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Li J, Cai Z, Vaites LP, Shen N, Mitchell DC, Huttlin EL, Paulo JA, Harry BL, Gygi SP. Proteome-wide mapping of short-lived proteins in human cells. Mol Cell 2021; 81:4722-4735.e5. [PMID: 34626566 DOI: 10.1016/j.molcel.2021.09.015] [Citation(s) in RCA: 49] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2021] [Revised: 08/11/2021] [Accepted: 09/13/2021] [Indexed: 12/13/2022]
Abstract
Rapid protein degradation enables cells to quickly modulate protein abundance. Dysregulation of short-lived proteins plays essential roles in disease pathogenesis. A focused map of short-lived proteins remains understudied. Cycloheximide, a translational inhibitor, is widely used in targeted studies to measure degradation kinetics for short-lived proteins. Here, we combined cycloheximide chase assays with advanced quantitative proteomics to map short-lived proteins under translational inhibition in four human cell lines. Among 11,747 quantified proteins, we identified 1,017 short-lived proteins (half-lives ≤ 8 h). These short-lived proteins are less abundant, evolutionarily younger, and less thermally stable than other proteins. We quantified 103 proteins with different stabilities among cell lines. We showed that U2OS and HCT116 cells express truncated forms of ATRX and GMDS, respectively, which have lower stability than their full-length counterparts. This study provides a large-scale resource of human short-lived proteins under translational arrest, leading to untapped avenues of protein regulation for therapeutic interventions.
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Affiliation(s)
- Jiaming Li
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Zhenying Cai
- Department of Cancer Biology, Dana-Farber Cancer Institute, Boston, MA 02215, USA; Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA 02115, USA
| | | | - Ning Shen
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA 02115, USA
| | - Dylan C Mitchell
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Edward L Huttlin
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Joao A Paulo
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA
| | - Brian L Harry
- Department of Pathology, Massachusetts General Hospital, Boston, MA 02114, USA; Department of Pathology, University of Colorado, Anschutz Medical Campus, Aurora, CO 80045, USA.
| | - Steven P Gygi
- Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
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Padmanabhan A, Candelaria N, Wong KK, Nikolai BC, Lonard DM, O'Malley BW, Richards JS. USP15-dependent lysosomal pathway controls p53-R175H turnover in ovarian cancer cells. Nat Commun 2018; 9:1270. [PMID: 29593334 PMCID: PMC5871815 DOI: 10.1038/s41467-018-03599-w] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2017] [Accepted: 02/27/2018] [Indexed: 01/10/2023] Open
Abstract
Gain-of-function p53 mutants such as p53-R175H form stable aggregates that accumulate in cells and play important roles in cancer progression. Selective degradation of gain-of-function p53 mutants has emerged as a highly attractive therapeutic strategy to target cancer cells harboring specific p53 mutations. We identified a small molecule called MCB-613 to cause rapid ubiquitination, nuclear export, and degradation of p53-R175H through a lysosome-mediated pathway, leading to catastrophic cancer cell death. In contrast to its effect on the p53-R175H mutant, MCB-613 causes slight stabilization of p53-WT and has weaker effects on other p53 gain-of-function mutants. Using state-of-the-art genetic and chemical approaches, we identified the deubiquitinase USP15 as the mediator of MCB-613's effect on p53-R175H, and established USP15 as a selective upstream regulator of p53-R175H in ovarian cancer cells. These results confirm that distinct pathways regulate the turnover of p53-WT and the different p53 mutants and open new opportunities to selectively target them.
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Affiliation(s)
- Achuth Padmanabhan
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA.
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA.
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, 77030, USA.
| | - Nicholes Candelaria
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Kwong-Kwok Wong
- Department of Gynecologic Oncology and Reproductive Medicine - Research, Division of Surgery, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Bryan C Nikolai
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - David M Lonard
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - Bert W O'Malley
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
| | - JoAnne S Richards
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, 77030, USA
- Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, 77030, USA
- Center for Reproductive Medicine, Baylor College of Medicine, Houston, TX, 77030, USA
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Magiera K, Tomala M, Kubica K, De Cesare V, Trost M, Zieba BJ, Kachamakova-Trojanowska N, Les M, Dubin G, Holak TA, Skalniak L. Lithocholic Acid Hydroxyamide Destabilizes Cyclin D1 and Induces G 0/G 1 Arrest by Inhibiting Deubiquitinase USP2a. Cell Chem Biol 2017; 24:458-470.e18. [PMID: 28343940 PMCID: PMC5404848 DOI: 10.1016/j.chembiol.2017.03.002] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 09/26/2016] [Accepted: 03/01/2017] [Indexed: 12/29/2022]
Abstract
USP2a is a deubiquitinase responsible for stabilization of cyclin D1, a crucial regulator of cell-cycle progression and a proto-oncoprotein overexpressed in numerous cancer types. Here we report that lithocholic acid (LCA) derivatives are inhibitors of USP proteins, including USP2a. The most potent LCA derivative, LCA hydroxyamide (LCAHA), inhibits USP2a, leading to a significant Akt/GSK3β-independent destabilization of cyclin D1, but does not change the expression of p27. This leads to the defects in cell-cycle progression. As a result, LCAHA inhibits the growth of cyclin D1-expressing, but not cyclin D1-negative cells, independently of the p53 status. We show that LCA derivatives may be considered as future therapeutics for the treatment of cyclin D1-addicted p53-expressing and p53-defective cancer types.
