1
|
Mabashi-Asazuma H, Jarvis DL. A new insect cell line engineered to produce recombinant glycoproteins with cleavable N-glycans. J Biol Chem 2021; 298:101454. [PMID: 34838817 PMCID: PMC8689212 DOI: 10.1016/j.jbc.2021.101454] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 11/16/2021] [Accepted: 11/21/2021] [Indexed: 01/09/2023] Open
Abstract
Glycoproteins are difficult to crystallize because they have heterogeneous glycans composed of multiple monosaccharides with considerable rotational freedom about their O-glycosidic linkages. Crystallographers studying N-glycoproteins often circumvent this problem by using β1,2-N-acetylglucosaminyltransferase I (MGAT1)–deficient mammalian cell lines, which produce recombinant glycoproteins with immature N-glycans. These glycans support protein folding and quality control but can be removed using endo-β-N-acetylglucosaminidase H (Endo H). Many crystallographers also use the baculovirus-insect cell system (BICS) to produce recombinant proteins for their work but have no access to an MGAT1-deficient insect cell line to facilitate glycoprotein crystallization in this system. Thus, we used BICS-specific CRISPR–Cas9 vectors to edit the Mgat1 gene of a rhabdovirus-negative Spodoptera frugiperda cell line (Sf-RVN) and isolated a subclone with multiple Mgat1 deletions, which we named Sf-RVNLec1. We found that Sf-RVN and Sf-RVNLec1 cells had identical growth properties and served equally well as hosts for baculovirus-mediated recombinant glycoprotein production. N-glycan profiling showed that a total endogenous glycoprotein fraction isolated from Sf-RVNLec1 cells had only immature and high mannose-type N-glycans. Finally, N-glycan profiling and endoglycosidase analyses showed that the vast majority of the N-glycans on three recombinant glycoproteins produced by Sf-RVNLec1 cells were Endo H-cleavable Man5GlcNAc2 structures. Thus, this study yielded a new insect cell line for the BICS that can be used to produce recombinant glycoproteins with Endo H-cleavable N-glycans. This will enable researchers to combine the high productivity of the BICS with the ability to deglycosylate recombinant glycoproteins, which will facilitate efforts to determine glycoprotein structures by X-ray crystallography.
Collapse
Affiliation(s)
| | - Donald L Jarvis
- Department of Molecular Biology, University of Wyoming, Laramie, Wyoming, USA; GlycoBac, LLC, Laramie, Wyoming, USA.
| |
Collapse
|
2
|
Moreno MJ, Teles Martins PA, Bernardino EF, Abel B, Ambudkar SV. Characterization of the Lipidome and Biophysical Properties of Membranes from High Five Insect Cells Expressing Mouse P-Glycoprotein. Biomolecules 2021; 11:biom11030426. [PMID: 33799403 PMCID: PMC8001469 DOI: 10.3390/biom11030426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 03/11/2021] [Accepted: 03/12/2021] [Indexed: 12/31/2022] Open
Abstract
The lipid composition of biomembranes influences the properties of the lipid bilayer and that of the proteins. In this study, the lipidome and the lipid/protein ratio of membranes from High Five™ insect cells overexpressing mouse P-glycoprotein was characterized. This provides a better understanding of the lipid environment in which P-glycoprotein is embedded, and thus of its functional and structural properties. The relative abundance of the distinct phospholipid classes and their acyl chain composition was characterized. A mass ratio of 0.57 ± 0.11 phospholipids to protein was obtained. Phosphatidylethanolamines are the most abundant phospholipids, followed by phosphatidylcholines. Membranes are also enriched in negatively charged lipids (phosphatidylserines, phosphatidylinositols and phosphatidylglycerols), and contain small amounts of sphingomyelins, ceramides and monoglycosilatedceramides. The most abundant acyl chains are monounsaturated, with significant amounts of saturated chains. The characterization of the phospholipids by HPLC-MS allowed identification of the combination of acyl chains, with palmitoyl-oleoyl being the most representative for all major phospholipid classes except for phosphatidylserines, which are mostly saturated. A mixture of POPE:POPC:POPS in the ratio 45:35:20 is proposed for the preparation of simple representative model membranes. The adequacy of the model membranes was further evaluated by characterizing their surface potential and fluidity.
Collapse
Affiliation(s)
- Maria João Moreno
- Coimbra Chemistry Center, Chemistry Department, FCTUC, University of Coimbra, 3004-535 Coimbra, Portugal; (P.A.T.M.); (E.F.B.)
- CNC—Center for Neuroscience and Cell Biology, University of Coimbra, 3004-535 Coimbra, Portugal
- Correspondence:
| | | | - Eva F. Bernardino
- Coimbra Chemistry Center, Chemistry Department, FCTUC, University of Coimbra, 3004-535 Coimbra, Portugal; (P.A.T.M.); (E.F.B.)
| | - Biebele Abel
- Laboratory of Cell Biology, CCR, National Cancer Institute, NIH, Bethesda, MD 20892, USA; (B.A.); (S.V.A.)
| | - Suresh V. Ambudkar
- Laboratory of Cell Biology, CCR, National Cancer Institute, NIH, Bethesda, MD 20892, USA; (B.A.); (S.V.A.)
