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Angewandte Chemie (International Ed. in... Aug 2022A short total synthesis of tunicamycin V (1), a non-selective phosphotransferase inhibitor, is achieved via a Büchner-Curtius-Schlotterbeck type reaction....
A short total synthesis of tunicamycin V (1), a non-selective phosphotransferase inhibitor, is achieved via a Büchner-Curtius-Schlotterbeck type reaction. Tunicamycin V can be synthesized in 15 chemical steps from D-galactal with 21 % overall yield. The established synthetic scheme is operationally very simple and flexible to introduce building blocks of interest. The inhibitory activity of one of the designed analogues 28 against human dolichyl-phosphate N-acetylglucosaminephosphotransferase 1 (DPAGT1) is 12.5 times greater than 1. While tunicamycins are cytotoxic molecules with a low selectivity, the novel analogue 28 displays selective cytostatic activity against breast cancer cell lines including a triple-negative breast cancer.
Topics: Antineoplastic Agents; Cytostatic Agents; Humans; Tunicamycin
PubMed: 35594368
DOI: 10.1002/anie.202203225 -
Bioorganic & Medicinal Chemistry Apr 2019Elucidating a structure-activity relationship study by evaluating a series of truncated analogues is a simple but important and effective tactic in medicinal chemistry...
Elucidating a structure-activity relationship study by evaluating a series of truncated analogues is a simple but important and effective tactic in medicinal chemistry based on natural products with a large and complex chemical structure. In this study, a series of truncated analogues of tunicamycin V were designed and synthesized and their MraY inhibitory activity was investigated in order to gain insight into the effect of these moieties on MraY inhibition.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Biological Products; Drug Design; Inhibitory Concentration 50; Staphylococcus aureus; Transferases; Transferases (Other Substituted Phosphate Groups); Tunicamycin
PubMed: 30850266
DOI: 10.1016/j.bmc.2019.02.035 -
The Analyst Nov 2019This paper describes how tunicamycin (Tu), the most widely used pharmacological agent for inducing endoplasmic reticulum (ER) stress, interacts with endothelial cells....
This paper describes how tunicamycin (Tu), the most widely used pharmacological agent for inducing endoplasmic reticulum (ER) stress, interacts with endothelial cells. Our results show that tunicamycin enters the cells and accumulates within the ER area. ER stress takes place when improperly folded or damaged proteins begin to accumulate; however, spectroscopic markers of these changes have not been identified as yet. In this work, Raman spectroscopy and scanning electron microscopy imaging of individual endothelial cells treated with Tu were performed. The changes in the biochemical composition of endothelial cells induced by Tu attributed to ER stress were studied in detail. A main feature of the Tu impact on the cells was a decrease of the phospholipid content in the area of ER, and the most abundant lipid with phosphorus groups found there, was identified as sphingomyelin.
Topics: Cell Line; Cluster Analysis; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Endothelial Cells; Humans; Principal Component Analysis; Spectrum Analysis, Raman; Sphingomyelins; Tunicamycin
PubMed: 31576836
DOI: 10.1039/c9an01456j -
Oncotarget Nov 2015Trastuzumab, a humanized monoclonal antibody targeting HER2, has demonstrated clinical benefits for women with HER2-positive breast cancer; however, trastuzumab...
Trastuzumab, a humanized monoclonal antibody targeting HER2, has demonstrated clinical benefits for women with HER2-positive breast cancer; however, trastuzumab resistance remains the biggest clinical challenge. In this study, results showed that tunicamycin, an inhibitor of N-glycosylation, synergistically enhanced the antitumor activity of trastuzumab against HER2-overexpressing breast cancer cells through induction of cell cycle arrest and apoptosis. Combined treatment of tunicamycin with trastuzumab dramatically decreased the expression of EGFR family and its down signaling pathway in SKBR3 and MCF-7/HER2 cells. Tunicamycin dose-dependently inhibited tumor growth in both of SKBR3 xenografts and MCF-7/HER2 xenografts. Optimal tunicamycin without inducing ER stress in liver tissue significantly increased the antitumor effect of trastuzumab in MCF-7/HER2 xenografts. Combinations of trastuzumab with N-glycosylation inhibitors tunicamycin may be a promising approach for improving clinical efficacy of trastuzumab.
Topics: Animals; Antineoplastic Combined Chemotherapy Protocols; Apoptosis; Breast Neoplasms; Cell Growth Processes; Drug Synergism; Female; Humans; MCF-7 Cells; Mice; Mice, Inbred BALB C; Mice, Nude; Trastuzumab; Tunicamycin; Xenograft Model Antitumor Assays
PubMed: 26498681
DOI: 10.18632/oncotarget.5334 -
Bioscience, Biotechnology, and... 2013We have developed a new series of R4L1 Gateway binary vectors (R4L1pGWB), which carry the bialaphos resistance gene (bar) or the UDP-N-acetylglucosamine:dolichol... (Review)
Review
Development of gateway binary vectors R4L1pGWB possessing the bialaphos resistance gene (bar) and the tunicamycin resistance gene as markers for promoter analysis in plants.
