Redox Regulation of Arabidopsis Mitochondrial Citrate Synthase

Purification and characterization of mitochondrial citrate synthase.

Mitochondrial citrate synthase was purified from leaves of Pisum sativum L. cv Progress 9. A three step purification was employed using ATP-Sepharose affinity chromatography which resulted in a 600-fold enrichment. Enzyme activity was assayed spectrophotometrically during greening of etiolated leaves under constant white light illumination. An increase (1.4 fold) in citrate synthase activity wa...

Biosynthesis of mitochondrial citrate synthase in Neurospora crassa.

The transfer of mitochondrial proteins coded for by nuclear DNA from their site of synthesis into the mitochondria is currently attracting much attention. Early proposals that this transfer occurs by a co-translational mechanism [ 1 ] have not been substantiated, rather evidence has been produced which supports a post-translational mechanism involving extramitochondrial precursors [2-61. The na...

Redox regulation of Arabidopsis 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase.

The cDNA for 3-deoxy-D-arabino-heptulosonate 7-phosphate synthase of Arabidopsis encodes a polypeptide with an amino-terminal signal sequence for plastid import. A cDNA fragment encoding the processed form of the enzyme was expressed in Escherichia coli. The resulting protein was purified to electrophoretic homogeneity. The enzyme requires Mn(2+) and reduced thioredoxin (TRX) for activity. Spin...

Human METTL12 is a mitochondrial methyltransferase that modifies citrate synthase

The protein methylome in mammalian mitochondria has been little studied until recently. Here, we describe that lysine-368 of human citrate synthase is methylated and that the modifying enzyme, localized in the mitochondrial matrix, is methyltransferase-like protein 12 (METTL12), a member of the family of 7β-strand methyltransferases. Lysine-368 is near the active site of citrate synthase, but r...

Molecular Medicine Redox Regulation of Mitochondrial ATP Synthase Implications for Cardiac Resynchronization Therapy