How does RISC utilize mRNA after processing?

The RNA-induced silencing complex (RISC) plays a critical role in gene regulation, particularly in the pathway of RNA interference (RNAi). After processing, RISC utilizes mRNA primarily by targeting it for degradation. Once RISC is loaded with small interfering RNA (siRNA) or microRNA (miRNA), it acts specifically by binding to complementary mRNA sequences. This binding prompts the endonucleolytic cleavage of the mRNA, effectively leading to its degradation.

This process is essential for regulating gene expression and is a key mechanism by which cells can ensure that certain genes are silenced when they are not needed, allowing for precise control over protein production. By degrading the targeted mRNA, RISC prevents translation into protein, thereby influencing various cellular functions and responses.

While translation initiation and storage of mRNA are critical aspects of gene expression and regulation, they do not describe the direct action that RISC takes on mRNA after processing. RISC's primary function is to degrade and inhibit translation of target mRNAs, confirming that degradation is the correct process utilized.