| |
Collapse
|
3
|
Fabri JHTM, de Sá NP, Malavazi I, Del Poeta M. The dynamics and role of sphingolipids in eukaryotic organisms upon thermal adaptation. Prog Lipid Res 2020; 80:101063. [PMID: 32888959 DOI: 10.1016/j.plipres.2020.101063] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 08/18/2020] [Accepted: 08/27/2020] [Indexed: 01/09/2023]
Abstract
All living beings have an optimal temperature for growth and survival. With the advancement of global warming, the search for understanding adaptive processes to climate changes has gained prominence. In this context, all living beings monitor the external temperature and develop adaptive responses to thermal variations. These responses ultimately change the functioning of the cell and affect the most diverse structures and processes. One of the first structures to detect thermal variations is the plasma membrane, whose constitution allows triggering of intracellular signals that assist in the response to temperature stress. Although studies on this topic have been conducted, the underlying mechanisms of recognizing thermal changes and modifying cellular functioning to adapt to this condition are not fully understood. Recently, many reports have indicated the participation of sphingolipids (SLs), major components of the plasma membrane, in the regulation of the thermal stress response. SLs can structurally reinforce the membrane or/and send signals intracellularly to control numerous cellular processes, such as apoptosis, cytoskeleton polarization, cell cycle arresting and fungal virulence. In this review, we discuss how SLs synthesis changes during both heat and cold stresses, focusing on fungi, plants, animals and human cells. The role of lysophospholipids is also discussed.
Collapse
Affiliation(s)
- João Henrique Tadini Marilhano Fabri
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA; Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP, Brazil
| | - Nivea Pereira de Sá
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA
| | - Iran Malavazi
- Departamento de Genética e Evolução, Centro de Ciências Biológicas e da Saúde, Universidade Federal de São Carlos, São Carlos, SP, Brazil
| | - Maurizio Del Poeta
- Department of Microbiology and Immunology, Stony Brook University, Stony Brook, New York, USA; Division of Infectious Diseases, School of Medicine, Stony Brook University, Stony Brook, New York, USA; Veterans Administration Medical Center, Northport, New York, USA.
| |
Collapse
|
4
|
Kotsarenko K, Vechtova P, Lieskovska J, Füssy Z, Cabral-de-Mello DC, Rego ROM, Alberdi P, Collins M, Bell-Sakyi L, Sterba J, Grubhoffer L. Karyotype changes in long-term cultured tick cell lines. Sci Rep 2020; 10:13443. [PMID: 32778731 PMCID: PMC7417564 DOI: 10.1038/s41598-020-70330-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2020] [Accepted: 07/20/2020] [Indexed: 01/08/2023] Open
Abstract
Tick cell lines are an easy-to-handle system for the study of viral and bacterial infections and other aspects of tick cellular processes. Tick cell cultures are often continuously cultivated, as freezing can affect their viability. However, the long-term cultivation of tick cells can influence their genome stability. In the present study, we investigated karyotype and genome size of tick cell lines. Though 16S rDNA sequencing showed the similarity between Ixodes spp. cell lines at different passages, their karyotypes differed from 2n = 28 chromosomes for parental Ixodes spp. ticks, and both increase and decrease in chromosome numbers were observed. For example, the highly passaged Ixodes scapularis cell line ISE18 and Ixodes ricinus cell lines IRE/CTVM19 and IRE/CTVM20 had modal chromosome numbers 48, 23 and 48, respectively. Also, the Ornithodoros moubata cell line OME/CTVM22 had the modal chromosome number 33 instead of 2n = 20 chromosomes for Ornithodoros spp. ticks. All studied tick cell lines had a larger genome size in comparison to the genomes of the parental ticks. Thus, highly passaged tick cell lines can be used for research purposes, but possible differences in encoded genetic information and downstream cellular processes, between different cell populations, should be taken into account.
Collapse
Affiliation(s)
- Kateryna Kotsarenko
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, 37005, Ceske Budejovice, Czech Republic. .,Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic. .,Central European Institute of Technology, Masaryk University, Kamenice 5, 62500, Brno, Czech Republic.
| | - Pavlina Vechtova
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, 37005, Ceske Budejovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic
| | - Jaroslava Lieskovska
- Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic
| | - Zoltán Füssy
- Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic
| | - Diogo C Cabral-de-Mello
- Department of General and Applied Biology, São Paulo State University, Rio Claro, São Paulo, Brazil
| | - Ryan O M Rego
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, 37005, Ceske Budejovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic
| | - Pilar Alberdi
- Neuroplasticity and Neurodegeneration Group, Regional Center for Biomedical Research (CRIB), Ciudad Real Medical School, University of Castilla-La Mancha, 13005, Ciudad Real, Spain
| | - Marisol Collins
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, L3 5RF, UK
| | - Lesley Bell-Sakyi
- Department of Infection Biology and Microbiomes, Institute of Infection, Veterinary and Ecological Sciences, University of Liverpool, Liverpool, L3 5RF, UK
| | - Jan Sterba
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, 37005, Ceske Budejovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic
| | - Libor Grubhoffer
- Institute of Parasitology, Biology Centre of the Czech Academy of Sciences, Branisovska 31, 37005, Ceske Budejovice, Czech Republic.,Faculty of Science, University of South Bohemia, Branisovska 1760, 37005, Ceske Budejovice, Czech Republic
| |
Collapse
|
5
|
Novak M, Čepin U, Hodnik V, Narat M, Jamnik M, Kraševec N, Sepčić K, Anderluh G. Functional studies of aegerolysin and MACPF-like proteins in Aspergillus niger. Mol Microbiol 2019; 112:1253-1269. [PMID: 31376198 DOI: 10.1111/mmi.14360] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/28/2019] [Indexed: 12/21/2022]
Abstract
Proteins of the aegerolysin family have a high abundance in Fungi. Due to their specific binding to membrane lipids, and their membrane-permeabilization potential in concert with protein partner(s) belonging to a membrane-attack-complex/perforin (MACPF) superfamily, they were proposed as useful tools in different biotechnological and biomedical applications. In this work, we performed functional studies on expression of the genes encoding aegerolysin and MACPF-like proteins in Aspergillus niger. Our results suggest the sporulation process being crucial for strong induction of the expression of all these genes. However, deletion of either of the aegerolysin genes did not influence the growth, development, sporulation efficiency and phenotype of the mutants, indicating that aegerolysins are not key factors in the sporulation process. In all our expression studies we noticed a strong correlation in the expression of one aegerolysin and MACPF-like gene. Aegerolysins were confirmed to be secreted from the fungus. We also showed the specific interaction of a recombinant A. niger aegerolysin with an invertebrate-specific membrane sphingolipid. Moreover, using this protein labelled with mCherry we successfully stained insect cells membranes containing this particular sphingolipid. Our combined results suggest, that aegerolysins in this species, and probably also in other aspergilli, could be involved in defence against predators.
