1
|
de la Peña Avalos B, Paquet N, Tropée R, Coulombe Y, Palacios H, Leung J, Masson JY, Duijf PG, Dray E. The protein phosphatase EYA4 promotes homologous recombination (HR) through dephosphorylation of tyrosine 315 on RAD51. Nucleic Acids Res 2024; 52:1173-1187. [PMID: 38084915 PMCID: PMC10853800 DOI: 10.1093/nar/gkad1177] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Revised: 11/20/2023] [Accepted: 11/27/2023] [Indexed: 01/07/2024] Open
Abstract
Efficient DNA repair and limitation of genome rearrangements rely on crosstalk between different DNA double-strand break (DSB) repair pathways, and their synchronization with the cell cycle. The selection, timing and efficacy of DSB repair pathways are influenced by post-translational modifications of histones and DNA damage repair (DDR) proteins, such as phosphorylation. While the importance of kinases and serine/threonine phosphatases in DDR have been extensively studied, the role of tyrosine phosphatases in DNA repair remains poorly understood. In this study, we have identified EYA4 as the protein phosphatase that dephosphorylates RAD51 on residue Tyr315. Through its Tyr phosphatase activity, EYA4 regulates RAD51 localization, presynaptic filament formation, foci formation, and activity. Thus, it is essential for homologous recombination (HR) at DSBs. DNA binding stimulates EYA4 phosphatase activity. Depletion of EYA4 decreases single-stranded DNA accumulation following DNA damage and impairs HR, while overexpression of EYA4 in cells promotes dephosphorylation and stabilization of RAD51, and thereby nucleoprotein filament formation. Our data have implications for a pathological version of RAD51 in EYA4-overexpressing cancers.
Collapse
Affiliation(s)
- Bárbara de la Peña Avalos
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Mays Cancer Center at UT Health San Antonio MD Anderson, San Antonio, TX, USA
| | - Nicolas Paquet
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Romain Tropée
- Queensland University of Technology, Translational Research Institute, Brisbane, QLD, Australia
| | - Yan Coulombe
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, Québec City, QC, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University Cancer Research Center, Québec City, QC, Canada
| | - Hannah Palacios
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Justin W Leung
- Department of Radiation Oncology, University of Texas Health and Science Center, San Antonio, TX 78229, USA
| | - Jean-Yves Masson
- Genome Stability Laboratory, CHU de Québec Research Center, HDQ Pavilion, Oncology Division, Québec City, QC, Canada
- Department of Molecular Biology, Medical Biochemistry and Pathology, Laval University Cancer Research Center, Québec City, QC, Canada
| | - Pascal H G Duijf
- Centre for Cancer Biology, Clinical and Health Sciences, University of South Australia & SA Pathology, Adelaide SA, Australia
- Institute of Clinical Medicine, Faculty of Medicine, University of Oslo, Oslo, Norway
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Eloïse Dray
- Department of Biochemistry and Structural Biology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Mays Cancer Center at UT Health San Antonio MD Anderson, San Antonio, TX, USA
- Greehey Children's Cancer Research Institute, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| |
Collapse
|
2
|
Gerdes C, Maasoumy B, Paquet N, Orozco FC, Kröger JR, Fetzner UK. [Peracute Diseases of the Esophagus - Bleeding from Esophageal Varices, Esophageal Varices]. Ther Umsch 2022; 79:212-216. [PMID: 35440199 DOI: 10.1024/0040-5930/a001351] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Peracute Diseases of the Esophagus - Bleeding from Esophageal Varices, Esophageal Varices Abstract. Due to a permanently increased portal venous pressure - usually due to infectious or ethyltoxic liver cirrhosis - varices can form in the lower esophagus due to expansion of the submucosal venous plexus. Acute bleeding from the esophageal varices is a life-threatening situation. In therapy, a distinction is made between primary prophylaxis of bleeding, control of acute bleeding and prevention of recurrent bleeding. In addition to non-selective betablockers, the transjugular intrahepatic portosystemic shunt (TIPS), which is introduced radiologically, plays a decisive role today, especially in the prophylaxis of recurrent bleeding. Apart from special indications, surgical shunt procedures are only of historical value. In liver cirrhosis patients, liver transplantation represents a causal treatment and lasting cure for esophageal varices.
