ubiquinone/arabidopsis

4-Hydroxybenzoate polyprenyl diphosphate transferase (4HPT) is the key enzyme that transfers the prenyl side chain to the benzoquione frame in ubiquinone (UQ) biosynthesis. The Arabidopsis AtPPT1 cDNA encoding 4HPT was cloned by reverse transcription-polymerase chain reaction (RT-PCR) based on the

A mutant of Saccharomyces cerevisiae deleted for the COQ3 gene was constructed. COQ3 encodes a 3,4-dihydroxy-5-hexaprenylbenzoate (DHHB) methyltransferase that catalyses the fourth step in the biosynthesis of ubiquinone from p-hydroxybenzoic acid. A full length cDNA encoding a homologue of

Land plants possess the unique capacity to derive the benzenoid moiety of the vital respiratory cofactor, ubiquinone (coenzyme Q), from phenylpropanoid metabolism via β-oxidation of p-coumarate to form 4-hydroxybenzoate. Approximately half of the ubiquinone in plants comes from this pathway; the

It is not known how plants make the benzenoid ring of ubiquinone, a vital respiratory cofactor. Here, we demonstrate that Arabidopsis thaliana uses for that purpose two separate biosynthetic branches stemming from phenylalanine and tyrosine. Gene network modeling and characterization of T-DNA

Ubiquinone (coenzyme Q) is the generic name of a class of lipid-soluble electron carriers formed of a redox active benzoquinone ring attached to a prenyl side chain. The length of the latter varies among species, and depends upon the product specificity of a trans-long-chain prenyl diphosphate

In bacteria and mitochondria, ABC1 (for Activity of bc1 complex)-like kinases regulate ubiquinone synthesis, mutations causing severe respiration defects, including neurological disorders in humans. Little is known about plant ABC1-like kinases; in Arabidopsis (Arabidopsis thaliana), five are

The NADH-ubiquinone oxidoreductase complex (complex I) (EC 1.6.5.3) is the main entrance site of electrons into the respiratory chain. In a variety of eukaryotic organisms, except animals and fungi (Opisthokonta), it contains an extra domain comprising trimers of putative γ-carbonic anhydrases,

Nitric oxide (NO) acts as a key molecule in many physiological processes in plants. In this study, the roles of NO in mitochondrial respiration were investigated in the calli from wild-type Arabidopsis and NO associated 1 mutant (Atnoa1) which has a reduced endogenous NO level. Long-term exposure of

OBJECTIVE Earlier studies have confirmed that mesenchymal stem cells (MSCs) can transdifferentiate into myocytes and improve heart function in 2 weeks. But the mechanism is not clear. In this study, the mechanism of improvement of heart function after transplantation of MSCs was examined with

Two solanesyl diphosphate synthases, designated SPS1 and SPS2, which are responsible for the synthesis of the isoprenoid side chain of either plastoquinone or ubiquinone in Arabidopsis thaliana, were identified. Heterologous expression of either SPS1 or SPS2 allowed the generation of UQ-9 in a

trans -Long-chain prenyl diphosphate synthases catalyse the sequential condensation of isopentenyl diphosphate (C(5)) units with allylic diphosphate to produce the C(30)-C(50) prenyl diphosphates, which are precursors of the side chains of prenylquinones. Based on the relationship between product

Solanesyl diphosphate (SPP) is regarded as the precursor of the side-chains of both plastoquinone and ubiquinone in Arabidopsis thaliana. We previously analyzed A. thaliana SPP synthase (At-SPS1) (Hirooka et al., Biochem. J., 370, 679-686 (2003)). In this study, we cloned a second SPP synthase

An aerobic, Gram-stain-negative, rod-shaped, DDT-resistant bacterium, designated strain CC-ALB-2(T), was isolated from the Arabidopsis thaliana rhizosphere. Strain CC-ALB-2(T) was able to grow at 25-37 °C, at pH 5.0-8.0, with 1.0% (w/v) NaCl and tolerate up to 200 mg l(-1) DDT. 16S rRNA gene

The alternative oxidase (AOX) of plant mitochondria transfers electrons from the ubiquinone pool to oxygen without energy conservation. AOX can use reductant in excess of cytochrome pathway capacity, preventing reactive oxygen species (ROS) formation from an over-reduced ubiquinone pool, and thus

In order to ensure the cooperative function with the photosynthetic system, the mitochondrial respiratory chain needs to flexibly acclimate to a fluctuating light environment. The non-phosphorylating alternative oxidase (AOX) is a notable respiratory component that may support a cellular redox