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Xiao J, Wang J, Gan R, Wu D, Xu Y, Peng L, Geng F. Quantitative N-glycoproteome analysis of bovine milk and yogurt. Curr Res Food Sci 2022; 5:182-190. [PMID: 35072106 PMCID: PMC8763629 DOI: 10.1016/j.crfs.2022.01.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Revised: 12/25/2021] [Accepted: 01/05/2022] [Indexed: 12/02/2022] Open
Abstract
Post-translational modification structure of food's proteins might be changed during processing, thereby affecting the nutritional characteristics of the food product. In this study, differences in protein N-glycosylation patterns between milk and yogurt were quantitatively compared based on glycopeptide enrichment, liquid chromatography separation, and tandem mass spectrometry analysis. A total of 181 N-glycosites were identified, among which 142 were quantified in milk and yogurt. Significant alterations in the abundance of 13 of these N-glycosites were evident after the fermentation of milk into yogurt. Overall, the N-glycosylation status of the majority of milk proteins remained relatively unchanged in yogurt, suggesting that their conformations, activities, and functions were maintained despite the fermentation process. Among the main milk proteins, N241 of cathepsin D and N358 of lactoperoxidase were markedly reduced after undergoing lactic acid fermentation to produce yogurt. Furthermore, a comparative analysis of current and previously reported N-glycoproteomic data revealed heterogeneity in the N-glycosylation of milk proteins. To sum up, a quantitative comparison of the N-glycoproteomes of milk and yogurt was presented here for the first time, providing evidence that the fermentation process of yogurt could cause changes in the N-glycosylation of certain milk proteins. 181 N-glycosites from 118 N-glycoproteins were identified in milk and yogurt. 13 N-glycosites changed significantly after fermentation of milk into yogurt. N241 of cathepsin D and N358 of lactoperoxidase was markedly reduced in yogurt. Heterogeneity of N-glycosylation of milk protein has been documented.
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Affiliation(s)
- Jing Xiao
- Key Laboratory of Coarse Cereal Processing (Ministry of Agriculture and Rural Affairs), School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, China
| | - Jinqiu Wang
- Key Laboratory of Coarse Cereal Processing (Ministry of Agriculture and Rural Affairs), School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, China
| | - Renyou Gan
- Research Center for Plants and Human Health, Institute of Urban Agriculture, Chinese Academy of Agricultural Sciences, Chengdu, 610213, Sichuan, China
| | - Di Wu
- Key Laboratory of Coarse Cereal Processing (Ministry of Agriculture and Rural Affairs), School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, China
| | - Yisha Xu
- Key Laboratory of Coarse Cereal Processing (Ministry of Agriculture and Rural Affairs), School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, China
| | - Lianxin Peng
- Key Laboratory of Coarse Cereal Processing (Ministry of Agriculture and Rural Affairs), School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, China
| | - Fang Geng
- Key Laboratory of Coarse Cereal Processing (Ministry of Agriculture and Rural Affairs), School of Food and Biological Engineering, Chengdu University, Chengdu, 610106, China
- Corresponding author.
