How does microRNA control the translation process?
Abstract. MicroRNAs (miRNAs) repress translation of target mRNAs by interaction with partially mismatched sequences in their 3′ UTR. The mechanism by which they act on translation has remained largely obscure.
Does microRNA promote translation?
MicroRNAs can promote translation of specific mRNAs in quiescent (G0) mammalian cells and immature Xenopus laevis oocytes.
What is the important role of microRNA in translation?
MicroRNAs (miRNAs) are pervasively expressed and regulate most biological functions. They function by modulating transcriptional and translational programs and therefore they orchestrate both physiological and pathological processes, such as development, cell differentiation, proliferation, apoptosis and tumor growth.
How do miRNAs mediate translational repression?
[40] reported that the mechanism of miRNA-mediated repression might depend on the promoter used for driving the target mRNA expression. These authors proposed that different promoters result in a distinct set of mRNPs on reporter mRNA, which in turn determine the type of translational repression mechanism.
Does miRNA affect transcription or translation?
By binding coding transcripts, miRNAs cause degradation or translation inhibition of their target genes and affect a multitude of biological processes, such as proliferation and tumor growth.
Is miRNA post translational regulation?
MicroRNAs constitute a large family of small, approximately 21-nucleotide-long, non-coding RNAs that have emerged as key post-transcriptional regulators of gene expression in metazoans and plants.
How do MicroRNAs promote gene silencing and translational repression?
MicroRNAs (miRNAs) repress the expression of mRNA targets by promoting translational repression and mRNA degradation. In animals, target degradation is initiated by accelerated deadenylation, which is normally followed by decapping and subsequent degradation of the mRNA body.
Can miRNA be translated?
The copurification of miRNAs with polysomes, confirmed by many studies in the last years, not only proves that miRNAs are involved in translational repression, but suggests that miRNA targets are actively translated. Taken together, these data suggest that mRNAs could be silenced by miRNAs at the post initiation step.
How are MicroRNAs synthesized?
MicroRNAs are transcribed by RNA polymerases II and III, generating precursors that undergo a series of cleavage events to form mature microRNA. The conventional biogenesis pathway consists of two cleavage events, one nuclear and one cytoplasmic.