Geranylgeranyl Pyrophosphate Synthase Research Articles

Enhancement of squalene synthesis in Candida tropicalis via combinatorial metabolic engineering strategies to rebuild pathways

Squalene has antioxidant, anti-cancer, and anti-radiation properties and is widely used in the cosmetic and pharmaceutical industries. In this study, squalene synthesis in Candida tropicalis was enhanced via combinatorial metabolic engineering strategies to rebuild pathways. By overexpressing the natural squalene synthase gene CtERG9 under the strong promoter PGAP1 in C. tropicalis DC03, squalene titer was increased by 12.1%. Replacing the natural gene CtERG9 in C. tropicalis with the squalene synthase gene ScERG9 from Saccharomyces cerevisiae increased squalene titer by 47.3%. The squalene titer in the engineered C. tropicalis CS13-D was increased by 15.4% by fusing the genes ScERG9 and ERG20. Deletion of one copy of the diacylglycerol diphosphate phosphatase gene DPP1, the geranylgeranyl pyrophosphate synthase gene BTS1, and the squalene epoxidase gene ERG1 in C. tropicalis CS19E increased squalene titer by 1.36-fold compared to control. Down-regulation of the transcription level of the single-copy gene ERG1 in C. tropicalis CS19E-G using the weak promoter PGPM1 resulted in a 38.5% increase in squalene titer. The squalene titer of C. tropicalis CS19E-G reached 433.06 mg/L in a 30-L fermenter, which was 13.5-fold higher than that of C. tropicalis DC03. This combinatorial strategy has the potential for efficient production of other high-value chemicals in C. tropicalis and other yeasts.

HSP47 complements cholesterol synthesis-independent HMGCoA-reductase pathway-mediated fibroblast bioenergetics

Fibrosis, characterized by excessive extracellular matrix (ECM) components deposition, is a common pathological process underlying numerous chronic diseases. Differentiating fibroblasts into myofibroblasts leads to the deposition of fibrous proteins like collagen in the ECM. Heat shock protein 47 (HSP47) is a molecular chaperone protein that assists in the folding of collagen. Recent studies show that inhibition of cholesterol synthesis-independent HMGCoA-reductase pathway enzyme geranylgeranyl pyrophosphate synthase 1 (GGPS1) decreases fibroblast differentiation and its bioenergetics. However, the role of HSP47 in this pathway is unknown, although recent observations show that HSP47 is decreased when GGPS1 is inhibited. Hence, we tested the hypothesis that HSP47 promotes cellular respiration in myofibroblasts. Seahorse assays were performed on different fibroblasts/myofibroblasts repeatedly and the oxygen consumption rate (OCR) and extracellular acidification rate (ECAR) were measured in the presence and absence of HSP47 inhibitor (HY124817). Complex V of the electron transport chain was measured by immunoblotting ATP-5A. HY124817 tends to decrease the OCR, basal respiration rate, ATP-linked, and spare respiratory capacity. Co-incubation with HY124817 and digeranyl bisphosphonate (DGBP), an inhibitor of GGPS1, significantly (P = 0.043) inhibited further the ATP-linked OCR compared to the TGF group. Immunoblotting showed that Complex V did not change significantly across treatments. These results suggest that HSP47 is involved in fibroblast bioenergetics related to ATP-linked OCR in both differentiated myofibroblasts and normal fibroblasts. Inhibition of HSP47 complements the decrease in myofibroblast cellular respiration caused by the GGPS1 inhibition. This finding is novel in that HSP47 plays a role in fibroblast bioenergetics regulated by the cholesterol synthesis-independent HMGCoA-reductase pathway. Further research is necessary to identify what HSP47 targets and regulatory elements involved in this process. This would provide more insight into the mechanisms that underlie critical fibrosis conditions like myocardial fibrosis and potential therapeutics. This experience was supported by the Medical College of Wisconsin's Advancing Student Potential for Inclusion with Research Experiences (ASPIRE) program. The program is funded by a federal grant from the National Heart, Lung, and Blood Institute. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Identification of the Geranylgeranyl Pyrophosphate Synthase (GGPS) Gene Family in Teak (Tectona grandis)

Identification of the Geranylgeranyl Pyrophosphate Synthase (GGPS) Gene Family in Teak (Tectona grandis)

Discovery and Evaluation of C6-Substituted Pyrazolopyrimidine-Based Bisphosphonate Inhibitors of the Human Geranylgeranyl Pyrophosphate Synthase and Evaluation of Their Antitumor Efficacy in Multiple Myeloma, Pancreatic Ductal Adenocarcinoma, and Colorectal Cancer.

