RNA interference

Definition

RNA interference (RNAi) is a biological process in which small RNA molecules inhibit gene expression or translation by targeting specific mRNA molecules for degradation. This mechanism plays a critical role in regulating gene expression, both in prokaryotic and eukaryotic organisms, and is also widely used in molecular biology techniques for gene silencing and functional studies.

5 Must Know Facts For Your Next Test

1. RNA interference was first discovered in the nematode Caenorhabditis elegans and has since been found in various organisms, including plants and mammals.
2. The RNAi pathway is essential for regulating gene expression during development, maintaining genome stability, and protecting against viral infections.
3. In molecular biology, researchers utilize RNAi to knock down the expression of specific genes to study their functions and roles in various biological processes.
4. Synthetic siRNAs can be designed and introduced into cells to selectively silence target genes, making RNA interference a valuable tool in therapeutic development.
5. Dysregulation of the RNAi pathway has been implicated in various diseases, including cancer, where improper gene silencing may contribute to tumorigenesis.

Review Questions

• How does RNA interference contribute to the regulation of gene expression in both prokaryotic and eukaryotic organisms?
  • RNA interference contributes to gene regulation by utilizing small RNA molecules that can target specific mRNAs for degradation or translational repression. In eukaryotes, this process often involves siRNAs or miRNAs that guide RISC to the complementary mRNA. In prokaryotes, while the mechanism is less understood, evidence suggests that similar pathways may exist, enabling these organisms to respond to environmental changes and manage gene expression effectively.
• Discuss the implications of RNA interference in molecular biology research and potential therapeutic applications.
  • RNA interference has revolutionized molecular biology research by providing a powerful method for silencing specific genes, allowing scientists to investigate gene function and associated biological processes. Therapeutically, RNAi holds promise for treating diseases caused by overactive genes or pathogens. By designing specific siRNAs that target disease-related genes, researchers aim to create treatments for conditions like cancer and viral infections, paving the way for innovative therapeutic strategies.
• Evaluate how dysregulation of the RNA interference pathway might influence disease progression and development, particularly in cancers.
  • Dysregulation of the RNA interference pathway can lead to improper gene silencing or activation, which may promote disease progression, particularly in cancers. For example, if tumor suppressor genes are not adequately expressed due to failed RNAi mechanisms, uncontrolled cell proliferation can occur. Conversely, if oncogenes are improperly silenced, it may contribute to cancer development. Understanding these dysregulations offers insights into potential therapeutic targets for restoring normal gene regulation and developing effective treatments.

Related terms

siRNA: Small interfering RNA (siRNA) are short double-stranded RNA molecules that play a key role in the RNAi process by guiding the RNA-induced silencing complex (RISC) to complementary mRNA targets.

miRNA: MicroRNA (miRNA) are small non-coding RNA molecules that regulate gene expression by binding to complementary sequences in mRNA, leading to mRNA degradation or inhibition of translation.

RISC:

The RNA-induced silencing complex (RISC) is a multi-protein complex that plays a central role in RNA interference, utilizing small RNAs to identify and degrade target mRNA.