RNAi

RNA interference (RNAi) is regulatory mechanism that controls gene expression through the post-transcriptional silencing of specific target genes and plays crucial roles in various cell processes. At the core of RNAi are small RNA molecules, typically 20-25 nucleotides in length that regulate gene expression. The two primary classes of small RNAs involved in RNAi are small interfering RNAs (siRNAs) and microRNAs (miRNAs). SiRNA are double-stranded RNA molecules usually derived from exogenous sources or introduced experimentally. SiRNAs guide the RNA-induced silencing complex (RISC) to target mRNAs with complementary sequences, leading to mRNA degradation. MiRNAs are endogenous single-stranded RNA molecules which are processed from longer precursors and regulate gene expression. MiRNAs also guide RISC to target mRNAs, but typically result in translational repression rather than mRNA degradation. RISC (RNA-Induced Silencing Complex) is the protein complex that associates with small RNAs, either siRNAs or miRNAs. RISC functions as the effector complex in RNAi, guiding the small RNA to complementary mRNA sequences. The core component of RISC is an Argonaute protein, involved in RNA target recognition and cleavage. They interact with the small RNA molecule and are responsible for cleaving or inhibiting the target mRNA. There are multiple Argonaute proteins in most organisms, but only one is typically associated with each RISC complex at a time. Dicer is an RNase III endonuclease that also plays an important role in RNAi by processing the long double-stranded RNA precursors, including those generated by exogenous sources or long hairpin structures within the cell. Dicer cleaves these precursors into smaller siRNA or miRNA duplexes, which are then loaded onto RISC. In the case of siRNAs, long double-stranded RNA molecules are processed by Dicer into 20-25 nucleotide siRNA duplexes. For miRNAs, endogenous genes produce long primary transcripts (pri-miRNAs) that are processed into precursor miRNAs (pre-miRNAs) by enzymes such as Drosha in the nucleus and subsequently into mature miRNAs by Dicer in the cytoplasm. The processed siRNAs or mature miRNAs are loaded onto the RISC complex and one strand of the duplex, the guide strand, is retained within RISC, whilst the other strand, the passenger strand, is discarded. RISC, with its loaded small RNA, then sequentially scans mRNAs for sequences that are complementary to the small RNA. When the small RNA finds a complementary mRNA target, it forms base pairs, allowing RISC to bind to the target mRNA. The consequence of RISC binding depends on the nature of the small RNA and the degree of complementarity with the target mRNA. For siRNAs, perfect complementarity typically results in mRNA cleavage, leading to rapid degradation of the mRNA. With miRNAs, which usually have imperfect complementarity, mRNA translation is inhibited, often by blocking ribosome binding or promoting mRNA decay. RNA interference has numerous crucial roles in cells and organisms. For example, during T cell development MiR-181a is critical for setting the threshold of T cell receptor (TCR) signaling, helping to ensure that thymocytes with TCRs of appropriate affinity for self-peptides are positively selected. We provide a comprehensive product catalogue of research reagents for studying RNAi, including eIF4EBP1 antibodies, eIF4E antibodies, PERK antibodies, eIF4G1 antibodies, and eIF4EBP1 ELISA Kits. Explore our full RNAi product range below and discover more, for less. Alternatively, you can explore our Eukaryotic Initiation Factors, Argonaute & Piwi, and Dicer product ranges.