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Kneissig M, Keuper K, de Pagter MS, van Roosmalen MJ, Martin J, Otto H, Passerini V, Campos Sparr A, Renkens I, Kropveld F, Vasudevan A, Sheltzer JM, Kloosterman WP, Storchova Z. Micronuclei-based model system reveals functional consequences of chromothripsis in human cells. eLife 2019; 8:e50292. [PMID: 31778112 PMCID: PMC6910827 DOI: 10.7554/elife.50292] [Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Accepted: 11/23/2019] [Indexed: 01/18/2023] Open
Abstract
Cancer cells often harbor chromosomes in abnormal numbers and with aberrant structure. The consequences of these chromosomal aberrations are difficult to study in cancer, and therefore several model systems have been developed in recent years. We show that human cells with extra chromosome engineered via microcell-mediated chromosome transfer often gain massive chromosomal rearrangements. The rearrangements arose by chromosome shattering and rejoining as well as by replication-dependent mechanisms. We show that the isolated micronuclei lack functional lamin B1 and become prone to envelope rupture, which leads to DNA damage and aberrant replication. The presence of functional lamin B1 partly correlates with micronuclei size, suggesting that the proper assembly of nuclear envelope might be sensitive to membrane curvature. The chromosomal rearrangements in trisomic cells provide growth advantage compared to cells without rearrangements. Our model system enables to study mechanisms of massive chromosomal rearrangements of any chromosome and their consequences in human cells.
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Affiliation(s)
- Maja Kneissig
- Department of Molecular GeneticsTU KaiserslauternKaiserslauternGermany
| | - Kristina Keuper
- Department of Molecular GeneticsTU KaiserslauternKaiserslauternGermany
| | - Mirjam S de Pagter
- Department of Genetics, Center for Molecular MedicineUniversity Medical CenterUniversiteitswegNetherlands
| | - Markus J van Roosmalen
- Department of Genetics, Center for Molecular MedicineUniversity Medical CenterUniversiteitswegNetherlands
| | - Jana Martin
- Department of Molecular GeneticsTU KaiserslauternKaiserslauternGermany
| | - Hannah Otto
- Department of Molecular GeneticsTU KaiserslauternKaiserslauternGermany
| | | | | | - Ivo Renkens
- Department of Genetics, Center for Molecular MedicineUniversity Medical CenterUniversiteitswegNetherlands
| | - Fenna Kropveld
- Department of Genetics, Center for Molecular MedicineUniversity Medical CenterUniversiteitswegNetherlands
| | - Anand Vasudevan
- Cold Spring Harbor LaboratoryCold Spring HarborUnited States
| | | | - Wigard P Kloosterman
- Department of Genetics, Center for Molecular MedicineUniversity Medical CenterUniversiteitswegNetherlands
| | - Zuzana Storchova
- Department of Molecular GeneticsTU KaiserslauternKaiserslauternGermany
- Max Planck Institute of BiochemistryMartinsriedGermany
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2
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Pawitan JA. Various stem cells in acupuncture meridians and points and their putative roles. J Tradit Complement Med 2018; 8:437-442. [PMID: 30302323 PMCID: PMC6174264 DOI: 10.1016/j.jtcme.2017.08.004] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2016] [Revised: 04/05/2017] [Accepted: 08/01/2017] [Indexed: 02/01/2023] Open
Abstract
Traditional Chinese and Korean medicine uses various manipulations on acupuncture points/acupoints that are located along imaginary lines on the surface of a human body, which are called 'meridians'. Acupuncture has been used from the ancient time till now to cure various diseases, including for the purpose of regenerative medicine. In various studies, meridians are alternatively called as Bong-Han ducts, primo vessels, or hyaluronic-acid rich ducts, while acupoints are called Bong-Han corpuscles, primo nodes, or hyaluronic-acid rich nodes. Meridians and acupuncture points form a system that is now called primo vascular system (PVS), which is claimed to contain various kinds of stem cells. The stem cell size is between 1-5 microns. The smallest is the primo microcells that have a putative role in regeneration. Other stem cells are adult pluripotent and hematopoietic stem cells that play a role in extra bone marrow hematopoiesis. The presence of PVS has been reproduced by many studies. However, the various stem cells need further studies to prove their existence and function, and harvesting PVS to isolate the stem cells might harm the health of the donor.