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Affiliation(s)
- Katarzyna Magiera
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland; Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland
| | - Marcin Tomala
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
| | - Katarzyna Kubica
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
| | - Virginia De Cesare
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Matthias Trost
- MRC Protein Phosphorylation and Ubiquitylation Unit, University of Dundee, Dundee DD1 5EH, Scotland, UK
| | - Bartosz J Zieba
- Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland
| | - Neli Kachamakova-Trojanowska
- Department of Medical Biotechnology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Krakow, Poland
| | - Marcin Les
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland
| | - Grzegorz Dubin
- Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland; Department of Microbiology, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, ul. Gronostajowa 7, 30-387 Krakow, Poland
| | - Tad A Holak
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland; Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland
| | - Lukasz Skalniak
- Department of Organic Chemistry, Faculty of Chemistry, Jagiellonian University, ul. Ingardena 3, 30-060 Krakow, Poland; Malopolska Centre of Biotechnology, Jagiellonian University, ul. Gronostajowa 7a, 30-387 Krakow, Poland.
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Jin D, Zhang YG, Wu S, Lu R, Lin Z, Zheng Y, Chen H, Cs-Szabo G, Sun J. Vitamin D receptor is a novel transcriptional regulator for Axin1. J Steroid Biochem Mol Biol 2017; 165:430-437. [PMID: 27601169 PMCID: PMC5180453 DOI: 10.1016/j.jsbmb.2016.09.002] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 08/31/2016] [Accepted: 09/02/2016] [Indexed: 02/06/2023]
Abstract
BACKGROUND Axin1 is a scaffold protein in the β-catenin destruction complex, which, if disrupted, contributes to pathogenesis of various human diseases, including colorectal carcinogenesis and inflammatory bowel diseases (IBD). We have previously demonstrated that Salmonella infection promotes the degradation and plasma sequestration of Axin1, leading to bacterial invasiveness and inflammatory responses. Vitamin D and the vitamin D receptor (VDR) appear to be important regulators of IBD and colon cancer. Although VDR and Axin1 are all involved in intestinal inflammation, it remains unclear whether these processes are related or function independently. In the current study, we hypothesize that VDR is an important regulator for the maintenance of physiological level of Axin1. METHODS Using the intestinal epithelial conditional VDR knockout mouse model (VDRΔIEC) and cultured cell lines, influences of VDR status on the expression of Axin1 was evaluated by Western blots and real-time PCR. Loss- and gain-of-function assays were used to investigate the regulation of VDR on Axin1 at the transcriptional and translational levels. Cells were treated with cycloheximide or actinomycin for molecular mechanistic studies. Candidate genomic VDR binding sites for Axin1 were tested by chromatin immunoprecipitation (ChIP) assay. Physical interactions among VDR, Axin1, and β-catenin were tested by immunoprecipitation. Cellular localization of Axin1 with different VDR status was determined by fractionation and immunohistochemistry. RESULTS We found that VDR deletion led to lower protein and mRNA levels of Axin1, whereas knockdown of Axin1 did not change the expression level of VDR protein. Immunoprecipitation data did not support physical interaction between VDR and Axin1. The VDR regulation of Axin1 was through a VDR genomic binding site for Axin1 gene on the regulatory region. Fractionation data showed that cytosolic Axin1 was significantly reduced due to VDR deletion, leaving the nuclear fraction unchanged. In ileum, Axin1 was distributed in the cytosol of apical epithelium and crypts. CONCLUSION VDR is important for the maintenance of physiological level of Axin1. The discovery of Axin1 as a VDR target gene provides novel and fundamental insights into the interactions between the VDR and β-catenin signaling pathways.
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Affiliation(s)
- Dapeng Jin
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA
| | - Yong-Guo Zhang
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Shaoping Wu
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA
| | - Rong Lu
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Zhijie Lin
- Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA
| | - Yuanyuan Zheng
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA
| | - Honglei Chen
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA
| | | | - Jun Sun
- Department of Biochemistry, Rush University, Chicago, IL, 60612, USA; Division of Gastroenterology and Hepatology, Department of Medicine, University of Illinois at Chicago, Chicago, IL, 60612, USA.
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Torsvik J, Johansson BB, Dalva M, Marie M, Fjeld K, Johansson S, Bjørkøy G, Saraste J, Njølstad PR, Molven A. Endocytosis of secreted carboxyl ester lipase in a syndrome of diabetes and pancreatic exocrine dysfunction. J Biol Chem 2014; 289:29097-111. [PMID: 25160620 PMCID: PMC4200264 DOI: 10.1074/jbc.m114.574244] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2014] [Revised: 08/21/2014] [Indexed: 12/17/2022] Open
Abstract
Maturity-onset diabetes of the young, type 8 (MODY8) is characterized by a syndrome of autosomal dominantly inherited diabetes and exocrine pancreatic dysfunction. It is caused by deletion mutations in the last exon of the carboxyl ester lipase (CEL) gene, resulting in a CEL protein with increased tendency to aggregate. In this study we investigated the intracellular distribution of the wild type (WT) and mutant (MUT) CEL proteins in cellular models. We found that both CEL-WT and CEL-MUT were secreted via the endoplasmic reticulum and Golgi compartments. However, their subcellular distributions differed, as only CEL-MUT was observed as an aggregate at the cell surface and inside large cytoplasmic vacuoles. Many of the vacuoles were identified as components of the endosomal system, and after its secretion, the mutant CEL protein was re-internalized, transported to the lysosomes, and degraded. Internalization of CEL-MUT also led to reduced viability of pancreatic acinar and beta cells. These findings may have implications for the understanding of how the acinar-specific CEL-MUT protein causes both exocrine and endocrine pancreatic disease.