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Rogers JR, McHugh SM, Lin YS. Predictions for α-Helical Glycopeptide Design from Structural Bioinformatics Analysis. J Chem Inf Model 2017; 57:2598-2611. [DOI: 10.1021/acs.jcim.7b00123] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Julia R. Rogers
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Sean M. McHugh
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
| | - Yu-Shan Lin
- Department of Chemistry, Tufts University, Medford, Massachusetts 02155, United States
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Meredith M, MacNeil AH, Trasler JM, Baltz JM. Growing Mouse Oocytes Transiently Activate Folate Transport via Folate Receptors As They Approach Full Size. Biol Reprod 2016; 94:125. [PMID: 27122634 PMCID: PMC4946804 DOI: 10.1095/biolreprod.115.137687] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2015] [Revised: 01/14/2016] [Accepted: 04/19/2016] [Indexed: 12/12/2022] Open
Abstract
The folate cycle is central to cellular one-carbon metabolism, where folates are carriers of one-carbon units that are critical for synthesis of purines, thymidylate, and S-adenosylmethionine, the universal methyl donor that forms the cellular methyl pool. Although folates are well-known to be important for early embryo and fetal development, their role in oogenesis has not been clearly established. Here, folate transport proteins were detected in developing neonatal ovaries and growing oocytes by immunohistochemistry, Western blot, and immunofluorescence. The folate receptors FOLR1 and FOLR2 as well as reduced folate carrier 1 (RFC1, SLC19A1 protein) each appeared to be present in follicular cells including granulosa cells. In growing oocytes, however, only FOLR2 immunoreactivity appeared abundant. Localization of apparent FOLR2 immunofluorescence near the plasma membrane increased with oocyte growth and peaked in oocytes as they neared full size. We assessed folate transport using the model folate leucovorin (folinic acid). Unexpectedly, there was a transient burst of folate transport activity for a brief period during oocyte growth as they neared full size, while folate transport was otherwise undetectable for the rest of oogenesis and in fully grown germinal vesicle stage oocytes. This folate transport was inhibited by dynasore, an inhibitor of endocytosis, but insensitive to the anion transport inhibitor stilbene 4-acetamido-40-isothiocyanato-stilbene-2,20-disulfonic acid, consistent with folate receptor-mediated transport but not with RFC1-mediated transport. Thus, near the end of their growth, growing oocytes may take up folates that could support the final stage of oogenesis or be stored to provide the endogenous folates needed in early embryogenesis.
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Affiliation(s)
- Megan Meredith
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada Department of Obstetrics and Gynecology and Department of Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
| | | | - Jacquetta M Trasler
- Montréal Children's Hospital and Research Institute of the McGill University Health Centre, Montréal, Quebec, Canada Departments of Human Genetics, Pediatrics, and Pharmacology and Therapeutics, McGill University, Montréal, Quebec, Canada
| | - Jay M Baltz
- Ottawa Hospital Research Institute, Ottawa, Ontario, Canada Department of Obstetrics and Gynecology and Department of Cellular and Molecular Medicine, University of Ottawa Faculty of Medicine, Ottawa, Ontario, Canada
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Stapf M, Pömpner N, Teichgräber U, Hilger I. Heterogeneous response of different tumor cell lines to methotrexate-coupled nanoparticles in presence of hyperthermia. Int J Nanomedicine 2016; 11:485-500. [PMID: 26893557 PMCID: PMC4745830 DOI: 10.2147/ijn.s94384] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
Today, the therapeutic efficacy of cancer is restricted by the heterogeneity of the response of tumor cells to chemotherapeutic drugs. Since those therapies are also associated with severe side effects in nontarget organs, the application of drugs in combination with nanocarriers for targeted therapy has been suggested. Here, we sought to assess whether the coupling of methotrexate (MTX) to magnetic nanoparticles (MNP) could serve as a valuable tool to circumvent the heterogeneity of tumor cell response to MTX by the combined treatment with hyperthermia. To this end, we investigated five breast cancer cell lines of different origin and with different mutational statuses, as well as a bladder cancer cell line in terms of their response to exposure to MTX as a free drug or after its coupling to MNP as well as in presence/absence of hyperthermia. We also assessed whether the effects could be connected to the cell line-specific expression of proteins related to the uptake and efflux of MTX and MNP. Our results revealed a very heterogeneous and cell line-dependent response to an exposure with MTX-coupled MNP (MTX–MNP), which was almost comparable to the efficacy of free MTX in the same cell line. Moreover, a cell line-specific and preferential uptake of MTX–MNP compared with MNP alone was found (probably by receptor-mediated endocytosis), agreeing with the observed cytotoxic effects. Opposed to this, the expression pattern of several cell membrane transport proteins noted for MTX uptake and efflux was only by tendency in agreement with the cellular toxicity of MTX–MNP in different cell lines. Higher cytotoxic effects were achieved by exposing cells to a combination of MTX–MNP and hyperthermal treatment, compared with MTX or thermo-therapy alone. However, the heterogeneity in the response of the tumor cell lines to MTX could not be completely abolished – even after its combination with MNP and/or hyperthermia – and the application of higher thermal dosages might be necessary.
