Antibodies Against Serine/Threonine Phosphatases

Protein phosphorylation and dephosphorylation is central to signal transduction mechanisms in the cell.
There are three classes of phosphatases responsible for the removal of phosphates from proteins: serine/threonine specific protein phosphatases, tyrosine-specific protein phosphatases, and dual specificity (serine/threonine or tyrosine) protein phosphatases. The serine/threonine protein phosphatases are encoded by two gene families termed PPM and PPP. The PPM family includes the PP2C enzyme which acts as a monomer and is magnesium dependent. The mammalian PPP family includes the PP1, PP2A, PP2B, PP4, PP5, and PP6 enzymes (1). Phylogenetic and structural analyses of the PPP family suggest that the PPP phosphatases PP1, PP2A, and PP2B represent a subfamily separate from PP5 (2). The PPP enzymes function as multisubunit holoenzymes comprised of a catalytic subunit that associates, in a mutually exclusive manner, with a variety of regulatory (R) subunits. The R subunits dictate enzyme function and specificity. The interaction between the catalytic and R subunits allows the PPP enzymes to participate in a variety of cellular processes. Therefore, studies of the R subunits are central to the analysis of PPP function.

Selected Reviews

1. P. T. Cohen, "Novel Protein Serine/Threonine Phosphatases: Variety Is the Spice of Life," Trends Biochem.Sci. 22, no. 7 (1997): 245-251.

2. A. V. Andreeva and M. A. Kutuzov, "PPP Family of Protein Ser/Thr Phosphatases: Two Distinct Branches?," Mol Biol Evol. 18, no. 3 (2001): 448-452.