Read by QxMD icon Read


Miho Takemura, Rie Tanaka, Norihiko Misawa
Cycloartenol is biosynthetically the first sterol skeleton, which is metabolized to phytosterols such as β-sitosterol and stigmasterol. β-Amyrin is the most commonly occurring aglycone skeleton for oleanane-type saponins such as glycyrrhizin and saikosaponins. It has been regarded that these cyclic triterpenes are unable to be produced in Escherichia coli, while no reports are available on their production with E. coli. Here, we describe a method to synthesize triterpene skeletons from higher plants, including cycloartenol and β-amyrin...
July 15, 2017: Applied Microbiology and Biotechnology
Piyamas Atiphasaworn, Sakon Monggoot, Eleni Gentekaki, Siraprapa Brooks, Patcharee Pripdeevech
Fourteen fungal endophytes were isolated from the Ocimum basilicum var. thyrsiflora leaves collected from Northern Thailand. Eight genera were identified including Aspergillus, Ascochyta, Nigrospora, Blastomyces, Colletotrichum, Exidia, Clitopilus, and Nomuraea. The antibacterial activity of crude extracts from all endophytic fungi was tested against nine human bacterial pathogens: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus subtilis, Bacillus cereus, Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Vibrio cholerae, and Vibrio parahaemolyticus...
July 12, 2017: Current Microbiology
John D Perpich, Awdhesh Kalia, Christopher T D Price, Snake C Jones, Kathy Wong, Kalle Gehring, Yousef Abu Kwaik
Within macrophages and amoeba, the Legionella-containing vacuole (LCV) membrane is derived from the ER. The bona fide F-box AnkB effector protein of L. pneumophila strain AA100/130b is anchored to the cytosolic side of the LCV membrane through host-mediated farnesylation of its C-terminal eukaryotic "CaaX" motif. Here we show that the AnkB homologue of the Paris strain has a frame shift mutation that led to a loss of the CaaX motif and a concurrent generation of a unique C-terminal KNKYAP motif, which resembles the eukaryotic di-lysine ER-retention motif (KxKxx)...
July 11, 2017: Scientific Reports
Anna K P Serquiña, Diane M Kambach, Ontara Sarker, Joseph M Ziegelbauer
From various screens, we found that Kaposi's sarcoma-associated herpesvirus (KSHV) viral microRNAs (miRNAs) target several enzymes in the mevalonate/cholesterol pathway. 3-Hydroxy-3-methylglutaryl-coenzyme A (CoA) synthase 1 (HMGCS1), 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR [a rate-limiting step in the mevalonate pathway]), and farnesyl-diphosphate farnesyltransferase 1 (FDFT1 [a committed step in the cholesterol branch]) are repressed by multiple KSHV miRNAs. Transfection of viral miRNA mimics in primary endothelial cells (human umbilical vein endothelial cells [HUVECs]) is sufficient to reduce intracellular cholesterol levels; however, small interfering RNAs (siRNAs) targeting only HMGCS1 did not reduce cholesterol levels...
July 11, 2017: MBio
Petrus Yesaya Samori, Koki Makabe, Norimasa Ohya, Bunpei Hatano, Satoshi Murakami, Tatsuro Kijima
Farnesyl diphosphate synthase (FPPase) is an enzyme that catalyzes the condensation between one molecule of dimethylallyl diphosphate (DMAPP) and two molecules of isopentenyl diphosphate (IPP) to produce farnesyl diphosphate (FPP). FPP is an important precursor in the isoprenoid synthesis pathway. In this study, the crystal structure of FPPase from Geobacillus stearothermophilus (GsFPPase) was determined at 2.31 Å resolution. The structure of GsFPPase shows a three-layered all α-helical fold and conserved functional domains similar to other prenyltransferases...