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Affiliation(s)
- Marcus Stapf
- Institute of Diagnostic and Interventional Radiology, Department of Experimental Radiology, Jena University Hospital, Friedrich-Schiller University, Jena, Germany
| | - Nadine Pömpner
- Institute of Diagnostic and Interventional Radiology, Department of Experimental Radiology, Jena University Hospital, Friedrich-Schiller University, Jena, Germany
| | - Ulf Teichgräber
- Institute of Diagnostic and Interventional Radiology, Department of Experimental Radiology, Jena University Hospital, Friedrich-Schiller University, Jena, Germany
| | - Ingrid Hilger
- Institute of Diagnostic and Interventional Radiology, Department of Experimental Radiology, Jena University Hospital, Friedrich-Schiller University, Jena, Germany
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5
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Merzel RL, Chen JJ, Marsh ENG, Holl MMB. Folate binding protein—Outlook for drug delivery applications. CHINESE CHEM LETT 2015. [DOI: 10.1016/j.cclet.2014.12.015] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Abstract
Folic acid, also known as vitamin B9 (Fig. 9.1), is an essential co-enzyme in one-carbon metabolism pathways, including the biosynthesis of nucleotides (i.e. purines, thymidine) and several amino acids. In general, two functionally different systems mediate the cellular uptake of folate: (1) the reduced folate carrier (RFC, Kd ∼ 10-6 M), an anion transporter that delivers folates across the plasma membrane in a bidirectional fashion, and (2) the folate receptor (FR, Kd ∼ 10-10 M), which internalizes folate through active receptor-mediated endocytosis. The RFC, a membrane-spanning anion transporter, is present in virtually all tissues and is responsible for the majority of folate transport in and out of cells. In contrast, FR expression is largely restricted to malignant cells, activated macrophages, and the proximal tubule cells of the kidneys. Because a variety of important diseases are caused by the former two cell types, interest in exploiting FR for drug targeting applications has rapidly increased. And achievement of this targeting objective, primarily through conjugation of drugs to folic acid is believed to enable (1) enhanced net drug uptake by pathologic cells, and more importantly (2) reduction in drug deposition into non-pathologic cells, thereby mitigating collateral toxicity to normal tissues.
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O'Riordan N, Kane M, Joshi L, Hickey RM. Structural and functional characteristics of bovine milk protein glycosylation. Glycobiology 2014; 24:220-36. [PMID: 24398766 DOI: 10.1093/glycob/cwt162] [Citation(s) in RCA: 116] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023] Open
Abstract
Most secreted and cell membrane proteins in mammals are glycosylated. Many of these glycoproteins are also prevalent in milk and play key roles in the biomodulatory properties of milk and ultimately in determining milk's nutritional quality. Although a significant amount of information exists on the types and roles of free oligosaccharides in milk, very little is known about the glycans associated with milk glycoproteins, in particular, the biological properties that are linked to their presence. The main glycoproteins found in bovine milk are lactoferrin, the immunoglobulins, glycomacropeptide, a glycopeptide derived from κ-casein, and the glycoproteins of the milk fat globule membrane. Here, we review the glycoproteins present in bovine milk, the information currently available on their glycosylation and the biological significance of their oligosaccharide chains.
