First Author | Le Guiner C | Year | 2001 |
Journal | J Biol Chem | Volume | 276 |
Issue | 44 | Pages | 40638-46 |
PubMed ID | 11514562 | Mgi Jnum | J:314554 |
Mgi Id | MGI:6827199 | Doi | 10.1074/jbc.M105642200 |
Citation | Le Guiner C, et al. (2001) TIA-1 and TIAR activate splicing of alternative exons with weak 5' splice sites followed by a U-rich stretch on their own pre-mRNAs. J Biol Chem 276(44):40638-46 |
abstractText | TIA-1 has recently been shown to activate splicing of specific pre-mRNAs transcribed from transiently transfected minigenes, and of some 5' splice sites in vitro, but has not been shown to activate splicing of any endogenous pre-mRNA. We show here that overexpression of TIA-1 or the related protein TIAR has little effect on splicing of several endogenous pre-mRNAs containing alternative exons, but markedly activates splicing of some normally rarely used alternative exons on the TIA-1 and TIAR pre-mRNAs. These exons have weak 5' splice sites followed by U-rich stretches. When the U-rich stretch following the 5' splice site of a TIA-1 alternative exon was deleted, TIAR overexpression induced use of a cryptic 5' splice site also followed by a U-rich stretch in place of the original splice site. Using in vitro splicing assays, we have shown that TIA-1 is directly involved in activating the 5' splice sites of the TIAR alternative exons. Activation requires a downstream U-rich stretch of at least 10 residues. Our results confirm that TIA-1 activates 5' splice sites followed by U-rich sequences and show that TIAR exerts a similar activity. They suggest that both proteins may autoregulate their expression at the level of splicing. |