Akinyi Maureen V, Frilander Mikko J
Institute of Biotechnology/Helsinki Institute of Life Science, University of Helsinki, Helsinki, Finland.
Front Genet. 2021 Jul 20;12:700744. doi: 10.3389/fgene.2021.700744. eCollection 2021.
Many eukaryotic species contain two separate molecular machineries for removing non-coding intron sequences from pre-mRNA molecules. The majority of introns (more than 99.5% in humans) are recognized and excised by the major spliceosome, which utilizes relatively poorly conserved sequence elements at the 5' and 3' ends of the intron that are used for intron recognition and in subsequent catalysis. In contrast, the minor spliceosome targets a rare group of introns (approximately 0.5% in humans) with highly conserved sequences at the 5' and 3' ends of the intron. Minor introns coexist in the same genes with major introns and while the two intron types are spliced by separate spliceosomes, the two splicing machineries can interact with one another to shape mRNA processing events in genes containing minor introns. Here, we review known cooperative and competitive interactions between the two spliceosomes and discuss the mechanistic basis of the spliceosome crosstalk, its regulatory significance, and impact on spliceosome diseases.
许多真核生物物种拥有两种独立的分子机制，用于从前体mRNA分子中去除非编码内含子序列。大多数内含子（人类中超过99.5%）由主要剪接体识别并切除，主要剪接体利用内含子5'和3'末端相对保守性较差的序列元件进行内含子识别及后续催化。相比之下，次要剪接体靶向一类罕见的内含子（人类中约0.5%），其内含子的5'和3'末端具有高度保守的序列。次要内含子与主要内含子共存于同一基因中，虽然这两种内含子类型由不同的剪接体进行剪接，但这两种剪接机制可以相互作用，以塑造含有次要内含子的基因中的mRNA加工事件。在此，我们综述了两种剪接体之间已知的协同和竞争相互作用，并讨论了剪接体串扰的机制基础、其调控意义以及对剪接体疾病的影响。