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Affiliation(s)
- Janniche Torsvik
- From the KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway, Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Bente B Johansson
- From the KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway, Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Monica Dalva
- From the KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway, Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway, Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, N-5021 Bergen, Norway
| | - Michaël Marie
- Department of Biomedicine and Molecular Imaging Center, University of Bergen, Bergen, Norway
| | - Karianne Fjeld
- From the KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway, Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Stefan Johansson
- From the KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway, Center for Medical Genetics and Molecular Medicine, Haukeland University Hospital, Bergen, Norway
| | - Geir Bjørkøy
- Centre of Molecular Inflammation Research, Department of Cancer Research and Molecular Medicine, Norwegian University of Science and Technology, Trondheim, Norway, Department of Technology, University College of Sør-Trøndelag, Trondheim, Norway
| | - Jaakko Saraste
- Department of Biomedicine and Molecular Imaging Center, University of Bergen, Bergen, Norway
| | - Pål R Njølstad
- From the KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway, Department of Pediatrics, Haukeland University Hospital, Bergen, Norway, and
| | - Anders Molven
- From the KG Jebsen Center for Diabetes Research, Department of Clinical Science, University of Bergen, Bergen, Norway, Gade Laboratory for Pathology, Department of Clinical Medicine, University of Bergen, N-5021 Bergen, Norway, Department of Pathology, Haukeland University Hospital, Bergen, Norway
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Staley ZR, Rohr JR, Senkbeil JK, Harwood VJ. Agrochemicals indirectly increase survival of E. coli O157:H7 and indicator bacteria by reducing ecosystem services. Ecol Appl 2014; 24:1945-1953. [PMID: 29185664 DOI: 10.1890/13-1242.1] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Storm water and agricultural runoff frequently contain agrochemicals, fecal indicator bacteria (FIB), and zoonotic pathogens. Entry of such contaminants into aquatic ecosystems may affect ecology and human health. This study tested the hypothesis that the herbicide atrazine and the fungicide chlorothalonil indirectly affect the survival of FIB (Escherichia coli and Enterococcus faecalis) and a pathogen (E. coli O157:H7) by altering densities of protozoan predators or by altering competition from autochthonous bacteria. Streptomycin-resistant E. coli, En. faecalis, and E. coli O157:H7 were added to microcosms composed of Florida river water containing natural protozoan and bacterial populations. FIB, pathogen, and protozoan densities were monitored over six days. Known metabolic inhibitors, cycloheximide and streptomycin, were used to inhibit autochthonous protozoa or bacteria, respectively. The inhibitors made it possible to isolate the effects of predation or competition on survival of allochthonous bacteria, and each treatment increased the survival of FIB and pathogens. Chlorothalonil's effect was similar to that of cycloheximide, significantly reducing protozoan densities and elevating densities of FIB and pathogens relative to the control. Atrazine treatment did not affect protozoan densities, but, through an effect on competition, resulted in significantly greater densities of En. faecalis and E. coli O157:H7. Hence, by reducing predaceous protozoa and bacterial competitors that facilitate purifying water bodies of FIBs and human pathogens, chlorothalonil and atrazine indirectly diminished an ecosystem service of fresh water.
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Guo HF, Li YH, Tao PZ, Yi H, Wang SQ, He WY, Jiang JD, Li ZR. [Antiviral activities of cycloheximide and its derivatives]. Yao Xue Xue Bao 2010; 45:268-273. [PMID: 21351439] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
Cycloheximide (CHX) inhibits protein synthesis in most eukaryotic cells and it is a well-known tool commonly used in biochemical research. In this paper, the antiviral spectrum of CHX against several DNA and RNA viruses have been evaluated. CHX showed strong inhibitory activities against several RNA viruses such as HIV-1, influenza viruses, coxsackie B virus, enterovirus (EV71) and several DNA viruses such as HSV and HCMV. Especially the strong inhibitory activities of CHX against coxsackie B virus and enterovirus caught our attention, since effective drugs available in clinic are limited. The SAR of CHX derivatives also has been discussed in the paper. The hydroxyl group at C-2' and carbonyl group at C-2" of CHX are essential for its antiviral activity. And modification to these groups results its derivatives' antiviral activities reduced or lost.
