RNA decay machines: deadenylation by the Ccr4-not and Pan2-Pan3 complexes

Biochim Biophys Acta. Jun-Jul 2013;1829(6-7):561-70. doi: 10.1016/j.bbagrm.2013.01.003. Epub 2013 Jan 19.


Shortening and removal of the 3' poly(A) tail of mature mRNA by poly(A)-specific 3' exonucleases (deadenylases) is the initial and often rate-limiting step in mRNA degradation. The majority of cytoplasmic deadenylase activity is associated with the Ccr4-Not and Pan2-Pan3 complexes. Two distinct catalytic subunits, Caf1/Pop2 and Ccr4, are associated with the Ccr4-Not complex, whereas the Pan2 enzymatic subunit forms a stable complex with Pan3. In this review, we discuss the composition and activity of these two deadenylases. In addition, we comment on generic and specific mechanisms of recruitment of Ccr4-Not and Pan2-Pan3 to mRNAs. Finally, we discuss specialised and redundant functions of the deadenylases and review the importance of Ccr4-Not subunits in the regulation of physiological processes. This article is part of a Special Issue entitled: RNA Decay mechanisms.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Carrier Proteins / chemistry
  • Carrier Proteins / genetics
  • Carrier Proteins / metabolism
  • Cytoplasm / enzymology
  • Exoribonucleases / chemistry
  • Exoribonucleases / genetics*
  • Exoribonucleases / metabolism
  • Exosomes / chemistry
  • Exosomes / genetics*
  • Exosomes / metabolism
  • Humans
  • Poly A / genetics
  • Protein Conformation
  • RNA Stability / genetics*
  • RNA, Messenger / chemistry
  • RNA, Messenger / genetics*


  • Carrier Proteins
  • PAN3 protein, human
  • RNA, Messenger
  • Poly A
  • Exoribonucleases
  • cNOT6 protein, human
  • PAN2 protein, human
  • poly(A)-specific ribonuclease