Usc bridge nurs 500 3.6 roles of RNA
mRNA is the intermidate between DNA and making proteins.
miRNA- Control genetic expression by shutting down genes or altering their expression. Inhibits the process of translation. Small RNAs that can use RNA interference machinery to interfere with and suppress mRNAs made by certain exons, thus effectively silencing them.
Riboswitches- folded RNA that switches off protein synthesis, can change shape. Folded RNAs that code like, mRNA, for a partilar protein. Differ from mRNAs as they can switch on or off in response to specific metabolic changes in the envirnment by changing shape, such as the concentration of vitamins, amino acids, nucleotides or other small molecules in the cell.
siRNAs- made by cells in response to an infection with an RNA virus. Defense mechanisim. Interfere with viral replication.
RNAi- RNA inhibition at the level of transcription to translation. May be useful to prevent expression of abnormal proteins. The process in which miRNA/siRNA work to silence transmission. Targets a specific mRNA for degradation- done by complementary base pairing.
mRNA that folds back on itself forming a stem loop is encoded by our genome, recognized by a protein called Drosha, cuts the protein down at the ends, leaving just the stem which is exported from the nucleus to the cytoplasm. The protein dicer cuts off the loop leaving a short piece of double stranded RNA-complementary to itself. One of the RNA strands ends up being removed, leaving a short piece of RNA. This base pairs to mRNA.
leaves a di strand to match with mRNA.
miRNAs regulate embryonic development
if genes are turned off in some tissues and on in others you can target certain gene expression and certain cell types
If a virus has a RNA genome, the virus ends up forming double stranded RNA.
abx can interfere with DNA transcription.