Yeast ubiquinone or coenzyme Q(6) (Q(6)) is a redox active lipid that plays a crucial role in the mitochondrial electron transport chain. At least nine proteins (Coq1p-9p) participate in Q(6) biosynthesis from 4-hydroxybenzoate (4-HB). We now show that the mitochondrial ferredoxin Yah1p and the ferredoxin reductase Arh1p are required for Q(6) biosynthesis, probably for the first hydroxylation of the pathway. Conditional Gal-YAH1 and Gal-ARH1 mutants accumulate 3-hexaprenyl-4-hydroxyphenol and 3-hexaprenyl-4-aminophenol. Para-aminobenzoic acid (pABA) is shown to be the precursor of 3-hexaprenyl-4-aminophenol and to compete with 4-HB for the prenylation reaction catalyzed by Coq2p. Yeast cells convert U-((13)C)-pABA into (13)C ring-labeled Q(6), a result that identifies pABA as a new precursor of Q(6) and implies an additional NH(2)-to-OH conversion in Q(6) biosynthesis. Our study identifies pABA, Yah1p, and Arh1p as three actors in Q(6) biosynthesis.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/j.chembiol.2010.03.014 | DOI Listing |
Plant Cell Environ
December 2024
Guangdong Provincial Key Laboratory for the Development Biology and Environmental Adaptation of Agricultural Organisms, College of Life Sciences, South China Agricultural University, Guangzhou, China.
Photorespiration is a complex metabolic process linked to primary plant metabolism and influenced by environmental factors, yet its regulation remains poorly understood. In this study, we identified the asprs3-1 mutant, which displays a photorespiratory phenotype with leaf chlorosis, stunted growth, and diminished photosynthesis under ambient CO, but normal growth under elevated CO conditions. Map-based cloning and genetic complementation identified AspRS3 as the mutant gene, encoding an aspartyl-tRNA synthetase.
View Article and Find Full Text PDFNat Commun
December 2024
Redox and Metalloprotein Research Group, Max Planck Institute of Biophysics, Max-von-Laue-Str. 3, 60438, Frankfurt am Main, Germany.
Iron-sulfur (FeS) protein biogenesis in eukaryotes begins with the de novo assembly of [2Fe-2S] clusters by the mitochondrial core iron-sulfur cluster assembly (ISC) complex. This complex comprises the scaffold protein ISCU2, the cysteine desulfurase subcomplex NFS1-ISD11-ACP1, the allosteric activator frataxin (FXN) and the electron donor ferredoxin-2 (FDX2). The structural interaction of FDX2 with the complex remains unclear.
View Article and Find Full Text PDFJ Clin Endocrinol Metab
November 2024
Pediatric Endocrinology, Diabetology and Metabolism, Department of Pediatrics, Inselspital, Bern University Hospital, University of Bern, Bern 3010, Switzerland.
J Biol Chem
December 2024
Broad Institute of MIT and Harvard, Cambridge, Massachusets, USA; Department of Pathology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, Massachusetts, USA. Electronic address:
Protein lipoylation, a vital lysine post-translational modification, plays a crucial role in the function of key mitochondrial tricarboxylic acid cycle enzymatic complexes. In eukaryotes, lipoyl post-translational modification synthesis occurs exclusively through de novo pathways, relying on lipoyl synthesis/transfer enzymes, dependent upon mitochondrial fatty acid and Fe-S cluster biosynthesis. Dysregulation in any of these pathways leads to diminished cellular lipoylation.
View Article and Find Full Text PDFAppl Spectrosc
November 2024
CAS Key Laboratory of Ion-Beam Bioengineering, Institute of Intelligent Machines, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China.
Ferroptosis, a regulated form of cell death driven by oxidative stress and lipid peroxidation, has emerged as a pivotal research focus with implications across various cellular contexts. In this study, we employed a multifaceted approach, integrating label-free Raman spectroscopy and microfluidics to study the mechanisms underpinning ferroptosis. Our investigations included the ferroptosis initiation based on the changes in the lipid Raman band at 1436 cm under different cellular states, the generation of reactive oxygen species (ROS), lipid peroxidation, DNA damage/repair, and mitochondrial dysfunction.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!