| First Author | Wang YC | Year | 1992 |
| Journal | J Biol Chem | Volume | 267 |
| Issue | 4 | Pages | 2728-36 |
| PubMed ID | 1733968 | Mgi Jnum | J:1997 |
| Mgi Id | MGI:50521 | Doi | 10.1016/s0021-9258(18)45940-6 |
| Citation | Wang YC, et al. (1992) Choice of 3' cleavage/polyadenylation site in beta-tropomyosin RNA processing is differentiation-dependent in mouse BC3H1 muscle cells. J Biol Chem 267(4):2728-36 |
| abstractText | The rodent beta-tropomyosin (TM) gene produces either a 1.2-kilobase (kb) skeletal muscle beta-TM mRNA or a 1.1-kb fibroblast/smooth muscle TM-1 mRNA through tissue-specific alternative exon splicing and 3' cleavage/polyadenylation at two alternative poly(A) sites. beta-TM mRNA contains exon 6b, 9a, and the poly(A) site immediately following exon 9a, whereas TM-1 mRNA contains exon 6a, 9b, and the poly(A) site following exon 9b. We isolated a novel 2.1-kb beta-TM cDNA clone, pUTM, from a cDNA library of 2-day differentiated mouse BC3H1 muscle-like cells. This cDNA contains the entire sequence of mature beta-TM mRNA with a normal but unused poly(A) site associated with exon 9a. Instead, 3' cleavage/polyadenylation of this cDNA occurred at the exon 9b-associated distal poly(A) site, resulting in the retention of a 1-kb intron and the TM-1 exon 9b. We identified a 2.3-kb functional mRNA, UTM RNA, corresponding to pUTM. UTM RNA appeared early during BC3H1 cell differentiation and gradually decreased as the beta-TM mRNA increased. UTM RNA was also detected in mouse C2C12 muscle cells and in skeletal muscle tissue isolated from mouse leg. Thus, in the processing of beta-TM gene transcripts, selection of alternative terminal exons and alternative poly(A) sites are not necessarily linked as they appear to be in other gene systems. |