Collapse
Affiliation(s)
- Maruša Novak
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Urška Čepin
- BioSistemika Ltd and National Institute of Biology, Ljubljana, Slovenia
| | - Vesna Hodnik
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Mojca Narat
- Department of Animal Science, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Maja Jamnik
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Nada Kraševec
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| | - Kristina Sepčić
- Department of Biology, Biotechnical Faculty, University of Ljubljana, Ljubljana, Slovenia
| | - Gregor Anderluh
- Department of Molecular Biology and Nanobiotechnology, National Institute of Chemistry, Ljubljana, Slovenia
| |
Collapse
|
6
|
García-Reina A, Rodríguez-García MJ, Ramis G, Galián J. Real-time cell analysis and heat shock protein gene expression in the TcA Tribolium castaneum cell line in response to environmental stress conditions. INSECT SCIENCE 2017; 24:358-370. [PMID: 26678377 DOI: 10.1111/1744-7917.12306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 08/11/2015] [Indexed: 06/05/2023]
Abstract
The rust red flour beetle, Tribolium castaneum (Herbst, 1797) (Coleoptera: Tenebrionidae), is a pest of stored grain and one of the most studied insect model species. Some of the previous studies involved heat response studies in terms of survival and heat shock protein expression, which are regulated to protect other proteins against environmental stress conditions. In the present study, we characterize the impedance profile with the xCELLigence Real-Time Cell Analyzer and study the effect of increased temperature in cell growth and viability in the cell line BCIRL-TcA-CLG1 (TcA) of T. castaneum. This novel system measures cells behavior in real time and is applied for the first time to insect cells. Additionally, cells are exposed to heat shock, increased salinity, acidic pH and UV-A light with the aim of measuring the expression levels of Hsp27, Hsp68a, and Hsp83 genes. Results show a high thermotolerance of TcA in terms of cell growth and viability. This result is likely related to gene expression results in which a significant up-regulation of all studied Hsp genes is observed after 1 h of exposure to 40 °C and UV light. All 3 genes show similar expression patterns, but Hsp27 seems to be the most affected. The results of this study validate the RTCA method and reveal the utility of insect cell lines, real-time analysis and gene expression studies to better understand the physiological response of insect cells, with potential applications in different fields of biology such as conservation biology and pest management.
Collapse
Affiliation(s)
- Andrés García-Reina
- Department of Zoology and Physical Anthropology, University of Murcia, Campus Mare Nostrum, E-30100, Murcia, Spain
| | | | - Guillermo Ramis
- Department of Animal Production, Faculty of Veterinary, University of Murcia, Campus Mare Nostrum, E-30100, Murcia, Spain
| | - José Galián
- Department of Zoology and Physical Anthropology, University of Murcia, Campus Mare Nostrum, E-30100, Murcia, Spain
| |
Collapse
|
7
|
Contreras-Gómez A, Sánchez-Mirón A, García-Camacho F, Molina-Grima E, Chisti Y. Protein production using the baculovirus-insect cell expression system. Biotechnol Prog 2014; 30:1-18. [PMID: 24265112 DOI: 10.1002/btpr.1842] [Citation(s) in RCA: 93] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 11/12/2013] [Accepted: 11/12/2013] [Indexed: 12/21/2022]
Abstract
The baculovirus-insect cell expression system is widely used in producing recombinant proteins. This review is focused on the use of this expression system in developing bioprocesses for producing proteins of interest. The issues addressed include: the baculovirus biology and genetic manipulation to improve protein expression and quality; the suppression of proteolysis associated with the viral enzymes; the engineering of the insect cell lines for improved capability in glycosylation and folding of the expressed proteins; the impact of baculovirus on the host cell and its implications for protein production; the effects of the growth medium on metabolism of the host cell; the bioreactors and the associated operational aspects; and downstream processing of the product. All these factors strongly affect the production of recombinant proteins. The current state of knowledge is reviewed.