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Affiliation(s)
- Jeanne Adiwinata Pawitan
- Department of Histology, Faculty of Medicine Universitas Indonesia, Jl. Salemba 6, Jakarta, 10430, Indonesia
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3
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Roellecke K, Jäger VD, Gyurov VH, Kowalski JP, Mielke S, Rettie AE, Hanenberg H, Wiek C, Girhard M. Ligand characterization of CYP4B1 isoforms modified for high-level expression in Escherichia coli and HepG2 cells. Protein Eng Des Sel 2017; 30:205-216. [PMID: 28073960 PMCID: PMC5421619 DOI: 10.1093/protein/gzw075] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2016] [Accepted: 12/06/2016] [Indexed: 01/25/2023] Open
Abstract
Human CYP4B1, a cytochrome P450 monooxygenase predominantly expressed in the lung, inefficiently metabolizes classical CYP4B1 substrates, such as the naturally occurring furan pro-toxin 4-ipomeanol (4-IPO). Highly active animal forms of the enzyme convert 4-IPO to reactive alkylating metabolite(s) that bind(s) to cellular macromolecules. By substitution of 13 amino acids, we restored the enzymatic activity of human CYP4B1 toward 4-IPO and this modified cDNA is potentially valuable as a suicide gene for adoptive T-cell therapies. In order to find novel pro-toxins, we tested numerous furan analogs in in vitro cell culture cytotoxicity assays by expressing the wild-type rabbit and variants of human CYP4B1 in human liver-derived HepG2 cells. To evaluate the CYP4B1 substrate specificities and furan analog catalysis, we optimized the N-terminal sequence of the CYP4B1 variants by modification/truncation and established their heterologous expression in Escherichia coli (yielding 70 and 800 nmol·l-1 of recombinant human and rabbit enzyme, respectively). Finally, spectral binding affinities and oxidative metabolism of the furan analogs by the purified recombinant CYP4B1 variants were analyzed: the naturally occurring perilla ketone was found to be the tightest binder to CYP4B1, but also the analog that was most extensively metabolized by oxidative processes to numerous non-reactive reaction products.
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Affiliation(s)
- Katharina Roellecke
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Vera D Jäger
- Institute of Biochemistry, Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Veselin H Gyurov
- Institute of Biochemistry, Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - John P Kowalski
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA 98195, USA
| | - Stephanie Mielke
- Institute of Biochemistry, Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Allan E Rettie
- Department of Medicinal Chemistry, School of Pharmacy, University of Washington, Seattle, WA 98195, USA
| | - Helmut Hanenberg
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich-Heine University, 40225 Düsseldorf, Germany.,Department of Pediatrics III, University Children's Hospital Essen, University of Duisburg-Essen, 45122 Essen, Germany
| | - Constanze Wiek
- Department of Otorhinolaryngology and Head/Neck Surgery, Heinrich-Heine University, 40225 Düsseldorf, Germany
| | - Marco Girhard
- Institute of Biochemistry, Heinrich-Heine University, 40225 Düsseldorf, Germany
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4
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Recillas‐Targa F, Guerrero G, Escamilla‐del‐Arenal M, Rincón‐Arano H. Gene Expression in Mammalian Cells. Genomics 2010. [DOI: 10.1002/9780470711675.ch7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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5
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Bishop-Hurley SL, Rea PJ, McSweeney CS. Phage-displayed peptides selected for binding to Campylobacter jejuni are antimicrobial. Protein Eng Des Sel 2010; 23:751-7. [PMID: 20682764 DOI: 10.1093/protein/gzq050] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
In developed countries, Campylobacter jejuni is a leading cause of zoonotic bacterial gastroenteritis in humans with chicken meat implicated as a source of infection. Campylobacter jejuni colonises the lower gastrointestinal tract of poultry and during processing is spread from the gastrointestinal tract onto the surface of dressed carcasses. Controlling or eliminating C.jejuni on-farm is considered to be one of the best strategies for reducing human infection. Molecules on the cell surface of C.jejuni interact with the host to facilitate its colonisation and persistence in the gastrointestinal tract of poultry. We used a subtractive phage-display protocol to affinity select for peptides binding to the cell surface of a poultry isolate of C.jejuni with the aim of finding peptides that could be used to control this microorganism in chickens. In total, 27 phage peptides, representing 11 unique clones, were found to inhibit the growth of C.jejuni by up to 99.9% in vitro. One clone was bactericidal, reducing the viability of C.jejuni by 87% in vitro. The phage peptides were highly specific. They completely inhibited the growth of two of the four poultry isolates of C.jejuni tested with no activity detected towards other Gram-negative and Gram-positive bacteria.
