JHIBRG:Abstract Mar 01 2007
miRNA-mediated repression of translation
Translation of mRNA is recently shown to be regulated by small interfering RNA (siRNA)through RNAi and micro RNA (miRNA). The process of RNAi and many of the components are currently being elucidated. However, little of microRNA (miRNA) mediated repression of translation is known compared to RNAi. In RNAi, an exogenous double strand RNA (dsRNA) is processed into ~20bp fragments and the short dsRNA forms an RNA-induced silencing complex (RISC). RISC then cleaves target mRNAs and subsequently down-regulates protein synthesis. On the other hand, miRNA originates from non-coding region of genome. Often, endogenous RNA hairpins are processed to generate miRNA and they form micro ribonucleoprotein (miRNP), which is equivalent to RISC in RNAi. Although there are many similarities between RNAi and miRNA-mediated repression, the mechanism of miRNP is not entirely determined and is under active investigation.
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