Post transcriptional processing refers to the set of modifications and events that occur to the RNA molecule after transcription, but before translation. These modifications are important for the stability, localization, and translation of the RNA molecule.
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Capping in post transcriptional processing
The addition of a modified guanine nucleotide to the 5′ end of the RNA molecule is called capping. The cap serves as a marker that signals to the cell that the RNA molecule is mature and ready for translation. It also protects the RNA molecule from degradation and helps to recruit the translation machinery.
Polyadenylation in post transcriptional processing
The addition of a string of adenine nucleotides to the 3′ end of the RNA molecule is called polyadenylation. The poly-A tail serves as a marker for the end of the RNA molecule and protects it from degradation. It also helps to recruit the translation machinery.
Splicing in post transcriptional processing
Splicing is the process of removing non-coding sequences called introns from the RNA molecule. Introns are transcribed along with the coding sequences called exons, but they do not contain any information that is needed to make a protein. Splicing occurs in the nucleus and is mediated by a complex of proteins and small RNA molecules called snRNPs (small nuclear ribonucleoproteins).
RNA editing
RNA editing is the process of changing the nucleotide sequence of the RNA molecule after transcription. This can occur through a variety of mechanisms, such as the insertion or deletion of nucleotides or the conversion of one nucleotide to another. RNA editing can change the coding sequence of the RNA molecule. This can result in different proteins being made from the same gene.
RNA localization
RNA localization is the process of directing the RNA molecule to a specific location within the cell. This can occur through the interaction of specific sequences on the RNA molecule with proteins that bind to them. RNA localization is important for the proper functioning of the cell. It can determine the fate of the protein that is made from the RNA molecule.
RNA stability
RNA stability refers to how long the RNA molecule lasts in the cell before it is degraded. The stability of an RNA molecule can be influenced by various factors such as the presence of a cap and poly-A tail, the presence of specific sequences, and the binding of specific proteins.
In summary, post-transcriptional processing is a series of modifications and events. It occurs to the RNA molecule after transcription, but before translation. These modifications are important for the stability, localization, and translation of the RNA molecule, and they can affect the final protein product made from the gene.