Collapse
|
8
|
Wagner JM, Pajerowski JD, Daniels CL, McHugh PM, Flynn JA, Balliet JW, Casimiro DR, Subramanian S. Enhanced production of Chikungunya virus-like particles using a high-pH adapted spodoptera frugiperda insect cell line. PLoS One 2014; 9:e94401. [PMID: 24713807 PMCID: PMC3979839 DOI: 10.1371/journal.pone.0094401] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2014] [Accepted: 03/14/2014] [Indexed: 11/18/2022] Open
Abstract
Chikungunya virus-like particles (VLPs) have potential to be used as a prophylactic vaccine based on testing in multiple animal models and are currently being evaluated for human use in a Phase I clinical trial. The current method for producing these enveloped alphavirus VLPs by transient gene expression in mammalian cells presents challenges for scalable and robust industrial manufacturing, so the insect cell baculovirus expression vector system was evaluated as an alternative expression technology. Subsequent to recombinant baculovirus infection of Sf21 cells in standard culture media (pH 6.2–6.4), properly processed Chikungunya structural proteins were detected and assembled capsids were observed. However, an increase in culture pH to 6.6–6.8 was necessary to produce detectable concentrations of assembled VLPs. Since this elevated production pH exceeds the optimum for growth medium stability and Sf21 culture, medium modifications were made and a novel insect cell variant (SfBasic) was derived by exposure of Sf21 to elevated culture pH for a prolonged period of time. The high-pH adapted SfBasic insect cell line described herein is capable of maintaining normal cell growth into the typical mammalian cell culture pH range of 7.0–7.2 and produces 11-fold higher Chikungunya VLP yields relative to the parental Sf21 cell line. After scale-up into stirred tank bioreactors, SfBasic derived VLPs were chromatographically purified and shown to be similar in size and structure to a VLP standard derived from transient gene expression in HEK293 cells. Total serum anti-Chikungunya IgG and neutralizing titers from guinea pigs vaccinated with SfBasic derived VLPs or HEK293 derived VLPs were not significantly different with respect to production method, suggesting that this adapted insect cell line and production process could be useful for manufacturing Chikungunya VLPs for use as a vaccine. The adaptation of Sf21 to produce high levels of recombinant protein and VLPs in an elevated pH range may also have applications for other pH-sensitive protein or VLP targets.
Collapse
Affiliation(s)
- James M. Wagner
- Vaccine Research and Development, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | - J. David Pajerowski
- Vaccine Research and Development, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | - Christopher L. Daniels
- Vaccine Research and Development, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | - Patrick M. McHugh
- Vaccine Research and Development, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | - Jessica A. Flynn
- Vaccine Research and Development, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | - John W. Balliet
- Vaccine Research and Development, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | - Danilo R. Casimiro
- Vaccine Research and Development, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania, United States of America
| | - Shyamsundar Subramanian
- Vaccine Research and Development, Merck Research Laboratories, Merck & Co., Inc., West Point, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
9
|
Whiteley G, Collins RF, Kitmitto A. Characterization of the molecular architecture of human caveolin-3 and interaction with the skeletal muscle ryanodine receptor. J Biol Chem 2012; 287:40302-16. [PMID: 23071107 PMCID: PMC3504746 DOI: 10.1074/jbc.m112.377085] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Caveolin-3 (cav-3), an integral membrane protein, is a building block of caveolae as well as a regulator of a number of physiological processes by facilitating the formation of multiprotein signaling complexes. We report that the expression of cav-3 in insect (Sf9) cells induces caveola formation, comparable in size with those observed in native tissue. We have also purified the recombinant cav-3 determining that it forms an oligomer of ∼220 kDa. We present the first three-dimensional structure for cav-3 (using transmission electron microscopy and single particle analysis methods) and show that nine cav-3 monomers assemble to form a complex that is toroidal in shape, ∼16.5 nm in diameter and ∼ 5.5 nm in height. Labeling experiments and reconstitution of the purified cav-3 into liposomes have allowed a proposal for the orientation of the protein with respect to the membrane. We have identified multiple caveolin-binding motifs within the ryanodine receptor (RyR1) sequence employing a bioinformatic analysis. We have then shown experimentally that there is a direct interaction between recombinant cav-3 nonamers and purified RyR1 homotetramers that would imply that at least one of the predicted cav-3-binding sites is exposed within the fully assembled RyR1 structure. The cav-3 three-dimensional model provides new insights as to how a cav-3 oligomer can bind multiple partners in close proximity to form signaling complexes. Furthermore, a direct interaction with RyR1 suggests a possible role for cav-3 as a modifier of muscle excitation-contraction coupling and/or for localization of the receptor to regions of the sarcoplasmic reticulum.
