ERK1/2 is dephosphorylated by a novel phosphatase--CacyBP/SIP

Biochem Biophys Res Commun. 2011 Jan 7;404(1):179-83. doi: 10.1016/j.bbrc.2010.11.088. Epub 2010 Nov 24.

Abstract

Recently, we have reported that the CacyBP/SIP protein binds ERK1/2 (Kilanczyk et al., BBRC, 2009). In this work we show that CacyBP/SIP exhibits a phosphatase activity toward ERK1/2 kinases while its E217K mutant does not. The K(m) and V(max) values established for a standard phosphatase substrate, p-NPP, are 16.9±3.6 mM and 4.3±0.4 μmol/min, respectively. The CacyBP/SIP phosphatase activity is decreased by okadaic acid (IC(50)=45 nM). Our experimental results are supported by a theoretical analysis which revealed important sequence similarities between CacyBP/SIP and the phosphatase-like proteins as well as certain MAP kinase phosphatases.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Calcium-Binding Proteins / genetics
  • Calcium-Binding Proteins / metabolism*
  • Cell Line, Tumor
  • Mice
  • Mitogen-Activated Protein Kinase 1 / metabolism*
  • Mitogen-Activated Protein Kinase 3 / metabolism*
  • Molecular Sequence Data
  • Phosphoric Monoester Hydrolases / genetics
  • Phosphoric Monoester Hydrolases / metabolism*
  • Phosphorylation
  • Protein Structure, Tertiary

Substances

  • Cacybp protein, mouse
  • Calcium-Binding Proteins
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3
  • Phosphoric Monoester Hydrolases