Taxol(Paclitaxel)is a diterpene from Taxus species and has been used in treatment of various kinds of cancers.Geranylgeranyl diphosphate synthase(GGPPS)catalyzes the formation of geranylgeranyl diphosphate(GGPP,the co...Taxol(Paclitaxel)is a diterpene from Taxus species and has been used in treatment of various kinds of cancers.Geranylgeranyl diphosphate synthase(GGPPS)catalyzes the formation of geranylgeranyl diphosphate(GGPP,the common precursor for diterpenes and plays a key role in taxol biosynthesis.Here we report a functional GGPPS gene from Taxus chinensis(designated TcGGPPS).TcGGPPS is an intron free gene and has a 1,182-bp open reading frame encoding a polypeptide of 393 amino acid residues with a calculated molecular mass of 42.63 kDa and an isoelectric point of 5.58.The catalytic activity of TcGGPPS for production of GGPP was verified by a color enhancement assay in the Escherichia coli cells harboring plasmid pAC-BETA.Multiple sequence alignment indicates that TcGGPPS is a little different in sequence from the functional GGPPS genes from other Taxus species such as T.canadensis,T.media and T.wallichiana,which are almost identical to each other.Protein structure prediction by using bioinformatics reveals that TcGGPPS consists of 52.2%α-helix,10.9%extended strand,8.4%β-turn and 28.5%random coil,and has a three-dimensional structure highly similar to the structurally known Sinapis alba GGPPS.In silicon predictions also demonstrate that TcGGPPS has a plastid-targeting peptide at the N-terminus,suggesting it is responsible for the synthesis of GGPP in plastids.展开更多
采用RT-PCR和RACE(Rapid amplification of c DNA ends)技术,从艾纳香(Blumea balsamifera L·DC)的叶片中克隆到二萜化合物合成的关键酶牻牛儿基牻牛儿基焦磷酸合成酶(Bb GGPS)基因。结果显示:Bb GGPS基因的c DNA全长1475 bp,包含...采用RT-PCR和RACE(Rapid amplification of c DNA ends)技术,从艾纳香(Blumea balsamifera L·DC)的叶片中克隆到二萜化合物合成的关键酶牻牛儿基牻牛儿基焦磷酸合成酶(Bb GGPS)基因。结果显示:Bb GGPS基因的c DNA全长1475 bp,包含开放阅读框(ORF)1002 bp,编码334个氨基酸;亚细胞结构定位于叶绿体,既非膜蛋白也非分泌性蛋白。疏水性分析显示,Bb GGPS是亲水性蛋白。同源性比对结果显示,Bb GGPS蛋白与其他植物中GGPS蛋白具有高度的相似性。系统发育分析表明,所有序列被聚为5大类,Bb GGPS与菊科植物刺菜蓟聚(Cynara cardunculus var)为一类,表明与其亲缘关系最近。展开更多
Plant isoprenoids(also known as terpenes or terpenoids)are a wide family of primary and secondary metabolites with multiple functions.In particular,most photosynthesis-related isoprenoids(including carotenoids and chl...Plant isoprenoids(also known as terpenes or terpenoids)are a wide family of primary and secondary metabolites with multiple functions.In particular,most photosynthesis-related isoprenoids(including carotenoids and chlorophylls)as well as diterpenes and polyterpenes derive from geranylgeranyl diphosphate(GGPP)produced by GGPP synthase(GGPPS)enzymes in several cell compartments.Plant genomes typically harbor multiple copies of differentially expressed genes encoding GGPPS-like pro-teins.While sequence comparisons allow to identify potential GGPPS candidates,experimental evidence is required to ascertain their enzymatic activity and biologi cal function.Actually,functional analyses of the full set of potential GGPPS paralogs are only available for a handful of plant species.Here we review our current knowledge on the GGPPS families of the model plant Arabidopsis thaliana and the crop species rice(0ryza sativa),pepper(Capsicum annuum)and tomato(Solanum lycopersicum).The results indicate that a major determinant of the biological role of particular GGPPS paralogs is the expression profile of the corresponding genes even though specific interactions with other proteins(including GGPP-consuming enzymes)might also contribute to subfunctionalization.In some species,however,a single GGPPS isoforms appears to be responsible for the production of most if not all GGPP required for cell functions.Deciphering the mechanisms regulating GGPPS activity in particular cell compartments,tissues,organs and plant species will be very useful for future metabolic engineering approaches aimed to manipulate the accumulation of particular GGPP-derived products of interest without negatively impacting the levels of other isoprenoids required to sustain essential cell functions.展开更多