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Affiliation(s)
- Hui-fang Guo
- Institute of Medicinal Biotechnology, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100050, China
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Haesler F, Hagn A, Frommberger M, Hertkorn N, Schmitt-Kopplin P, Munch JC, Schloter M. In vitro antagonism of an actinobacterial Kitasatospora isolate against the plant pathogen Phytophthora citricola as elucidated with ultrahigh resolution mass spectrometry. J Microbiol Methods 2008; 75:188-95. [PMID: 18588924 DOI: 10.1016/j.mimet.2008.05.028] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2008] [Revised: 05/29/2008] [Accepted: 05/29/2008] [Indexed: 11/19/2022]
Abstract
Many soil microorganisms antagonistic to soil borne plant pathogens are well known for their ability to control diseases in situ. A variety of substances, like lytic enzymes, siderophores and antibiotics, produced by these organisms have the potential to protect roots against pathogens. Understanding the ecology and a functional assessment of antagonistic microbial communities in soil requires in-depth knowledge of the mechanisms involved in these interactions, a challenging task in complex systems if low-resolution methods are applied. We propose an information-rich strategy of general relevance, composed of adequate preconcentration in conjunction with ultrahigh resolution ion cyclotron resonance Fourier transform mass spectrometry (ICR-FT/MS) and nuclear magnetic resonance (NMR) spectroscopy to identify any bioactive substances in complex systems. This approach is demonstrated on the specific example of substance identification considered responsible for in vitro antagonism of an actinobacterial antagonist isolated from European beech (Fagus sylvatica) rhizosphere soil against the oomycetous root rot pathogen Phytophthora citricola. The isolate belonging to the genus Kitasatospora exhibited strong antibiosis against the oomycete in vitro. The bioactive substance was observed to exhibit a molar mass of 281.1699 g/mol in positive electrospray ionization mass spectra, and the high mass accuracy of the ICR-FT/MS measurements allowed a precise assignment of a molecular formula that was found identical to the macrolide polyketide cycloheximide C(15)H(23)NO(4)+H(+); its identity was then unequivocally confirmed by the information-rich atomic signature of proton NMR spectroscopy. In conclusion, the combination of the near orthogonal methods (pre)fractionation, ultrahigh-resolution ICR-FT mass spectrometry (yielding molecular and MS(n) fragment signatures) and nuclear magnetic resonance spectroscopy (providing atomic signatures) has been found capable of identifying a biocontrol active compound of Kitasatospora active against Phytophthora citricola expediently, quickly, and accurately. This straightforward approach is of general applicability to elucidate biocontrol mechanisms in any complex system with improved efficiency.
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Affiliation(s)
- Felix Haesler
- Department of Terrestrial Ecogenetics, Institute of Soil Ecology, Helmholtz Zentrum München - German Research Center for Environmental Health (GmbH), Germany.
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Abstract
DNA repair is regulated on many levels by ubiquitination. In order to identify novel connections between DNA repair pathways and ubiquitin signaling, we used mass spectrometry to identify proteins that interact with lysine 6-linked polyubiquitin chains. From this proteomic screen, we identified the DNA repair protein WRNIP1 (Werner helicase-interacting protein 1), along with nucleosome assembly protein 1, as novel ubiquitin-interacting proteins. We found that a small zinc finger domain at the N terminus of WRNIP1 is sufficient and necessary for noncovalent ubiquitin binding. This ubiquitin-binding zinc finger (UBZ) domain binds polyubiquitin but not monoubiquitin and appears to show no specificity for polyubiquitin chain linkage. A homologous zinc finger domain in RAD18 also binds polyubiquitin, suggesting a wider role for the UBZ domain in DNA repair. The WRNIP1 ubiquitin-binding function, along with its previously established ATPase activity, suggests that WRNIP1 plays a role in the metabolism of ubiquitinated proteins. Supporting this model, deletion of MGS1, the yeast homolog of WRNIP1, slows the rate of ubiquitin turnover, rendering yeast resistant to cycloheximide. We also find that WRNIP1 is heavily modified with ubiquitin and SUMO, revealing complex layers in the involvement of ubiquitin pathway proteins in the regulation of DNA repair. The novel ubiquitin-binding ability of WRNIP1 sheds light on the role of UBZ domain-containing proteins in postreplication DNA repair.
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Affiliation(s)
- Rebecca A Bish
- Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, New York 11724, USA
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Abstract
Cycloheximide (CYH) is a heterocyclic, glutarimide antibiotic that is a potent inhibitor of protein biosynthesis in most eukaryotes. This study demonstrated that yeasts from all species of the Lipomycetaceae, with the exception of Dipodascopsis spp., can grow in the presence of up to 5 g·L–1 CYH — a concentration that is five times higher than the accepted “highest” concentration of 1 g·L–1 used in physiological tests for yeast identification. Lipomycetaceous yeasts are known to utilize heterocyclic nitrogen-containing compounds such as thymine as sole nitrogen source. CYH contains a glutarimide ring, which is chemically similar to thymine. We investigated the possibility that CYH resistance in the Lipomycetaceae might be due to an ability to degrade CYH and use it as the sole nitrogen source. However, we were unable to demonstrate significant growth on CYH as sole nitrogen source. When thymine was used as positive control, we could demonstrate its utilization as sole nitrogen source.
