| Summary |
microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in post-transcriptional regulation of gene expression in multicellular organisms by affecting both the stability and translation of mRNAs. miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts (pri-miRNAs) that can be either protein-coding or non-coding. The primary transcript is cleaved by the Drosha ribonuclease III enzyme to produce an approximately 70-nt stem-loop precursor miRNA (pre-miRNA), which is further cleaved by the cytoplasmic Dicer ribonuclease to generate the mature miRNA and antisense miRNA star (miRNA*) products. The mature miRNA is incorporated into a RNA-induced silencing complex (RISC), which recognizes target mRNAs through imperfect base pairing with the miRNA and most commonly results in translational inhibition or destabilization of the target mRNA. The RefSeq represents the predicted microRNA stem-loop. [provided by RefSeq, Sep 2009] Biosynthesis of stable cellular RNAs such as tRNAs, rRNAs, snRNAs, and snoRNAs is aided by covalent nucleotide modification after transcription. The modified nucleotides are involved in correct RNA folding, establishment of correct RNA-RNA and RNA-protein interactions, and in the correct function of mature RNAs. The RNA encoded by this gene is thought to mediate the pseudouridylation of residues U105 and U1244 of 18S rRNA. [provided by RefSeq, Feb 2009]
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Version 5.4