SiRNA and miRNA Essay Example

SiRNA and miRNA Essay Example SiRNA and miRNA Essay SiRNA and miRNA Essay SiRNA (small interfering RNA) belongs to a class of 20-25 nucleotide-long and double-stranded RNA molecules. It is known that siRNA plays important role in biological processes. For example, it is involved in the interference of RNA pathway and is responsible for expression of a specific gene there. Additionally, its role is to act in RNAi-related pathway. It means that siRNA acts as antiviral mechanism shaping the chromatin structure of a genome. It is necessary to admit that siRNA has a well defined structure. It is a short double-strand of RNA having overhangs on both ends. SiRNA’s strands have 5’ phosphate group and 3’ hydroxyl group. Biologists claim that siRNA’s structure results from the processing by dicer (i.e. enzyme being responsible for converting long dsRNAs and small hairpin RNAs into siRNAs). Transfection methods are involved to make siRNAs be introduced into cells with the purpose to cause knockdown of a gene of interest. Therefore, siRNA p lays important role in gene expressions and validation of drug target. First siRNA was discovered as a past of â€Å"post-transcriptional gene silencing†, whereas miRNA was discovered as a part of primary microRNA   Comparing siRNA and miRNA, siRNA is a short inferring RNA being generated mostly in vitro or can be synthesized, whereas miRNA is a short double-stranded RNA molecule resulted from dicing long pre-miRNA molecules. Actually, miRNA differs from siRNA as it is obtained from single-stranded RNA precursors. Additionally, in contrast to siRNA, miRNA shows only partial complementary to mRNA targets. MirNA is known to perform wide range of functions; especially it is responsible for cell growth and adoptosis as well as for cell development, insulin secretion and neuronal remodeling. MiRNAs are implicated in diseases. Both siRNA and miRNA are able to regulate expression of a specific gene, though miRNA regulates it at the level of translational inhibition. Finally, it is admitted that miRNA can also guide mRNA in a similar way to siRNA. Loewenstein, Werner. Molecular Information, Cell Communication, and the Foundations of Life. New York: Oxford University Press, 1999.