Collapse
Affiliation(s)
- Christoph Gerdes
- Klinik für Gastroenterologie, Hepatologie und Endokrinologie, Medizinische Hochschule Hannover, Deutschland
| | - Benjamin Maasoumy
- Klinik für Gastroenterologie, Hepatologie und Endokrinologie, Medizinische Hochschule Hannover, Deutschland
| | | | - Francisco Cuan Orozco
- Klinik für Allgemeinchirurgie, Viszeral-, Thorax-, Kinder- und Endokrine Chirurgie, Mühlenkreiskliniken, Universitätsklinikum der Ruhr-Universität Bochum, Minden, Deutschland
| | - Jan Robert Kröger
- Universitätsinstitut für Radiologie, Neuroradiologie und Nuklearmedizin, Mühlenkreiskliniken, Universitätsklinikum der Ruhr-Universität Bochum, Minden, Deutschland
| | - Ulrich Klaus Fetzner
- Klinik für Allgemeinchirurgie, Viszeral-, Thorax-, Kinder- und Endokrine Chirurgie, Mühlenkreiskliniken, Universitätsklinikum der Ruhr-Universität Bochum, Minden, Deutschland.,Klinik für Allgemein-, Viszeral- und Transplantationschirurgie, Universitätsmedizin der Johannes-Gutenberg-Universität Mainz, Deutschland
| |
Collapse
|
3
|
Fallon C, Lemire M, Dumont D, Parent E, Figueroa E, Cummings I, Brousseau J, Marquis M, Paquet N, Plante S, Witteman HO. Toward Food Sovereignty for Coastal Communities of Eastern Québec: Co-designing A Website to Support Consumption of Edible Resources from the St. Lawrence River, Estuary, and Gulf. MDM Policy Pract 2022; 7:23814683221094477. [PMID: 35479298 PMCID: PMC9036343 DOI: 10.1177/23814683221094477] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/24/2022] [Indexed: 11/25/2022] Open
Abstract
Background. Despite the abundance and proximity of edible marine resources, coastal communities along the St. Lawrence in Eastern Québec rarely consume these resources. Within a community-based food sovereignty project, Manger notre Saint-Laurent (“Sustenance from our St. Lawrence”), members of participating communities (3 non-Indigenous, 1 Indigenous) identified a need for a web-based decision tool to help make informed consumption choices. Methods. We thus aimed to co-design a prototype website that facilitates informed choices about consuming local edible marine resources based on seasonal and regional availability, food safety, nutrition, and sustainability, with community members, regional stakeholders, and experts in user experience design and web development. We conducted 48 interviews with a variety of people over 3 iterative cycles, assessing the prototype’s ease of use with a validated measure, the System Usability Scale. Results. Community members, regional stakeholders, and other experts identified problematic elements in initial versions of the website (e.g., confusing symbols). We resolved issues and added features people identified as useful. Usability scores reached “best imaginable” for both the second and the third versions and did not differ significantly between sociodemographic groups. The final prototype includes a tool to explore each species and index cards to regroup accurate evidence relevant to each species. Conclusions. Engaging co-designers with different sociodemographic characteristics brought together a variety of perspectives. Several components would not have been included without co-designers’ input; other components were greatly improved thanks to their feedback. Co-design approaches in research and intervention development are preferable to foster the inclusion of a variety of people. Once the prototype is programmed and available online, we hope to evaluate the website to determine its effects on food choices.