Novel C6-substituted pyrazolo[3,4-d]pyrimidine- and C2-substituted purine-based bisphosphonate (C6-PyraP-BP and C2-Pur-BP, respectively) inhibitors of the human geranylgeranyl pyrophosphate synthase (hGGPPS) were designed and evaluated for their ability to block the proliferation of multiple myeloma (MM), pancreatic ductal adenocarcinoma (PDAC), and colorectal cancer (CRC) cells. Pyrazolo[3,4-d]pyrimidine analogs were identified that induce selective intracellular target engagement leading to apoptosis and downregulate the prenylation of Rap-1A in MM, PDAC, and CRC cells. The C6-PyraP-BP inhibitor RB-07-16 was found to exhibit antitumor efficacy in xenograft mouse models of MM and PDAC, significantly reducing tumor growth without substantially increasing liver enzymes or causing significant histopathologic damage, usually associated with hepatotoxicity. RB-07-16 is a metabolically stable compound in cross-species liver microsomes, does not inhibit key CYP 450 enzymes, and exhibits good systemic circulation in rat. Collectively, the current studies provide encouraging support for further optimization of the pyrazolo[3,4-d]pyrimidine-based GGPPS inhibitors as potential human therapeutics for various cancers.

Characterisation of lepidopteran geranylgeranyl diphosphate synthase as a putative pesticide target.

Geranylgeranyl pyrophosphate (diphosphate) synthase (GGPPS) plays an important role in various physiological processes in insects, such as isoprenoid biosynthesis and protein prenylation. Here, we functionally characterised the GGPPS from the major agricultural lepidopteran pests Spodoptera frugiperda and Helicoverpa armigera. Partial disruption of GGPPS by CRISPR in S. frugiperda decreased embryo hatching rate and larval survival, suggesting that this gene is essential. Functional expression in vitro of Helicoverpa armigera GGPPS in Escherichia coli revealed a catalytically active enzyme. Next, we developed and optimised an enzyme assay to screen for potential inhibitors, such as the zoledronate and the minodronate, which showed a dose-dependent inhibition. Phylogenetic analysis of GGPPS across insects showed that GGPPS is highly conserved but also revealed several residues likely to be involved in substrate binding, which were substantially different in bee pollinator and human GGPPS. Considering the essentiality of GGPPS and its putative binding residue variability qualifies a GGPPS as a novel pesticide target. The developed assay may contribute to the identification of novel insecticide leads.

Genome-Wide Identification, Characterization, and Expression Analysis of the Geranylgeranyl Pyrophosphate Synthase (GGPPS) Gene Family Reveals Its Importance in Chloroplasts of Brassica oleracea L.

GGPPS (geranylgeranyl pyrophosphate synthase) is a crucial enzyme in the terpene biosynthesis pathway. Terpenoids play essential roles in chlorophyll biosynthesis and the development of cabbage (Brassica oleracea L. var. capitata L.), a major cruciferous vegetable worldwide. However, limited information is available regarding B. oleracea GGPPS genes. In this study, we examined 10 BoGGPPS genes from the B. oleracea genome. The subcellular localization prediction suggests that BoGGPPS proteins are mainly expressed in chloroplasts and plastids. Similar BoGGPPS genes exhibited a similar structure and motif. Distribution, collinearity, and Ka/Ks analysis revealed multiple duplication events within the BoGGPPS gene family. Cabbage BoGGPPS may participate in light and hormone responses via analysis of cis-acting elements. Three-dimensional structure analysis demonstrated the abundance of α-helices and random coils among BoGGPPS members, suggesting their important functions. Based on qRT-PCR, we observed notable differences in the transcript levels of BoGGPPS genes between leaves and siliques. Bol028967 exhibited significantly higher transcript levels in WT (Wild-type) siliques compared to in Boas1 (Brassica oleracea albino silique 1), and subcellular localization analysis confirmed its expression in chloroplasts, implying its essential role in chloroplast synthesis. These findings lay the groundwork for further exploration and in-depth functional analysis of BoGGPPS genes and their relationship with terpenoids in the context of chlorophyll synthesis in B. oleracea.

