What is the role of microRNAs in gene regulation?

MicroRNAs play a crucial role in gene regulation by controlling the expression of target genes.

MicroRNAs (miRNAs) are small, non-coding RNA molecules that regulate gene expression at the post-transcriptional level. They bind to the 3' untranslated region (UTR) of target messenger RNA (mRNA) molecules, leading to either mRNA degradation or translational repression. This results in decreased protein production from the target gene.

MiRNAs are involved in a wide range of biological processes, including development, differentiation, and disease. They can act as either tumour suppressors or oncogenes, depending on the specific target genes they regulate.

MiRNAs are transcribed from DNA by RNA polymerase II and undergo several processing steps before becoming mature miRNAs. The primary transcript, called pri-miRNA, is processed by the Drosha-DGCR8 complex to form a hairpin-shaped precursor miRNA (pre-miRNA). The pre-miRNA is then transported to the cytoplasm and further processed by Dicer to form the mature miRNA.

MiRNAs can regulate multiple target genes, and a single gene can be regulated by multiple miRNAs. This complex network of miRNA-gene interactions allows for fine-tuned regulation of gene expression.

In conclusion, miRNAs play a crucial role in gene regulation by controlling the expression of target genes. Their involvement in various biological processes highlights their importance in maintaining cellular homeostasis.