Hodges D, Bernstein S I
Biology Department, San Diego State University, CA 92182.
Mech Dev. 1992 May;37(3):127-40. doi: 10.1016/0925-4773(92)90075-u.
Using a Drosophila cell-free system, we have analyzed the regulation of alternative splicing of Drosophila muscle myosin heavy chain (MHC) transcripts. Splicing of MHC 3' end transcripts results in exclusion of adult-specific alternative exon 18, as is observed in embryonic and larval muscle in vivo. Mutations that strengthen either the 5' or the 3' splice sites of exon 18 do not promote inclusion of this exon. However, strengthening both splice junctions results in efficient removal of both introns and completely inhibits skip splicing. Our data suggest that the affinity of exons 17 and 19, as well as failure of constitutive splicing factors to recognize exon 18 splice sites, causes the exclusion of exon 18 in wild-type transcripts processed in vitro.
利用果蝇无细胞系统，我们分析了果蝇肌肉肌球蛋白重链（MHC）转录本可变剪接的调控。如在体内胚胎和幼虫肌肉中所观察到的那样，MHC 3'端转录本的剪接导致成体特异性可变外显子18被排除。增强外显子18的5'或3'剪接位点的突变并不会促进该外显子的包含。然而，增强两个剪接连接会导致两个内含子的有效去除并完全抑制跳跃剪接。我们的数据表明，外显子17和19的亲和力，以及组成型剪接因子未能识别外显子18的剪接位点，导致在体外加工的野生型转录本中外显子18被排除。