Overexpression of geranyl diphosphate synthase 1 (NnGGPPS1) from Nelumbo nucifera enhances carotenoid and chlorophyll content and biomass

As the traditional herb with pharmacological compounds in China, the key genes related with terpenoid biosynthesis are still unveiled in Nelumbo nucifera. Geranylgeranyl pyrophosphate synthase (GGPPS) is one of the key enzymes in terpenoids biosynthesis, synthesizing the common precursor of GGPP for downstream enzymes for generating various terpenoids. In this study, four NnGGPPS genes were isolated from N. nucifera. Sequence and phylogenetic analyses indicate that NnGGPPS1 and NnGGPPS2 belong to large subunit (LSU). Whereas NnGGPPS3 and NnGGPPS4 are classified as small subunit (SSU) of SSU Ⅱ and SSU I, respectively. Among four NnGGPPSs, only NnGGPPS1 and NnGGPPS2 can produce GGPP in bacterial pigment complementation assay. Combination analysis of subcellular localization and gene co-expression analysis (GCN) illustrates that NnGGPPS1 is the main transcript related with methylerythritol phosphate (MEP) pathway, abscisic acid (ABA) biosynthesis, carotenoid and chlorophyll biosynthesis and degradation. Overexpression of NnGGPPS1 improves the growth of transgenic tobacco, and increases carotenoids and chlorophyll contents. Moreover, NnGGPPS1 transgenic tobacco exhibits improved photosynthesis efficiency and ROS scavenging ability. The up-regulated expression of the key genes in MEP pathway, carotenoid biosynthesis and chlorophyll biosynthesis, result in the increase of metabolic flux in NnGGPPS1 transgenic lines. Furthermore, the elevated MEP-derived primary metabolites of carotenoid and chlorophyll was attributed to enhancement of plant biomass of NnGGPPS1 transgenic lines. Therefore, NnGGPPS1 plays a vital role in biosynthesis of carotenoid and chlorophyll.

Unraveling transcriptomics of sorghum grain carotenoids: a step forward for biofortification

BackgroundSorghum (Sorghum bicolor [L.] Moench) is a promising target for pro-vitamin A biofortification as it is a global staple crop, particularly in regions where vitamin A deficiency is prevalent. As with most cereal grains, carotenoid concentrations are low in sorghum, and breeding could be a feasible strategy to increase pro-vitamin A carotenoids to biologically relevant concentrations. However, there are knowledge gaps in the biosynthesis and regulation of sorghum grain carotenoids, which can limit breeding effectiveness. The aim of this research was to gain an understanding of the transcriptional regulation of a priori candidate genes in carotenoid precursor, biosynthesis, and degradation pathways.ResultsWe used RNA sequencing of grain to compare the transcriptional profile of four sorghum accessions with contrasting carotenoid profiles through grain development. Most a priori candidate genes involved in the precursor MEP, carotenoid biosynthesis, and carotenoid degradation pathways were found to be differentially expressed between sorghum grain developmental stages. There was also differential expression of some of the a priori candidate genes between high and low carotenoid content groups at each developmental time point. Among these, we propose geranyl geranyl pyrophosphate synthase (GGPPS), phytoene synthase (PSY), and phytoene desaturase (PDS) as promising targets for pro-vitamin A carotenoid biofortification efforts in sorghum grain.ConclusionsA deeper understanding of the controls underlying biosynthesis and degradation of sorghum grain carotenoids is needed to advance biofortification efforts. This study provides the first insights into the regulation of sorghum grain carotenoid biosynthesis and degradation, suggesting potential gene targets to prioritize for molecular breeding.

Identification and Functional Analysis of Two Novel Genes-Geranylgeranyl Pyrophosphate Synthase Gene (AlGGPPS) and Isopentenyl Pyrophosphate Isomerase Gene (AlIDI)-from Aurantiochytrium limacinum Significantly Enhance De Novo β-Carotene Biosynthesis in Escherichia coli.

