Question

What happens during splicing?

Answer 1

RNA splicing:

1. RNA splicing is the process by which newly synthesized pre-mRNA, also called as hnRNA, (heterogeneous nuclear RNA) is processed and forms mature mRNA.
2. hnRNA is then processed in the nucleus and converted to mRNA, which then comes to the cytoplasm and undergoes translation or protein synthesis.
3. In the RNA splicing process, the non-coding intervening regions known as ‘introns’ are removed and the coding regions called as ‘exons’ are joined together.
4. It is referred as a post-transcriptional modification.
5. The spliceosome then catalyzes the RNA splicing process.
6. Ribozymes (catalytic RNA) catalyze their own splicing.
7. Additionally, 5’ capping occus with the modified Guanine nucleotide and tailing is done with Poly-A (Adenylate) residues at 3’ end to protect the coding segments and to provide stability to the mature mRNA.
8. In prokaryotes like bacteria, the newly transcribed RNA is ready for translation & both processes can even occur simultaneously in the mRNA.
9. Most of the eukaryotic genes are transcribed in the form of pre-mRNA and then have to be processed before undergoing protein synthesis.