排序方式: 共有21条查询结果,搜索用时 406 毫秒
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Thabet I Guirimand G Courdavault V Papon N Godet S Dutilleul C Bouzid S Giglioli-Guivarc'h N Clastre M Simkin AJ 《Journal of plant physiology》2011,168(17):2110-2116
Farnesyl diphosphate (FPP) synthase (FPS: EC.2.5.1.1, EC.2.5.1.10) catalyzes the formation of FPP from isopentenyl diphosphate and dimethylallyl diphosphate via two successive condensation reactions. A cDNA designated CrFPS, encoding a protein showing high similarities with trans-type short FPS isoforms, was isolated from the Madagascar periwinkle (Catharanthus roseus). This cDNA was shown to functionally complement the lethal FPS deletion mutant in the yeast Saccharomyces cerevisiae. At the subcellular level, while short FPS isoforms are usually described as cytosolic proteins, we showed, using transient transformations of C. roseus cells with yellow fluorescent protein-fused constructs, that CrFPS is targeted to peroxisomes. This finding is discussed in relation to the subcellular distribution of FPS isoforms in plants and animals and opens new perspectives towards the understanding of isoprenoid biosynthesis. 相似文献
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Bertheau Lucie Chefdor Françoise Guirimand Grégory Courdavault Vincent Depierreux Christiane Morabito Domenico Brignolas Franck Héricourt François Carpin Sabine 《BMC plant biology》2012,12(1):1-15
Background
Mechanosensing and its downstream responses are speculated to involve sensory complexes containing Ca2+-permeable mechanosensitive channels. On recognizing osmotic signals, plant cells initiate activation of a widespread signal transduction network that induces second messengers and triggers inducible defense responses. Characteristic early signaling events include Ca2+ influx, protein phosphorylation and generation of reactive oxygen species (ROS). Pharmacological analyses show Ca2+ influx mediated by mechanosensitive Ca2+ channels to influence induction of osmotic signals, including ROS generation. However, molecular bases and regulatory mechanisms for early osmotic signaling events remain poorly elucidated.Results
We here identified and investigated OsMCA1, the sole rice homolog of putative Ca2+-permeable mechanosensitive channels in Arabidopsis (MCAs). OsMCA1 was specifically localized at the plasma membrane. A promoter-reporter assay suggested that OsMCA1 mRNA is widely expressed in seed embryos, proximal and apical regions of shoots, and mesophyll cells of leaves and roots in rice. Ca2+ uptake was enhanced in OsMCA1-overexpressing suspension-cultured cells, suggesting that OsMCA1 is involved in Ca2+ influx across the plasma membrane. Hypo-osmotic shock-induced ROS generation mediated by NADPH oxidases was also enhanced in OsMCA1-overexpressing cells. We also generated and characterized OsMCA1-RNAi transgenic plants and cultured cells; OsMCA1-suppressed plants showed retarded growth and shortened rachises, while OsMCA1-suppressed cells carrying Ca2+-sensitive photoprotein aequorin showed partially impaired changes in cytosolic free Ca2+ concentration ([Ca2+]cyt) induced by hypo-osmotic shock and trinitrophenol, an activator of mechanosensitive channels.Conclusions
We have identified a sole MCA ortholog in the rice genome and developed both overexpression and suppression lines. Analyses of cultured cells with altered levels of this putative Ca2+-permeable mechanosensitive channel indicate that OsMCA1 is involved in regulation of plasma membrane Ca2+ influx and ROS generation induced by hypo-osmotic stress in cultured rice cells. These findings shed light on our understanding of mechanical sensing pathways. 相似文献15.
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Guirimand G Guihur A Ginis O Poutrain P Héricourt F Oudin A Lanoue A St-Pierre B Burlat V Courdavault V 《The FEBS journal》2011,278(5):749-763
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Gregory G. Y. Guirimand Takahiro Bamba Mami Matsuda Kentaro Inokuma Kenta Morita Yuki Kitada Yuma Kobayashi Takahiro Yukawa Kengo Sasaki Chiaki Ogino Tomohisa Hasunuma Akihiko Kondo 《Biotechnology journal》2019,14(9)
Xylitol is a highly valuable commodity chemical used extensively in the food and pharmaceutical industries. The production of xylitol from d ‐xylose involves a costly and polluting catalytic hydrogenation process. Biotechnological production from lignocellulosic biomass by micro‐organisms like yeasts is a promising option. In this study, xylitol is produced from lignocellulosic biomass by a recombinant strain of Saccharomyces cerevisiae (S. cerevisiae) (YPH499‐SsXR‐AaBGL) expressing cytosolic xylose reductase (Scheffersomyces stipitis xylose reductase [SsXR]), along with a β‐d ‐glucosidase (Aspergillus aculeatus β‐glucosidase 1 [AaBGL]) displayed on the cell surface. The simultaneous cofermentation of cellobiose/xylose by this strain leads to an ≈2.5‐fold increase in Yxylitol/xylose (=0.54) compared to the use of a glucose/xylose mixture as a substrate. Further improvement in the xylose uptake by the cell is achieved by a broad evaluation of several homologous and heterologous transporters. Homologous maltose transporter (ScMAL11) shows the best performance in xylose transport and is used to generate the strain YPH499‐XR‐ScMAL11‐BGL with a significantly improved xylitol production capacity from cellobiose/xylose coutilization. This report constitutes a promising proof of concept to further scale up the biorefinery industrial production of xylitol from lignocellulose by combining cell surface and metabolic engineering in S. cerevisiae. 相似文献
