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1.
Two independent biochemical pathways for isopentenyl diphosphate and isoprenoid biosynthesis in higher plants 总被引:15,自引:0,他引:15
In the early times of isoprenoid research, a single pathway was found for the formation of the C5 monomer, isopentenyl diphosphate (IPP), and this acetate/mevalonate pathway was supposed to occur ubiquitously in all living organisms. Now, 40 years later, a totally different IPP biosynthesis route has been detected in eubacteria, green algae and higher plants. In this new pathway glyceraldehyde 3-phosphate (GAP) and pyruvate are precursors of isopentenyl diphosphate, but not acetyl-CoA and mevalonic acid. In green tissues of three higher plants it was shown that all chloroplastbound isoprenoids (β-carotene, phytyl chains of chlorophylls and nona-prenyl chain of plastoquinone-9) are formed via the GAP/pyruvate pathway, whereas the cytoplasmic sterols are formed via the acetate/mevalonate pathway. Also, isoprene, emitted by various plants at high light conditions by action of the plastid-bound isoprene synthase, is formed via the new GAP/pyruvate pathway. Thus, in higher plants, there exist two separate and biochemically different IPP biosynthesis pathways: (1) the novel alternative GAP/pyruvate pathway apparently bound to the plastidic compartment and (2) the classical cytoplasmic acetate/mevalonate pathway. This new GAP/pyruvate pathway for IPP formation allows a reasonable interpretation of previous odd results concerning the biosynthesis of chloroplast isoprenoids, which, so far, had mainly been interpreted assuming compartmentation differences. The novel GAP/pyruvate pathway for IPP formation in plastids appears as a heritage of their prokaryotic, endosymbiotic ancestors. 相似文献
2.
Dedicated Roles of Plastid Transketolases during the Early Onset
of Isoprenoid Biogenesis in Pepper Fruits 总被引:15,自引:1,他引:14 下载免费PDF全文
Florence Bouvier Alain d''Harlingue Claude Suire Ralph A. Backhaus Bilal Camara 《Plant physiology》1998,117(4):1423-1431
Isopentenyl diphosphate (IPP), which is produced from mevalonic acid or other nonmevalonic substrates, is the universal precursor of isoprenoids in nature. Despite the presence of several isoprenoid compounds in plastids, enzymes of the mevalonate pathway leading to IPP formation have never been isolated or identified to our knowledge. We now describe the characterization of two pepper (Capsicum annuum L.) cDNAs, CapTKT1 and CapTKT2, that encode transketolases having distinct and dedicated specificities. CapTKT1 is primarily involved in plastidial pentose phosphate and glycolytic cycle integration, whereas CapTKT2 initiates the synthesis of isoprenoids in plastids via the nonmevalonic acid pathway. From pyruvate and glyceraldehyde-3-phosphate, CapTKT2 catalyzes the formation of 1-deoxy-xylulose-5-phosphate, the IPP precursor. CapTKT1 is almost constitutively expressed during the chloroplast-to-chromoplast transition, whereas CapTKT2 is overexpressed during this period, probably to furnish the IPP necessary for increased carotenoid biosynthesis. Because deoxy-xylulose phosphate is shared by the plastid pathways of isoprenoid, thiamine (vitamin B1), and pyridoxine (vitamin B6) biosynthesis, our results may explain why albino phenotypes usually occur in thiamine-deficient plants. 相似文献
3.
Chlorophyta exclusively use the 1-deoxyxylulose 5-phosphate/2-C-methylerythritol 4-phosphate pathway for the biosynthesis of isoprenoids 总被引:2,自引:0,他引:2
The biosynthesis of the C5 building block of isoprenoids, isopentenyl diphosphate (IPP), proceeds in higher plants via two basically different pathways; in the cytosolic compartment sterols are formed via mevalonate (MVA), whereas in the plastids the isoprenoids are formed via the 1-deoxyxylulose 5-phosphate/2-C-methylerythritol 4-phosphate pathway (DOXP/MEP pathway). In the present investigation, we found for the Charophyceae, being close relatives to land plants, and in the original green flagellate Mesostignma virilde the same IPP biosynthesis pattern as in higher plants: sterols are formed via MVA, and the phytol-moiety of chlorophylls via the DOXP/MEP pathway. In contrast, representatives of four classes of the Chlorophyta (Chlorophyceae, Ulvophyceae, Trebouxiophyceae, Prasinophyceae) did not incorporate MVA into sterols or phytol. Instead, they incorporated [1-2H1]-1-deoxy-D-xylulose into phytol and sterols. The results indicate that the entire Chlorophyta lineage, which is well separated from the land plant/Charophyceae lineage, is devoid of the acetate/ MVA pathway and uses the DOXP/MEP pathway not only for plastidic, but also for cytosolic isoprenoid formation. 相似文献
4.