Collapse
Affiliation(s)
- Gareth Whiteley
- School of Biomedicine, Cardiovascular Group, Faculty of Medical and Human Sciences, University of Manchester, Manchester M13 9NT, UK
| | | | | |
Collapse
|
10
|
Drugmand JC, Schneider YJ, Agathos SN. Insect cells as factories for biomanufacturing. Biotechnol Adv 2012; 30:1140-57. [DOI: 10.1016/j.biotechadv.2011.09.014] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2011] [Revised: 09/13/2011] [Accepted: 09/16/2011] [Indexed: 10/17/2022]
|
11
|
Stanojcic S, Gimenez S, Permal E, Cousserans F, Quesneville H, Fournier P, d'Alençon E. Correlation of LNCR rasiRNAs expression with heterochromatin formation during development of the holocentric insect Spodoptera frugiperda. PLoS One 2011; 6:e24746. [PMID: 21980354 PMCID: PMC3184123 DOI: 10.1371/journal.pone.0024746] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2011] [Accepted: 08/16/2011] [Indexed: 01/30/2023] Open
Abstract
Repeat-associated small interfering RNAs (rasiRNAs) are derived from various genomic repetitive elements and ensure genomic stability by silencing endogenous transposable elements. Here we describe a novel subset of 46 rasiRNAs named LNCR rasiRNAs due to their homology with one long non-coding RNA (LNCR) of Spodoptera frugiperda. LNCR operates as the intermediate of an unclassified transposable element (TE-LNCR). TE-LNCR is a very invasive transposable element, present in high copy numbers in the S. frugiperda genome. LNCR rasiRNAs are single-stranded RNAs without a prominent nucleotide motif, which are organized in two distinct, strand-specific clusters. The expression of LNCR and LNCR rasiRNAs is developmentally regulated. Formation of heterochromatin in the genomic region where three copies of the TE-LNCR are embedded was followed by chromatin immunoprecipitation (ChIP) and we observed this chromatin undergo dynamic changes during development. In summary, increased LNCR expression in certain developmental stages is followed by the appearance of a variety of LNCR rasiRNAs which appears to correlate with subsequent accumulation of a heterochromatic histone mark and silencing of the genomic region with TE-LNCR. These results support the notion that a repeat-associated small interfering RNA pathway is linked to heterochromatin formation and/or maintenance during development to establish repression of the TE-LNCR transposable element. This study provides insights into the rasiRNA silencing pathway and its role in the formation of fluctuating heterochromatin during the development of one holocentric organism.
Collapse
Affiliation(s)
| | - Sylvie Gimenez
- UMR1333 INRA, Université Montpellier II, Montpellier, France
| | - Emmanuelle Permal
- UR1164, INRA, Centre de Recherche de Versailles, bât.18, RD10, Versailles, France
| | | | - Hadi Quesneville
- UR1164, INRA, Centre de Recherche de Versailles, bât.18, RD10, Versailles, France
| | | | | |
Collapse
|
12
|
Establishment, growth kinetics, and susceptibility to AcMNPV of heat tolerant lepidopteran cell lines. Virol Sin 2011; 26:198-205. [PMID: 21667340 DOI: 10.1007/s12250-011-3177-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2010] [Accepted: 03/30/2011] [Indexed: 10/18/2022] Open
Abstract
Lepidopteran heat-tolerant (ht) cell lines have been obtained with sf-9, sf-21 and several Bombyx cells. They have a distinct karyotype, membrane lipid composition, morphology and growth kinetics from the parental cell lines. In this paper, we report the development of ht cell lines from other insect species and examination of their growth characteristics and virus susceptibility. Adaptation of cell lines sf-9, BTI-TN-5B1-4 (High5) and BTI-TN-MG1 (MG1) to 33°C and 35°C was carried out by shifting the culture temperature between 28°C and higher temperatures by a gradual stepwise increase in temperature. The process of adaption to a higher culture temperature was accomplished over a period of 2 months. The cell lines with the temperature adaption were designated as sf9-ht33, sf9-ht35, High5-ht33, High5-ht35, MG1-ht33, MG1-ht35. These cell lines have been subcultured over 70 passages. Adaption to high temperatures was confirmed by a constant population doubling time with individual cell lines. The population doubling time of heat adapted cell lines were 1-4 h less than these of parental cell lines. Cell shapes did not show obvious change, however, the cell size of sf9-ht cells was enlarged and those of High5 and MG1 ht cells were reduced after heat adaption. When the cell lines were infected with Autographa californica nuclear polyhedrosis virus (AcMNPV) at 28°C, 33°C, 35°C and 37°C, production of budded virus and occlusion bodies in each cell line was optimum at its own adapted temperature.
Collapse
|
13
|
Jensen NA, Gerth K, Grotjohann T, Kapp D, Keck M, Niehaus K. Establishment of a high content assay for the identification and characterisation of bioactivities in crude bacterial extracts that interfere with the eukaryotic cell cycle. J Biotechnol 2009; 140:124-34. [DOI: 10.1016/j.jbiotec.2008.12.002] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 11/21/2008] [Accepted: 12/03/2008] [Indexed: 01/18/2023]
|
14
|
Biological enrichment of Mycoplasma agents by cocultivation with permissive cell cultures. Appl Environ Microbiol 2008; 74:5383-91. [PMID: 18606798 DOI: 10.1128/aem.00720-08] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In this study, we describe our results on the evaluation of the ability of different permissive mammalian cell lines to support the biological enrichment of mycoplasma species known to be bacterial contaminants of cell substrates. The study showed that this approach is able to significantly improve the efficiency of mycoplasma detection based on nucleic acid testing or biochemical technologies (e.g., MycoAlert mycoplasma detection). Of 10 different cell lines (Vero, MDBK, HEK-293, Hep-G2, CV-1, EBTr, WI-38, R9ab, MDCK, and High Five) used in the study, only MDCK cell culture was found to support the efficient growth of all the tested mycoplasmas (Mycoplasma arginini, M. bovis, M. fermentans, M. gallinaceum, M. gallisepticum, M. synoviae, M. hominis, M. hyorhinis, M. orale, M. salivarium, and Acholeplasma laidlawii) known to be most frequently associated with contamination of cell substrates and cell lines in research laboratories or manufacturing facilities. The infection of MDCK cells with serial dilutions of each mycoplasma species demonstrated that these common cell line contaminants can be detected reliably after 7-day enrichment in MDCK cell culture at contamination levels of 0.05 to 0.25 CFU/ml. The High Five insect cell line was also found to be able to support the efficient growth of most mycoplasma species tested, except for M. hyorhinis strain DBS1050. However, mycoplasma growth in insect cell culture was demonstrated to be temperature dependent, and the most efficient growth was observed when the incubation temperature was increased from 28 degrees C to between 35 and 37 degrees C. We believe that this type of mycoplasma enrichment is one of the most promising approaches for improving the purity and safety testing of cell substrates and other cell-derived biologics and pharmaceuticals.