Collapse
Affiliation(s)
| | - Mélanie Lemire
- Faculty of Medicine, Laval University, Québec City, Qc, Canada
- Research Center of CHU de Québec, Institut de biologie intégrative et des systèmes, Laval University, Québec City, Québec, Canada
| | - Dany Dumont
- Institut des sciences de la mer de Rimouski, Université du Québec à Rimouski, Rimouski, Qc, Canada
| | | | | | - Isabelle Cummings
- Centre de recherche sur les milieux insulaires et maritimes, Havre-aux-Maisons, Qc, Canada
| | - Julie Brousseau
- Faculty of Medicine, University of Montreal, Montreal, Qc, Canada
| | - Marie Marquis
- Faculty of Medicine, University of Montreal, Montreal, Qc, Canada
| | - Nicolas Paquet
- franC doc, rang Saint-Adolphe, Saint-Alexandre-de-Kamouraska, Qc, Canada
| | - Steve Plante
- Université du Québec à Rimouski, Rimouski, Qc, Canada
| | | |
Collapse
|
4
|
Lefebvre-Raine M, Paquet N, Triffault-Bouchet G, Langlois VS. Embryotoxicity of Five Cytostatics in Fathead Minnow (Pimephales promelas) Larvae. Bull Environ Contam Toxicol 2021; 106:747-752. [PMID: 33713142 DOI: 10.1007/s00128-021-03146-2] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 02/05/2021] [Indexed: 06/12/2023]
Abstract
Cytostatics are compounds used in chemotherapy, known to be genotoxic, mutagenic, and teratogenic at low concentrations. The amount of cytostatic drugs prescribed increases every year as does their release into the aquatic ecosystems, which possibly is a major concern for the health of aquatic organisms. This study aimed to evaluate the putative toxicity of five cytostatics to fathead minnow (Pimephales promelas) larvae: tamoxifen, capecitabine, methotrexate, cyclophosphamide, and ifosfamide. Eggs collected post-fertilization were exposed for 6 days to a range of concentrations, including one above environmental level. At all environmental concentrations, no significant difference in mortality, hatching time, length, heart rate, and presence of malformations were found. Altogether, these cytostatics do not seem embryotoxic to fish. Although, an increased proportion of complete swim bladder were found after ifosfamide's exposure, suggesting an interaction with the thyroid axis, involved in swim bladder development. Complementary work should address other endpoints, such as behavioral changes, reproductive success, and transgenerational effects.
Collapse
Affiliation(s)
- M Lefebvre-Raine
- Institut National de La Recherche Scientifique (INRS), Centre Eau Terre Environnement (ETE), Québec, QC, Canada
| | - N Paquet
- Ministère de L'Environnement et de La Lutte Contre Les Changements Climatiques (MELCC), Centre D'expertise en Analyse Environnementale du Québec (CEAEQ), Québec, QC, Canada
| | - G Triffault-Bouchet
- Ministère de L'Environnement et de La Lutte Contre Les Changements Climatiques (MELCC), Centre D'expertise en Analyse Environnementale du Québec (CEAEQ), Québec, QC, Canada
| | - V S Langlois
- Institut National de La Recherche Scientifique (INRS), Centre Eau Terre Environnement (ETE), Québec, QC, Canada.
| |
Collapse
|
5
|
Bomberg H, Paquet N, Huth A, Wagenpfeil S, Kessler P, Wulf H, Wiesmann T, Standl T, Gottschalk A, Döffert J, Hering W, Birnbaum J, Kutter B, Winckelmann J, Liebl-Biereige S, Meissner W, Vicent O, Koch T, Bürkle H, Sessler DI, Raddatz A, Volk T. Epidural needle insertion : A large registry analysis. Anaesthesist 2018; 67:922-930. [PMID: 30338337 DOI: 10.1007/s00101-018-0499-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2018] [Revised: 09/18/2018] [Accepted: 09/27/2018] [Indexed: 01/20/2023]
Abstract
BACKGROUND Dural puncture, paraesthesia and vascular puncture are the most common complications of epidural catheter insertion. Their association with variation in midline needle insertion depth is unknown. OBJECTIVE This study evaluated the risk of dural and vascular punctures and the unwanted events paraesthesia and multiple skin punctures related to midline needle insertion depth. MATERIAL AND METHODS A total of 14,503 epidural catheter insertions including lumbar (L1-L5; n = 5367), low thoracic (T7-T12, n = 8234) and upper thoracic (T1-T6, n = 902) insertions, were extracted from the German Network for Regional Anaesthesia registry between 2007 and 2015. The primary outcomes were compared with logistic regression and adjusted (adj) for confounders to determine the risk of complications/events. Results are presented as odds ratios (OR, [95% confidence interval]). MAIN RESULTS Midline insertion depth depended on body mass index, sex, and spinal level. After adjusting for confounders increased puncture depth (cm) remained an independent risk factor for vascular puncture (adjOR 1.27 [1.09-1.47], p = 0.002) and multiple skin punctures (adjOR 1.25 [1.21-1.29], p < 0.001). In contrast, dural punctures occurred at significantly shallower depths (adjOR 0.73 [0.60-0.89], p = 0.002). Paraesthesia was unrelated to insertion depth. Body mass index and sex had no influence on paraesthesia, dural and vascular punctures. Thoracic epidural insertion was associated with a lower risk of vascular puncture than at lumbar sites (adjOR 0.39 [0.18-0.84], p = 0.02). CONCLUSION Variation in midline insertion depth is an independent risk factor for epidural complications; however, variability precludes use of depth as a reliable guide to insertion in individual patients.