Genetic evidence for the role of isopentenyl diphosphate isomerases in the mevalonate pathway and plant development in Arabidopsis 总被引:1,自引:0,他引:1
Okada K Kasahara H Yamaguchi S Kawaide H Kamiya Y Nojiri H Yamane H 《Plant & cell physiology》2008,49(4):604-616
Isopentenyl/dimethylallyl diphosphate isomerase (IPI) catalyzes the interconversion of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP), which are the universal C(5) units of isoprenoids. In plants, IPP and DMAPP are synthesized via the cytosolic mevalonate (MVA) and plastidic methylerythritol phosphate (MEP) pathways, respectively. However, the role of IPI in each pathway and in plant development is unknown due to a lack of genetic studies using IPI-defective mutants. Here, we show that the atipi1atipi2 double mutant, which is defective in two Arabidopsis IPI isozymes, exhibits dwarfism and male sterility under long-day conditions and decreased pigmentation under continuous light, whereas the atipi1 and atipi2 single mutants are phenotypically normal. We also show that the sterol and ubiquinone levels in the double mutant are <50% of those in wild-type plants, and that the male-sterile phenotype is chemically complemented by squalene, a sterol precursor. In vivo isotope labeling experiments using the atipi1atipi2 double mutant revealed a decrease in the incorporation of MVA (in its lactone form) into sterols, with no decrease in the incorporation of MEP pathway intermediates into tocopherol. These results demonstrate a critical role for IPI in isoprenoid biosynthesis via the MVA pathway, and they imply that IPI is essential for the maintenance of appropriate levels of IPP and DMAPP in different subcellular compartments in plants. 相似文献
5.
Mevalonic acid partially restores chloroplast and etioplast development in Arabidopsis lacking the non-mevalonate pathway 总被引:6,自引:0,他引:6
Isopentenyl diphosphate (IPP) is produced via two independent biosynthetic pathways in higher plants: the mevalonate (MVA) pathway in the cytoplasm and the non-mevalonate 2-C-methyl- D-erythritol-4-phosphate (MEP) pathway in plastids. It has been previously suggested that IPP or IPP-derived products can be exchanged between the cytoplasm and plastids. However, the issue of whether the exchanged products reflect efficient synthesis of functional isoprenoids remains unresolved. We fed exogenous mevalonic acid to the Arabidopsis thaliana (L.) Heynh. albino mutant cla1-1, a null mutant of the first-step enzyme in the MEP pathway. This resulted in the recovery of thylakoid membrane stacking in chloroplasts in the light, and the formation of prolamellar bodies and plastoglobuli in etioplasts in the dark. By contrast, exogenous lovastatin, an inhibitor of mevalonic acid biosynthesis, induced complete depigmentation and further inhibition of plastid development in both the light and the dark. These results suggest that mevalonic acid-derived products contribute to the formation of functional plastidic isoprenoids, such as the chlorophylls and carotenoids required for plastid development. 相似文献
6.
Hailin Meng Yong Wang Qiang Hua Siliang Zhang Xiaoning Wang 《Biotechnology and Bioprocess Engineering》2011,16(2):205-215
The biosynthesis of terpenoids in heterologous hosts has become increasingly popular. Isopentenyl diphosphate (IPP) is the
central precursor of all isoprenoids, and the synthesis can proceed via two separate pathways in different organisms: The 1-deoxylulose 5-phosphate (DXP) pathway and the mevalonate (MVA) pathway.