Collapse
|
15
|
Parathath S, Connelly MA, Rieger RA, Klein SM, Abumrad NA, De La Llera-Moya M, Iden CR, Rothblat GH, Williams DL. Changes in plasma membrane properties and phosphatidylcholine subspecies of insect Sf9 cells due to expression of scavenger receptor class B, type I, and CD36. J Biol Chem 2004; 279:41310-8. [PMID: 15280390 DOI: 10.1074/jbc.m404952200] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In mammalian cells scavenger receptor class B, type I (SR-BI), mediates the selective uptake of high density lipoprotein (HDL) cholesteryl ester into hepatic and steroidogenic cells. In addition, SR-BI has a variety of effects on plasma membrane properties including stimulation of the bidirectional flux of free cholesterol (FC) between cells and HDL and changes in the organization of plasma membrane FC as indicated by increased susceptibility to exogenous cholesterol oxidase. Recent studies in SR-BI-deficient mice and in SR-BI-expressing Sf9 insect cells showed that SR-BI has significant effects on plasma membrane ultrastructure. The present study was designed to test the range of SR-BI effects in Sf9 insect cells that typically have very low cholesterol content and a different phospholipid profile compared with mammalian cells. The results showed that, as in mammalian cells, SR-BI expression increased HDL cholesteryl ester selective uptake, cellular cholesterol mass, FC efflux to HDL, and the sensitivity of membrane FC to cholesterol oxidase. These activities were diminished or absent upon expression of the related scavenger receptor CD36. Thus, SR-BI has fundamental effects on cholesterol flux and membrane properties that occur in cells of evolutionarily divergent origins. Profiling of phospholipid species by electrospray ionization mass spectrometry showed that scavenger receptor expression led to the accumulation of phosphatidylcholine species with longer mono- or polyunsaturated acyl chains. These changes would be expected to decrease phosphatidylcholine/cholesterol interactions and thereby enhance cholesterol desorption from the membrane. Scavenger receptor-mediated changes in membrane phosphatidylcholine may contribute to the increased flux of cholesterol and other lipids elicited by these receptors.
Collapse
Affiliation(s)
- Saj Parathath
- Department of Pharmacological Sciences, University Medical Center, State University of New York, Stony Brook, New York 11794-8651, USA.
| | | | | | | | | | | | | | | | | |
Collapse
|
16
|
Rocher J, Ravallec M, Barry P, Volkoff AN, Ray D, Devauchelle G, Duonor-Cérutti M. Establishment of cell lines from the wasp Hyposoter didymator (Hym., Ichneumonidae) containing the symbiotic polydnavirus H. didymator ichnovirus. J Gen Virol 2004; 85:863-868. [PMID: 15039529 DOI: 10.1099/vir.0.19713-0] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Cell lines derived from polydnavirus-associated wasps should constitute a valuable tool for investigations of polydnavirus replication, but none is yet available. In this work, we describe the first cell lines, named Hd-AA, -AD, -BBA and -K, to have been established from the ichneumonid wasp Hyposoter didymator, associated with the polydnavirus H. didymator ichnovirus (HdIV). Southern blot analysis indicated that the viral DNA was present in all four cell lines and co-localized with high molecular mass DNA, probably the wasp chromosomes. Northern blot analysis of mRNAs extracted from the AA cell line showed transcription of some HdIV-encoded genes, although at low level. The effects of ecdysone treatment, HdIV re-infection and 42 degrees C heat-shock were analysed in the AA cell line. No effect was detected at the DNA (virus replication) or RNA (gene expression) levels, which may be due to the limitation of the present available tools.