Restricted genetic diversity can supply only a limited number of elite genes for modern plant cultivation and transgenesis.In this study,we demonstrate that rational design enables the engineering of geranyl-geranyl d...Restricted genetic diversity can supply only a limited number of elite genes for modern plant cultivation and transgenesis.In this study,we demonstrate that rational design enables the engineering of geranyl-geranyl diphosphate synthase(NtGGPPS),an enzyme of the methylerythritol phosphate pathway(MEP)in the model plant Nicotiana tabacum.As the crucial bottleneck in carotenoid biosynthesis,NtGGPPS1 interacts with phytoene synthase(NtPSY1)to channel GGPP into the production of carotenoids.Loss of this enzyme in the ntggpps1 mutant leads to decreased carotenoid accumulation.With the aim of enhanc-ing NtGGPPS1 activity,we undertook structure-guided rational redesign of its substrate binding pocket in combination with sequence alignment.The activity of the designed NtGGPPS1(a pentuple mutant of five sites V154A/I161L/F218Y/I209S/V233E,d-NtGGPPS1)was measured by a high-throughput colorimetric assay.d-NtGGPPS1 exhibited significantly higher conversion of IPP and each co-substrate(DMAPP~1995.5-fold,GPP~25.9-fold,and FPP~16.7-fold)for GGPP synthesis compared with wild-type NtGGPPS1.Importantly,the transient and stable expression of d-NtGGPPS1 in the ntggpps1 mutant increased carotenoid levels in leaves,improved photosynthetic efficiency,and increased biomass relative to NtGGPPS1.These findings provide a firm basis for the engineering of GGPPS and will facilitate the development of quality and yield traits.Our results open the door for the structure-guided rational design of elite genes in higher plants。展开更多
Terpenes are the largest and most diverse class of plant specialized metabolites.Sesterterpenes(C25),which are derived from the plastid methylerythritol phosphate pathway,were recently characterized in plants.In Arabi...Terpenes are the largest and most diverse class of plant specialized metabolites.Sesterterpenes(C25),which are derived from the plastid methylerythritol phosphate pathway,were recently characterized in plants.In Arabidopsis thaliana,four genes encoding geranylfarnesyl diphosphate synthase(GFPPS)(AtGFPPS1 to 4)are responsible for the production of GFPP,which is the common precursor for sesterterpene biosynthesis.However,the interplay between sesterterpenes and other known terpenes remain elusive.Here,we first provide genetic evidence to demonstrate that GFPPSs are responsible for sesterterpene production in Arabidopsis.Blockage of the sesterterpene pathway at the GFPPS step increased the production of geranylgeranyl diphosphate(GGPP)-derived terpenes.Interestingly,co-expression of sester TPSs in GFPPSOE(overexpression)plants rescued the phenotypic changes of GFPPS-OE plants by restoring the endogenous GGPP.We further demonstrated that,in addition to precursor(DMAPP/IPP)competition by GFPPS and GGPP synthase(GGPPS)in plastids,GFPPS directly decreased the activity of GGPPS through protein-protein interaction,ultimately leading to GGPP deficiency in planta.Our study provides a new regulatory mechanism of the plastidial terpenoid network in plant cells.展开更多
文摘Taxol(Paclitaxel)is a diterpene from Taxus species and has been used in treatment of various kinds of cancers.Geranylgeranyl diphosphate synthase(GGPPS)catalyzes the formation of geranylgeranyl diphosphate(GGPP,the common precursor for diterpenes and plays a key role in taxol biosynthesis.Here we report a functional GGPPS gene from Taxus chinensis(designated TcGGPPS).TcGGPPS is an intron free gene and has a 1,182-bp open reading frame encoding a polypeptide of 393 amino acid residues with a calculated molecular mass of 42.63 kDa and an isoelectric point of 5.58.The catalytic activity of TcGGPPS for production of GGPP was verified by a color enhancement assay in the Escherichia coli cells harboring plasmid pAC-BETA.Multiple sequence alignment indicates that TcGGPPS is a little different in sequence from the functional GGPPS genes from other Taxus species such as T.canadensis,T.media and T.wallichiana,which are almost identical to each other.Protein structure prediction by using bioinformatics reveals that TcGGPPS consists of 52.2%α-helix,10.9%extended strand,8.4%β-turn and 28.5%random coil,and has a three-dimensional structure highly similar to the structurally known Sinapis alba GGPPS.In silicon predictions also demonstrate that TcGGPPS has a plastid-targeting peptide at the N-terminus,suggesting it is responsible for the synthesis of GGPP in plastids.
