Functional roles of DExD/H-box RNA helicases in Pre-mRNA splicing

Splicing of precursor mrna takes place via two consecutive steps of transesterification catalyzed by a large ribonucleoprotein complex called the spliceosome. the spliceosome is assembled through ordered binding to the pre-mrna of five small nuclear rnas and numerous protein factors,and is disassembled after completion of the reaction to recycle all components. throughout the splicing cycle,the spliceosome changes its structure,rearranging rna-rna,rna-protein and protein-protein interactions,for positioning and repositioning of splice sites. dexd/h-box rna helicases play important roles in mediating structural changes of the spliceosome by unwinding of rna duplexes or disrupting rna-protein interactions. dexd/h-box proteins are also implicated in the fidelity control of the splicing process at various steps. this review summarizes the functional roles of dexd/h-box proteins in pre-mrna splicing according to studies conducted mostly in yeast and will discuss the concept of the complicated splicing reaction based on recent findings. © 2015 liu and cheng.