New insights in protein phosphorylation: a signature for protein phosphatase 1 interacting proteins.

Protein phosphatase 1 is regulated by the interaction between a catalytic subunit (PP1c) and multiple interacting proteins that allow the specific dephosphorylation of diverse cellular targets. This communication proposes to use the simultaneous presence of distinct consensus PP1c docking motifs R/K-x(0,1)-V-x-F and F-x-x-R/K-x-R/K as a signature to identify proteins putatively interacting with the PP1c. To develop this concept, we propose a new website, http://pp1 signature.pasteur.fr, which allows the identification of putative PP1-interacting proteins containing the two distinct PP1c docking consensus motifs represented in the Swissprot library. To validate the new concept of signature, we were able to characterise, by co-immunoprecipitation, four new PP1c interacting proteins randomly selected from the database in our website.