miRNAmolekyylit

miRNAmolekyylit, or microRNA molecules, are a class of non-coding RNAs that play crucial roles in gene regulation within cells. They are typically about 22 nucleotides in length and are involved in post-transcriptional gene silencing by guiding the RNA-induced silencing complex (RISC) to target messenger RNAs (mRNAs) for degradation or translational repression.

miRNAs are transcribed by RNA polymerase II as part of capped and polyadenylated primary transcripts, which are then processed to yield mature miRNAs. This processing involves the cleavage of the primary transcript by the Drosha enzyme, followed by export to the cytoplasm where the Dicer enzyme further processes the transcript into a miRNA duplex. One strand of the duplex is incorporated into the RISC complex, while the other is degraded.

miRNAs can target multiple genes, and a single gene can be targeted by multiple miRNAs. This complex regulatory network allows miRNAs to fine-tune gene expression patterns, influencing various biological processes such as development, differentiation, and response to external stimuli. Dysregulation of miRNA expression has been linked to numerous diseases, including cancer, making miRNAs valuable targets for therapeutic interventions.

Research into miRNAs has led to the discovery of their roles in a wide range of biological functions and their potential as biomarkers for disease diagnosis and therapeutic targets. However, the precise mechanisms by which miRNAs regulate gene expression are still an active area of investigation.