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Affiliation(s)
- Sharon L Bishop-Hurley
- CSIRO-Livestock Industries, Queensland Biosciences Precinct, 306 Carmody Road, St. Lucia, QLD 4067, Australia.
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6
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Kuzmicheva GA, Jayanna PK, Eroshkin AM, Grishina MA, Pereyaslavskaya ES, Potemkin VA, Petrenko VA. Mutations in fd phage major coat protein modulate affinity of the displayed peptide. Protein Eng Des Sel 2009; 22:631-9. [PMID: 19633313 DOI: 10.1093/protein/gzp043] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Multibillion-clone libraries of phages displaying guest peptides fused to the major coat protein pVIII (landscape libraries) are a rich source of probes for proteinaceous and non-proteinaceous targets. As opposed to the pIII-type fusion phages, which display peptides as independent structural domains, the guest peptides in the pVIII-fusion phages can be structurally and functionally influenced by contiguous subunits. To decipher the impact of the locale of a guest peptide on its affinity characteristics, we constructed a library of phages carrying beta-galactosidase-binding peptide ADTFAKSMQ at the N-terminus of the pVIII protein surrounded by random amino acids. It was found that mutagenesis of amino acids 12-19 (domain C) has polar effects on target binding affinity of the displayed peptide. The phages with highest affinity are characterized by: (i) a net electrostatic charge around -1 of domain C of the mutated phages at pH 7.0; (ii) a lower radius of cylinder coaxial to alpha-helix formed by domain C; (iii) a lower higher occupied molecular orbital (HOMO) of domain C leading to a decreased formation of hydrogen bonds and (iv) positively charged surface and torsion energy of domain C, which may require a conformational transition of N-terminal peptide ADTFAKSMQ for its binding with beta-galactosidase. Influence of the guest peptide on the diversity of mutations in the neighboring landscape area was also observed.
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Affiliation(s)
- G A Kuzmicheva
- Department of Pathobiology, Auburn University, 252 Greene Hall, College of Veterinary Medicine, Auburn, AL 36849, USA
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7
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Stark K, Wu ZL, Bartleson CJ, Guengerich FP. mRNA distribution and heterologous expression of orphan cytochrome P450 20A1. Drug Metab Dispos 2008; 36:1930-7. [PMID: 18541694 DOI: 10.1124/dmd.108.022020] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cytochrome P450 (P450) 20A1 is one of the so-called "orphan" P450s without assigned biological function. mRNA expression was detected in human liver, and extrahepatic expression was noted in several human brain regions, including substantia nigra, hippocampus, and amygdala, using conventional polymerase chain reaction and RNA dot blot analysis. Adult human liver contained 3-fold higher overall mRNA levels than whole brain, although specific regions (i.e., hippocampus and substantia nigra) exhibited higher mRNA expression levels than liver. Orthologous full-length and truncated transcripts of P450 20A1 were transcribed and sequenced from rat liver, heart, and brain. In rat, the concentrations of full-length transcripts were 3- to 4-fold higher in brain and heart than in liver. In situ hybridization of rat whole brain sections showed an mRNA expression pattern similar to that observed for human P450 20A1, indicating expression in substantia nigra, hippocampus, and amygdala. A number of N-terminal modifications of the codon-optimized human P450 20A1 sequence were prepared and expressed in Escherichia coli, and two of the truncated derivatives showed characteristic P450 spectra (200-280 nmol of P450/l). Although the recombinant enzyme system oxidized NADPH, no catalytic activity was observed with the heterologously expressed protein when a number of potential steroids and biogenic amines were surveyed as potential substrates. The function of P450 20A1 remains unknown; however, the sites of mRNA expression in human brain and the conservation among species may suggest possible neurophysiological function.
