scholarly journals Isolation and functional expression of human COQ2, a gene encoding a polyprenyl transferase involved in the synthesis of CoQ

2004 ◽  
Vol 382 (2) ◽  
pp. 519-526 ◽  
Author(s):  
Margareta FORSGREN ◽  
Anneli ATTERSAND ◽  
Staffan LAKE ◽  
Jacob GRÜNLER ◽  
Ewa SWIEZEWSKA ◽  
...  

The COQ2 gene in Saccharomyces cerevisiae encodes a Coq2 (p-hydroxybenzoate:polyprenyl transferase), which is required in the biosynthetic pathway of CoQ (ubiquinone). This enzyme catalyses the prenylation of p-hydroxybenzoate with an all-trans polyprenyl group. We have isolated cDNA which we believe encodes the human homologue of COQ2 from a human muscle and liver cDNA library. The clone contained an open reading frame of length 1263 bp, which encodes a polypeptide that has sequence homology with the Coq2 homologues in yeast, bacteria and mammals. The human COQ2 gene, when expressed in yeast Coq2 null mutant cells, rescued the growth of this yeast strain in the absence of a non-fermentable carbon source and restored CoQ biosynthesis. However, the rate of CoQ biosynthesis in the rescued cells was lower when compared with that in cells rescued with the yeast COQ2 gene. CoQ formed when cells were incubated with labelled decaprenyl pyrophosphate and nonaprenyl pyrophosphate, showing that the human enzyme is active and that it participates in the biosynthesis of CoQ.

2015 ◽  
Vol 25 (1) ◽  
pp. 45-50 ◽  
Author(s):  
Dai-Joong Kim ◽  
Gui-Hye Hwang ◽  
Ji-Na Um ◽  
Jae-Yong Cho

Overexpression of the NCgl0462 open reading frame, encoding a class II aminotransferase, was studied in conjunction with other enzymes in <smlcap>L</smlcap>-ornithine biosynthesis in an <smlcap>L</smlcap>-ornithine-producing strain. Expression of the wild-type NCgl0462 open reading frame, which displayed aminotransferase activity, was amplified by placing it under the control of the glyceraldehyde 3-phosphate dehydrogenase gene promoter in the pEK0 plasmid and in the genome. <smlcap>L</smlcap>-Ornithine production in <i>Corynebacterium</i><i>glutamicum</i> SJC8260 harboring plasmid and the genomic NCgl0462 open reading frame was increased by 8.8 and 21.6%, respectively. In addition, the combined overexpression of the NCgl0462 open reading frame within the genome along with the mutated <smlcap>L</smlcap>-ornithine biosynthesis genes <i>(argCJBD)</i> placed in the pEK0 plasmid in <i>C</i>. <i>glutamicum</i> SJC8260 resulted in significant improvement in <smlcap>L</smlcap>-ornithine production (12.48 g/l for combined overexpression compared with 8.42 g/l for the control). These results suggest that overexpression of the aminotransferase-encoding NCgl0462 open reading frame plays an unequivocal role in the <smlcap>L</smlcap>-ornithine biosynthetic pathway, with overlapping substrate specificity in <i>C</i>. <i>glutamicum</i>.


Genetics ◽  
1998 ◽  
Vol 149 (4) ◽  
pp. 1707-1715 ◽  
Author(s):  
J L Patton-Vogt ◽  
S A Henry

Abstract Phosphatidylinositol catabolism in Saccharomyces cerevisiae cells cultured in media containing inositol results in the release of glycerophosphoinositol (GroPIns) into the medium. As the extracellular concentration of inositol decreases with growth, the released GroPIns is transported back into the cell. Exploiting the ability of the inositol auxotroph, ino1, to use exogenous GroPIns as an inositol source, we have isolated mutants (Git−) defective in the uptake and metabolism of GroPIns. One mutant was found to be affected in the gene encoding the transcription factor, SPT7. Mutants of the positive regulatory gene INO2, but not of its partner, INO4, also have the Git− phenotype. Another mutant was complemented by a single open reading frame (ORF) termed GIT1 (glycerophosphoinositol). This ORF consists of 1556 bp predicted to encode a polypeptide of 518 amino acids and 57.3 kD. The predicted Git1p has similarity to a variety of S. cerevisiae transporters, including a phosphate transporter (Pho84p), and both inositol transporters (Itr1p and Itr2p). Furthermore, Git1p contains a sugar transport motif and 12 potential membrane-spanning domains. Transport assays performed on a git1 mutant together with the above evidence indicate that the GIT1 gene encodes a permease involved in the uptake of GroPIns.


2021 ◽  
Vol 85 (1) ◽  
pp. 42-52
Author(s):  
Taro Shiraishi ◽  
Tomohisa Kuzuyama

Abstract Phosphonates are organophosphorus compounds possessing a characteristic C−P bond in which phosphorus is directly bonded to carbon. As phosphonates mimic the phosphates and carboxylates of biological molecules to potentially inhibit metabolic enzymes, they could be lead compounds for the development of a variety of drugs. Fosfomycin (FM) is a representative phosphonate natural product that is widely used as an antibacterial drug. Here, we review the biosynthesis of FM, which includes a recent breakthrough to find a missing link in the biosynthetic pathway that had been a mystery for a quarter-century. In addition, we describe the genome mining of phosphonate natural products using the biosynthetic gene encoding an enzyme that catalyzes C–P bond formation. We also introduce the chemoenzymatic synthesis of phosphonate derivatives. These studies expand the repertoires of phosphonates and the related biosynthetic machinery. This review mainly covers the years 2012-2020.