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Affiliation(s)
- Noelle O'Riordan
- Teagasc Food Research Centre, Moorepark, Fermoy, County Cork, Ireland
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Jaiswal N, Saraswat S, Ratnam M, Isailovic D. Analysis of Folate Binding Protein N-linked Glycans by Mass Spectrometry. J Proteome Res 2012; 11:1551-60. [DOI: 10.1021/pr2006044] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Nidhi Jaiswal
- Department of Chemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Suraj Saraswat
- Department of Chemistry, University of Toledo, Toledo, Ohio 43606, United States
| | - Manohar Ratnam
- Department of Biochemistry and
Cancer Biology, Medical University of Ohio, Toledo, Ohio 43614, United States
| | - Dragan Isailovic
- Department of Chemistry, University of Toledo, Toledo, Ohio 43606, United States
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Bonnon C, Wendeler MW, Paccaud JP, Hauri HP. Selective export of human GPI-anchored proteins from the endoplasmic reticulum. J Cell Sci 2010; 123:1705-15. [PMID: 20427317 DOI: 10.1242/jcs.062950] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
Selective export of transmembrane proteins from the endoplasmic reticulum (ER) relies on recognition of cytosolic-domain-localized transport signals by the Sec24 subunit of the COPII vesicle coat. Human cells express four Sec24 isoforms, termed Sec24A, Sec24B, Sec24C and Sec24D that are differentially required for selective, signal-mediated ER export of transmembrane proteins. By contrast, luminally exposed glycosylphosphatidylinositol (GPI)-anchored membrane proteins cannot bind directly to Sec24 and must either use membrane-spanning cargo receptors or alternative mechanisms for ER export. Little is known about the mechanism underlying export of GPI-anchored proteins from the ER in higher eukaryotes. Using siRNA-based silencing, we identified that ER-to-Golgi transport of the human GPI-anchored protein CD59 requires Sec24, with preference for the Sec24C and Sec24D isoforms, and the recycling transmembrane protein complex p24-p23 that exhibited the same Sec24C-Sec24D isoform preference for ER export. Co-immunoprecipitation indicated unprecedented physical interaction of CD59 as well as a GFP-folate-receptor-GPI-anchor hybrid with a p24-p23 complex. Density gradient centrifugation revealed co-partitioning of CD59 and p24-p23 into biosynthetically early lipid raft fractions, and CD59 transport to the Golgi was cholesterol dependent. The results suggest that the 24p-23p complex acts as a cargo receptor for GPI-anchored proteins by facilitating their export from the ER in a Sec24-isoform-selective manner involving lipid rafts as early sorting platforms.
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Affiliation(s)
- Carine Bonnon
- Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland
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10
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Pinhassi RI, Assaraf YG, Farber S, Stark M, Ickowicz D, Drori S, Domb AJ, Livney YD. Arabinogalactan−Folic Acid−Drug Conjugate for Targeted Delivery and Target-Activated Release of Anticancer Drugs to Folate Receptor-Overexpressing Cells. Biomacromolecules 2009; 11:294-303. [DOI: 10.1021/bm900853z] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Roy I. Pinhassi
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Yehuda G. Assaraf
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Shimon Farber
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Michal Stark
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Diana Ickowicz
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Stavit Drori
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Abraham J. Domb
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
| | - Yoav D. Livney
- Laboratory of Biopolymers and Food Nanotechnology, Department of Biotechnology and Food Engineering, The Russell Berrie Nanotechnology Institute, and The Fred Wyszkowski Cancer Research Laboratory, Department of Biology, The Technion, Israel Institute of Technology, Israel, and Institute of Drug Research, School of Pharmacy, Faculty of Medicine, The Hebrew University of Jerusalem, Israel
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11
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Wheeler DS, Wong HR, Shanley TP. Genetic Polymorphisms in Critical Care and Illness. SCIENCE AND PRACTICE OF PEDIATRIC CRITICAL CARE MEDICINE 2009. [PMCID: PMC7123127 DOI: 10.1007/978-1-84800-921-9_16] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Derek S. Wheeler