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Affiliation(s)
- Katarina Stark
- Department of Biochemistry and Center in Molecular Toxicology, Vanderbilt University School of Medicine, Nashville, Tennessee 37232-0146, USA
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8
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Recillas-Targa F. Multiple strategies for gene transfer, expression, knockdown, and chromatin influence in mammalian cell lines and transgenic animals. Mol Biotechnol 2007; 34:337-54. [PMID: 17284781 DOI: 10.1385/mb:34:3:337] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/1999] [Revised: 11/30/1999] [Accepted: 11/30/1999] [Indexed: 12/31/2022]
Abstract
Manipulation of the eukaryotic genome has contributed to the progress in our knowledge of multicellular organisms but has also ameliorated our experimental strategies. Biological questions can now be addressed with more efficiency and reproducibility. There are new and varied strategies for gene transfer and sequence manipulation with improved methodologies that facilitate the acquisition of results. Cellular systems and transgenic animals have demonstrated their invaluable benefits. In this review, I present an overview of the methods of gene transfer with particular attention to cultured cell lines and large-scale sequence vectors, like artificial chromosomes, with the possibility of their manipulation based on homologous recombination strategies. Alternative strategies of gene transfer, including retroviral vectors, are also described and the applications of such methods are discussed. Finally, several comments are made about the influence of chromatin structure on gene expression. Recent experimental data have shown that for convenient stable transgene expression, the influence of chromatin structure should be seriously taken into account. Novel chromatin regulatory and structural elements are proposed as an alternative for proper and sustained gene expression. These chromatin elements are facing a new era in transgenesis and we are probably beginning a new generation of gene and cancer therapy vectors.
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Affiliation(s)
- Félix Recillas-Targa
- Instituto de Fisiología Celular, Departamento de Genética Molecular, Universidad Nacional Autónoma de México Apartado Postal 70-242, México D.F. 04510.
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9
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Locuson CW, Hutzler JM, Tracy TS. Visible spectra of type II cytochrome P450-drug complexes: evidence that "incomplete" heme coordination is common. Drug Metab Dispos 2007; 35:614-22. [PMID: 17251307 DOI: 10.1124/dmd.106.012609] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The visible spectrum of a ligand-bound cytochrome P450 is often used to determine the nature of the interaction between the ligand and the P450. One particularly characteristic form of spectra arises from the coordination of nitrogen-containing ligands to the P450 heme iron. These type II ligands tend to be inhibitors because they stabilize the low reduction potential P450 and prevent oxygen binding to the heme. Yet, several type II ligands containing aniline, imidazole, and triazole moieties are also known to be substrates of P450, although P450 binding spectra are not often scrutinized to make this distinction. Therefore, the three nitrogenous ligands aniline, imidazole, and triazole were used as binding spectra standards with purified human CYP3A4 and CYP2C9, because their small size should not present any steric limitations in their accessing the heme prosthetic group. Next, the spectra of P450 with drugs containing the three nitrogenous groups were collected for comparison. The absolute spectra demonstrated that the red-shift of the low-spin Soret band is mostly dependent on the electronic properties of the nitrogen ligand since they tended to match their respective standards, aniline, imidazole, and triazole. On the other hand, difference spectra seemed to be more sensitive to the steric properties of the ligand because they facilitated comparison of the spectral amplitudes achieved with the drugs versus those with the standard nitrogen ligands. Therefore, difference spectra may help reveal "weak" coordination to the heme that results from suboptimal orientation or ligand binding to more remote locations within the P450 active sites.