August 2017: 3 Biotech
Saubhik Mitra, Amarnath Karmakar, Abhishek Mukherjee, Anandamay Barik
Larvae and adults of Altica cyanea (Weber) (Coleoptera: Chrysomelidae) feed on the rice-field weed Ludwigia octovalvis (Jacq.) Raven (Onagraceae), commonly known as willow primrose, which is considered a biocontrol agent of the weed. Volatile organic compounds from undamaged plants, plants after 4, 12, and 36 h of continuous feeding by A. cyanea larvae or adult females and after mechanical damaging were identified by GC-MS and GC-FID analyses. Twenty nine compounds were identified from undamaged plants. 2Z-Penten-1-ol, geraniol, and 1-tridecanol were present in all plants damaged by larvae...
July 10, 2017: Journal of Chemical Ecology
Lixia Yang, Liangzhen Jiang, Wei Li, Yun Yang, Guolin Zhang, Yinggang Luo
Geranyl diphosphate (GPP), the unique precursor for all monoterpenoids, is biosynthesized from isopentenyl diphosphate and dimethylallyl diphosphate via the head-to-tail condensation reaction catalyzed by GPP synthase (GPPS). Herein a homomeric GPPS from Camptotheca acuminata, a camptothecin-producing plant, was obtained from 5'- and 3'-rapid amplification of cDNA ends and subsequent overlap extension and convenient PCR amplifications. The truncate CaGPPS was introduced to replace ispA of pBbA5c-MevT(CO)-MBIS(CO, ispA), a de novo biosynthetic construct for farnesyl diphosphate generation, and overexpressed in Escherichia coli, together with the truncate geraniol synthase-encoding gene from C...
July 10, 2017: Journal of Industrial Microbiology & Biotechnology
Naomi O Hodgins, Julie Tzu-Wen Wang, Khuloud T Al-Jamal
Nitrogen containing bisphosphonates (N-BPs) including zoledronate (ZOL) and alendronate (ALD) inhibit farnesyl diphosphate synthase, and have been shown to have a cytotoxic affect against cancer cells as a monotherapy and to also sensitise tumour cells to destruction by γδ T cells. γδ T cells are a subset of human T lymphocytes and have a diverse range of roles in the immune system including the recognition and destruction of cancer cells. This property of γδ T cells can be harnessed for use in cancer immunotherapy through in vivo expansion or the adoptive transfer of ex vivo activated γδ T cells...
July 7, 2017: Advanced Drug Delivery Reviews
Lin-Lin Teng, Tian-Yang Song, Zi-Fei Xu, Xiao Liu, Rong Dai, Yong-Hong Chen, Sheng-Hong Li, Ke-Qin Zhang, Xue-Mei Niu
Sesquiterpenyl epoxy-cyclohexenoids (SECs) show impressive biological activities. However, the key pathways for SECs still remain unambiguous. Unexpectedly, 11 new SECs and derivatives with diverse oxidation patterns were isolated after the deletion of gene 274. A high accumulation of toluquinol and its new glycosides in mutant Δ276 and further isolation of the most crucial precursors farnesyl hydroquinone, farnesyl quinone, and three new derivatives from mutant Δ278 confirm that farnesylation at toluquinol is the key step for SECs...
July 10, 2017: Organic Letters
Miu Iijima, Ryosuke Munakata, Hironobu Takahashi, Hiromichi Kenmoku, Ryuichi Nakagawa, Takeshi Kodama, Yoshinori Asakawa, Ikuro Abe, Kazufumi Yazaki, Fumiya Kurosaki, Futoshi Taura
Daurichromenic acid (DCA) synthase catalyzes the oxidative cyclization of grifolic acid to produce DCA, an anti-HIV meroterpenoid isolated from Rhododendron dauricum. We identified a novel cDNA encoding DCA synthase by transcriptome-based screening from young leaves of R. dauricum. The gene coded for a 533-amino acid polypeptide with moderate homologies to FAD oxidases from other plants. The primary structure contained an N-terminal signal peptide, and conserved amino acid residues to form bicovalent linkage to FAD isoalloxazine ring at His112 and Cys175...