Collapse
Affiliation(s)
- Janick Rocher
- Laboratoire de Pathologie Comparée, INRA, 30380 Saint Christol-lez-Alès, France
| | - Marc Ravallec
- Laboratoire de Pathologie Comparée, INRA, 30380 Saint Christol-lez-Alès, France
| | - Patrick Barry
- Laboratoire de Pathologie Comparée, INRA, 30380 Saint Christol-lez-Alès, France
| | | | - Dominique Ray
- Laboratoire de Pathologie Comparée, INRA, 30380 Saint Christol-lez-Alès, France
| | - Gérard Devauchelle
- Laboratoire de Pathologie Comparée, INRA, 30380 Saint Christol-lez-Alès, France
| | | |
Collapse
|
17
|
d'Alençon E, Piffanelli P, Volkoff AN, Sabau X, Gimenez S, Rocher J, Cérutti P, Fournier P. A genomic BAC library and a new BAC-GFP vector to study the holocentric pest Spodoptera frugiperda. INSECT BIOCHEMISTRY AND MOLECULAR BIOLOGY 2004; 34:331-341. [PMID: 15041017 DOI: 10.1016/j.ibmb.2003.12.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2003] [Revised: 12/04/2003] [Accepted: 12/16/2003] [Indexed: 05/24/2023]
Abstract
Two genomic tools for the study of Lepidoptera and the holocentric structure of their chromosomes are presented in this paper. A bacterial artificial chromosome (BAC) library was constructed using nuclear DNA partially digested with HindIII from eggs of Spodoptera frugiperda. The library contains a total of 36,864 clones with an average insert size of 125 kb, which corresponds to approximately 11.5 genome equivalents. Hybridization screening of the library was performed with eight single-copy genes, giving an average hit of 10 clones per marker gene. Colinearity between the genome and BACs was demonstrated at the triose phosphate isomerase (tpi) locus. Probing of the library with a PCR fragment internal to the 18S ribosomal gene allowed an estimation of the rDNA locus size close to 115 repeats per haploid genome. A new vector (pBAC3.6eGFP) for transient transfection into S. frugiperda cell lines has been constructed. It is based on the BAC vector, pBAC3.6e, in which a gene encoding GFP was inserted under the control of the densovirus P9 promoter. This vector has the advantage to accommodate large genomic inserts and to be transfected in a large lepidopteran host range. It was used to construct a second BAC library from Sf9 cell nuclear DNA in order to allow a comparison between somatic and cell line genome organization.
Collapse
Affiliation(s)
- Emmanuelle d'Alençon
- Laboratoire de Pathologie Comparée, Institut National de la Recherche Agronomique (INRA) UMR 1231, Centre National de la recherche Scientifique (CNRS) FRE 2689, Univ. Montpellier II, 30380 Saint Christol-les-Alès, France.
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Bossin H, Fournier P, Royer C, Barry P, Cérutti P, Gimenez S, Couble P, Bergoin M. Junonia coenia densovirus-based vectors for stable transgene expression in Sf9 cells: influence of the densovirus sequences on genomic integration. J Virol 2003; 77:11060-71. [PMID: 14512554 PMCID: PMC224968 DOI: 10.1128/jvi.77.20.11060-11071.2003] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
The invertebrate parvovirus Junonia coenia densovirus (JcDNV) shares similarities with terminal hairpins and nonstructural (NS) protein activities of adeno-associated virus (AAV) despite their evolutionary divergence (B. Dumas, M. Jourdan, A. M. Pascaud, and M. Bergoin, Virology, 191:202-222, 1992, and C. Ding, M. Urabe, M. Bergoin, and R. M. Kotin, J. Virol. 76:338-345, 2002). We demonstrate here that persistent transgene expression in insect cells results from stable integration of transfected JcDNV-derived vectors into the host genome. To assess the integrative properties of JcDNV vectors, the green fluorescent protein (GFP) gfp marker gene was fused in frame into the major open reading frame (ORF1) of the viral sequence under the control of the P9 capsid protein promoter. In addition, the influence of the nonstructural proteins on the posttransfection maintenance of the vectors was examined by interruption of one or all three NS ORFs. Following transfection of Sf9 cells with each of the JcDNV constructs, clones showing persistent GFP expression were isolated. Structural analyses revealed that the majority of the JcDNV plasmid sequence was integrated into the genome of the fluorescent clones. Integration was observed whether or not NS proteins were expressed. However, the presence of NS genes in the constructs greatly influenced the number of integrated copies and their distribution in the host genome. Disruption of NS genes expression resulted in integration of head-to-tail concatemers at multiple sites within the genome. Further analyses demonstrated that the cis JcDNV 5' inverted terminal repeat region was the primary site of recombination. Sequence analyses of integration junctions showed rearrangements of both flanking and internal sequences for most integrations. These findings demonstrate that JcDNV vectors integrate into insect cells in a manner similar to AAV plasmids in mammalian cells.
Collapse
Affiliation(s)
- Hervé Bossin
- Unité de Virologie Moléculaire, UMR5087, INRA-CNRS-UMII, Station de Recherches de Pathologie Comparée, 30380 Saint-Christol-les-Alès, and Laboratoire de Pathologie Comparée, Université Montpellier II, France
| | | | | | | | | | | | | | | |
Collapse
|
19
|
Landais I, Pommet J, Mita K, Nohata J, Gimenez S, Fournier P, Devauchelle G, Duonor-Cerutti M, Ogliastro M. Characterization of the cDNA encoding the 90 kDa heat-shock protein in the Lepidoptera Bombyx mori and Spodoptera frugiperda. Gene 2001; 271:223-31. [PMID: 11418243 DOI: 10.1016/s0378-1119(01)00523-6] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
This report presents the first hsp90 complete cDNA sequences from two Lepidoptera. The Bombyx mori full sequence was reconstituted from 15 partial cDNA clones belonging to expressed sequence tag libraries obtained from different tissues or cultured cells, thus showing the ubiquitous expression of the hsp90 gene. The Spodoptera frugiperda cDNA was isolated as a full-length clone from a cDNA library established from the Sf9 cell line. Both cDNAs are highly homologous and display the classical amino acid (aa) stretches representing the HSP90 signature. They potentially encode a 716 aa (B. mori) and a 717 aa (S. frugiperda) protein, with a calculated molecular mass of 83 kDa similar to the Drosophila homologous protein. We show that, unlike the vertebrates, hsp90 is a unique gene in both S. frupiperda and B. mori genomes. Sequencing of the corresponding genomic region shows that, contrary to the dipteran homologous gene, the lepidopteran hsp90 gene does not display any intron. Phylogenetic analysis based on the two lepidopteran and 23 other HSP90 aa sequences displays a high consistency with known phylogeny at both high and low taxonomic levels. Transcriptional analysis performed in S. frugiperda shows that the induction of the hsp90 gene only occurs 14 degrees C above physiological growth conditions (42 degrees C).