In this study, an in silico comparison was made between the maximum theoretical IPP yields and the thermodynamic properties of the DXP and MVA pathways
using different hosts and carbon sources. We found that Escherichia coli and its DXP pathway have the most potential for IPP production. Consequently, codon usage redesign, and combinations of chromosomal
engineering and various strains were considered for optimizing taxadiene biosynthesis through the endogenic DXP pathway. A
high production strain yielding 876 ± 60 mg/L taxadiene, with an overall volumetric productivity of 8.9 mg/(L × h), was successfully
obtained by combining the chromosomal engineered upstream DXP pathway and the downstream taxadiene biosynthesis pathway. This
is the highest yield thus far reported for taxadiene production in a heterologous host. These results indicate that genetic
manipulation of the DXP pathway has great potential to be used for production of terpenoids, and that chromosomal engineering
is a powerful tool for heterologous biosynthesis of natural products. 相似文献
7.
Feeding tobacco BY-2 cells with [2-13C,4-2H]deoxyxylulose revealed from the 13C labeling that the plastid isoprenoids, synthesized via the MEP pathway, are essentially derived from the labeled precursor. The ca. 15% 2H retention observed in all isoprene units corresponds to the isopentenyl diphosphate (IPP)/dimethylallyl diphosphate (DMAPP) ratio (85:15) directly produced by the hydroxymethylbutenyl diphosphate reductase, the last enzyme of the MEP pathway. 2H retention characterizes the isoprene units derived from the DMAPP branch, whereas 2H loss represents the signature of the IPP branch. Taking into account the enantioselectivity of the reactions catalyzed by the (E)-4-hydroxy-3-methylbut-2-enyl diphosphate reductase, the IPP isomerase and the trans-prenyl transferase, a single biogenetic scheme allows to interpret all labeling patterns observed in bacteria or plants upon incubation with 2H labeled deoxyxylulose. 相似文献
8.
《Journal of Plant Interactions》2013,8(4):195-204
Abstract Isoprenoids are a large and structurally diverse family of compounds that play essential roles in plants as hormones, photosynthetic pigments, electron carriers, and membrane components as well as serving in communication and defense. Now it is unequivocally proved that two distinct and independent biosynthetic routes exist to isopentenyl diphosphate (IPP) and its allylic isomer dimethylallyl diphosphate (DMAPP), the two building blocks for isoprenoids in plants. The cytosolic pathway is triggered by Acetyl Coenzyme A where classical intermediate mevalonic acid is formed which, in turn, converts into IPP and DMAPP. These further combine to elongate into sesquiterpenes (C15) and triterpenes (C30); whereas the plastidial pathway provides precursors for the biosynthesis of isoprene (C5), monoterpenes (C10), diterpenes (C20), and tetraterpenes (C40). The pathway is initiated by the transketolase-type condensation of pyruvate (C-2 and C-3) and glyceraldehyde-3-phosphate to 1-deoxyxylulose-5-phosphate (DXP), followed by the isomerization and reduction of this intermediate to 2-C-methylerythritol-4-phosphate (MEP), formation of the cytidine 5'-diphosphate (CDP) derivative, phosphorylation at C2, and cyclization to 2-C-methylerythritol-2,4-cyclodiphosphate (CDP-Me2P as the last defined step). The genes encoding each enzyme of the plastid pathway up to formation of the cyclic diphosphate have been isolated from plants and from eubacteria where the pathway exists. Studies on the complete biosynthetic pathways using radio-labeled substrates will help in characterizing and identifying the enzymes involved in each and every step of cyclization, isomerization, chain elongation, hydrogen shifts, oxidation and hydroxylation during the formation of many isoprenoid compounds present in food and flavor substances and are highly useful to human beings. 相似文献
9.
《Bioscience, biotechnology, and biochemistry》2013,77(12):2376-2383
The mevalonic acid (MVA) and methylerythritol phosphate (MEP) pathways for isoprenoid biosynthesis both culminate in the production of the two-five carbon prenyl diphosphates: dimethylallyl diphosphate (DMAPP) and isopentenyl diphosphate (IPP). These are the building blocks for higher isoprenoids, including many that have industrial and pharmaceutical applications. With growing interest in producing commercial isoprenoids through microbial engineering, reports have appeared of toxicity associated with the accumulation of prenyl diphosphates in Escherichia coli expressing a heterologous MVA pathway. Here we explored whether similar prenyl diphosphate toxicity, related to MEP pathway flux, could also be observed in the bacterium Bacillus subtilis. After genetic and metabolic manipulations of the endogenous MEP pathway in B. subtilis, measurements of cell growth, MEP pathway flux, and DMAPP contents suggested cytotoxicity related to prenyl diphosphate accumulation. These results have implications as to understanding the factors impacting isoprenoid biosynthesis in microbial systems. 相似文献
10.
