Regulatory role of acetylation on enzyme activity and fluxes of energy metabolism pathways

• Published in: Biochimica et biophysica acta. General subjects 2021-12, Vol.1865 (12), p.130021, Article 130021
• Main Authors: Moreno-Sánchez, Rafael, Gallardo-Pérez, Juan Carlos, Pacheco-Velazquez, Silvia Cecilia, Robledo-Cadena, Diana Xochiquetzal, Rodríguez-Enríquez, Sara, Encalada, Rusely, Saavedra, Emma, Marín-Hernández, Álvaro
• Format: Article
• Language: English
• Subjects: Acetyl Coenzyme A - metabolism; Acetyl-CoA; Acetylation; Animals; Cancer cells; Cytosol - metabolism; Energy Metabolism; Glycolysis; HeLa Cells; Humans; Lysine - metabolism; Mitochondria - metabolism; Mitochondria, Liver - metabolism; Niacinamide - metabolism; Niacinamide - pharmacology; Nicotinamide; Rats; Sirt3; Sirtuin 3 - metabolism; Valproic acid; Valproic Acid - pharmacology
• ISSN: 0304-4165; 1872-8006; 1872-8006
• DOI: 10.1016/j.bbagen.2021.130021

Most of the enzymes involved in the central carbon metabolism are acetylated in Lys residues. It has been claimed that this covalent modification represents a novel regulatory mechanism by which both enzyme/transporter activities and pathway fluxes can be modulated. To establish which enzymes are regulated by acetylation, a systematic experimental analysis of activities and acetylation profile for several energy metabolism enzymes and pathway fluxes was undertaken in cells and mitochondria. The majority of the glycolytic and neighbor enzymes as well as mitochondrial enzymes indeed showed Lys-acetylation, with GLUT1, HPI, CS, ATP synthase displaying comparatively lower acetylation patterns. The incubation of cytosolic and mitochondrial fractions with recombinant Sirt-3 produced lower acetylation signals, whereas incubation with acetyl-CoA promoted protein acetylation. Significant changes in acetylation levels of MDH and IDH-2 from rat liver mitochondria revealed no change in their activities. Similar observations were attained for the cytosolic enzymes from AS-30D and HeLa cells. A minor but significant (23%) increase in the AAT-MDH complex activity induced by acetylation was observed. To examine this question further, AS-30D and HeLa cells were treated with nicotinamide and valproic acid. These compounds promoted changes in the acetylation patterns of glycolytic proteins, although their activities and the glycolytic flux (as well as the OxPhos flux) revealed no clear correlation with acetylation. Acetylation seems to play no predominant role in the control of energy metabolism enzyme activities and pathway fluxes. The physiological function of protein acetylation on energy metabolism pathways remains to be elucidated. •Changes in acetylation do not promote variation of some metabolism enzyme activities.•Acetylation changes of some enzymes do not affect energy metabolism pathway fluxes.•Nicotinamide increased the protein content of several enzymes in HeLa cells.•Nicotinamide and valproic acid modified cell proliferation parameters.