Kinetic and functional properties of human mitochondrial phosphoenolpyruvate carboxykinase

Escós, M. ; Latorre, P. (Universidad de Zaragoza) ; Hidalgo, J. ; Hurtado-Guerrero, R. (Universidad de Zaragoza) ; Carrodeguas, J.A. (Universidad de Zaragoza) ; López-Buesa, P. (Universidad de Zaragoza)

Resumen: The cytosolic form of phosphoenolpyruvate carboxykinase (PCK1) plays a regulatory role in gluconeogenesis and glyceroneogenesis. The role of the mitochondrial isoform (PCK2) remains unclear. We report the partial purification and kinetic and functional characterization of human PCK2. Kinetic properties of the enzyme are very similar to those of the cytosolic enzyme. PCK2 has an absolute requirement for Mn2+ ions for activity; Mg2+ ions reduce the Km for Mn2+ by about 60 fold. Its specificity constant is 100 fold larger for oxaloacetate than for phosphoenolpyruvate suggesting that oxaloacetate phosphorylation is the favored reaction in vivo. The enzyme possesses weak pyruvate kinase-like activity (kcat=2.7 s-1). When overexpressed in HEK293T cells it enhances strongly glucose and lipid production showing that it can play, as the cytosolic isoenzyme, an active role in glyceroneogenesis and gluconeogenesis.

Idioma: Inglés

DOI: 10.1016/j.bbrep.2016.06.007

Año: 2016

Publicado en: Biochemistry and Biophysics Reports 7 (2016), 124-129
ISSN: 2405-5808

Factor impacto SCIMAGO: 0.259 - Biochemistry (Q4) - Molecular Biology (Q4) - Cell Biology (Q4) - Biophysics (Q4)

Financiación: info:eu-repo/grantAgreement/ES/DGA/A51
Financiación: info:eu-repo/grantAgreement/ES/MEC/AGL2015–66177-R
Financiación: info:eu-repo/grantAgreement/ES/UZ/2015-BIO-01

Tipo y forma: Artículo (Versión definitiva)

Área (Departamento): Área Bioquímica y Biolog.Mole. (Dpto. Bioq.Biolog.Mol. Celular)
Área (Departamento): Área Tecnología de Alimentos (Dpto. Produc.Animal Cienc.Ali.)