Higher plants, several algae, bacteria, some strains of Streptomyces and possibly malaria parasite Plasmodium falciparum contain the novel, plastidic DOXP/MEP pathway for isoprenoid biosynthesis. This pathway, alternative with respect to the classical mevalonate pathway, starts with condensation of pyruvate and glyceraldehyde-3-phosphate which yields 1-deoxy-D-xylulose 5-phosphate (DOXP); the latter product can be converted to isopentenyl diphosphate (IPP) and eventually to isoprenoids or thiamine and pyridoxal. Subsequent reactions of this pathway involve transformation of DOXP to 2-C-methyl-D-erythritol 4-phosphate (MEP) which after condensation with CTP forms 4-diphosphocytidyl-2-amethyl-D-erythritol (CDP-ME). Then CDP-ME is phosphorylated to 4-diphosphocytidyl-2-amethyl-D-erythritol 2-phosphate (CDP-ME2P) and to 2-C-methyl-D-erythritol-2,4-cyclodiphosphate (ME-2,4cPP) which is the last known intermediate of the DOXP/MEP pathway. For- mation of IPP and dimethylallyl diphosphate (DMAPP) from ME-2,4cPP still requires clarification. This novel pathway appears to be involved in biosynthesis of carotenoids, phytol (side chain of chlorophylls), isoprene, mono-, di-, tetraterpenes and plastoquinone whereas the mevalonate pathway is responsible for formation of sterols, sesquiterpenes and triterpenes. Several isoprenoids were found to be of mixed origin suggesting that some exchange and/or cooperation exists between these two pathways of different biosynthetic origin. Contradictory results described below could indicate that these two pathways are operating under different physiological conditions of the cell and are dependent on the developmental state of plastids. 相似文献
11.
The potent antimalarial sesquiterpene lactone, artemisinin, is produced in low quantities by the plant Artemisia annua L. The source and regulation of the isopentenyl diphosphate (IPP) used in the biosynthesis of artemisinin has not been completely
characterized. Terpenoid biosynthesis occurs in plants via two IPP-generating pathways: the mevalonate pathway in the cytosol,
and the non-mevalonate pathway in plastids. Using inhibitors specific to each pathway, it is possible to resolve which supplies
the IPP precursor to the end product. Here, we show the effects of inhibition on the two pathways leading to IPP for artemisinin
production in plants. We grew young (7–14 days post cotyledon) plants in liquid culture, and added mevinolin to the medium
to inhibit the mevalonate pathway, or fosmidomycin to inhibit the non-mevalonate pathway. Artemisinin levels were measured
after 7–14 days incubation, and production was significantly reduced by each inhibitor compared to controls, thus, it appears
that IPP from both pathways is used in artemisinin production. Also when grown in miconazole, an inhibitor of sterol biosynthesis,
there was a significant increase in artemisinin compared to controls suggesting that carbon was shifted from sterols into
sesquiterpenes. Collectively these results indicate that artemisinin is probably biosynthesized from IPP pools from both the
plastid and the cytosol, and that carbon from competing pathways can be channeled toward sesquiterpenes. This information
will help advance our understanding of the regulation of in planta production of artemisinin. 相似文献
12.