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Affiliation(s)
- W J Müller
- Department of Microbial, Biochemical, and Food Biotechnology, University of the Free State, Bloemfontein, South Africa
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Masuda D, Ishida M, Yamaguchi K, Yamaguchi I, Kimura M, Nishiuchi T. Phytotoxic effects of trichothecenes on the growth and morphology of Arabidopsis thaliana. J Exp Bot 2007; 58:1617-26. [PMID: 17426057 DOI: 10.1093/jxb/erl298] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Non-volatile sesquiterpenoids, a trichothecene family of phytotoxins such as deoxynivalenol (DON) and T-2 toxin, contain numerous molecular species and are synthesized by phytopathogenic Fusarium species. Although trichothecene chemotypes might play a role in the virulence of individual Fusarium strains, the phytotoxic action of individual trichothecenes has not been systematically studied. To perform a comparative analysis of the phytotoxic action of representative trichothecenes, the growth and morphology of Arabidopsis thaliana growing on media containing these compounds was investigated. Both DON and diacetoxyscirpenol (DAS) preferentially inhibited root elongation. DON-treated roots were less organized compared with control roots. Moreover, preferential inhibition of root growth by DON was also observed in wheat plants. In addition, T-2 toxin-treated seedlings exhibited dwarfism with aberrant morphological changes (e.g. petiole shortening, curled dark-green leaves, and reduced cell size). These results imply that the phytotoxic action of trichothecenes differed among their molecular species. Cycloheximide (CHX)-treated seedlings displayed neither feature, although it is known that trichothecenes inhibit translation in eukaryotic ribosomes. Microarray analyses suggested that T-2 toxin caused a defence response, the inactivation of brassinosteroid (BR), and the generation of reactive oxygen species in Arabidopsis. This observation is in agreement with our previous reports in which trichothecenes such as T-2 toxin have an elicitor-like activity when infiltrated into the leaves of Arabidopsis. Since it has been reported that BR plays an important role in a broad range of disease resistance in tobacco and rice, inactivation of BR might affect pathogenicity during the infection of host plants by trichothecene-producing fungi.
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Affiliation(s)
- Daisuke Masuda
- Division of Life Science, Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa 920-1192, Japan
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Dahan A, Hoffman A. Use of a Dynamic in Vitro Lipolysis Model to Rationalize Oral Formulation Development for Poor Water Soluble Drugs: Correlation with in Vivo Data and the Relationship to Intra-Enterocyte Processes in Rats. Pharm Res 2006; 23:2165-74. [PMID: 16902814 DOI: 10.1007/s11095-006-9054-x] [Citation(s) in RCA: 153] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2006] [Accepted: 05/05/2006] [Indexed: 11/25/2022]
Abstract
PURPOSE To examine the correlation between the in vitro solubilization process of lipophilic compounds from different lipid solutions and the corresponding in vivo oral bioavailability data. In particular, to assess the influence of intra-enterocyte processes (metabolism and lymphatic absorption) on this correlation. MATERIALS AND METHODS The dissolution of progesterone and vitamin D3 in long (LCT), medium (MCT) and short (SCT) chain triglyceride solutions were tested in a dynamic in vitro lipolysis model. The absolute oral bioavailability of the drugs from the tested formulations was investigated in rats. Vitamin D3 bioavailability was also examined following lymphatic transport blockage induced by cycloheximide (3 mg/kg). RESULTS The dynamic in vitro lipolysis experiments indicated a rank order of MCT > LCT > SCT for both progesterone and vitamin D3. The bioavailability of progesterone correlated with the in vitro data, despite its significant pre-systemic metabolism. For vitamin D3, an in vivo performance rank order of LCT > MCT > SCT was obtained. However, when the lymphatic transport was blocked the bioavailability of vitamin D3 correlated with in vitro data. CONCLUSIONS The in vitro lipolysis model is useful for optimization of oral lipid formulations even in the case of pre-systemic metabolism in the gut. However, when lymphatic transport is a significant route of absorption, the in vitro lipolysis data may not be predictive for actual in vivo absorption.
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Affiliation(s)
- Arik Dahan
- Department of Pharmaceutics, School of Pharmacy Faculty of Medicine, The Hebrew University of Jerusalem, PO Box 12065, Jerusalem 91120, Israel
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Edlich F, Weiwad M, Wildemann D, Jarczowski F, Kilka S, Moutty MC, Jahreis G, Lücke C, Schmidt W, Striggow F, Fischer G. The Specific FKBP38 Inhibitor N-(N′,N′-Dimethylcarboxamidomethyl)cycloheximide Has Potent Neuroprotective and Neurotrophic Properties in Brain Ischemia. J Biol Chem 2006; 281:14961-70. [PMID: 16547004 DOI: 10.1074/jbc.m600452200] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
FK506 and FK506-derived inhibitors of the FK506-binding protein (FKBP)-type peptidylprolyl cis/trans-isomerases (PPIase) display potent neuroprotective and neuroregenerative properties in various neurodegeneration models, showing the importance of neuroimmunophilins as targets for the treatment of acute and chronic neurodegenerative diseases. However, the PPIase activity targeted by active site-directed ligands remains unknown so far. Here we show that neurotrophic FKBP ligands, such as GPI1046 and N-[methyl(ethoxycarbonyl)]cycloheximide, inhibit the calmodulin/Ca(2+) (CaM/Ca(2+))-regulated FKBP38 with up to 80-fold higher affinity than FKBP12. In contrast, the non-neurotrophic rapamycin inhibits FKBP38.CaM/Ca(2+) 500-fold less affine than other neuroimmunophillins. In the context of the high expression of FKBP38 in neuroblastoma cells, these data suggest that FKBP38.CaM/Ca(2+) inhibition can mediate neurotrophic properties of FKBP ligands. The FKBP38-specific cycloheximide derivative, N-(N',N'-dimethylcarboxamidomethyl)cycloheximide (DM-CHX) was synthesized and used in a rat model of transient focal cerebral ischemia. Accordingly, DM-CHX caused neuronal protection as well as neural stem cell proliferation and neuronal differentiation at a dosage of 27.2 mug/kg. These effects were still dominant, if DM-CHX was applied 2-6 h post-insult. In parallel, sustained motor behavior deficits of diseased animals were improved by drug administration, revealing a potential therapeutic relevance. Thus, our results demonstrate that FKBP38 inhibition by DM-CHX regulates neuronal cell death and proliferation, providing a promising strategy for the treatment of acute and/or chronic neurodegenerative diseases.