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Affiliation(s)
- Charles W Locuson
- Department of Experimental and Clinical Pharmacology, University of Minnesota, College of Pharmacy, 7-115B Weaver-Densford Hall, 308 Harvard Street SE, Minneapolis, MN 55455, USA
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10
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Uno Y, Fujino H, Kito G, Kamataki T, Nagata R. CYP2C76, a Novel Cytochrome P450 in Cynomolgus Monkey, Is a Major CYP2C in Liver, Metabolizing Tolbutamide and Testosterone. Mol Pharmacol 2006; 70:477-86. [PMID: 16648389 DOI: 10.1124/mol.106.022673] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Monkeys are widely used as a primate model to study drug metabolism because they generally show a metabolic pattern similar to humans. However, the paucity of information on cytochrome P450 (P450) genes has hampered a deep understanding of drug metabolism in the monkey. In this study, we report identification of the CYP2C76 cDNA newly identified in cynomolgus monkey and characterization of this CYP2C along with cynomolgus CYP2C20, CYP2C43, and CYP2C75. The CYP2C76 cDNA contains the open reading frame encoding a protein of 489 amino acids that are only approximately 80% identical to any human or monkey P450 cDNAs. Gene and protein expression of CYP2C76 was confirmed in the liver of cynomolgus and rhesus monkeys but not in humans or the great apes. Moreover, CYP2C76 is located at the end of the CYP2C gene cluster in the monkey genome, the region of which corresponds to the intergenic region adjacent to the CYP2C cluster in the human genome, strongly indicating that this gene does not have the ortholog in humans. Among the four CYP2C genes expressing predominantly in the liver, the expression level of CYP2C76 was the greatest, suggesting that CYP2C76 is a major CYP2C in the monkey liver. Assays for the capacity of CYP2C76 to metabolize drugs using several substrates typical for human CYP2Cs revealed that CYP2C76 showed unique metabolic activity. These results suggest that CYP2C76 contributes to overall drug-metabolizing activity in the monkey liver and might account for species difference occasionally seen in drug metabolism between monkeys and humans.
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Affiliation(s)
- Yasuhiro Uno
- Laboratory of Translational Research, Graduate School of Pharmaceutical Sciences, Hokkaido University, Kita 14 Nishi 6, Kita-ku, Sapporo, 060-0812, Japan.
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11
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Irvine DV, Shaw ML, Choo KHA, Saffery R. Engineering chromosomes for delivery of therapeutic genes. Trends Biotechnol 2005; 23:575-83. [PMID: 16242803 DOI: 10.1016/j.tibtech.2005.10.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2005] [Revised: 06/03/2005] [Accepted: 10/06/2005] [Indexed: 02/02/2023]
Abstract
The ability to create fully functional human chromosome vectors represents a potentially exciting gene-delivery system for the correction of human genetic disorders with several advantages over viral delivery systems. However, for the full potential of chromosome-based gene-delivery vectors to be realized, several key obstacles must be overcome. Methods must be developed to insert therapeutic genes reliably and efficiently and to enable the stable transfer of the resulting chromosomal vectors to different therapeutic cell types. Research to achieve these outcomes continues to encounter major challenges; however recent developments have reiterated the potential of chromosome-based vectors for therapeutic gene delivery. Here we review the different strategies under development and discuss the advantages and problems associated with each.
