Name – Anjali Krishnan, Department of Botany
Topic -
polyadenylation
Most eukaryotic mRNA undergoes a quite complicated series
of modification and processing events before translation
occurs
...
Polyadenylation is the addition of a poly(A) tail to
a messenger RNA.
The poly(A) tail consists of multiple adenosine
mono...
The poly(A) tail is important for the nuclear export,
translation, and stability of mRNA. The tail is shortened
over time,...
mRNA molecules in both prokaryotes and eukaryotes
have polyade9nylated 3'-ends, with the prokaryotic
poly(A) tails general...
3'-Polyadenylylation
 Termination of transcription occurs only after RNA
polymerase has transcribed past a consensus AAUA...
iGenetics - Peter j. Russell
Second edition
Genetics – P.S. Verma
V.K.Agarwal
.
Polyadenylation
Polyadenylation
Polyadenylation
Polyadenylation
Polyadenylation
of 13

Polyadenylation

Genetics
Published on: Mar 4, 2016
Published in: Science      
Source: www.slideshare.net


Transcripts - Polyadenylation

  • 1. Name – Anjali Krishnan, Department of Botany Topic - polyadenylation
  • 2. Most eukaryotic mRNA undergoes a quite complicated series of modification and processing events before translation occurs This include:- Chemical modification. Polyadenylation. Removal of introns .
  • 3. Polyadenylation is the addition of a poly(A) tail to a messenger RNA. The poly(A) tail consists of multiple adenosine monophosphates; in other words, it is a stretch of RNA that has only adenine bases. In eukaryotes, polyadenylation is part of the process that produces mature messenger RNA (mRNA) for translation. It, therefore, forms part of the larger process of gene expression.
  • 4. The poly(A) tail is important for the nuclear export, translation, and stability of mRNA. The tail is shortened over time, and, when it is short enough, the mRNA is enzymatically degraded. However, in a few cell types, mRNAs with short poly(A) tails are stored for later activation by re-polyadenylation in the cytosol .In contrast, when polyadenylation occurs in bacteria, it promotes RNA degradation. This is also sometimes the case for eukaryotic non-coding RNAs.
  • 5. mRNA molecules in both prokaryotes and eukaryotes have polyade9nylated 3'-ends, with the prokaryotic poly(A) tails generally shorter and less mRNA molecules polyadenylated.
  • 6. 3'-Polyadenylylation  Termination of transcription occurs only after RNA polymerase has transcribed past a consensus AAUAAA sequence - the poly(A)+ addition site  10-30 nucleotides past this site, a string of 100 to 200 adenine residues are added to the mRNA transcript - the poly(A)+ tail  poly(A) polymerase adds these A residues  Function not known for sure, but poly(A) tail may govern stability of the mRNA
  • 7. iGenetics - Peter j. Russell Second edition Genetics – P.S. Verma V.K.Agarwal
  • 8. .

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