What is miRNA biogenesis?
Table of Contents
What is miRNA biogenesis?
miRNAs biogenesis starts from DNA sequences, called miRNA genes, or from clusters genes which are only transcripted as miRNA molecules or together as polycistronic transcripts, respectively (7, 8). Alternatively, the miRNAs localize within an intron or untranslated region (UTR) of a protein-coding gene (8).
What is the origin of miRNA?
Novel microRNAs can originate from the random formation of hairpins in “non-coding” sections of DNA (i.e. introns or intergene regions), but also by the duplication and modification of existing microRNAs.
How are miRNA created?
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.
When was miRNA first discovered?
1993
miRNAs were discovered in 1993 by Lee and colleagues93 in the nematode Caenorhabditis elegans. In these organisms, the downregulation of LIN-14 protein was found to be essential for the progression from the first larval stage (L1) to L2.
Where is miRNA found?
Mature miRNAs localize in multiple subcellular locations in the cytoplasm, such as RNA granules, endomembranes, and mitochondria, and secrete outside cells via exosomes. Recent studies have revealed that mature miRNAs can also localize to the nucleus, where they could function in epigenetic regulation.
Who discovered miRNA?
miRNAs were discovered in 1993 by Lee and colleagues93 in the nematode Caenorhabditis elegans. In these organisms, the downregulation of LIN-14 protein was found to be essential for the progression from the first larval stage (L1) to L2.
What is the first step in the production of a miRNA?
Step 1: Gene activation A cell begins making a protein by activating the gene that contains the information for the protein. A protein called a transcription factor binds with the gene, and this activates it.
What is the importance of microRNA?
MicroRNAs are now recognized to play a pivotal role in the regulation of certain processes related to development in all eukaryotes and because of their potential role as agents controlling cell growth and differentiation, they have been proposed to be good candidates for cancer therapy (51, 52).
What is the function of microRNA?
microRNAs (miRNAs) are small noncoding RNAs that play important roles in posttranscriptional gene regulation. In animal cells, miRNAs regulate their targets by translational inhibition and mRNA destabilization.
Where are miRNAs made?
In animals, miRNAs are synthesized from primary miRNAs (pri-miRNAs) in two stages by the action of two RNase III-type proteins: Drosha in the nucleus and Dicer in the cytoplasm [13].
