MicroRNA 222 is a
MicroRNA that in humans is encoded by the MIR222
gene, and is a known extracellular RNA (exRNA).
Function
microRNAs (miRNAs) are short (20-24 nt) non-coding RNAs that are involved in
post-transcriptional regulation of
gene expression
Gene expression is the process by which information from a gene is used in the synthesis of a functional gene product that enables it to produce end products, protein or non-coding RNA, and ultimately affect a phenotype, as the final effect. The ...
in multicellular organisms by affecting both the stability and translation of
mRNAs
In molecular biology, messenger ribonucleic acid (mRNA) is a single-stranded molecule of RNA that corresponds to the genetic sequence of a gene, and is read by a ribosome in the process of synthesizing a protein.
mRNA is created during the p ...
. 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
Dicer, also known as endoribonuclease Dicer or helicase with RNase motif, is an enzyme that in humans is encoded by the gene. Being part of the RNase III family, Dicer cleaves double-stranded RNA (dsRNA) and pre-microRNA (pre-miRNA) into short d ...
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.
References
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