Precursor regulation has been an effective strategy to improve carotenoid production and the availability of novel precursor synthases facilitates engineering improvements. In this work, the putative geranylgeranyl pyrophosphate synthase encoding gene (AlGGPPS) and isopentenyl pyrophosphate isomerase encoding gene (AlIDI) from Aurantiochytrium limacinum MYA-1381 were isolated. We applied the excavated AlGGPPS and AlIDI to the de novo β-carotene biosynthetic pathway in Escherichia coli for functional identification and engineering application. Results showed that the two novel genes both functioned in the synthesis of β-carotene. Furthermore, AlGGPPS and AlIDI performed better than the original or endogenous one, with 39.7% and 80.9% increases in β-carotene production, respectively. Due to the coordinated expression of the 2 functional genes, β-carotene content of the modified carotenoid-producing E. coli accumulated a 2.99-fold yield of the initial EBIY strain in 12 h, reaching 10.99 mg/L in flask culture. This study helped to broaden current understanding of the carotenoid biosynthetic pathway in Aurantiochytrium and provided novel functional elements for carotenoid engineering improvements.

Genome-wide identification of the geranylgeranyl pyrophosphate synthase (GGPS) gene family involved in chlorophyll synthesis in cotton

BackgroundGeranylgeranyl pyrophosphate synthase (GGPS) is a structural enzyme of the terpene biosynthesis pathway that is involved in regulating plant photosynthesis, growth and development, but this gene family has not been systematically studied in cotton.ResultsIn the current research, genome-wide identification was performed, and a total of 75 GGPS family members were found in four cotton species, Gossypium hirsutum, Gossypium barbadense, Gossypium arboreum and Gossypium raimondii. The GGPS genes were divided into three subgroups by evolutionary analysis. Subcellular localization prediction showed that they were mainly located in chloroplasts and plastids. The closely related GGPS contains a similar gene structure and conserved motif, but some genes are quite different, resulting in functional differentiation. Chromosome location analysis, collinearity and selection pressure analysis showed that many fragment duplication events occurred in GGPS genes. Three-dimensional structure analysis and conservative sequence analysis showed that the members of the GGPS family contained a large number of α-helices and random crimps, and all contained two aspartic acid-rich domains, DDxxxxD and DDxxD (x is an arbitrary amino acid), suggesting its key role in function. Cis-regulatory element analysis showed that cotton GGPS may be involved in light response, abiotic stress and other processes. A GGPS gene was silenced successfully by virus-induced gene silencing (VIGS), and it was found that the chlorophyll content in cotton leaves decreased significantly, suggesting that the gene plays an important role in plant photosynthesis.ConclusionsIn total, 75 genes were identified in four Gossypium species by a series of bioinformatics analysis. Gene silencing from GGPS members of G. hirsutum revealed that GGPS plays an important regulatory role in photosynthesis. This study provides a theoretical basis for the biological function of GGPS in cotton growth and development.

Gibberellic acid overproduction in Fusarium fujikuroi using regulatory modification and transcription analysis.

Gibberellic acid (GA3), one of the natural diterpenoids produced by Fusarium fujikuroi, serves as an important phytohormone in agriculture for promoting plant growth. Presently, the metabolic engineering strategies for increasing the production of GA3 are progressing slowly, which seriously restricted the advancing of the cost-effective industrial production of GA3. In this study, an industrial strain with high-yield GA3 of F. fujikuroi was constructed by metabolic modification, coupling with transcriptome analysis and promoter engineering. The over-expression of AreA and Lae1, two positive factors in the regulatory network, generated an initial producing strain with GA3 production of 2.78g L-1. Compared with a large abundance of transcript enrichments in the GA3 synthetic gene cluster discovered by the comparative transcriptome analysis, geranylgeranyl pyrophosphate synthase 2 (Ggs2), and cytochrome P450-3 genes, two key genes that respectively participated in the initial and final step of biosynthesis, were identified to be downregulated when the highest GA3 productivity was obtained. Employing with a nitrogen-responsive bidirectional promoter, the two rate-limiting genes were dynamically upregulated, and therefore, the production of GA3 was increased to 3.02g L-1. Furthermore, the top 20 upregulated genes were characterized in GA3 over-production, and their distributions in chromosomes suggested potential genomic regions with a high transcriptional level for further strain development. The construction of a GA3 high-yield-producing strain was successfully achieved, and insights into the enriched functional transcripts provided novel strain development targets of F. fujikuroi, offering an efficient microbial development platform for industrial GA3 production. KEY POINTS: • Global regulatory modification was achieved in F. fujikuroi for GA3 overproduction. • Comparative transcriptome analysis revealed bottlenecks in GA specific-pathway. • A dynamically nitrogen-regulated bidirectional promoter was cloned and employed.

