serine/threonine protein phosphatase 4 (PP4)

Function

• protein phosphatase with role in:
  • microtubule organization at centrosomes
  • maturation of spliceosomal snRNPs
  • apoptosis
  • TNF-alpha signaling
  • activation of c-Jun N-terminal kinase MAPK8
  • regulation of histone acetylation
  • DNA damage checkpoint signaling
  • NF-kappa-B activation
  • cell migration
• the PPP4C-PPP4R1 PP4 complex may play a role in dephosphorylation & regulation of HDAC3
• the PPP4C-PPP4R2-PPP4R3A PP4 complex specifically dephosphorylates H2AFX phosphorylated on Ser-140 (gamma-H2AFX) generated during DNA replication & required for DNA double-strand break repair
• dephosphorylates NDEL1 at CDC2/Cdk1 phosphorylation sites & negatively regulates CDC2/Cdk1 activity in interphase (putative)

Structure

• different assemblies of the catalytic & one or more regulatory subunits
• PP4 complexes PPP4C-PPP4R1, PPP4C-PPP4R2, PPP4C-PPP4R2-PPP4R3A, PPP4C-PPP4R2-PPP4R3B & PPP4C-PPP4R4
• the PPP4C-PPP4R2 complex appears to be a tetramer composed of 2 molecules of catalytic subunit PPP4C & 2 molecules of the core regulatory subunit PPP4R2

More general terms

• serine/threonine phosphatase
• molecular complex

Additional terms

• serine/threonine protein phosphatase 4 regulatory subunit 1-like (PRO1085, PPP4R1L, C20orf192)