Deadenylation of mRNA (R-HSA-429947) [Homo sapiens]


Deadenylation of mRNA proceeds in two steps. According to current models, in the first step the poly(A) tail is shortened from about 200 adenosine residues to about 80 residues by the PAN2-PAN3 complex. In the second step the poly(A) tail is further shortened to 10-15 residues by either the CCR4-NOT complex or by the PARN exoribonuclease. How a particular mRNA is targeted to CCR4-NOT or PARN is unknown.
A number of other deadenylase enzymes can be identified in genomic searches. One particularly interesting one is nocturin, a protein that is related to the CCR-1 deadenylase and plays a role in circadian rhythms.
There is also evidence for networking between deadenylation and other aspects of gene expression. CCR4-NOT, for example, is known to be a transcription factor. PARN is part of a complex that regulates poly(A) tail length and hence translation in developing oocytes.

Locations in the PathwayBrowser
Additional Information
Compartment cytosol
GO Biological Process nuclear-transcribed mRNA poly(A) tail shortening (0000289)
Literature References
pubMedId Title Journal Year
17245413 The highways and byways of mRNA decay Nat Rev Mol Cell Biol 2007
15475613 Messenger RNA decay in mammalian cells: the exonuclease perspective Cell Biochem Biophys 2004
19239894 The many pathways of RNA degradation Cell 2009
16141059 From birth to death: the complex lives of eukaryotic mRNAs Science 2005
14749774 The enzymes and control of eukaryotic mRNA turnover Nat Struct Mol Biol 2004
11283721 The cap-to-tail guide to mRNA turnover Nat Rev Mol Cell Biol 2001
18608124 NOC out the fat: a short review of the circadian deadenylase Nocturnin Ann Med 2008
17052452 Opposing polymerase-deadenylase activities regulate cytoplasmic polyadenylation Mol Cell 2006
Inferred Entries
Orthologous events