Elimination of enzymes catalysis compartmentalization enhancing taxadiene production in Saccharomyces cerevisiae.

Taxadiene is an important precursor in taxol biosynthesis pathway, but its biosynthesis in eukaryotic cell factories is limited, which seriously hinders the biosynthesis of taxol. In this study, it is found that there was the catalysis compartmentalization between two key exogenous enzymes of geranylgeranyl pyrophosphate synthase and taxadiene synthase (TS) for taxadiene synthesis progress, due to their different subcellular localization. Firstly, the enzyme-catalysis compartmentalization was overcome by means of the intracellular relocation strategies of taxadiene synthase, including N-terminal truncation of taxadiene synthase and enzyme fusion of GGPPS-TS. With the help of two strategies for enzyme relocation, the taxadiene yield was increased by 21% and 54% respectively, among them the GGPPS-TS fusion enzyme is more effective. Further, the expression of GGPPS-TS fusion enzyme was improved via the multi-copy plasmid, resulting that the taxadiene titer was increased by 38% to 21.8mg/L at shake-flask level. Finally, the maximum taxadiene titer of 184.2mg/L was achieved by optimization of the fed-batch fermentation conditions in 3L bioreactor, which is the highest reported titer of taxadiene biosynthesis accomplished in eukaryotic microbes. This study provides a successful example for improving biosynthesis of complex natural products by solving the critical problem of multistep enzymes catalysis compartmentalization.

Disruption of protein geranylgeranylation in the cerebellum causes cerebellar hypoplasia and ataxia via blocking granule cell progenitor proliferation

The prenylation of proteins is involved in a variety of biological functions. However, it remains unknown whether it plays an important role in the morphogenesis of the cerebellum. To address this question, we generated a mouse model, in which the geranylgeranyl pyrophosphate synthase (Ggps1) gene is inactivated in neural progenitor cells in the developing cerebellum. We report that conditional knockout (cKO) of Ggps1 leads to severe ataxia and deficient locomotion. To identify the underlying mechanisms, we completed a series of cellular and molecular experiments. First, our morphological analysis revealed significantly decreased population of granule cell progenitors (GCPs) and impaired proliferation of GCPs in the developing cerebellum of Ggps1 cKO mice. Second, our molecular analysis showed increased expression of p21, an important cell cycle regulator in Ggps1 cKO mice. Together, this study highlights a critical role of Ggpps-dependent protein prenylation in the proliferation of cerebellar GCPs during cerebellar development.

Large-scale bioproduction of natural astaxanthin in Yarrowia lipolytica

Astaxanthin is a high-value chemical with strong antioxidant, anti-inflammatory and coloration properties. Here, a set of novel genetic engineering and culturing strategies for efficient astaxanthin bioproduction in Yarrowia lipolytica is reported. Modular pathway engineering and the fusion of two key enzymes (geranylgeranyl pyrophosphate synthase and bifunctional lycopene cyclase/phytoene synthase) yielded a recombinant strain with enhanced β-carotene and astaxanthin production, accumulating astaxanthin up to 131.9 mg/L in small-scale cultures with sucrose and 587.3 mg/L in a 3-L bioreactor with glucose as carbon sources, respectively. Notably, formation of intracellular carotenoid crystals was observed. Addition of oil overlayer at different regimes in 3-L bioreactors promoted secretion of astaxanthin and increased astaxanthin titer up to 973.4 g/L. Lastly, fed-batch fermentation in a 100-L bioreactor with glycerol as the carbon source resulted in a final astaxanthin titer of 812.3 mg/L after 114 h, representing the highest astaxanthin titer reported so far in large-scale cultures.

