Phosphatase Subfamily PPM1K
PPM1K is a mitochondrial phosphatase that regulates the membrane permeability transition pore and is part of the BCKDA complex.
The PPM1K subfamily has an N-terminal mitochondria target signal (MTS) and phosphatase domain [1, 2]. The MTS (predicted by MitoProt) and phosphatase domain are conserved throughout the PPM1K subfamily.
PPM1K is localized to mitochondrial matrix . It regulates mitochondrial membrane permeability transition pore (MPTP) opening, but the underlying molecular mechanism(s) is unclear . It also functions as pSer phosphatase of the branched-chain a-keto acid dehydrogenase (BCKD) complex . Its loss in Ecdysozoa parallels the loss of the opposing BCKDK kinase. Human PPM1K is widely expressed in different tissues, most abundant in heart [1, 2] and GTEx database.
- Joshi M, Jeoung NH, Popov KM, and Harris RA. Identification of a novel PP2C-type mitochondrial phosphatase. Biochem Biophys Res Commun. 2007 Apr 27;356(1):38-44. DOI:10.1016/j.bbrc.2007.02.108 |
- Lu G, Ren S, Korge P, Choi J, Dong Y, Weiss J, Koehler C, Chen JN, and Wang Y. A novel mitochondrial matrix serine/threonine protein phosphatase regulates the mitochondria permeability transition pore and is essential for cellular survival and development. Genes Dev. 2007 Apr 1;21(7):784-96. DOI:10.1101/gad.1499107 |