Dicer

Dicer is an enzyme involved in the RNA interference (RNAi) pathway, a highly conserved mechanism responsible for regulating gene expression, defending against viral infections, and maintaining genome stability. Structurally, Dicer contains two RNase III domains, responsible for its endoribonuclease activity. These domains cleave long dsRNA molecules into smaller RNA duplexes of a specific length, typically around 21-25 nucleotides for miRNAs and siRNAs. The PAZ (Piwi-Argonaute-Zwille) domain is located at the N-terminus of Dicer and is involved in binding the 3' overhang of dsRNA substrates, helping to position the RNA for cleavage and essential for the accuracy of miRNA and siRNA processing. Some Dicer enzymes possess a DExH RNA helicase domain located at the C-terminus. This domain can unwind dsRNA substrates, enhancing cleavage by the RNase III domains. Dicer can form dimers, and dimerization interfaces are important for its stability and activity. Dimerization may also facilitate cooperative binding and processing of dsRNA substrates. Lastly, Dicer contains binding sites for dsRNA-binding proteins such as TRBP (TAR RNA-binding protein) and PACT (protein activator of the interferon-induced protein kinase). These interactions are thought to enhance the efficiency and specificity of Dicer-mediated cleavage. Dicer is primarily responsible for the processing of precursor RNA molecules into smaller, functional RNA fragments. It acts on several types of precursors, including long double-stranded RNA (dsRNA), precursor microRNAs (pre-miRNAs), and long hairpin small interfering RNAs (siRNAs). Dicer cleaves these precursors into mature, single-stranded small RNA molecules, which subsequently guide various RNAi pathways. One of the best-known functions of Dicer is in miRNA biogenesis. Here, Dicer cleaves pre-miRNAs, hairpin-shaped structures formed from primary miRNA transcripts. The resulting mature miRNAs are loaded into the RNA-induced silencing complex (RISC), where they guide RISC to target mRNAs with complementary sequences. This binding can lead to translational repression or degradation of the target mRNA. An example is the let-7 miRNA, which regulates developmental timing by targeting specific mRNAs involved in development. Dicer is also involved in the generation of siRNAs, which play a vital role in the innate immune response against viral infections. During a viral infection, long dsRNA molecules originating from the viral genome are recognized by cellular sensors and processed by Dicer into siRNAs. These siRNAs guide the RNA-induced silencing complex (RISC) to target and cleave viral RNA, effectively silencing viral gene expression. In the case of miRNA biogenesis, Dicer selects one strand of the miRNA duplex as the mature miRNA strand, discarding the other (passenger) strand, ensuring that only one functional miRNA strand is incorporated into RISC. After Dicer cleaves the precursor RNA and selects the mature strand, the resulting small RNA is loaded into an effector complex. In the case of miRNAs, it's loaded into the miRNA-induced silencing complex (miRISC), whilst siRNAs are loaded into the RNA-induced silencing complex (RISC). These complexes then guide the small RNAs to target mRNAs, where they exert their regulatory functions. We provide a wide product range of research tools for investigating Dicer, including TRBP antibodies, Dicer antibodies, and Drosha antibodies. Explore our full Dicer product range below and discover more, for less.