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Affiliation(s)
- Danielle V Irvine
- Chromosome Research Group, Murdoch Childrens Research Institute, Royal Children's Hospital, Department of Paediatrics, University of Melbourne, Flemington Road, Parkville 3052, Australia
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12
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Wang H, Zhao Y, Bradbury JA, Graves JP, Foley J, Blaisdell JA, Goldstein JA, Zeldin DC. Cloning, Expression, and Characterization of Three New Mouse Cytochrome P450 Enzymes and Partial Characterization of Their Fatty Acid Oxidation Activities. Mol Pharmacol 2004; 65:1148-58. [PMID: 15102943 DOI: 10.1124/mol.65.5.1148] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The mammalian CYP2C subfamily is one of the largest and most complicated in the cytochrome P450 superfamily. In this report, we describe the organization of the mouse Cyp2c locus, which contains 15 genes and four pseudogenes, all of which are located in a 5.5-megabase region on chromosome 19. We cloned three novel mouse CYP2C cDNAs (designated CYP2C50, CYP2C54, and CYP2C55) from mouse heart, liver, and colon, respectively. All three cDNAs contain open reading frames that encode 490 amino acid polypeptides that are 57 to 95% identical to other CYP2Cs. The recombinant CYP2C proteins were expressed in Escherichia coli after N-terminal modification, partially purified, and shown to be active in the metabolism of both arachidonic acid (AA) and linoleic acid, albeit with different catalytic efficiencies and profiles. CYP2C50 and CYP2C54 metabolize AA to epoxyeicosatrienoic acids (EETs) primarily, and linoleic acid to epoxyoctadecenoic acids (EOAs) primarily, whereas CYP2C55 metabolizes AA to EETs and hydroxyeicosatetraenoic acids and linoleic acid to EOAs and hydroxyoctadecadienoic acids. Northern blotting and reverse transcription-polymerase chain reaction analysis reveal that CYP2C50 transcripts are abundant in liver and heart; CYP2C54 transcripts are present in liver, kidney, and stomach; and CYP2C55 transcripts are abundant in liver, colon, and kidney. Immunoblotting studies demonstrate that CYP2C50 protein is expressed in liver and heart, CYP2C54 protein is detected primarily in liver, and CYP2C55 protein is present primarily in colon. Immunohistochemistry reveals that CYP2C55 is most abundant in surface columnar epithelium in the cecum. We conclude that these new CYP2C enzymes are probably involved in AA and linoleic acid metabolism in mouse hepatic and extrahepatic tissues.
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Affiliation(s)
- Hong Wang
- Laboratories of Respiratory Biology, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, North Carolina 27709, USA
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13
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DeLozier TC, Tsao CC, Coulter SJ, Foley J, Bradbury JA, Zeldin DC, Goldstein JA. CYP2C44, a New Murine CYP2C That Metabolizes Arachidonic Acid to Unique Stereospecific Products. J Pharmacol Exp Ther 2004; 310:845-54. [PMID: 15084647 DOI: 10.1124/jpet.104.067819] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The human CYP2Cs have been studied extensively with respect to the metabolism of clinically important drugs and endogenous chemicals such as arachidonic acid (AA). Five members of the mouse CYP2C family have previously been described that metabolize arachidonic acid into regio- and stereospecific epoxyeicosatrienoic acids (EETs) and hydroxyeicosatetraenoic acids, which have many important physiological roles. Herein, we describe the cloning and characterization of a new mouse cytochrome P450 (P450), CYP2C44, which has the lowest homology with other known mouse CYP2Cs. Western blotting and real-time polymerase chain reaction detected CYP2C44 mRNA and protein in liver >> kidney > adrenals. Kidney contained approximately 10% of the CYP2C44 mRNA content of liver. CYP2C44 metabolized AA to unique stereospecific products, 11R,12S-EET and 8R, 9S-EET, which are similar to those produced by rat CYP2C23. CY2C23 is highly expressed in rat kidney and has been suggested to be important in producing compensatory renal artery vasodilation in response to salt-loading in this species. Immunohistochemistry showed the presence of CYP2C44 in hepatocytes, biliary cells of the liver, and the proximal tubules of the kidney. Unlike mouse CYP2C29, CYP2C38, and CYP2C39, CYP2C44 did not metabolize the common CYP2C substrate tolbutamide. CYP2C44 was not induced by phenobarbital or pregnenolone-16alpha-carbonitrile, two prototypical inducers of hepatic P450s. The presence of CYP2C44 in mouse liver, kidney, and adrenals and the unique stereospecificity of its arachidonic acid metabolites are consistent with the possibility that it may have unique physiological roles within these tissues, such as modulation of electrolyte transport or vascular tone.