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Grégory Guirimand Vincent Burlat Audrey Oudin Arnaud Lanoue Benoit St-Pierre Vincent Courdavault 《Plant cell reports》2009,28(8):1215-1234
The monoterpene indole alkaloids (MIA) synthesized in Catharanthus roseus are highly valuable metabolites due to their pharmacological properties. In planta, the MIA biosynthetic pathway exhibits
a complex compartmentation at the cellular level, whereas subcellular data are sparse. To gain insight into this level of
organization, we have developed a high efficiency green fluorescent protein (GFP) imaging approach to systematically localize
MIA biosynthetic enzymes within C. roseus cells following a biolistic-mediated transient transformation. The biolistic transformation protocol has been first optimized
to obtain a high number of transiently transformed cells with a ~12-fold increase compared to previous protocols and thus
to clearly and easily identify the fusion GFP expression patterns in numerous cells. On the basis of this protocol, the subcellular
localization of hydroxymethylbutenyl 4-diphosphate synthase (HDS), a methyl erythritol phosphate pathway enzyme and geraniol
10-hydroxylase (G10H), a monoterpene-secoiridoid pathway enzyme has been next characterized. Besides showing the accumulation
of HDS within plastids of C. roseus cells, we also provide evidences of the presence of HDS in long stroma-filled thylakoid-free extensions budding from plastids,
i.e. stromules that are in close association with other organelles such as endoplasmic reticulum (ER) or mitochondria in agreement
with their proposed function in enhancing interorganelle metabolite exchanges. Furthermore, we also demonstrated that G10H
is an ER-anchored protein, consistent with the presence of a transmembrane helix at the G10H N-terminal end, which is both
necessary and sufficient to drive the ER anchoring.
Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users. 相似文献
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Takahiro Yukawa Takahiro Bamba Gregory Guirimand Mami Matsuda Tomohisa Hasunuma Akihiko Kondo 《Biotechnology and bioengineering》2021,118(1):175-185
1,2,4‐Butanetriol (BT) is used as a precursor for the synthesis of various pharmaceuticals and the energetic plasticizer 1,2,4‐butanetriol trinitrate. In Saccharomyces cerevisiae, BT is biosynthesized from xylose via heterologous four enzymatic reactions catalyzed by xylose dehydrogenase, xylonate dehydratase, 2‐ketoacid decarboxylase, and alcohol dehydrogenase. We here aimed to improve the BT yield in S. cerevisiae by genetic engineering. First, the amount of the key intermediate 2‐keto‐3‐deoxy‐xylonate as described previously was successfully reduced in 41% by multiple integrations of Lactococcus lactis 2‐ketoacid decarboxylase gene kdcA into the yeast genome. Since the heterologous BT synthetic pathway is independent of yeast native metabolism, this manipulation has led to NADH/NADPH imbalance and deficiency during BT production. Overexpression of the NADH kinase POS5Δ17 lacking the mitochondrial targeting sequence to relieve NADH/NADPH imbalance resulted in the BT titer of 2.2 g/L (31% molar yield). Feeding low concentrations of glucose and xylose to support the supply of NADH resulted in BT titer of 6.6 g/L with (57% molar yield). Collectively, improving the NADH/NADPH ratio and supply from glucose are essential for the construction of a xylose pathway, such as the BT synthetic pathway, independent of native yeast metabolism. 相似文献
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Natalja Kulagina Grégory Guirimand Céline Melin Pamela Lemos-Cruz Ines Carqueijeiro Johan-Owen De Craene Audrey Oudin Vladimir Heredia Konstantinos Koudounas Marianne Unlubayir Arnaud Lanoue Nadine Imbault Benoit St-Pierre Nicolas Papon Marc Clastre Nathalie Giglioli-Guivarc’h Jillian Marc Sébastien Besseau Vincent Courdavault 《Microbial biotechnology》2021,14(6):2693-2699
The pharmaceutical industry faces a growing demand and recurrent shortages in many anticancer plant drugs given their extensive use in human chemotherapy. Efficient alternative strategies of supply of these natural products such as bioproduction by microorganisms are needed to ensure stable and massive manufacturing. Here, we developed and optimized yeast cell factories efficiently converting tabersonine to vindoline, a precursor of the major anticancer alkaloids vinblastine and vincristine. First, fine-tuning of heterologous gene copies restrained side metabolites synthesis towards vindoline production. Tabersonine to vindoline bioconversion was further enhanced through a rational medium optimization (pH, composition) and a sequential feeding strategy. Finally, a vindoline titre of 266 mg l−1 (88% yield) was reached in an optimized fed-batch bioreactor. This precursor-directed synthesis of vindoline thus paves the way towards future industrial bioproduction through the valorization of abundant tabersonine resources. 相似文献