How does microRNA affect gene expression?
How does microRNA affect gene expression?
microRNA controls gene expression mainly by binding with messenger RNA (mRNA) in the cell cytoplasm. Instead of being translated quickly into a protein, the marked mRNA will be either destroyed and its components recycled, or it will be preserved and translated later.
How do MicroRNAs miRNAs block gene expression?
miRNAs (microRNAs) are short non-coding RNAs that regulate gene expression post-transcriptionally. They generally bind to the 3′-UTR (untranslated region) of their target mRNAs and repress protein production by destabilizing the mRNA and translational silencing.
What is miRNA silencing?
MicroRNAs (miRNAs) silence gene expression by repressing translation and accelerating target mRNA degradation. In this pathway, mRNAs are first deadenylated, then decapped and finally degraded from the 5′ end. The GW182 proteins play a central part in silencing.
How many genes are regulated by microRNA?
The discovery of the first microRNA (miRNA) over 20 years ago has ushered in a new era in molecular biology. There are now over 2000 miRNAs that have been discovered in humans and it is believed that they collectively regulate one third of the genes in the genome.
How do MicroRNAs downregulate gene expression?
It was primarily acknowledged that miRNAs result in gene expression repression at both the level of mRNA stability by conducting mRNA degradation and the level of translation (at initiation and after initiation) by inhibiting protein translation or degrading the polypeptides through binding complementarily to 3′UTR of …
How do siRNA and miRNA affect gene expression?
For instance, the siRNA regulates the expression of different genes while the miRNA regulates the expression of similar types of genes or genes having the same origin. Keep in mind that the duo has a direct role in the process of RNA interference but has different effects, targets and modes of action.
What is post transcriptional gene silencing?
Post-transcriptional gene silencing (PTGS) is one mechanism that degrades specific messenger RNAs and thereby reduces the expression of a specific gene. PTGS has many names: cosuppression in plants, quelling in fungi and RNA interference in animals, but in all cases, degraded mRNA decreases gene expression.
What is transcriptional repression?
Transcriptional repression is an essential mechanism in the precise control of gene expression. While these initial studies focused on regulation of the lactose operon of Escherichia coli, it was soon realized that transcriptional repression is a general mechanism affecting gene expression in prokaryotes.
How is microRNA regulated?
The expression of miRNAs is regulated by multiple factors and molecular mechanisms, from those affecting the DNA copy number, methylation of CpGs, transcription factors, and miRNA biogenesis, to those modifying the miRNA binding site’s availability in the mRNA sequence.