文摘Plant isoprenoids(also known as terpenes or terpenoids)are a wide family of primary and secondary metabolites with multiple functions.In particular,most photosynthesis-related isoprenoids(including carotenoids and chlorophylls)as well as diterpenes and polyterpenes derive from geranylgeranyl diphosphate(GGPP)produced by GGPP synthase(GGPPS)enzymes in several cell compartments.Plant genomes typically harbor multiple copies of differentially expressed genes encoding GGPPS-like pro-teins.While sequence comparisons allow to identify potential GGPPS candidates,experimental evidence is required to ascertain their enzymatic activity and biologi cal function.Actually,functional analyses of the full set of potential GGPPS paralogs are only available for a handful of plant species.Here we review our current knowledge on the GGPPS families of the model plant Arabidopsis thaliana and the crop species rice(0ryza sativa),pepper(Capsicum annuum)and tomato(Solanum lycopersicum).The results indicate that a major determinant of the biological role of particular GGPPS paralogs is the expression profile of the corresponding genes even though specific interactions with other proteins(including GGPP-consuming enzymes)might also contribute to subfunctionalization.In some species,however,a single GGPPS isoforms appears to be responsible for the production of most if not all GGPP required for cell functions.Deciphering the mechanisms regulating GGPPS activity in particular cell compartments,tissues,organs and plant species will be very useful for future metabolic engineering approaches aimed to manipulate the accumulation of particular GGPP-derived products of interest without negatively impacting the levels of other isoprenoids required to sustain essential cell functions.
基金the Natural Science Foundation of Henan Province(182300410053)the China Postdoctoral Science Foundation(2020M672308)+3 种基金Henan Postdoctoral Science Foundation(227462)Science Project(902019AA0140)the National Key Research and Development Program of China(2019YFA0905100)the National Natural Science Foundation of China(U2004143)。
文摘Restricted genetic diversity can supply only a limited number of elite genes for modern plant cultivation and transgenesis.In this study,we demonstrate that rational design enables the engineering of geranyl-geranyl diphosphate synthase(NtGGPPS),an enzyme of the methylerythritol phosphate pathway(MEP)in the model plant Nicotiana tabacum.As the crucial bottleneck in carotenoid biosynthesis,NtGGPPS1 interacts with phytoene synthase(NtPSY1)to channel GGPP into the production of carotenoids.Loss of this enzyme in the ntggpps1 mutant leads to decreased carotenoid accumulation.With the aim of enhanc-ing NtGGPPS1 activity,we undertook structure-guided rational redesign of its substrate binding pocket in combination with sequence alignment.The activity of the designed NtGGPPS1(a pentuple mutant of five sites V154A/I161L/F218Y/I209S/V233E,d-NtGGPPS1)was measured by a high-throughput colorimetric assay.d-NtGGPPS1 exhibited significantly higher conversion of IPP and each co-substrate(DMAPP~1995.5-fold,GPP~25.9-fold,and FPP~16.7-fold)for GGPP synthesis compared with wild-type NtGGPPS1.Importantly,the transient and stable expression of d-NtGGPPS1 in the ntggpps1 mutant increased carotenoid levels in leaves,improved photosynthetic efficiency,and increased biomass relative to NtGGPPS1.These findings provide a firm basis for the engineering of GGPPS and will facilitate the development of quality and yield traits.Our results open the door for the structure-guided rational design of elite genes in higher plants。
基金financially supported by the National Key R&D Program of China(2018YFA0900600)the National Natural Science Foundation of China(31970315)+1 种基金the Key R&D Program of Shandong Province(2019JZZY020610)the State Key Laboratory of Plant Genomics of China(grant no.SKLPG2016A-13)。
文摘Terpenes are the largest and most diverse class of plant specialized metabolites.Sesterterpenes(C25),which are derived from the plastid methylerythritol phosphate pathway,were recently characterized in plants.In Arabidopsis thaliana,four genes encoding geranylfarnesyl diphosphate synthase(GFPPS)(AtGFPPS1 to 4)are responsible for the production of GFPP,which is the common precursor for sesterterpene biosynthesis.However,the interplay between sesterterpenes and other known terpenes remain elusive.Here,we first provide genetic evidence to demonstrate that GFPPSs are responsible for sesterterpene production in Arabidopsis.Blockage of the sesterterpene pathway at the GFPPS step increased the production of geranylgeranyl diphosphate(GGPP)-derived terpenes.Interestingly,co-expression of sester TPSs in GFPPSOE(overexpression)plants rescued the phenotypic changes of GFPPS-OE plants by restoring the endogenous GGPP.We further demonstrated that,in addition to precursor(DMAPP/IPP)competition by GFPPS and GGPP synthase(GGPPS)in plastids,GFPPS directly decreased the activity of GGPPS through protein-protein interaction,ultimately leading to GGPP deficiency in planta.Our study provides a new regulatory mechanism of the plastidial terpenoid network in plant cells.
