An investigation of the substrate specificity of protein phosphatase 2C using synthetic peptide substrates; comparison with protein phosphatase 2A

Arianna Donella Deana, Clare H. Mac Gowan, Philip Cohen, Fernando Marchiori, Helmut E. Meyer, Lorenzo A. Pinna

    Research output: Contribution to journalArticle

    70 Citations (Scopus)


    The synthetic phosphopeptide RRATpVA was found to be the most effective substrate for protein phosphatase 2C (PP2C) so far identified. Replacement of phosphothreonine by phosphoserine decreased activity over 20-fold and a striking preference for phosphothreonine was also observed with two other substrates (RRSpTpVA and casein) that were phosphorylated on both serine and threonine. Replacement of the C-terminal valine in RRATpVA by proline abolished dephosphorylation, while exchanging the N-terminal alanine by proline had no effect. The preference for phosphothreonine and the effect of proline are similar to protein phosphatase 2A (PP2A). However, the peptide RRREEETpEEEAA, an excellent substrate for PP2A, was not dephosphorylated by PP2C, and substitution of the C-terminal valine in RRATpVA by glutamic acid reduced the rate of dephosphorylation by PP2C over 10-fold, without affecting dephosphorylation by PP2A. Addition of two extra N-terminal arginine residues to RRASpVA increased PP2A catalysed dephosphorylation 4- to 5-fold, without altering dephosphorylation by PP2C. These results represent the first study of the specificity of PP2C using synthetic peptides, and strengthen the view that this approach may lead to the development of more effective and specific substrates for the serine / threonine-specific protein phosphatases.

    Original languageEnglish
    Pages (from-to)199-202
    Number of pages4
    JournalBBA - Molecular Cell Research
    Issue number2
    Publication statusPublished - 19 Feb 1990



    • Cell regulation
    • Enzymology
    • Protein phosphatase
    • Protein phosphorylation
    • Substrate specificity
    • Synthetic peptides

    Cite this