PPM1K Antibody – Mouse Polyclonal

This gene encodes a member of the PPM family of Mn2+/Mg2+-dependent protein phosphatases. The encoded protein, essential for cell survival and development, is targeted to the mitochondria where it plays a key role in regulation of the mitochondrial permeability transition pore. [provided by RefSeq, Sep 2012]

Function: Regulates the mitochondrial permeability transition pore and is essential for cellular survival and development. Ref.1

Catalytic activity: A phosphoprotein + H2O = a protein + phosphate.

Cofactor: Binds 1 magnesium or manganese ion per subunit.

Subcellular location: Mitochondrion matrix Ref.1 Ref.3.

Involvement in disease: Maple syrup urine disease, mild variant (MSUDMV) [MIM:615135]: A mild form of maple syrup urine disease, a metabolic disorder due to an enzyme defect in the catabolic pathway of the branched-chain amino acids leucine, isoleucine, and valine. Accumulation of these 3 amino acids and their corresponding keto acids leads to encephalopathy and progressive neurodegeneration. Clinical features include mental and physical retardation, feeding problems, and a maple syrup odor to the urine. The keto acids of the branched-chain amino acids are present in the urine. If untreated, maple syrup urine disease can lead to seizures, coma, and death. The disease is often classified by its pattern of signs and symptoms. The most common and severe form of the disease is the classic type, which becomes apparent soon after birth. Variant forms of the disorder become apparent later in infancy or childhood and are typically milder, but they still involve developmental delay and other medical problems if not treated. MSUDMV is characterized by increased plasma levels of branched-chain amino acids (BCAA) apparent at birth. Treatment with a low-protein diet free of BCAA can result in normal psychomotor development and lack of metabolic episodes.Note: The gene represented in this entry is involved in disease pathogenesis. Ref.10

Sequence similarities: Belongs to the PP2C family.Contains 1 PP2C-like domain.

Caution: Ref.11 has crystallized PPM1K in the presence of magnesium ions. However, Ref.3 reported that no activity toward p-nitrophenylphosphate was seen in the absence of manganese ions and magnesium could not substitute for manganese.

Biophysicochemical propertiesKinetic parameters:Half maximal activity toward p-nitrophenylphosphate achieved with 3.7 mM of manganese ions.KM=10.7 mM for p-nitrophenylphosphate Ref.3Vmax=3.6 µmol/min/mg enzyme toward p-nitrophenylphosphate (at 30 degrees Celsius)Vmax=4 nmol/min/mg enzyme toward branched-chain alpha-ketoacid dehydrogenase complex (at 37 degrees Celsius)