Poly A tail: Difference between revisions
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The addition of a poly(A) tail is a modification to pre-[[MRNA|MRNA]] at the 3' end. Most [[Eukaryotic|eukaryotic]] [[ | The addition of a poly(A) tail is a modification to pre-[[MRNA|MRNA]] at the 3' end. Most [[Eukaryotic|eukaryotic]] [[MRNA|mRNAs]] contain a poly(A) tail after [[Transcription|transcription]]. [[Polyadenylation|Polyadenylation]] is the process by which the tail is added. In this process a specific [[Endonucleases|endonuclease]] cleaves the [[RNA|RNA]] just downstream from a sequence 'AAUAAA', then following this cleavage a [[poly(A) polymerase|poly(A) polymerase]] adds around 100- 250 adenylate residues forming the poly(A) tail, using [[ATP|ATP]] as the energy source. Once mRNA has this poly(A) tail it is deemed 'polyadenylated'. The function of the poly(A) tail has still not been fully discovered, but evidence suggests it improves [[Translation|translation]] efficiency and refines [[MRNA|mRNA]] stability. The poly A tail enables the [[mRNA|mRNA]] to be able to leave the nucleus via a [[nuclear pore|nuclear pore]] and begin the process of [[translation|translation]]<ref>Nature Education. (2014). poly-A-tail. Available: http://www.nature.com/scitable/definition/poly-A-tail-276. Last accessed 20/10/15.</ref>. <br> | ||
=== References === | === References === | ||
<references /> | <references /> | ||
Latest revision as of 08:08, 28 November 2016
The addition of a poly(A) tail is a modification to pre-MRNA at the 3' end. Most eukaryotic mRNAs contain a poly(A) tail after transcription. Polyadenylation is the process by which the tail is added. In this process a specific endonuclease cleaves the RNA just downstream from a sequence 'AAUAAA', then following this cleavage a poly(A) polymerase adds around 100- 250 adenylate residues forming the poly(A) tail, using ATP as the energy source. Once mRNA has this poly(A) tail it is deemed 'polyadenylated'. The function of the poly(A) tail has still not been fully discovered, but evidence suggests it improves translation efficiency and refines mRNA stability. The poly A tail enables the mRNA to be able to leave the nucleus via a nuclear pore and begin the process of translation[1].
References
- ↑ Nature Education. (2014). poly-A-tail. Available: http://www.nature.com/scitable/definition/poly-A-tail-276. Last accessed 20/10/15.