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Affiliation(s)
- Tracy C DeLozier
- Laboratory of Pharmacology, National Institute of Environmental Health Sciences, P.O. Box 12233, 111 T.W. Alexander Drive, Building 101, Research Triangle Park, NC 27709
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14
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Carr BA, Ramakanth S, Dannan GA, Yost GS. Characterization of pulmonary CYP4B2, specific catalyst of methyl oxidation of 3-methylindole. Mol Pharmacol 2003; 63:1137-47. [PMID: 12695542 DOI: 10.1124/mol.63.5.1137] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The selective toxicity of chemicals to lung tissues is predominantly mediated by the selective expression of certain pulmonary cytochrome P450 enzymes. This report describes the purification, cloning, and characterization of a unique enzyme, CYP4B2, from goat lung. The purified P450 enzyme was isolated by multistep ion exchange chromatography to electrophoretic homogeneity with an apparent molecular mass of 55,000 Da. Western blotting studies demonstrated that CYP4B enzymes were selectively expressed in lung tissues of rabbits, rats, and mice. Two cDNAs, CYP4B2 and CYP4B2v, were cloned from goat lung tissue. CYP4B2 was predicted to be 511 amino acids and approximately 82% similar to the four known CYP4B1 proteins. Concurrently, a variant of the known human CYP4B1 cDNA, that contained a S207 insertion, was cloned from human lung tissue. The modified recombinant goat CYP4B2 was expressed in Escherichia coli and the enzyme catalyzed the N-hydroxylation of the prototypical substrate 2AF. CYP4B2 preferentially dehydrogenated, rather than hydroxylated, the pneumotoxicant 3-methylindole (3MI) (V(max) = 4.61 versus 0.83 nmol/nmol of P450/min, respectively). To investigate the relevance of covalent heme binding of CYP4 enzymes in CYP4B2-mediated metabolism of 3MI, a site-directed mutant (CYP4B2/A315E) was evaluated. The mutation had little effect on the V(max) of either dehydrogenation or hydroxylation but increased the K(m), which decreased the catalytic efficiency (V/K) for 3MI. The A315E mutation shifted the absorbance maximum of the enzyme from 448 to 451 nm, suggesting that the electron density of the heme was altered. These results demonstrate that CYP4B2 is highly specific for methyl group oxidation of 3MI, without formation of ring-oxidized metabolites, and seems to be predominately responsible for the highly organ-specific toxicity of 3MI in goats.
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Affiliation(s)
- Brian A Carr
- Department of Pharmacology and Toxicology, University of Utah Salt Lake City, 84112-5820, USA
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15
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Matthews LJ, Davis R, Smith GP. Immunogenically fit subunit vaccine components via epitope discovery from natural peptide libraries. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 169:837-46. [PMID: 12097387 DOI: 10.4049/jimmunol.169.2.837] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Antigenic peptides that bind pathogen-specific Abs are a potential source of subunit vaccine components. To be effective the peptides must be immunogenically fit: when used as immunogens they must elicit Abs that cross-react with native intact pathogen. In this study, antigenic peptides obtained from phage display libraries through epitope discovery were systematically examined for immunogenic fitness. Peptides selected from random peptide libraries, in which the phage-displayed peptides are encoded by synthetic degenerate oligonucleotides, had marginal immunogenic fitness. In contrast, 50% of the peptides selected from a natural peptide library, in which phage display segments of actual pathogen polypeptides, proved very successful. Epitope discovery from natural peptide libraries is a promising route to subunit vaccines.