We have developed a new series of R4L1 Gateway binary vectors (R4L1pGWB), which carry the bialaphos resistance gene (bar) or the UDP-N-acetylglucosamine:dolichol phosphate N-acetylglucosamine-1-P transferase (GPT) gene as selection markers that confer BASTA® and tunicamycin resistance on plants respectively. R4L1pGWBs have an attR4-attL1-reporter and can accept an attL4-promoter-attR1 entry clone for easy construction of an attB4-promoter-attB1-reporter clone. The new R4L1pGWBs facilitate promoter:reporter analysis in pre-existing transgenic plants that are resistant to kanamycin or hygromycin.
Topics: Biomarkers; Cinnamates; Drug Resistance, Microbial; Genetic Vectors; Hygromycin B; Kanamycin; Organophosphorus Compounds; Plants, Genetically Modified; Promoter Regions, Genetic; Tunicamycin; Uridine Diphosphate Sugars
PubMed: 23924715
DOI: 10.1271/bbb.130405 -
Journal of Agricultural and Food... Oct 2022Endoplasmic reticulum (ER) stress is a crucial factor in the pathogenesis of intestinal diseases. Pterostilbene (PT) has been demonstrated to mitigate ER stress and...
Endoplasmic reticulum (ER) stress is a crucial factor in the pathogenesis of intestinal diseases. Pterostilbene (PT) has been demonstrated to mitigate ER stress and protect against intestinal disorders. Here, we investigated the effects of PT on tunicamycin (TM)-induced intestinal ER stress and intestinal barrier damage in piglets and in intestinal porcine epithelial cell-jejunum 2 (IPEC-J2) cells. Results indicated that PT prevented TM-induced body weight loss (-0.67 ± 0.16 vs -0.48 ± 0.08 kg) and improved intestinal barrier integrity and goblet cell function of the TM-challenged piglets ( < 0.05). PT also inhibited ER stress, restored redox homeostasis and autophagic flux, and decreased apoptosis in the TM-challenged jejunum and the TM-exposed IPEC-J2 cells ( < 0.05). However, these attenuating effects of PT in the TM-treated IPEC-J2 cells were blunted by the knockdown of sirtuin 1 ( < 0.05). Moreover, PT increased the Ace index (390.12 ± 60.05 vs 460.27 ± 42.83) and downregulated the prevalence of the phylum (48.73% ± 12.62% vs 32.10% ± 11.08%) of cecal microbiota of the TM-challenged piglets ( < 0.05). In conclusion, PT alleviated TM-induced intestinal barrier damage by regulating ER homeostasis, oxidative stress, autophagic flux, and gut microbiota.
Topics: Animals; Swine; Tunicamycin; Endoplasmic Reticulum Stress; Gastrointestinal Microbiome; Sirtuin 1; Autophagy; Apoptosis; Oxidative Stress
PubMed: 36225099
DOI: 10.1021/acs.jafc.2c06041 -
American Journal of Physiology. Cell... Aug 2021Prolonged endoplasmic reticulum (ER) stress can mediate inflammatory myopathies and insulin signaling pathways. The double-stranded RNA (dsRNA)-activated protein kinase...
Prolonged endoplasmic reticulum (ER) stress can mediate inflammatory myopathies and insulin signaling pathways. The double-stranded RNA (dsRNA)-activated protein kinase R (PKR) has been implicated in skeletal muscle dysfunction. However, pathological roles of PKR in ER stress in muscle are not fully understood. The current study aimed to investigate the effect of imoxin (IMX), a selective PKR inhibitor, on tunicamycin (TN)-induced promotion of ER stress and suppression of insulin signaling in C2C12 myotubes. Cells were pretreated with 5 µM IMX for 1 h and exposed to 0.5 µg/mL TN for 23 h. A subset of cells was stimulated with 100 nM insulin for the last 15 min. mRNA expression and protein levels involved in ER stress were measured by RT-PCR and Western blotting, respectively. TN significantly augmented PKR phosphorylation by 231%, which was prevented by IMX. In addition, IMX reduced mRNA and protein levels of ER stress-related markers, including CCAAT-enhancer-binding protein homologous protein (CHOP, mRNA: 95% decrease; protein: 98% decrease), activating transcription factor 4 (ATF4, mRNA: 69% decrease; protein: 99% decrease), cleavage of ATF6, and spliced X-box-binding protein 1 (XBP-1s, mRNA: 88% decrease; protein: 79% decrease), which were induced by TN. Furthermore, IMX ameliorated TN-induced suppression of phospho-insulin receptor β (317% increase) and Akt phosphorylation (by 36% at Ser473 and 30% at Thr308) in myotubes, while augmenting insulin-stimulated AS160 phosphorylation and glucose uptake (by ∼30%). These findings suggest that IMX may protect against TN-induced skeletal muscle ER stress and insulin resistance, which are potentially mediated by PKR.