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Affiliation(s)
- Frank Edlich
- Max Planck Research Unit for Enzymology of Protein Folding, Weinbergweg 22, D-06120 Halle/Saale, Germany
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Abstract
Variation exists in the sensitivity of individual rodents and humans to different bitter tastants. An absence of uniform correlation in responsiveness to different bitter substances across individuals within a species suggests heterogeneity in the mechanisms underlying stimulus processing within this taste modality. Here, we examined taste responsiveness of individual rats to three bitter compounds (quinine hydrochloride, denatonium benzoate, and cycloheximide) in short-term lick tests to determine the magnitude of covariation among responses to these stimuli and infer commonalities in their receptor and neural mechanisms. Rats were tested with a given pair of bitter stimuli during three sessions comprising randomized trial blocks of six concentrations of each stimulus + deionized water. Psychophysical functions were generated for individual rats for respective stimulus pairs, and concentrations of each stimulus that produced equivalent lick suppression relative to water were correlated across animals. Behavioral taste responsiveness to quinine hydrochloride strongly covaried with responsiveness to denatonium benzoate (r = +0.82). Lick responsiveness to quinine was less robustly correlated with that to cycloheximide (r = +0.44), and denatonium and cycloheximide responses failed to correlate. These results imply substantial overlap in the bitter taste coding mechanisms for quinine and denatonium but some degree of independence in the mechanisms responsible for gustatory processing of cycloheximide. More generally, these data reinforce the notion that bitter taste processing is not a homogeneous event.
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Affiliation(s)
- Susan M Brasser
- Department of Anatomy and Neurobiology, University of Tennessee Health Science Center, 855 Monroe Avenue, Memphis, TN 38163, USA.
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15
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Abstract
BACKGROUND To better understand the differences between in vivo (IVO) and in vitro (IVM) matured oocytes, we studied the chronological changes in cortical granule (CG) distribution and nuclear progression during maturation, and the competence of CG release and embryo development of mouse oocytes matured under different conditions. METHODS Oocytes matured in vivo or in different culture media were used and CG distribution and release were assessed by fluorescein isothiocyanate-labelled Lens culinaris agglutinin and laser confocal microscopy. RESULTS Tempos of nuclear maturation and CG redistribution were slower, and competence for CG exocytosis, cleavage and blastulation were lower in the IVM oocytes than in the IVO oocytes. These parameters also differed among oocytes matured in different culture media. Hypoxanthine (HX, 4 mM) blocked germinal vesicle breakdown (GVBD), postponed CG migration and prevented CG-free domain (CGFD) formation. Cycloheximide (CHX) facilitated both GVBD and CG migration, but inhibited CGFD formation. The presence of serum in maturation media enhanced CG release after aging or activation of oocytes. Maintenance of germinal vesicle intact for some time by a trace amount (0.18 mM) of HX was beneficial to oocyte cytoplasmic maturation. CONCLUSION CGs behaved differently in mouse oocytes matured under different conditions, and cytoplasmic maturity was not fully achieved in the IVM oocytes.
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Affiliation(s)
- Xin-Yong Liu
- Laboratory for Animal Reproduction and Embryology, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Tai-an City 271018, Shandong Province, People's Republic of China
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Chen DH, Wu KT, Hung CJ, Hsieh M, Li C. Effects of adenosine dialdehyde treatment on in vitro and in vivo stable protein methylation in HeLa cells. J Biochem 2005; 136:371-6. [PMID: 15598895 DOI: 10.1093/jb/mvh131] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Adenosine dialdehyde (AdOx) is an indirect methyltransferase inhibitor broadly used in cell culture to accumulate methyl-accepting proteins in hypomethylated states for in vitro protein methylation analyses. In this study we included a translation inhibitor, cycloheximide, in the AdOx treatment of HeLa cells. The methyl-accepting proteins disappeared in the double treatment, indicating that they were most likely newly synthesized in the AdOx incubation period. AdOx treatment could also be used in combination with in vivo methylation, another technique frequently used to study protein methylation. AdOx treatment prior to in vivo methylation accumulated methyl-accepting proteins for the labeling reaction. The continued presence of AdOx in the in vivo labeling period decreased the methylation of the majority of in vivo methyl-accepting polypeptides. The level and pattern of the in vivo methylated polypeptides did not change after a 12-h chase, supporting the notion that the methylated polypeptide as well as the methyl groups on the modified polypeptides are stable. On the other hand, methylarginine-specific antibodies detected limited but consistent reduction of the methylarginine-containing proteins in AdOx-treated samples compared to the untreated ones. Thus, AdOx treatment probably only blocked a small fraction of stable protein methylation. Overall, it is likely that base-stable methylation are formed soon after the synthesis of the polypeptide and remain stable after the modification.
