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History of Micrornas: From Gene Controlling Development of Nematodes to a Promising Tool for Molecular Therapy Cover

History of Micrornas: From Gene Controlling Development of Nematodes to a Promising Tool for Molecular Therapy

Acta Medica Martiniana
Volume 24 (2024): Issue 3 (December 2024)
By:   
Open Access
|Dec 2024
Figures & tables

Figures & Tables

Fig. 1

Canonical and non-canonical pathways of miRNA biogenesis. miRNAs are usually transcribed by polymerase II. However, some miRNAs can be transcribed by polymerase III (e.g. from miRNA clusters that are spread among Alu repeats). In canonical biogenesis, the primary transcript (pri-miRNA) has a post-transcription typical loop structure that can be hundreds of base pairs long. Pri-miRNA is recognized by the protein DGCR8. Enzyme Drosha is associated with DGCR8 to form a microprocessor complex which removes the tails of miRNA and cut pri-miRNA into smaller precursor miRNA (pre-miRNA). Pre-miRNAs can then be exported into the cytoplasm. It is carried out from the nucleus through the nucleopore by the transporting molecule Exportin-5. In the cytoplasm pre-miRNA is recognized by the large RNAse protein Dicer. Dicer cleaves the stem loop to form a double stranded miRNA molecule. In the next step after cleavage, the guide strand is loaded into the Argonaute family of proteins and the passenger strand is degraded. The miRNA-induced silencing complex (miRISC) is formed. miRISC is then targeted to its target mRNA sequence. Once bound (usually at 3’ UTR region of mRNA), there are two ways that miRISC can inactivate mRNA – mRNA can be directly cleaved by RISC activity or this complex physically prevents ribosome subunits from binding and this leads to inhibition of translation. This figure also depicts two non-canonical miRNA biogenesis pathways.
DOI: https://doi.org/10.2478/acm-2024-0019 | Journal eISSN: 1338-4139 | Journal ISSN: 1335-8421
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Language: English
Page range: 153 - 162
Submitted on: Nov 9, 2024
Accepted on: Nov 10, 2024
Published on: Dec 20, 2024
Published by: Sciendo
In partnership with: Paradigm Publishing Services
Publication frequency: 3 issues per year
Keywords:
microRNAs,
non-coding RNAs,
gene expression regulation,
inhibition,
messenger RNA,
molecular therapy
Related subjects:
Medicine,
Clinical medicine,
Internal medicine,
Cardiology

© 2024 Brany Dusan, published by Sciendo
This work is licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 License.

Volume 24 (2024): Issue 3 (December 2024)
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