Phosphatase Subfamily PPP5C
Phosphatase Classification: Fold MTDP: Superfamily MTDP: Family PPP: Subfamily PPP5C
Evolution
The PPP5C subfamily is found throughout eukaryotes, including opisthokonta, amoebazoa, plants and etc. PPP5Cs have tandem tetratricopeptide repeat (TPR) structural motifs at N-terminal, which distinguish them from other PPP subfamilies, and were used to find and classify PPP5C in yeast and dicty in phosphatome.net.
Domain
The PPP5C subfamily has tandem tetratricopeptide repeat (TPR), a structural motif, at N-terminal and phosphatase domain at C-terminal.
Functions
PP5 is widely expressed but at a lower level than most other serine/threonine protein phosphatases in mammals, and it is highly conserved among other eukaryotes [2], [3]. Unlike most other phosphatases having isoforms encoded by different genes, the regulatory and catalytic domains of PP5 are combined within the same chain. PP5 contains three tetratricopeptide repeat (TPR) motifs at its N-terminus which serve as protein-protein interaction motifs. Removal of the TPR domains by limited proteolysis leads to a substantially elevated phosphatase activity [4], and recent structural analyses indicate that the access to the active site of the phosphatase is blocked by TPR domains [5]. Moreover, TPR domains are also involved in the stimulation of PP5 activity via interaction with polyunsaturated fatty acids [4], [6]. Mammalian PP5 has been found to play an important role in hormone and stress induced signaling, DNA repair, intracellular proliferation, differentiation, migration, survival and death [7]–[9]. However, knowledge about PP5 in insects is poorly known.