- Medical Center, Div. of Critical Care Medicine, Cincinnati Children's Hospital, Burnet Avenue 3333, Cincinnati, 45229 U.S.A
| | - Hector R. Wong
- Medical Center, Div. of Critical Care Medicine, Cincinnati Children's Hospital, Burnet Avenue 3333, Cincinnati, 45229 U.S.A
| | - Thomas P. Shanley
- C.S. Mott Children's Hospital , Pediatric Critical Care Medicine , University of Michigan, E. Medical Center Drive 1500, Ann Arbor, 48109-0243 U.S.A
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Abstract
CONTEXT Wide variability exists in the susceptibility to and outcome from sepsis even within similar intensive care unit populations. Some of this variability in the host may be due to genetic variation in genes coding for components of the innate immune response. OBJECTIVE To review the evidence for a genetic influence on the susceptibility to and outcome from sepsis. DESIGN Literature review. PATIENTS Variety of adult and pediatric patients with various critical illnesses and infections. INTERVENTIONS None. MAIN OUTCOME MEASURES Susceptibility to clinical symptoms of sepsis and outcome as measured by severity of disease and mortality. RESULTS Polymorphisms in genes coding for proteins involved in the recognition of bacterial pathogens (Toll-like receptor 4, CD14, Fc(gamma)RIIa, and mannose-binding lectin) and the response to bacterial pathogens (tumor necrosis factor-alpha, interleukin (IL)-1alpha, IL-1beta, IL-1 receptor agonist, IL-6, IL-10, heat shock proteins, angiotensin I converting enzyme, plasminogen activator inhibitor-1) can influence the amount or function of the protein produced in response to bacterial stimuli. Evidence is discussed suggesting that some of these genetic polymorphisms influence the susceptibility to and outcome from sepsis. CONCLUSION Host genetic variability in the regulatory and coding regions of genes for components of the innate immune system may influence the susceptibility to and/or outcome from sepsis. The disparate results observed in many studies of polymorphisms in sepsis emphasize the need for future studies to be larger, to include the analysis of multiple polymorphisms, and to be better designed with respect to control populations to identify the degree of influence that genetic variability has on sepsis.
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Affiliation(s)
- Mary K Dahmer
- Department of Molecular Sciences, University of Tennessee Health Science Center, Memphis, TN, USA
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Neuendorf E, Weber A, Saalmueller A, Schatzl H, Reifenberg K, Pfaff E, Groschup MH. Glycosylation Deficiency at Either One of the Two Glycan Attachment Sites of Cellular Prion Protein Preserves Susceptibility to Bovine Spongiform Encephalopathy and Scrapie Infections. J Biol Chem 2004; 279:53306-16. [PMID: 15448157 DOI: 10.1074/jbc.m410796200] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The conversion into abnormally folded prion protein (PrP) plays a key role in prion diseases. PrP(C) carries two N-linked glycan chains at amino acid residues 180 and 196 (mouse). Previous in vitro data indicated that the conversion process may not require glycosylation of PrP. However, it is conceivable that these glycans function as intermolecular binding sites during the de novo infection of cells on susceptible organisms and/or play a role for the interaction of both PrP isoforms. Such receptor-like properties could contribute to the formation of specific prion strains. However, in earlier studies, mutations at the glycosylation sites of PrP led to intracellular trafficking abnormalities, which made it impossible to generate PrP glycosylation-deficient mice that were susceptible to bovine spongiform encephalopathy (BSE) or scrapie. We have now tested more than 25 different mutations at both consensus sites and found one nonglycosylated (T182N/T198A) and two monoglycosylated (T182N and T198A) mutants that rather retained authentic cellular trafficking properties. In vitro all three mutants were converted into PrP(res). PrP mutant T182N/T198A also provoked a strong dominant-negative inhibition on the endogenous wild type PrP conversion reaction. By using the two monoglycosylated mutants, we generated transgenic mice overexpressing PrP(C) in their brains at levels of 2-4 times that of nontransgenic mice. Most interestingly, such mice proved readily susceptible to a challenge with either scrapie (Chandler and Me7) or with BSE. Incubation times were comparable or in some instances even significantly shorter than those of nontransgenic mice. These data indicate that diglycosylation of PrP(C) is not mandatory for prion infection in vivo.
