-5 respectively. Little is known about the regulation of their expression. To enable the study of the promoters of IL-3R-beta-IL-3 and IL-3R-beta-C, we have characterized their respective 5' untranslated regions using a modified 5' RACE protocol. Four classes of alternatively spliced transcripts were isolated that initiate in a 400 nt region upstream from a previously reported start site(1). The initially reported partial IL-3R-beta-IL-3 clone belongs to the first class of transcripts(2). The second class starts in the middle of an intron as defined by the first class. The 3rd and 4th class establish 2 novel splice donor sites. These results were confirmed by RNAse-protection assay. The complex organization as evident from our data establishes an experimental framework for future experiments aimed at the study of the promoters for the murine IL-3R-beta genes.