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Affiliation(s)
- Da-Huang Chen
- Department of Life Sciences, Chung Shan Medical University, Taichung, Taiwan, ROC
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Verma AK, Sachin K, Saxena A, Bohidar HB. Release kinetics from bio-polymeric nanoparticles encapsulating protein synthesis inhibitor- cycloheximide, for possible therapeutic applications. Curr Pharm Biotechnol 2005; 6:121-30. [PMID: 15853691 DOI: 10.2174/1389201053642349] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Cycloheximide, a protein synthesis inhibitor, was encapsulated in cross-linked gelatin nanoparticles (Type B, Bovine skin, 75 Bloom) of 168 nm diameter with 26% entrapment efficiency. In-vitro release kinetics of the drug from the nanoparticles was done in phosphate buffer saline (PBS) at pH 7.4 and pH 5.8. The release kinetics showed a bi-phasic curve. Interestingly, the release of drug is approx 90% in acidic pH as compared to 50% release in neutral pH. The particle size was determined by Dynamic Light Scattering (DLS) technique, and size distribution spectra at different pH were observed to vary inversely with increase in pH. These drug loaded nanoparticles were found to be stable in whole blood showing negligible haemolysis. Cytotoxicity in HBL-100 and MCF-7, breast cancer cell lines was done in a 24-72 hrs assay, showing increased anti-tumour activity over a period of time indicating slow release. Dose dependent cytotoxicity was observed after 24 hours upto 72 hours of incubation of nanoparticles while the drug per se (<4 microg) showed 93% toxicity within 24 hours. Phase contrast microscopy of nanoparticle-cell interaction, clearly indicated aggregation along the lipid cell-membrane. Electron Microscopy (TEM, SEM) studies revealed its size and spherical shape. The stability of the particle, the slow and controlled release of drug from the gelatin nanoparticles indicate that it is a good candidate to deliver bio-pharmaceuticals. These behave as "intelligent" carriers for drug delivery, and can be exploited to empty their drug load in acidic medium. The paper focuses on the release kinetics of the gelatin nanoparticles that can be successfully exploited to treat solid tumors.
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Affiliation(s)
- Anita K Verma
- Department of Zoology, K. M. College, University of Delhi, Delhi-110007, India.
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De Boever P, Demaré W, Vanderperren E, Cooreman K, Bossier P, Verstraete W. Optimization of a yeast estrogen screen and its applicability to study the release of estrogenic isoflavones from a soygerm powder. Environ Health Perspect 2001; 109:691-7. [PMID: 11485867 PMCID: PMC1240372 DOI: 10.1289/ehp.01109691] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/18/2023]
Abstract
Here we describe a redesigned protocol of the yeast estrogen screen developed by Routledge and Sumpter. The redesigned test comprises two steps. First, a large amount of yeast with estrogenic compounds is incubated for 24 hr. Subsequently, a mixture of cycloheximide and the chromogenic substrate chlorophenol red-beta-d-galactopyranoside (CPRG) is added. The cycloheximide stops protein synthesis and allows for an end-point measurement of beta-galactosidase activity generated during the first 24 hr. CPRG is converted to chlorophenol red and reflects beta-galactosidase activity, which is indicative of the estrogenic activity. The modifications shorten the duration of the assay at least 1 day and avoid interference of the estrogenic CPRG or chlorophenol red. The redesigned and the original protocol were used to study the estrogenic activity of bisphenol A, methoxychlor, p,p'-DDT, and isoflavones (genistein, daidzein, and glycitein). Bisphenol A, methoxychlor, and genistein triggered higher levels of beta-galactosidase activity in the redesigned protocol. Estrogenic activity of p,p'-DDT could only be demonstrated with the redesigned protocol. Glycitein and daidzein failed to give a response with both protocols. We also studied deconjugation of beta-glycosidic isoflavones present in soygerm powder. Treatment of the soygerm powder with beta-glycosidase released isoflavones. The estrogenic response of the samples was confirmed with the redesigned protocol and correlated with the amount of genistein present. The release of isoflavones under conditions prevailing in the intestines was studied. Bacterial beta-glycosidase present in the large intestine released isoflavones, and moderate estrogenic activity could be demonstrated.
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Affiliation(s)
- P De Boever
- Laboratory of Microbial Ecology and Technology, Faculty of Agricultural and Applied Biological Sciences, Coupure links 653, 9500 Gent, Belgium
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Sugimoto H, Kataoka T, Igarashi M, Hamada M, Takeuchi T, Nagai K. E-73, an acetoxyl analogue of cycloheximide, blocks the tumor necrosis factor-induced NF-kappaB signaling pathway. Biochem Biophys Res Commun 2000; 277:330-3. [PMID: 11032726 DOI: 10.1006/bbrc.2000.3680] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Proinflammatory cytokines such as tumor necrosis factor (TNF) and interleukin (IL)-1 activate the NF-kappaB signaling pathway which induces the expression of a variety of genes such as the encoding intercellular adhesion molecule (ICAM)-1. We have found that E-73, an acetoxyl analogue of cycloheximide, specifically blocks TNF-induced ICAM-1 expression even at concentrations unable to affect protein synthesis. By contrast, cycloheximide inhibited both TNF- and IL-1-induced ICAM-1 expression primarily due to the blockage of protein synthesis. The nuclear translocation of NF-kappaB as well as the IkappaB degradation induced by TNF, but not by IL-1, was significantly prevented by E-73. These observations suggest that E-73 blocks the TNF-induced NF-kappaB signaling pathway upstream of IkappaB degradation.