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Affiliation(s)
- Erdmute Neuendorf
- Institute for Novel and Emerging Infectious Diseases, Federal Research Centre for Virus Diseases of Animals, 17943 Greifswald, Isle of Riems, Germany
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14
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Quasney MW, Waterer GW, Dahmer MK, Kron GK, Zhang Q, Kessler LA, Wunderink RG. Association between surfactant protein B + 1580 polymorphism and the risk of respiratory failure in adults with community-acquired pneumonia. Crit Care Med 2004; 32:1115-9. [PMID: 15190959 DOI: 10.1097/01.ccm.0000124872.55243.5a] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Pulmonary surfactant protein (SP)-B plays a vital role in the formation and function of surfactant in the lung. A genetic polymorphism (SP-B + 1580) is postulated to result in diminished activity of SP-B. The objective was to determine whether the SP-B + 1580 CC genotype is associated with an increased risk of respiratory failure and ARDS in adults with community-acquired pneumonia. DESIGN Prospective cohort of adults diagnosed with community-acquired pneumonia. SETTING Hospital system. PATIENTS We enrolled 402 adults > or = 18 yrs of age with community-acquired pneumonia; 158 were white, 243 were African American, and one was Asian. INTERVENTIONS Genotypic analysis was performed on DNA isolated from whole blood using polymerase chain reaction amplification and DdeI restriction enzyme digestion. MEASUREMENTS AND MAIN RESULTS We recorded the requirement for mechanical ventilation, the presence of acute respiratory distress syndrome (ARDS) or septic shock, and mortality. Sixty-three patients required mechanical ventilation, 12 patients developed ARDS, and 35 patients developed septic shock. Genotypic frequencies at the SP-B + 1580 site were T/T 183 of 402 (0.45), T/C 160 of 402 (0.40), and C/C 59 of 402 (0.15). Of the 59 patients who were C/C at the SP-B + 1580 site, 21 (0.356) required mechanical ventilation, compared with 26 of 160 patients (0.163) who were T/C and 16 of 183 (0.087) patients who were T/T (p < .001). ARDS developed in five of 59 (0.085) patients with the C/C genotype, compared with six of 160 (.038) patients with T/C and one of 183 patients with T/T (0.005, p < .009). Septic shock occurred in 12 of 59 (0.203) patients with the C/C genotype, compared with 13 of 160 (0.081) patients with T/C and ten of 183 (0.055) patients with T/T (p < .001). Mortality rate was not different between the three genotypes. CONCLUSION Carriage of the C allele at the SP-B + 1580 site is associated with ARDS, septic shock, and the need for mechanical ventilation in adults with community-acquired pneumonia.
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Affiliation(s)
- Michael W Quasney
- Division of Critical Care, Department of Pediatrics, University of Tennessee, Memphis, Children's Foundation Research Center of Memphis, Le Bonheur Children's Medical Center, 50 N. Dunlap, Memphis, TN 38103, USA.