Facile biosynthesis of taxadiene by a newly constructed Escherichia coli strain fusing enzymes taxadiene synthase and geranylgeranyl pyrophosphate synthase

Taxadiene has received extensive attention as the hydrocarbon backbone of a well-known anti-cancer drug, Paclitaxel. In this study, a de novo pathway for taxadiene biosynthesis from cheap carbon sources was newly constructed using Escherichia coli BL21 (DE3) as a chassis cell. The total biosynthesis pathway of taxadiene was divided into upstream and downstream modules for respective optimization. To facilitate the cyclization of the diterpene substrate geranylgeranyl pyrophosphate, two of the key downstream module enzymes, taxadiene synthase and geranylgeranyl pyrophosphate synthase, were genetically expressed in the form of fusion protein. After a series of optimization, the best recombinant strain, designated as E. coli strain ECU5008, achieved a titer of 93.5 mg/L taxadiene in shake flask cultivation. In addition, a commercially available macroporous adsorption resin was employed for the extraction and purification of taxadiene, in which each gram of resin Hz-816 could adsorb about 13.2 mg of taxadiene from the methanol extract of the cultured E. coli cells. The application of macroporous adsorption resin effecctively improved the isolation yield of taxadiene from fermentation broth. Availability data and materialsAll data generated or analyzed during this study are included in this article and its Supplementary information file.

Potential biomarkers for inflammatory response in acute lung injury

Acute lung injury (ALI) is a severe respiratory disorder occurring in critical care medicine, with high rates of mortality and morbidity. This study aims to screen the potential biomarkers for ALI.Microarray data of lung tissues from lung-specific geranylgeranyl pyrophosphate synthase large subunit 1 knockout and wild-type mice treated with lipopolysaccharide were downloaded. Differentially expressed genes (DEGs) between ALI and wild-type mice were screened. Functional analysis and the protein–protein interaction (PPI) modules were analyzed. Finally, a miRNA-transcription factor (TF)-target regulation network was constructed.Totally, 421 DEGs between ALI and wild-type mice were identified. The upregulated DEGs were mainly enriched in the peroxisome proliferator-activated receptor signaling pathway, and fatty acid metabolic process, while downregulated DEGs were related to cytokine–cytokine receptor interaction and regulation of cytokine production. Cxcl5, Cxcl9, Ccr5, and Cxcr4 were key nodes in the PPI network. In addition, three miRNAs (miR505, miR23A, and miR23B) and three TFs (PU1, CEBPA, and CEBPB) were key molecules in the miRNA-TF-target network. Nine genes including ADRA2A, P2RY12, ADORA1, CXCR1, and CXCR4 were predicted as potential druggable genes.As a conclusion, ADRA2A, P2RY12, ADORA1, CXCL5, CXCL9, CXCR1, and CXCR4 might be novel markers and potential druggable genes in ALI by regulating inflammatory response.

Efficient production of retinol in Yarrowia lipolytica by increasing stability using antioxidant and detergent extraction

The demand for bio-based retinol (vitamin A) is currently increasing, however its instability represents a major bottleneck in microbial production. Here, we developed an efficient method to selectively produce retinol in Yarrowia lipolytica. The β-carotene 15,15′-dioxygenase (BCO) cleaves β-carotene into retinal, which is reduced to retinol by retinol dehydrogenase (RDH). Therefore, to produce retinol, we first generated β-carotene-producing strain based on a high-lipid-producer via overexpressing genes including heterologous β-carotene biosynthetic genes, GGS1F43I mutant of endogenous geranylgeranyl pyrophosphate synthase isolated by directed evolution, and FAD1 encoding flavin adenine dinucleotide synthetase, while deleting several genes previously known to be beneficial for carotenoid production. To produce retinol, 11 copies of BCO gene from marine bacterium 66A03 (Mb.Blh) were integrated into the rDNA sites of the β-carotene overproducer. The resulting strain produced more retinol than retinal, suggesting strong endogenous promiscuous RDH activity in Y. lipolytica. The introduction of Mb.Blh led to a considerable reduction in β-carotene level, but less than 5% of the consumed β-carotene could be detected in the form of retinal or retinol, implying severe degradation of the produced retinoids. However, addition of the antioxidant butylated hydroxytoluene (BHT) led to a >20-fold increase in retinol production, suggesting oxidative damage is the main cause of intracellular retinol degradation. Overexpression of GSH2 encoding glutathione synthetase further improved retinol production. Raman imaging revealed co-localization of retinol with lipid droplets, and extraction of retinol using Tween 80 was effective in improving retinol production. By combining BHT treatment and extraction using Tween 80, the final strain CJ2104 produced 4.86 g/L retinol and 0.26 g/L retinal in fed-batch fermentation in a 5-L bioreactor, which is the highest retinol production titer ever reported. This study demonstrates that Y. lipolytica is a suitable host for the industrial production of bio-based retinol.

