Lipid metabolism is highly controlled by the nutritional state of the organism. In this study, we identify the mitochondrial sirtuin, SIRT4, as a critical regulator of lipid homeostasis. We find that SIRT4 represses fatty acid oxidation while promoting lipid anabolism. Mechanistically, SIRT4 regulates this balance by inhibiting malonyl-CoA decarboxylase (MCD), an enzyme that produces acetylCoA ...

An uncommon autosomal recessive organic acid disease is malonic aciduria. This may be easily identified and included in the NBS programmes by means of widespread use tandem mass spectrometry’s study amino acid/acylcarnitine profile using dried blood spots (DBS) for newborn screening. In Tamil Nadu, we reported first screened diagnosed with aciduria screening (NBS) early neonatal period. The pat...

The Streptomyces glaucescens beta-ketoacyl-acyl carrier protein (ACP) synthase III (KASIII) initiates straight- and branched-chain fatty acid biosynthesis by catalyzing the decarboxylative condensation of malonyl-ACP with different acyl-coenzyme A (CoA) primers. This KASIII has one cysteine residue, which is critical for forming an acyl-enzyme intermediate in the first step of the process. Thre...

that cardiac decompensation can be avoided in MCD-deficient patients. Finally, by analogy with fatty acid oxidation disorders such as medium-chain acyl-CoA dehydrogenase deficiency (13), one may conclude that knowledge of the diagnosis will improve outcome because early intervention is then possible in catabolic episodes that otherwise may lead to metabolic derange-ment. It therefore seems reas...

Oxaloacetate decarboxylase (EC 4.1 .1.3) from Klebsiella aerogenes [l] and methylmalonyl-CoA decarboxylase (EC 4.1 .1.41) from Micrococcus lactilyticus [2] have been shown to be avidin-sensitive and were therefore classified as biotin enzymes. It has further been assumed that these decarboxylases, like other biotin enzymes, perform a transfer reaction to synthesize the carboxy-biotin intermedia...

Pyruvate decarboxylase-negative (Pdc(-)) mutants of Saccharomyces cerevisiae require small amounts of ethanol or acetate to sustain aerobic, glucose-limited growth. This nutritional requirement has been proposed to originate from (i) a need for cytosolic acetyl coenzyme A (acetyl-CoA) for lipid and lysine biosynthesis and (ii) an inability to export mitochondrial acetyl-CoA to the cytosol. To t...

A C7 dicarboxylic (pimelic) acid derivative is postulated as an intermediate in anaerobic degradation of benzoate. Four strains of Gram-negative, nitrate-reducing bacteria capable of growth with both pimelate and benzoate as sole carbon and energy source were isolated. The metabolism of strain LP-1, which was enriched from activated sludge with pimelate as substrate, was studied in detail. This...

The brain plays an important role in the regulation of energy balance in higher animals. Global energy balance is monitored by sets of neurons in the hypothalamus that respond to peripheral hormonal and afferent neural signals that sense the energy status. Malonyl-CoA, an intermediate in the biosynthesis of fatty acids, appears to function in this hypothalamic energy-sensing system. The steady-...

Dicarboxylic acids with 2-5 carbon atoms can be degraded fermentatively by pure cultures of various strictly anaerobic bacteria. The small amount of free energy released in these decarboxylations (about 20-25 kJ mol-1) is conserved as sole source of growth energy either through sodium-pumping decarboxylases or through electrogenic substrate/product transport devices. In the glutarate-fermenting...