Christoph A. Schuhr Tanja Radykewicz Silvia Sagner Christoph Latzel Meinhart H. Zenk Duilio Arigoni Adelbert Bacher Felix Rohdich Wolfgang Eisenreich 《Phytochemistry Reviews》2003,2(1-2):3-16
Plants have been shown to use the mevalonate pathway for the biosynthesis of sterols and triterpenes in the cytoplasm and the recently discovered deoxyxylulose phosphate pathway for the biosynthesis of a variety of hemiterpenes, monoterpenes, diterpenes, as well as for the biosynthesis of carotenoids and the phytol side chain of chlorophyll in plastids. Despite the compartmental separation, at least one terpene precursor can be exchanged between the two pathways. In order to assess quantitatively the crosstalk between the two isoprenoid pathways, [2-13C1]mevalonolactone or [U-13C6]glucose were supplied to cell cultures of Catharanthus roseus grown under illumination or in darkness. Sitosterol, lutein and phytol were isolated and analysed by NMR spectroscopy. The incorporations of exogenous [2-13C1]mevalonolactone were 48% and 7% into the DMAPP and IPP precursors of sitosterol and lutein, respectively. With [U-13C6]glucose as precursor, at least 95% of sitosterol precursors were obtained via the mevalonate pathway, whereas phytol appeared to be biosynthesised via the deoxyxylulose phosphate pathway (approximately 60%) as well via the mevalonate pathway (approximately 40%). The apparent ratios for the contribution of the two pathways depend on the nature of the precursor supplied as well as the nature of the target compound. Thus, crosstalk between the two terpenoid pathways cannot be explained in detail by a simple two compartment model and requires an additional in depth study of complex regulatory mechanisms. 相似文献
13.
A mevalonate-independent pathway for the biosynthesis of isopentenyl diphosphate (IPP) and dimethylallyl diphosphate (DMAPP) that has been elucidated during the last decade is essential in plants, many eubacteria and apicomplexan parasites, but is absent in Archaea and animals. The enzymes of the pathway are potential targets for the development of novel antibiotic, antimalarial and herbicidal agents. This review is focused on the late steps of this pathway. The intermediate 2C-methyl-D-erythritol 2,4-cyclodiphosphate is converted into IPP and DMAPP via 1-hydroxy-2-methyl-2-(E)-butenyl 4-diphosphate by the consecutive action of the iron-sulfur proteins IspG and IspH. IPP and DMAPP can be interconverted by IPP isomerase which is essential in microorganisms using the mevalonate pathway, whereas its presence is optional in microorganisms using the non-mevalonate pathway. A hitherto unknown family of IPP isomerases using FMN as coenzyme has been discovered recently in Archaea and certain eubacteria. 相似文献
14.
The subcellular compartmentation of isopentenyl diphosphate (IPP) synthesis was examined in secretory cells isolated from glandular trichomes of peppermint (Mentha x piperita L. cv. Black Mitcham). As a consequence of their anatomy and the conditions of their isolation, the isolated secretory cells are non-specifically permeable to low-molecular-weight water-soluble metabolites. Thus, the cytoplasm is readily accessible to the exogenous buffer whereas the selective permeability of subcellular organelles is maintained. With the appropriate choice of exogenous substrates, this feature allows the assessment of cytoplasmic and organellar (e.g. plastidic) metabolism in situ. Glycolytic substrates such as [14C]glucose-6-phosphate and [14C]pyruvic acid are incorporated into both monoterpenes and sesquiterpenes with a monoterpene:sesquiterpene ratio that closely mimics that observed in vivo, indicating that the correct subcellular partitioning of these substrates is maintained in this model system. Additionally, exogenous [14C]mevalonic acid and [14C]IPP, which are both intitially metabolized in the cytoplasm, produce an abnormally high proportion of sesquiterpenes. In contrast, incubation with either [14C]citrate or [14C]acetyl-CoA results in the accumulation of 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) with no detectable isoprenoids formed. Taken together, these results indicate that the cytoplasmic mevalonic acid pathway is blocked at HMG-CoA reductase and that the IPP utilized for both monoterpene and sesquiterpene biosynthesis is synthesized exclusively in the plastids. 相似文献
15.
The mevalonic acid (MVA) and methylerythritol phosphate (MEP) pathways for isoprenoid biosynthesis both culminate in the production of the two-five carbon prenyl diphosphates: dimethylallyl diphosphate (DMAPP) and isopentenyl diphosphate (IPP). These are the building blocks for higher isoprenoids, including many that have industrial and pharmaceutical applications. With growing interest in producing commercial isoprenoids through microbial engineering, reports have appeared of toxicity associated with the accumulation of prenyl diphosphates in Escherichia coli expressing a heterologous MVA pathway. Here we explored whether similar prenyl diphosphate toxicity, related to MEP pathway flux, could also be observed in the bacterium Bacillus subtilis. After genetic and metabolic manipulations of the endogenous MEP pathway in B. subtilis, measurements of cell growth, MEP pathway flux, and DMAPP contents suggested cytotoxicity related to prenyl diphosphate accumulation. These results have implications as to understanding the factors impacting isoprenoid biosynthesis in microbial systems. 相似文献
16.