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15
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Doucette MM, Stevens VL. Point mutations alter the cellular distribution of the human folate receptor in cultured Chinese hamster ovary cells. J Nutr 2004; 134:308-16. [PMID: 14747665 DOI: 10.1093/jn/134.2.308] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Diminished cellular need for folate results in decreased function of the human folate receptor (FR) but increased expression of this protein in cells grown at different rates. Much of this FR is intracellular and not available for vitamin transport, raising the following question: what is the function of this excess receptor? In this study, we characterized the effects of three point mutations on FR regulation in Chinese hamster ovary cells stably transfected to express either wild-type receptor or FR containing mutations at positions 67(S-->P),144(E-->D), and/or 201(N-->D). The 201(N-->D) FR responded functionally like the wild-type receptor but was localized predominantly at the cell surface (>90% vs. <40% for wild-type). This mutation disrupted a N-linked glycosylation site and generated a partially deglycosylated receptor. The 67(S-->P) mutation also shifted the cellular distribution such that more FR was surface accessible ( approximately 80%) but did not affect glycosylation. Because previous results showed that these mutations influence the conformation of FR, our findings suggest that structural changes in the receptor facilitate its trafficking to the cell surface. FR containing the 67(S-->P) mutation with either a 144(E-->D) or 201(N-->D) change was not processed from the high-mannose to complex glycoform but was still transported to the cell surface and able to transport folates. Thus, conformational changes introduced by specific point mutations can influence FR processing and/or trafficking to the cell surface. Furthermore, the fact that mutated FR can be trafficked to the cell surface more efficiently suggests that the native receptor may be retained intracellularly to perform some function there.
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Affiliation(s)
- Michele M Doucette
- Division of Cancer Biology, Department of Radiation Oncology, Emory University School of Medicine, Atlanta, GA 30335, USA
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16
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Lin Z, Pearson C, Chinchilli V, Pietschmann SM, Luo J, Pison U, Floros J. Polymorphisms of human SP-A, SP-B, and SP-D genes: association of SP-B Thr131Ile with ARDS. Clin Genet 2000; 58:181-91. [PMID: 11076040 DOI: 10.1034/j.1399-0004.2000.580305.x] [Citation(s) in RCA: 153] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
An allele association study of 19 polymorphisms in surfactant proteins SP-A1, SP-A2, SP-B, and SP-D genes in acute respiratory distress syndrome (ARDS) was carried out. Trend-test analysis revealed differences (p < 0.05) in the frequency of alleles for some of the microsatellite markers flanking SP-B, and for one polymorphism (C/T) at nucleotide 1580 [C/T (1580)], within codon 131 (Thr131Ile) of the SP-B gene. The latter determines the presence or absence of a potential N-linked glycosylation site. Multivariate analysis revealed significant differences only for the C/T (1580) polymorphism. When the ARDS population was divided into subgroups, idiopathic (i.e., pneumonia, etc.) or exogenic (i.e., trauma, etc.), significant differences were observed for the C/T (1580), for the idiopathic ARDS group, and the frequency of the C/C genotype was increased in this group. Based on the odds ratio, the C allele may be viewed as a susceptibility factor for ARDS. Although the expression of both C and T alleles occurs in heterozygous individuals, it is currently not known whether these alleles correspond to similar levels of SP-B protein. These data suggest that SP-B or a linked gene contributes to susceptibility to ARDS.
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Affiliation(s)
- Z Lin
- Department of Cellular and Molecular Physiology, The Pennsylvania State University College of Medicine, Hershey 17033, USA
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Trippett TM, Bertino JR. Therapeutic strategies targeting proteins that regulate folate and reduced folate transport. J Chemother 1999; 11:3-10. [PMID: 10078775 DOI: 10.1179/joc.1999.11.1.3] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Folate is an essential vitamin which acts as a precursor for cofactors that regulate a variety of biochemical reactions. Cellular uptake of endogenous folates as well as antifolate agents such as methotrexate may be regulated by two independent transport proteins, the folate receptor and the reduced folate carrier. This paper reviews the molecular and functional characteristics of these transport systems and potential therapeutic approaches exploiting these targets in the treatment of cancer. Understanding of the molecular basis and functional characteristics of the transport of endogenous folates and folate analogs via the folate receptor and the reduced folate carrier has led to the development of novel antifolate agents through rational drug design and targeted therapeutic approaches for tumors that express or lack the presence of these transport proteins. With this knowledge, new and selective treatment will become available to more effectively treat patients with a variety of malignancies.
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Affiliation(s)
- T M Trippett
- Department of Pediatrics, Memorial Sloan-Kettering Cancer Center, New York, NY 10021, USA.
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