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Guillem-Amat A, López-Errasquín E, García-Ricote I, Barbero JL, Sánchez L, Casas-Tintó S, Ortego F. Immunodetection of Truncated Forms of the α6 Subunit of the nAChR in the Brain of Spinosad Resistant Ceratitis capitata Phenotypes. Insects 2023; 14:857. [PMID: 37999056 PMCID: PMC10672392 DOI: 10.3390/insects14110857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/10/2023] [Revised: 10/30/2023] [Accepted: 11/01/2023] [Indexed: 11/25/2023]
Abstract
The α6 subunit of the nicotinic acetylcholine receptor (nAChR) has been proposed as the target for spinosad in insects. Point mutations that result in premature stop codons in the α6 gene of Ceratitis capitata flies have been previously associated with spinosad resistance, but it is unknown if these transcripts are translated and if so, what is the location of the putative truncated proteins. In this work, we produced a specific antibody against C. capitata α6 (Ccα6) and validated it by ELISA, Western blotting and immunofluorescence assays in brain tissues. The antibody detects both wild-type and truncated forms of Ccα6 in vivo, and the protein is located in the cell membrane of the brain of wild-type spinosad sensitive flies. On the contrary, the shortened transcripts present in resistant flies generate putative truncated proteins that, for the most part, fail to reach their final destination in the membrane of the cells and remain in the cytoplasm. The differences observed in the locations of wild-type and truncated α6 proteins are proposed to determine the susceptibility or resistance to spinosad.
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Affiliation(s)
- Ana Guillem-Amat
- Centro de Investigaciones Biológicas Margaritas Salas, CSIC, 28040 Madrid, Spain (F.O.)
| | - Elena López-Errasquín
- Centro de Investigaciones Biológicas Margaritas Salas, CSIC, 28040 Madrid, Spain (F.O.)
| | | | - José Luis Barbero
- Centro de Investigaciones Biológicas Margaritas Salas, CSIC, 28040 Madrid, Spain (F.O.)
| | - Lucas Sánchez
- Centro de Investigaciones Biológicas Margaritas Salas, CSIC, 28040 Madrid, Spain (F.O.)
| | | | - Félix Ortego
- Centro de Investigaciones Biológicas Margaritas Salas, CSIC, 28040 Madrid, Spain (F.O.)
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Paul A, Martin F, Simard B, Scher J, Gaiani C, le Floch-Fouere C, Jeantet R, Burgain J. Deciphering the segregation of proteins in high-protein dairy powders after spray-drying. J Dairy Sci 2023; 106:843-851. [PMID: 36526460 DOI: 10.3168/jds.2022-22133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 09/09/2022] [Indexed: 12/15/2022]
Abstract
High-protein dairy powders are ingredients mainly produced by spray-drying, then subjected to aging during transport and storage. They often undergo physicochemical changes at this stage, such as the development of the Maillard reaction, primarily because of their intrinsic chemical properties, but also as a result of nonoptimal storage conditions. Components present at the particle surface are the first to be targeted by moisture and other environmental disruptions. Consequently, the identification, control, and prediction of particle surface components are useful to anticipate the effect of powder aging on product quality. Here, a new diafiltration method is proposed which fractionates proteins from a binary colloidal dispersion of 80% casein micelles and 20% whey proteins, according to their presence at the surface or core of the particle. This method shows that whey proteins are strongly enriched at the particle surface, whereas casein micelles are located at the core of the particles. This protocol also allows the identification of the rehydration kinetics for each rehydrated protein layer of the particle, revealing that 2 distinct forms of swelling occur: (1) a rapid swelling and elution of whey proteins present at the particle surface, and (2) a swelling of casein micelles located below the whey proteins, associated with a slow elution of casein micelles from the particles being rehydrated.
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Affiliation(s)
- A Paul
- Laboratoire LIBio, Université de Lorraine, F-54000 Nancy, France; Centre National Interprofessionnel de l'Economie Laitière (CNIEL), F-75314 Paris, France
| | - F Martin
- Centre National Interprofessionnel de l'Economie Laitière (CNIEL), F-75314 Paris, France; STLO, UMR 1253, INRA, L'institut Agro, F-35000 Rennes, France
| | - B Simard
- Laboratoire LIBio, Université de Lorraine, F-54000 Nancy, France
| | - J Scher
- Laboratoire LIBio, Université de Lorraine, F-54000 Nancy, France
| | - C Gaiani
- Laboratoire LIBio, Université de Lorraine, F-54000 Nancy, France; Institut Universitaire de France (IUF)
| | | | - R Jeantet
- STLO, UMR 1253, INRA, L'institut Agro, F-35000 Rennes, France
| | - J Burgain
- Laboratoire LIBio, Université de Lorraine, F-54000 Nancy, France.