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Affiliation(s)
- H Sugimoto
- Department of Bioengineering, Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama, 226-8501, Japan
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Booth PJ, Vajta G, Høj A, Holm P, Jacobsen H, Greve T, Callesen H. Full-term development of nuclear transfer calves produced from open-pulled straw (OPS) vitrified cytoplasts: work in progress. Theriogenology 1999; 51:999-1006. [PMID: 10729021 DOI: 10.1016/s0093-691x(99)00045-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Cryopreservation of cytoplasts would help to resolve the logistics of matching the availability of oocytes with embryo donors in nuclear transfer. Therefore, the developmental potential of nuclear transfer bovine embryos reconstructed using vitrified cytoplasts was investigated. In vitro matured oocytes were denuded, enucleated, activated with calcium ionophore (10 microM, 5 min) and cycloheximide (10 microg/mL, 6 h) and then vitrified by the open pulled straw (OPS) method. After immediate warming, the nuclear transfer embryos were reconstructed using blastomeres from nonvitrified,in vitro-produced embryo donors. Compared with control nuclear transfer embryos that were reconstructed using nonvitrified cytoplasts, fusion rates (% +/- SEM) were not affected (83.7+/-9.2 vs. 79.8+/-4.6; P>0.05), but cleavage (55.7+/-2.9 vs. 92.8+/-3.9; P = 0.0002) and blastocyst rates (7.2+/-5.0 vs. 32.6+/-7.8; P = 0.0025, vitrified vs. nonvitrified cytoplasts, respectively) per successful fusion were reduced. One nuclear transfer blastocyst reconstructed from a vitrified cytoplast was transferred to a synchronized recipient. After a normal length gestation (265 d), twin calves (21 and 26 kg) were delivered. Microsatellite analysis confirmed that the calves were homozygotic (the embryo split in utero), and were derived from the in vitro-produced embryo donor. The twins were dead at birth, but post-mortem analysis of the calves indicated no abnormalities or infections, suggesting that their death was related to the twin pregnancy and the known fragility of nuclear transfer calves. These data demonstrate that open pulled straw-vitrified cytoplasts are capable of supporting full-term development of nuclear transfer embryos.
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Affiliation(s)
- P J Booth
- Embryo Technology Center, Danish Institute of Agricultural Sciences.
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21
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Abstract
The kinetic parameters of inhibition of camel retinal acetylcholinesterase (AChE) activity by cycloheximide (CH) were investigated. For the control system, the Michaelis-Menten constant (K(m)) for the hydrolysis of acetylthiocholine iodide was found to be 0.076 mmol/L and the Vmax was 0.547 mumol/min per mg protein. In contrast, these parameters were decreased in the CH-treated systems. Dixon and Lineweaver-Burk plots, and their secondary replots, indicated that the inhibition was of the linear mixed type, which seems to be a combination of partial competitive and pure noncompetitive inhibition. The values of K'i(slope) and KI(intercept) were estimated to be 3.50 and 5.68 mmol/L, respectively. Ki was greater than K'i, indicating that CH has a greater binding affinity for the peripheral site than the active site.
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Affiliation(s)
- A A al-Jafari
- Department of Biochemistry, College of Science, King Saud University, Riyadh, Saudi Arabia
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Abstract
While the choice of stationary phase, organic modifier, and gradient strength can have significant effects on biomolecule separations, mobile phase additives can also have a significant effect on the chromatographic selectivity, recovery, efficiency and resolution. Given the importance of stationary phase coverage, the beneficial, silanol-masking properties of amines, and the potential for selectivity modification through ion-pair interactions, cyclohexylamine was examined as a mobile phase additive and compared with triethylamine and trifluoroacetic acid. Greatly improved separation was possible when cyclohexylamine was used as compared with phosphate buffer, and cyclohexylamine did not require purification before use, while triethylamine required distillation before 'clean' chromatograms were obtained.
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Affiliation(s)
- S R Cole
- Department of Chemistry, University of Cincinnati, OH 45221-0172, USA
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Kondo H, Oritani T, Yamashita K. Syntheses and biological activities of (+/-)-streptovitacin A and E-73. Agric Biol Chem 1990; 54:1531-6. [PMID: 1368568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/25/2023]
Abstract
(+/-)-Streptovitacin A (1) and its stereoisomers were synthesized by an aldol reaction of (+/-)-2,4-dimethyl-4-trimethylsiloxy-1-cyclohexanones (4b and 9) with 4-(2-oxoethyl)-2,6-piperidinedione (5). E-72 (2) was derived from synthetic 1. (+/-)-1 showed moderate growth inhibition against fungi and lettuce seeds.
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Affiliation(s)
- H Kondo
- Department of Agricultural Chemistry, Tohoku University, Sendai, Japan
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