17.
Background
Juvenile hormones (JH) regulate development and reproductive maturation in insects. JHs are synthesized through the mevalonate pathway (MVAP), an ancient metabolic pathway present in the three domains of life. Mevalonate kinase (MVK) is a key enzyme in the MVAP. MVK catalyzes the synthesis of phosphomevalonate (PM) by transferring the γ-phosphoryl group from ATP to the C5 hydroxyl oxygen of mevalonic acid (MA). Despite the importance of MVKs, these enzymes have been poorly characterized in insects.Results
We functionally characterized an Aedes aegypti MVK (AaMVK) expressed in the corpora allata (CA) of the mosquito. AaMVK displayed its activity in the presence of metal cofactors. Different nucleotides were used by AaMVK as phosphoryl donors. In the presence of Mg2+, the enzyme has higher affinity for MA than ATP. The activity of AaMVK was regulated by feedback inhibition from long-chain isoprenoids, such as geranyl diphosphate (GPP) and farnesyl diphosphate (FPP).Conclusions
AaMVK exhibited efficient inhibition by GPP and FPP (Ki less than 1 μM), and none by isopentenyl pyrophosphate (IPP) and dimethyl allyl pyrophosphate (DPPM). These results suggest that GPP and FPP might act as physiological inhibitors in the synthesis of isoprenoids in the CA of mosquitoes. Changing MVK activity can alter the flux of precursors and therefore regulate juvenile hormone biosynthesis. 相似文献18.
19.
Marc Clastre Nicolas Papon Vincent Courdavault Nathalie Giglioli-Guivarc’h Benoit St-Pierre Andrew J. Simkin 《Plant signaling & behavior》2011,6(12):2044-2046
The role of peroxisomes in isoprenoid metabolism, especially in plants, has been questioned in several reports. A recent study of Sapir-Mir et al.1 revealed that the two isoforms of isopentenyl diphosphate (IPP) isomerase, catalyzing the isomerisation of IPP to dimethylallyl diphosphate (DMAPP) are found in the peroxisome. In this addendum, we provide additional data describing the peroxisomal localization of 5-phosphomevalonate kinase and mevalonate 5-diphosphate decarboxylase, the last two enzymes of the mevalonic acid pathway leading to IPP.2 This finding was reinforced in our latest report showing that a short isoform of farnesyl diphosphate, using IPP and DMAPP as substrates, is also targeted to the organelle.3 Therefore, the classical sequestration of isoprenoid biosynthesis between plastids and cytosol/ER can be revisited by including the peroxisome as an additional isoprenoid biosynthetic compartment within plant cells. 相似文献
20.
Malcolm Possell Annette Ryan Claudia E. Vickers Philip M. Mullineaux C. Nicholas Hewitt 《Photosynthesis research》2010,104(1):49-59
In higher plants, many isoprenoids are synthesised via the chloroplastic 1-deoxy-d-xylulose 5-phosphate/2-C-methyl-d-erythritol 4-phosphate (MEP) pathway. Attempts to elucidate the function of individual isoprenoids have used the antibiotic/herbicidal
compound fosmidomycin (3-[N-formyl-N-hydroxy amino] propyl phosphonic acid) to inhibit this pathway. Examination of the effect of fosmidomycin on the major components
of photosynthesis in leaves of white poplar (Populus alba) and tobacco (Nicotiana tabacum) was made. Fosmidomycin reduced net photosynthesis in both species within 1 h of application, but only when photosynthesis
was light-saturated. In P. alba, these reductions were confounded by high light and fosmidomycin inducing stomatal patchiness. In tobacco, this was caused
by significant reductions in PSII chlorophyll fluorescence and reductions in V
cmax and J
max. Our data indicate that the diminution of photosynthesis is likely a complex effect resulting from the inhibition of multiple
MEP pathway products, resulting in photoinhibition and photo-damage. These effects should be accounted for in experimental
design and analysis when using fosmidomycin to avoid misinterpretation of results as measured by gas exchange and chlorophyll
fluorescence. 相似文献