ERK1/2 is dephosphorylated by a novel phosphatase--CacyBP/SIP.
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.
Pubmed ID: 21110948
- Kilanczyk E
- Filipek S
- Filipek A
Biochemical and biophysical research communications
January 7, 2011
- Amino Acid Sequence
- Calcium-Binding Proteins
- Cell Line, Tumor
- Mitogen-Activated Protein Kinase 1
- Mitogen-Activated Protein Kinase 3
- Molecular Sequence Data
- Phosphoric Monoester Hydrolases
- Protein Structure, Tertiary