Topics: Animals; Endoplasmic Reticulum; Endoplasmic Reticulum Stress; Imidazoles; Indoles; Insulin; Insulin Resistance; Mice; Muscle Fibers, Skeletal; Phosphorylation; Signal Transduction; Tunicamycin
PubMed: 34077277
DOI: 10.1152/ajpcell.00544.2020 -
Nature Structural & Molecular Biology Mar 2018N-linked glycosylation is a predominant post-translational modification of protein in eukaryotes, and its dysregulation is the etiology of several human disorders. The...
N-linked glycosylation is a predominant post-translational modification of protein in eukaryotes, and its dysregulation is the etiology of several human disorders. The enzyme UDP-N-acetylglucosamine:dolichyl-phosphate N-acetylglucosaminephosphotransferase (GlcNAc-1-P-transferase or GPT) catalyzes the first and committed step of N-linked glycosylation in the endoplasmic reticulum membrane, and it is the target of the natural product tunicamycin. Tunicamycin has potent antibacterial activity, inhibiting the bacterial cell wall synthesis enzyme MraY, but its usefulness as an antibiotic is limited by off-target inhibition of human GPT. Our understanding of how tunicamycin inhibits N-linked glycosylation and efforts to selectively target MraY are hampered by a lack of structural information. Here we present crystal structures of human GPT in complex with tunicamycin. Structural and functional analyses reveal the difference between GPT and MraY in their mechanisms of inhibition by tunicamycin. We demonstrate that this difference could be exploited to design MraY-specific inhibitors as potential antibiotics.
Topics: Anti-Bacterial Agents; Bacterial Proteins; Enzyme Inhibitors; Glycosylation; Humans; Magnesium; Models, Molecular; Protein Binding; Protein Multimerization; Substrate Specificity; Transferases; Transferases (Other Substituted Phosphate Groups); Tunicamycin
PubMed: 29459785
DOI: 10.1038/s41594-018-0031-y -
Australian Veterinary Journal Aug 1987Quantitative toxicity studies were carried out in sheep using corynetoxin, tunicamycin and toxic annual ryegrass (Lolium rigidum). Sheep were very sensitive to these...
Quantitative toxicity studies were carried out in sheep using corynetoxin, tunicamycin and toxic annual ryegrass (Lolium rigidum). Sheep were very sensitive to these toxins. The lethal dose was about 35 micrograms/kg bodyweight for pure tunicamycin given by subcutaneous injection and 3 to 5 mg/kg for corynetoxin administered orally as slurries of bacterial galls of known corynetoxin content. The total lethal dose was of the same order, whether given as a single dose or as repeated smaller doses, the maximum interval tested being 9 weeks between doses. This finding indicates that a second exposure of animals to toxic rye grass in the one season would present a greater risk than would a first exposure to the same field. It also demonstrates the advisability of the monitoring of pasture levels of gall contamination, as levels below those that produce clinical signs of the disease may still contribute to an accumulating burden of toxicity.
Topics: Administration, Oral; Animals; Female; Glycolipids; Injections, Subcutaneous; Male; Sheep; Sheep Diseases; Toxins, Biological; Tunicamycin
PubMed: 3689261
DOI: 10.1111/j.1751-0813.1987.tb09689.x -
International Journal of Molecular... Aug 2017Disorders of hepatic energy metabolism, which can be regulated by endoplasmic reticulum (ER) stress, lead to metabolic diseases such as hepatic steatosis and...
Disorders of hepatic energy metabolism, which can be regulated by endoplasmic reticulum (ER) stress, lead to metabolic diseases such as hepatic steatosis and hypoglycemia. Tunicamycin, a pharmacological ER stress inducer, is used to develop an anti-cancer drug. However, the effects of tunicamycin on hepatic energy metabolism have not been well elucidated. Mice were intraperitoneally injected with tunicamycin or vehicle. Twenty-four hours later, hepatic triglyceride and glycogen content and serum lipids profiles were analyzed, as well as the expression of lipogenic and gluconeogenic genes. Tunicamycin significantly induced hepatic a yellowish color and ER stress, as well as increasing serum levels of aspartate transaminase and alanine transaminase. Besides, tunicamycin remarkably increased hepatic triglyceride content and suppressed the expression of apolipoprotein B100. In addition, tunicamycin-treated mice had lower serum levels of triglyceride, apolipoprotein B, low-density lipoprotein cholesterol and high-density lipoprotein cholesterol. Gene expression of peroxisome proliferator-activated receptor α was decreased by tunicamycin, but the protein level was increased. Furthermore, blood glucose level and hepatic glycogen content were decreased in tunicamycin-treated mice. Protein kinase B signaling was attenuated in the tunicamycin-treated liver, but the expression and activities of phosphoenolpyruvate carboxykinase and glucose-6-phosphatase were unchanged. Tunicamycin alters hepatic energy homeostasis by increasing triglyceride accumulation and decreasing glycogen content.
Topics: Animals; Blood Glucose; Endoplasmic Reticulum Stress; Energy Metabolism; Gene Expression Regulation; Glycogen; Homeostasis; Lipogenesis; Lipoproteins; Liver; Male; Mice, Inbred C57BL; Triglycerides; Tunicamycin
PubMed: 28777337
DOI: 10.3390/ijms18081710