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Aznar-Moreno JA, Sánchez R, Gidda SK, Martínez-Force E, Moreno-Pérez AJ, Venegas Calerón M, Garcés R, Mullen RT, Salas JJ. New Insights Into Sunflower ( Helianthus annuus L.) FatA and FatB Thioesterases, Their Regulation, Structure and Distribution. Front Plant Sci 2018; 9:1496. [PMID: 30459777 PMCID: PMC6232763 DOI: 10.3389/fpls.2018.01496] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2018] [Accepted: 09/25/2018] [Indexed: 05/13/2023]
Abstract
Sunflower seeds (Helianthus annuus L.) accumulate large quantities of triacylglycerols (TAG) between 12 and 28 days after flowering (DAF). This is the period of maximal acyl-acyl carrier protein (acyl-ACP) thioesterase activity in vitro, the enzymes that terminate the process of de novo fatty acid synthesis by catalyzing the hydrolysis of the acyl-ACPs synthesized by fatty acid synthase. Fatty acid thioesterases can be classified into two families with distinct substrate specificities, namely FatA and FatB. Here, some new aspects of these enzymes have been studied, assessing how both enzymes contribute to the acyl composition of sunflower oil, not least through the changes in their expression during the process of seed filling. Moreover, the binding pockets of these enzymes were modeled based on new data from plant thioesterases, revealing important differences in their volume and geometry. Finally, the subcellular location of the two enzymes was evaluated and while both possess an N-terminal plastid transit peptide, only in FatB contains a hydrophobic sequence that could potentially serve as a transmembrane domain. Indeed, using in vivo imaging and organelle fractionation, H. annuus thioesterases, HaFatA and HaFatB, appear to be differentially localized in the plastid stroma and membrane envelope, respectively. The divergent roles fulfilled by HaFatA and HaFatB in oil biosynthesis are discussed in the light of our data.
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Affiliation(s)
- Jose A. Aznar-Moreno
- Department of Biochemistry and Molecular Biophysics, Kansas State University, Manhattan, KS, United States
| | - Rosario Sánchez
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| | - Satinder K. Gidda
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | | | | | - Mónica Venegas Calerón
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Seville, Spain
| | - Rafael Garcés
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
| | - Robert T. Mullen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, ON, Canada
| | - Joaquín J. Salas
- Instituto de la Grasa (CSIC), Campus Universitario Pablo de Olavide, Seville, Spain
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Morris CA, Owen JR, Thomas MC, El-Hiti GA, Harwood JL, Kille P. Intracellular localization and induction of a dynamic RNA-editing event of macro-algal V-ATPase subunit A (VHA-A) in response to copper. Plant Cell Environ 2014; 37:189-203. [PMID: 23738980 DOI: 10.1111/pce.12145] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/06/2013] [Revised: 05/15/2013] [Accepted: 05/18/2013] [Indexed: 06/02/2023]
Abstract
A V-ATPase subunit A protein (VHA-A) transcript together with a variant (C793 to U), which introduces a stop codon truncating the subunit immediately downstream of its ATP binding site, was identified within a Fucus vesiculosus cDNA from a heavy metal contaminated site. This is intriguing because the VHA-A subunit is the crucial catalytic subunit responsible for the hydrolysis of ATP that drives ion transport underlying heavy metal detoxification pathways. We employed a chemiluminescent hybridization protection assay to quantify the proportion of both variants directly from mRNA while performing quantification of total transcript using Q-PCR. Polyclonal antisera raised against recombinant VHA-A facilitated simultaneous detection of parent and truncated VHA-A and revealed its cellular and subcellular localization. By exploiting laboratory exposures and samples from an environmental copper gradient, we showed that total VHA-A transcript and protein, together with levels of the truncated variant, were induced by copper. The absence of a genomic sequence representing the truncated variant suggests a RNA editing event causing the production of the truncated VHA-A. Based on these observations, we propose RNA editing as a novel molecular process underpinning VHA trafficking and intracellular sequestration of heavy metals under stress.
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Affiliation(s)
- C A Morris
- School of Biosciences, Cardiff University, Cardiff, CF10 3AT, Wales, UK
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Jones LN, Rogers GE, Rufaut N, Sinclair RD. Location of Keratin-associated Proteins in Developing Fiber Cuticle Cells using Immunoelectron Microscopy. Int J Trichology 2010; 2:89-95. [PMID: 21712910 PMCID: PMC3107965 DOI: 10.4103/0974-7753.77512] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
AIMS To investigate the location of keratin-associated proteins (KAPs) in developing hair fiber cuticle cells using transmission electron microscopy with immunogold techniques and specific antibodies. Other studies were aimed at detecting the presence of cornified envelope proteins including involucrin and loricrin. MATEIALS AND METHODS: Polyclonal antibodies were produced in rabbits against peptides from KAPS 5.1, KAPS 10.1 ultra high-sulfur proteins. RESULTS The KAP proteins were found to form part of the developing exocuticle and a- layer. Cornified envelope proteins (involucrin and loricrin) were absent consistent with recent findings. CONCLUSIONS The results have been discussed in terms of a revised model for fiber cuticle surface barriers including their role in fiber cuticle surface function.
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Affiliation(s)
- LN Jones
- Department of Dermatology, University of Melbourne (St. Vincent’s Hospital), Fitzroy, Australia
| | - GE Rogers
- School of Molecular and Biomedical Science, University of Adelaide, Adelaide, Australia
| | - N Rufaut
- Department of Dermatology, University of Melbourne (St. Vincent’s Hospital), Fitzroy, Australia
| | - RD Sinclair
- Department of Dermatology, University of Melbourne (St. Vincent’s Hospital), Fitzroy, Australia
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