July 5, 2017: Plant Physiology
Shengping You, Qingdian Yin, Jianye Zhang, Chengyu Zhang, Wei Qi, Lan Gao, Zhiping Tao, Rongxin Su, Zhimin He
Farnesene has been identified as suitable jet fuel substitutes and metabolic engineering for microbial production of farnesene is an alternative and attractive route. In this study, due to accumulation of toxic intermediate isopentenyl pyrophosphate (IPP), an engineered Escherichia coli strain harboring heterologous mevalonate pathway produced only 4.11mg/L β-farnesene. Through higher-level expression of isopentenyl diphosphate isomerase and farnesyl diphosphate synthase to minimize the accumulated IPP, another engineered strain with relatively balanced mevalonate pathway was constructed and had the highest production of β-farnesene to date (8...
June 13, 2017: Bioresource Technology
Le T Huong, Nguyen V Hung, Mai V Chung, Do N Dai, Isiaka A Ogunwande
The chemical constituents identified in the essential oils hydrodistilled from the leaves of Amomum gagnepainii T.L.Wu, K.Larsen and Turland and Amomum repoense Pierre ex Gagnep (Zingiberaceae) of Vietnam origin are reported. The chemical analyses were performed by means of gas chromatography-flame ionisation detector (GC-FID) and gas chromatography coupled with mass spectrometry (GC-MS). The main compounds of A. gagnepainii were farnesyl acetate (18.5%), zerumbone (16.4%) and β-caryophyllene (10.5%). On the other hand, Amomum repoense comprised of monoterpenes dominated by β-pinene (33...
July 3, 2017: Natural Product Research
Melissa M Cadelis, Marie-Lise Bourguet-Kondracki, Joëlle Dubois, Marcel Kaiser, Jean Michel Brunel, David Barker, Brent R Copp
Marine meroterpenoids, thiaplidiaquinones A and B and their respective non-natural dioxothiazine regioisomers have been shown to inhibit mammalian and protozoal farnesyltransferase (FTase) with the regioisomers exhibiting activity in the nanomolar range. In order to explore the structure-activity relationship (SAR) of this class of marine natural products, analogues of thiaplidiaquinones A and B and their regioisomers were synthesised, with variation in the number of isoprene units present in their side chains to afford prenyl and farnesyl analogues...
June 19, 2017: Bioorganic & Medicinal Chemistry
Ling Qiu, Hui Yang, Gaochao Lv, Ke Li, Guiqing Liu, Wei Wang, Shanshan Wang, Xueyu Zhao, Minhao Xie, Jianguo Lin
A platinum(II) complex [Pt(en)]2ZL [en = ethylenediamine; ZL = 1-hydroxy-3(1H-imidazol-1-yl)ethane-1,1-diylbisphosphonic acid, commonly called as zoledronic acid] has been designed and synthesized recently in order to look for new anticancer drugs with high efficacy and low side effects. It exhibited cytotoxic effects on the human cancer cells SGC7901, HepG2, MCF-7, MDA-MB-231, HCT116, and U2OS, and the cytotoxicity against SGC7901 is particularly remarkable. It also showed higher cytotoxicity and better selectivity than the corresponding ligand ZL in inhibiting cancer cells SGC7901 and HepG2 rather than normal cells GES-1 and LO2...
June 27, 2017: European Journal of Pharmacology
Ayumi Tanaka, Mohamed O Radwan, Akiyuki Hamasaki, Asumi Ejima, Emiko Obata, Ryoko Koga, Hiroshi Tateishi, Yoshinari Okamoto, Mikako Fujita, Mitsuyoshi Nakao, Kazuo Umezawa, Fuyuhiko Tamanoi, Masami Otsuka
Protein prenylation such as farnesylation and geranylgeranylation is associated with various diseases. Thus, many inhibitors of prenyltransferase have been developed. We report novel inhibitors of farnesyltransferase with a zinc-site recognition moiety and a farnesyl/dodecyl group. Molecular docking analysis showed that both parts of the inhibitor fit well into the catalytic domain of farnesyltransferase. The synthesized inhibitors showed activity against farnesyltransferase in vitro and inhibited proliferation of the pancreatic cell line AsPC-1...