Cloning and homologous characterization of geranylgeranyl pyrophosphate synthase (GGPPS) from Withania somnifera revealed alterations in metabolic flux towards gibberellic acid biosynthesis.

Overexpression of a novel geranylgeranyl pyrophosphate synthase gene (WsGGPPS) in planta resulted in increased levels of gibberellic acid and decrease in withanolide content. Withania somnifera (L.) Dunal, the herb from family Solanaceae is one of the most treasured medicinal plant used in traditional medicinal systems owing to its unique stockpile of pharmaceutically active secondary metabolites. Phytochemical and pharmacological studies in this plant were well established, but the genes affecting the regulation of biosynthesis of major metabolites were not well elucidated. In this study cloning and functional characterization of a key enzyme in terpenoid biosynthetic pathway viz. geranylgeranyl pyrophosphate synthase (EC 2.5.1.29) gene from Withania somnifera was performed. The full length WsGGPPS gene contained 1,104 base pairs that encode a polypeptide of 365 amino acids. The quantitative expression analysis suggested that WsGGPPS transcripts were expressed maximally in flower tissues followed by berry tissues. The expression levels of WsGGPPS were found to be regulated by methyl jasmonate (MeJA) and salicylic acid (SA). Amino acid sequence alignment and phylogenetic studies suggested that WsGGPPS had close similarities with GGPPS of Solanum tuberosum and Solanum pennellii. The structural analysis provided basic information about three dimensional features and physicochemical parameters of WsGGPPS protein. Overexpression of WsGGPPS in planta for its functional characterization suggested that the WsGGPPS was involved in gibberellic acid biosynthesis.

Synthesis and Evaluation of Structurally Diverse C-2-Substituted Thienopyrimidine-Based Inhibitors of the Human Geranylgeranyl Pyrophosphate Synthase.

Novel analogues of C-2-substituted thienopyrimidine-based bisphosphonates (C2-ThP-BPs) are described that are potent inhibitors of the human geranylgeranyl pyrophosphate synthase (hGGPPS). Members of this class of compounds induce target-selective apoptosis of multiple myeloma (MM) cells and exhibit antimyeloma activity in vivo. A key structural element of these inhibitors is a linker moiety that connects their (((2-phenylthieno[2,3-d]pyrimidin-4-yl)amino)methylene)bisphosphonic acid core to various side chains. The structural diversity of this linker moiety, as well as the side chains attached to it, was investigated and found to significantly impact the toxicity of these compounds in MM cells. The most potent inhibitor identified was evaluated in mouse and rat for liver toxicity and systemic exposure, respectively, providing further optimism for the potential value of such compounds as human therapeutics.

A geranylgeranyl pyrophosphate synthase gene, IbGGPS, increases carotenoid contents in transgenic sweetpotato

Geranylgeranyl pyrophosphate synthase (GGPS) plays an important role in the biosynthesis of carotenoids. In a previous study, the IbGGPS gene was isolated from a sweetpotato, Ipomoea batatas (L.) Lam., line Nongdafu 14 with high carotenoid contents, but its role and underlying mechanisms in carotenoid biosynthesis in sweetpotato were not investigated. In the present study, the IbGGPS gene was introduced into a sweetpotato cv. Lizixiang and the contents of β-carotene, β-cryptoxanthin, zeaxanthin and lutein were significantly increased in the storage roots of the IbGGPS-overexpressing sweetpotato plants. Further analysis showed that IbGGPS gene overexpression systematically up-regulated the genes involved in the glycolytic, 2-C-methyl-D-erythritol-4-phosphate (MEP) and carotenoid pathways, which increased the carotenoid contents in the transgenic plants. These results indicate that the IbGGPS gene has the potential for use in improving the carotenoid contents in sweetpotato and other plants.