PP2A holoenzyme assembly: in cauda venenum (the sting is in the tail)

Trends Biochem Sci. 2008 Mar;33(3):113-21. doi: 10.1016/j.tibs.2007.12.004.


Protein phosphatase 2A (PP2A), a major phospho-serine/threonine phosphatase, is conserved throughout eukaryotes. It dephosphorylates a plethora of cellular proteins, including kinases and other signaling molecules involved in cell division, gene regulation, protein synthesis and cytoskeleton organization. PP2A enzymes typically exist as heterotrimers comprising catalytic C-, structural A- and regulatory B-type subunits. The B-type subunits function as targeting and substrate-specificity factors; hence, holoenzyme assembly with the appropriate B-type subunit is crucial for PP2A specificity and regulation. Recently, several biochemical and structural determinants have been described that affect PP2A holoenzyme assembly. Moreover, the effects of specific post-translational modifications of the C-terminal tail of the catalytic subunit indicate that a 'code' might regulate dynamic exchange of regulatory B-type subunits, thus affecting the specificity of PP2A.

Publication types

  • Research Support, Non-U.S. Gov't
  • Review

MeSH terms

  • Animals
  • Catalysis
  • Holoenzymes / chemistry
  • Holoenzymes / metabolism
  • Humans
  • Models, Biological
  • Protein Conformation
  • Protein Phosphatase 2 / chemistry*
  • Protein Phosphatase 2 / metabolism*
  • Protein Structure, Secondary
  • Protein Subunits / chemistry
  • Protein Subunits / metabolism
  • Substrate Specificity


  • Holoenzymes
  • Protein Subunits
  • Protein Phosphatase 2