2001 ◽  
Vol 12 (11) ◽  
pp. 3631-3643 ◽  
Author(s):  
Cintia R. C. Rocha ◽  
Klaus Schröppel ◽  
Doreen Harcus ◽  
Anne Marcil ◽  
Daniel Dignard ◽  
...  

The human fungal pathogen Candida albicans switches from a budding yeast form to a polarized hyphal form in response to various external signals. This morphogenetic switching has been implicated in the development of pathogenicity. We have cloned theCaCDC35 gene encoding C. albicansadenylyl cyclase by functional complementation of the conditional growth defect of Saccharomyces cerevisiae cells with mutations in Ras1p and Ras2p. It has previously been shown that these Ras homologues regulate adenylyl cyclase in yeast. The C. albicans adenylyl cyclase is highly homologous to other fungal adenylyl cyclases but has less sequence similarity with the mammalian enzymes. C. albicans cells deleted for both alleles ofCaCDC35 had no detectable cAMP levels, suggesting that this gene encodes the only adenylyl cyclase in C. albicans. The homozygous mutant cells were viable but grew more slowly than wild-type cells and were unable to switch from the yeast to the hyphal form under all environmental conditions that we analyzed in vitro. Moreover, this morphogenetic switch was completely blocked in mutant cells undergoing phagocytosis by macrophages. However, morphogenetic switching was restored by exogenous cAMP. On the basis of epistasis experiments, we propose that CaCdc35p acts downstream of the Ras homologue CaRas1p. These epistasis experiments also suggest that the putative transcription factor Efg1p and components of the hyphal-inducing MAP kinase pathway depend on the function of CaCdc35p in their ability to induce morphogenetic switching. Homozygouscacdc35Δ cells were unable to establish vaginal infection in a mucosal membrane mouse model and were avirulent in a mouse model for systemic infections. These findings suggest that fungal adenylyl cyclases and other regulators of the cAMP signaling pathway may be useful targets for antifungal drugs.


2014 ◽  
Vol 1010-1012 ◽  
pp. 1181-1184
Author(s):  
Yan Zhao Zhang ◽  
Yan Wei Cheng ◽  
Hui Yuan Ya ◽  
Chao Yun ◽  
Jian Ming Han ◽  
...  

Anthocyanin mainly responsible for flowers color in many plant species, it also accumulated in response to lots of environmental stress to reduce the damage to plant cell. Anthocyanin synthesis (ANS) protein is an important synthetase participated in anthocyanin biosynthetic pathway. In this study, we isolated the PsANS gene from transcriptome database built by our previous study. The PsANS gene contain an 1050bp open reading frame encoding 349 amino acid, phylogenetic analysis revealed that PsANS was segrated into a group with ANS from others plant species. Secondary and thri-dimension structure prediction also revealed that it may have similar function with ANS in others plant species. The identified PsANS gene would be helpful for further research in flower color modification and resistance breeding.


2017 ◽  
Vol 30 (11) ◽  
pp. 876-885 ◽  
Author(s):  
Jamuna Risal Paudel ◽  
Charlotte Davidson ◽  
Jun Song ◽  
Itkin Maxim ◽  
Asaph Aharoni ◽  
...  

Steroidal glycoalkaloids (SGAs) are major secondary metabolites constitutively produced in cultivated potato Solanum tuberosum, and α-solanine and α-chaconine are the most abundant SGAs. SGAs are toxic to humans at high levels but their role in plant protection against pests and pathogens is yet to be established. In this study, levels of SGAs in potato were reduced by RNA interference (RNAi)-mediated silencing of GLYCOALKALOID METABOLISM 4 (GAME4)—a gene encoding cytochrome P450, involved in an oxidation step in the conversion of cholesterol to SGA aglycones. Two GAME4 RNAi lines, T8 and T9, were used to investigate the effects of manipulation of the SGA biosynthetic pathway in potato. Growth and development of an insect pest, Colorado potato beetle (CPB), were affected in these lines. While no effect on CPB leaf consumption or weight gain was observed, early instar larval death and accelerated development of the insect was found while feeding on leaves of GAME4 RNAi lines. Modulation of SGA biosynthetic pathway in GAME4 RNAi plants was associated with a larger alteration to the metabolite profile, including increased levels of one or both the steroidal saponins or phytoecdysteroids, which could affect insect mortality as well as development time. Colonization by Verticillium dahliae on GAME4 RNAi plants was also tested. There were increased pathogen levels in the T8 GAME4 RNAi line but not in the T9. Metabolite differences between T8 and T9 were found and may have contributed to differences in V. dahliae infection. Drought responses created by osmotic stress were not affected by modulation of SGA biosynthetic pathway in potato.


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