Collapse
Affiliation(s)
- I Landais
- Laboratoire de Pathologie Comparée, INRA-CNRS-Université Montpellier II, UMR 5087, 30380 Saint-Christol-les-Alès, France
| | | | | | | | | | | | | | | | | |
Collapse
|
20
|
Lin G, Li G, Granados RR, Blissard GW. Stable cell lines expressing baculovirus P35: resistance to apoptosis and nutrient stress, and increased glycoprotein secretion. In Vitro Cell Dev Biol Anim 2001; 37:293-302. [PMID: 11513084 DOI: 10.1007/bf02577545] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The baculovirus P35 protein is a caspase inhibitor that prevents the induction of apoptosis during infection of Sf21 cells by Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV). P35 inhibits the induction of apoptosis in a broad range of cells and circumstances. In this study, we examined the effects of constitutive cellular P35 expression on the response of cells to stressful culture conditions and on protein production in AcMNPV infected cells. Sf9 cell lines expressing AcMNPV P35 or an epitope-tagged P35 protein were generated using a double selection technique, involving selection in the antibiotic G418, followed by a second round of selection by exposure to actinomycin D, a potent inducer of apoptosis in Sf9 cells. Clonal cell lines were generated and examined for (1) resistance to actinomycin D induced apoptosis, (2) resistance to nutrient deprivation, and (3) baculovirus expression of intracellular and secreted proteins. When compared with Sf9 cells, two P35-expressing cell lines (Sf9P35AcV5-1 and Sf9P35AcV5-3) showed increased resistance to actinomycin D-induced apoptosis and a profound resistance to nutrient deprivation. When these cell lines were infected with a recombinant baculovirus expressing a secreted glycoprotein (secreted alkaline phosphatase), expression of the glycoprotein from these cells exceeded that from the parental Sf9 cells and was comparable to expression levels obtained from Tn5B1-4 cells, the best available cell line for high-level expression. Increased levels of protein secretion in Sf9P35AcV5-1 and Sf9P35AcV5-3 cells appear to result from a prolonged infection cycle and accumulation of the secreted glycoprotein.
Collapse
Affiliation(s)
- G Lin
- Boyce Thompson Institute at Cornell University, Ithaca, New York 14853-1801, USA
| | | | | | | |
Collapse
|
21
|
Volkoff AN, Rocher J, Cérutti P, Ohresser MCP, d'Aubenton-Carafa Y, Devauchelle G, Duonor-Cérutti M. Persistent expression of a newly characterized Hyposoter didymator polydnavirus gene in long-term infected lepidopteran cell lines. J Gen Virol 2001; 82:963-969. [PMID: 11257204 DOI: 10.1099/0022-1317-82-4-963] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
An Hyposoter didymator ichnovirus (HdIV) gene was stably maintained and efficiently transcribed in lepidopteran cell lines more than 3 years after HdIV infection. This K-gene had two introns and the fully spliced cDNA, named K19, comprised a short open reading frame and a long 3'-untranslated region with 13 imperfectly repeated sequences (44 to 102 nt). Transcripts related to the K-gene were detected in several long-term infected cell lines (Sf9, Spodoptera littoralis haemocytes, Trichoplusia ni). Conversely, no transcripts related to seven other viral cDNAs were detected, suggesting that the K-related DNA is selectively retained in long-term infected Sf9 cells. The function of the K-gene product and its association with stably transformed insect cell lines remains to be investigated.
Collapse
Affiliation(s)
- Anne-Nathalie Volkoff
- Laboratoire de Recherches de Pathologie Comparée, INRA-CNRS, 30380 Saint-Christol-les-Alès, France1
| | - Janick Rocher
- Laboratoire de Recherches de Pathologie Comparée, INRA-CNRS, 30380 Saint-Christol-les-Alès, France1
| | - Pierre Cérutti
- Laboratoire de Recherches de Pathologie Comparée, INRA-CNRS, 30380 Saint-Christol-les-Alès, France1
| | - Marc C P Ohresser
- Laboratoire de Recherches de Pathologie Comparée, INRA-CNRS, 30380 Saint-Christol-les-Alès, France1
| | | | - Gérard Devauchelle
- Laboratoire de Recherches de Pathologie Comparée, INRA-CNRS, 30380 Saint-Christol-les-Alès, France1
| | - Martine Duonor-Cérutti
- Laboratoire de Recherches de Pathologie Comparée, INRA-CNRS, 30380 Saint-Christol-les-Alès, France1
| |
Collapse
|
22
|
LIN GUANGYUN, LI GUOXUN, GRANADOS ROBERTR, BLISSARD GARYW. STABLE CELL LINES EXPRESSING BACULOVIRUS P35: RESISTANCE TO APOPTOSIS AND NUTRIENT STRESS, AND INCREASED GLYCOPROTEIN SECRETION. ACTA ACUST UNITED AC 2001. [DOI: 10.1290/1071-2690(2001)037<0293:sclebp>2.0.co;2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
|