Epigenetic Modification - Micro RNA

Question 1

What is Micro RNA ?

Answer 1

Is small non-coding RNA molecule
Containing about 22 nucleotide
Found in plants , animals and some viruses.

Question 2

Function

Answer 2

In RNA slicing and post transcriptional regulation of gene expression.

Question 3

History

Answer 3

Discovered in 1990s

Question 4

How does it affect gene regulation ?

Answer 4

Bind to 3 utr of target mRNA and repress proteins production by destablizing mRNA and transnational silencing .

Process of gene expression involves two stages .

Riboswitches are short sequences of RNA that change their conformation on binding small molecules such as metabolises.

Question 5

mRNA stability in bacteria

Answer 5

Unstable having half lives of less than a couple of mintues

Exonuclease , degrades in 3-5 direction responsible for rapid destruction of these mRNA

mRNA both rapidly synthesises and rapidly degraded , a bacterium can adapt quickly to environmental changes

Yes stable in Eukaryotes

Question 6

Features which make micro RNA good regulators of gene expression ?

Answer 6

Can regulate a whole set of different mRNAs

Regulation by micro RNA can be combinational , base pairing between micro and mRNA

Meaning when a base pairing between micro RNA and RNA falls to initiate cleavage same mRNA levels to further reduction

Micro RNA acquires little space in the hence why it was discovered recently .