RNA interference

Definition

RNA interference (RNAi) is a biological process in which RNA molecules inhibit gene expression or translation by neutralizing targeted mRNA molecules. This mechanism plays a crucial role in regulating gene expression, providing a means for cells to control which genes are active at any given time and helping to protect against viral infections and transposons.

5 Must Know Facts For Your Next Test

1. RNA interference was first discovered in the 1990s and has since been recognized as a vital mechanism for regulating gene expression in various organisms.
2. The process involves the action of proteins called Argonautes, which bind to the siRNA or miRNA and facilitate the degradation or inhibition of target mRNA.
3. RNAi can be triggered artificially in laboratory settings, allowing researchers to selectively silence genes, which has implications for gene therapy and drug development.
4. This mechanism serves as a defense system against viral infections by targeting viral RNA for degradation, thus preventing replication.
5. In addition to its role in gene regulation, RNA interference is also involved in cellular processes such as development, differentiation, and response to environmental changes.

Review Questions

• How does RNA interference contribute to the regulation of gene expression within a cell?
  • RNA interference contributes to gene regulation by targeting specific mRNA molecules for degradation or translational inhibition. This process is mediated by small interfering RNAs (siRNAs) or microRNAs (miRNAs), which bind to complementary sequences on their target mRNAs. By controlling the stability and translation of these mRNAs, RNAi effectively regulates protein production and helps maintain cellular homeostasis.
• Discuss the role of Dicer in the RNA interference pathway and its importance in the formation of functional RNA molecules.
  • Dicer plays a crucial role in the RNA interference pathway by processing long double-stranded RNA into shorter fragments known as small interfering RNAs (siRNAs) or microRNAs (miRNAs). This processing is essential because only these shorter RNA molecules can effectively associate with Argonaute proteins to form the RNA-induced silencing complex (RISC). Without Dicer's activity, the generation of functional RNAi molecules would be impaired, leading to a failure in regulating gene expression through this mechanism.
• Evaluate the potential applications of RNA interference technology in biomedical research and therapeutic interventions.
  • RNA interference technology holds significant promise in biomedical research and therapeutic interventions due to its ability to selectively silence specific genes. Researchers are exploring its use for treating genetic disorders, cancer, and viral infections by targeting and degrading malfunctioning or disease-associated mRNAs. Additionally, RNAi can be harnessed for developing novel drugs that specifically inhibit disease-causing genes, making it a powerful tool in precision medicine. However, challenges such as delivery mechanisms and off-target effects need to be addressed before widespread clinical application can be realized.

Related terms

Small interfering RNA (siRNA): A class of double-stranded RNA that is involved in the RNA interference pathway, leading to the degradation of mRNA molecules with complementary sequences.

MicroRNA (miRNA): Short, single-stranded RNA molecules that regulate gene expression by binding to complementary sequences on target mRNAs, often resulting in their silencing.

Dicer:

An enzyme that processes long double-stranded RNA into short interfering RNAs (siRNAs) or microRNAs (miRNAs), which are essential for the RNA interference pathway.