MECHANISMS OF REGULATED PRE-mRNA SPLICING

摘要: Most messenger RNAs in higher eukaryotes are transcribed as precursors containing intervening sequences (introns). Introns removed by a sophisticated processing machinery that splices together the (exons) which form mature mRNA (reviewed chapters 3–5). Although origin of introns is unclear, cells have learned to harness splicing process regulate gene expression. Retaining an intron or using alternative splice sites can be used switch genes on off, synthesize proteins with differences their structural domains. The protein variants may differ presence absence nuclear localization signal, membrane attachment region, phosphorylation site, dimerization motif, transcriptional activation domain, etc. These important consequences for functional properties protein, and even physiology identity cell. A single decision can, example, define sex flies, trigger programmed cell death turn nonmetastatic tumor into malignant cancer. Table 6.1 summarizes some these effects.