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MESH Headings
- Amino Acid Sequence
- Animals
- Antibodies, Viral/biosynthesis
- Antigens, Viral/immunology
- Antigens, Viral/isolation & purification
- Antigens, Viral/metabolism
- Bacteriophage T4/immunology
- Bacteriophage T4/metabolism
- Binding Sites, Antibody
- Cross Reactions
- Epitopes/immunology
- Epitopes/metabolism
- Immune Sera/biosynthesis
- Immunity, Innate
- Mice
- Mice, Inbred BALB C
- Molecular Mimicry
- Molecular Sequence Data
- Peptide Library
- Peptides/immunology
- Peptides/isolation & purification
- Peptides/metabolism
- Recombinant Fusion Proteins/immunology
- Recombinant Fusion Proteins/metabolism
- Vaccines, Subunit/immunology
- Vaccines, Subunit/metabolism
- Vaccines, Synthetic/immunology
- Vaccines, Synthetic/metabolism
- Viral Proteins/immunology
- Viral Proteins/isolation & purification
- Viral Proteins/metabolism
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Affiliation(s)
- Leslie J Matthews
- Division of Biological Sciences, University of Missouri, Columbia, MO 65211-7400, USA.
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Saffery R, Wong LH, Irvine DV, Bateman MA, Griffiths B, Cutts SM, Cancilla MR, Cendron AC, Stafford AJ, Choo KH. Construction of neocentromere-based human minichromosomes by telomere-associated chromosomal truncation. Proc Natl Acad Sci U S A 2001; 98:5705-10. [PMID: 11331754 PMCID: PMC33277 DOI: 10.1073/pnas.091468498] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2000] [Indexed: 11/18/2022] Open
Abstract
Neocentromeres (NCs) are fully functional centromeres that arise ectopically in noncentromeric regions lacking alpha-satellite DNA. Using telomere-associated chromosome truncation, we have produced a series of minichromosomes (MiCs) from a mardel(10) marker chromosome containing a previously characterized human NC. These MiCs range in size from approximately 0.7 to 1.8 Mb and contain single-copy intact genomic DNA from the 10q25 region. Two of these NC-based Mi-Cs (NC-MiCs) appear circular whereas one is linear. All demonstrate stability in both structure and mitotic transmission in the absence of drug selection. Presence of a functional NC is shown by binding a host of key centromere-associated proteins. These NC-MiCs provide direct evidence for mitotic segregation function of the NC DNA and represent examples of stable mammalian MiCs lacking centromeric repeats.
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Affiliation(s)
- R Saffery
- The Murdoch Children's Research Institute, Royal Children's Hospital, Flemington Road, Melbourne 3052, Australia
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Mewes HW, Albermann K, Heumann K, Liebl S, Pfeiffer F. MIPS: a database for protein sequences, homology data and yeast genome information. Nucleic Acids Res 1997; 25:28-30. [PMID: 9016498 PMCID: PMC146421 DOI: 10.1093/nar/25.1.28] [Citation(s) in RCA: 173] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023] Open
Abstract
The MIPS group (Martinsried Institute for Protein Sequences) at the Max-Planck-Institute for Biochemistry, Martinsried near Munich, Germany, collects, processes and distributes protein sequence data within the framework of the tripartite association of the PIR-International Protein Sequence Database (,). MIPS contributes nearly 50% of the data input to the PIR-International Protein Sequence Database. The database is distributed on CD-ROM together with PATCHX, an exhaustive supplement of unique, unverified protein sequences from external sources compiled by MIPS. Through its WWW server (http://www.mips.biochem.mpg.de/ ) MIPS permits internet access to sequence databases, homology data and to yeast genome information. (i) Sequence similarity results from the FASTA program () are stored in the FASTA database for all proteins from PIR-International and PATCHX. The database is dynamically maintained and permits instant access to FASTA results. (ii) Starting with FASTA database queries, proteins have been classified into families and superfamilies (PROT-FAM). (iii) The HPT (hashed position tree) data structure () developed at MIPS is a new approach for rapid sequence and pattern searching. (iv) MIPS provides access to the sequence and annotation of the complete yeast genome (), the functional classification of yeast genes (FunCat) and its graphical display, the 'Genome Browser' (). A CD-ROM based on the JAVA programming language providing dynamic interactive access to the yeast genome and the related protein sequences has been compiled and is available on request.
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Affiliation(s)
- H W Mewes
- MIPS, Max-Planck-Institut für Biochemie, Am Klopferspitz 18, D-82152 Martinsried, Germany.
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