What is RNA interference and how does it regulate gene
expression?
RNA interference (RNAi) is a regulatory mechanism involved in controlling gene
expression at the post-transcriptional level in eukaryotic cells. This process involves
the silencing of gene expression by targeting specific mRNAs for degradation,
inhibiting their translation, or altering their splicing patterns. RNAi is mediated by
small RNA molecules, including microRNAs (miRNAs) and small interfering RNAs
(siRNAs), which bind to complementary mRNA sequences and induce gene
silencing.
The RNAi pathway begins with the production of double-stranded RNA (dsRNA)
molecules, which are processed by Dicer enzymes into small RNA fragments,
typically 21-23 nucleotides in length. These small RNAs are then loaded onto protein
complexes known as RNA-induced silencing complexes (RISCs), which guide them
to their target mRNAs. The RISC complex binds to the mRNA, leading to its
degradation or repression.
RNAi plays a critical role in many biological processes, including development,
differentiation, and defense against viruses and other pathogens. Dysregulation of
RNAi has been associated with a variety of diseases, including cancer,
neurodegenerative disorders, and viral infections.
Reference:
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siRNAs. Cell, 136(4), 642-655.
2. Meister, G., & Tuschl, T. (2004). Mechanisms of gene silencing by double-stranded RNA.
Nature, 431(7006), 343-349.
3. Fire, A., Xu, S., Montgomery, M. K., Kostas, S. A., Driver, S. E., & Mello, C. C. (1998).
Potent and specific genetic interference by double-stranded RNA in Caenorhabditis elegans.
Nature, 391(6669), 806-811.