June 20, 2017: Bioorganic & Medicinal Chemistry Letters
Ying Yang, Xiqing Rong, Xue Lv, Wenbing Jiang, Yuan Yang, Dongwu Lai, Shiming Xu, Guosheng Fu
AIM: We previously demonstrated that anoxia-mediated Ca(2+) handling dysfunction could be ameliorated through inhibition of mevalonate pathway via RhoA- and Ras-related mechanisms in H9c2 cells. In this study, we further explored whether inhibition of mevalonate pathway is associated with cardiac remodeling and dysfunction in ischemic cardiomyopathy, and discuss the possible role of Ras, Rac and RhoA in cardiac dysfunction. METHODS: We investigated the role of mevalonate pathway in cardiac remodeling and cardiomyocyte Ca(2+) handling proteins expression in a rat model of cardiac dysfunction due to myocardial infarction (MI)...
June 30, 2017: Cardiovascular Therapeutics
Evan B Stubbs
Small monomeric GTPases, including those belonging to the Rho family, regulate a diverse array of intracellular signaling pathways which affect vesicle transport/trafficking, endocytosis, cell cycle progression, cell contractility, and formation of stress fibers or focal adhesions. Functional activation of newly synthesized small monomeric GTPases is facilitated by a multistep post-translational process involving transferase-catalyzed addition of farnesyl or geranylgeranyl isoprenoids to conserved cysteine residues within a unique carboxy terminal CaaX motif...
2017: Methods in Molecular Biology
Christopher Ritchie, Andrew Mack, Logan Harper, Ayna Alfadhli, Philip J S Stork, Xiaolin Nan, Eric Barklis
BACKGROUND: Mutations of the human K-Ras 4B (K-Ras) G protein are associated with a significant proportion of all human cancers. Despite this fact, a comprehensive analysis of K-Ras interactions is lacking. Our investigations focus on characterization of the K-Ras interaction network. MATERIALS AND METHODS: We employed a biotin ligase-tagging approach, in which tagged K-Ras proteins biotinylate neighbor proteins in a proximity-dependent fashion, and proteins are identified via mass spectrometry (MS) sequencing...
July 2017: Cancer Genomics & Proteomics
Sergii Shydlovskyi, Anke Y Zienert, Semra Ince, Christine Dovengerds, Annika Hohendahl, Julia M Dargazanli, Ailisa Blum, Saskia D Günther, Nikolay Kladt, Michael Stürzl, Astrid C Schauss, Miriam Kutsch, Aurélien Roux, Gerrit J K Praefcke, Christian Herrmann
Dynamin-like proteins (DLPs) mediate various membrane fusion and fission processes within the cell, which often require the polymerization of DLPs. An IFN-inducible family of DLPs, the guanylate-binding proteins (GBPs), is involved in antimicrobial and antiviral responses within the cell. Human guanylate-binding protein 1 (hGBP1), the founding member of GBPs, is also engaged in the regulation of cell adhesion and migration. Here, we show how the GTPase cycle of farnesylated hGBP1 (hGBP1F) regulates its self-assembly and membrane interaction...
June 23, 2017: Proceedings of the National Academy of Sciences of the United States of America
Jaap S Sinninghe Damsté, W Irene C Rijpstra, Svetlana N Dedysh, Bärbel U Foesel, Laura Villanueva
Hopanoids are pentacyclic triterpenoid lipids synthesized by different bacterial groups. Methylated hopanoids were believed to be exclusively synthesized by cyanobacteria and aerobic methanotrophs until the genes encoding for the methylation at the C-2 and C-3 position (hpnP and hpnR) were found to be widespread in the bacterial domain, invalidating their use as specific biomarkers. These genes have been detected in the genome of the Acidobacterium "Ca. Koribacter versatilis," but our knowledge of the synthesis of hopanoids and the presence of genes of their biosynthetic pathway in other member of the Acidobacteria is limited...
2017: Frontiers in Microbiology
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"