Collapse
Affiliation(s)
- H Bomberg
- Department of Anaesthesiology, Intensive Care Medicine and Pain Medicine, University Medical Centre, Saarland University, Kirrbergerstraße 1, 66421, Homburg/Saar, Germany.
| | - N Paquet
- Department of Anaesthesiology, Intensive Care Medicine and Pain Medicine, University Medical Centre, Saarland University, Kirrbergerstraße 1, 66421, Homburg/Saar, Germany
| | - A Huth
- Department of Anaesthesiology, Intensive Care Medicine and Pain Medicine, University Medical Centre, Saarland University, Kirrbergerstraße 1, 66421, Homburg/Saar, Germany
| | - S Wagenpfeil
- Institute for Medical Biometry, Epidemiology and Medical Informatics, University Medical Centre, Saarland University, Homburg/Saar, Germany
| | - P Kessler
- Department of Anaesthesiology, Intensive Care and Pain Medicine, Orthopaedic University Hospital, Frankfurt, Germany
| | - H Wulf
- Department of Anaesthesiology and Intensive Care Therapy, Philipps University Marburg, Marburg, Germany
| | - T Wiesmann
- Department of Anaesthesiology and Intensive Care Therapy, Philipps University Marburg, Marburg, Germany
| | - T Standl
- Department of Anaesthesia, Intensive and Palliative Care Medicine, Academic Hospital Solingen, Solingen, Germany
| | - A Gottschalk
- Department of Anaesthesiology, Intensive Care- and Pain Medicine, Friederikenstift Hannover, Hannover, Germany
| | - J Döffert
- Department of Anaesthesiology and Intensive Care Medicine, Hospital Calw-Nagold, Calw-Nagold, Germany
| | - W Hering
- Department of Anaesthesiology, St. Marien-Hospital, Siegen, Germany
| | - J Birnbaum
- Department of Anaesthesiology and Operative Intensive Care Medicine, Charité Campus Virchow Klinikum and Campus Mitte, Charité University Medicine Berlin, Berlin, Germany
| | - B Kutter
- Department of Anaesthesiology, Intensive Care and Pain Therapy, University and Rehabilitation Clinics, Ulm, Germany
| | - J Winckelmann
- Department of Anaesthesiology, Intensive Care and Pain Therapy, University and Rehabilitation Clinics, Ulm, Germany
| | - S Liebl-Biereige
- Department of Anaesthesiology, Intensive Care and Pain Therapy, HELIOS Hospital Erfurt, Erfurt, Germany
| | - W Meissner
- Department of Anaesthesiology and Intensive Care, Jena University Hospital, Jena, Germany
| | - O Vicent
- Department of Anaesthesiology, Intensive Care and Pain Medicine, University Hospital Carl Gustav Carus, Technische Universität, Dresden, Germany
| | - T Koch
- Department of Anaesthesiology, Intensive Care and Pain Medicine, University Hospital Carl Gustav Carus, Technische Universität, Dresden, Germany
| | - H Bürkle
- Department of Anaesthesiology and Critical Care, Medical Center, Medical Faculty University Freiburg, University of Freiburg, Freiburg, Germany
| | - D I Sessler
- Department of Outcomes Research, Anesthesiology Institute, Cleveland Clinic, Cleveland, OH, USA
| | - A Raddatz
- Department of Anaesthesiology, Intensive Care Medicine and Pain Medicine, University Medical Centre, Saarland University, Kirrbergerstraße 1, 66421, Homburg/Saar, Germany
| | - T Volk
- Department of Anaesthesiology, Intensive Care Medicine and Pain Medicine, University Medical Centre, Saarland University, Kirrbergerstraße 1, 66421, Homburg/Saar, Germany
| |
Collapse
|
6
|
Croteau E, Castellano C, Fortier M, Bocti C, Fulop T, Paquet N, Cunnane S. A cross-sectional comparison of brain glucose and ketone metabolism in cognitively healthy older adults, mild cognitive impairment and early Alzheimer's disease. Exp Gerontol 2018; 107:18-26. [DOI: 10.1016/j.exger.2017.07.004] [Citation(s) in RCA: 116] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2017] [Revised: 06/30/2017] [Accepted: 07/01/2017] [Indexed: 12/24/2022]
|
7
|
Croft LV, Ashton NW, Paquet N, Bolderson E, O'Byrne KJ, Richard DJ. hSSB1 associates with and promotes stability of the BLM helicase. BMC Mol Biol 2017; 18:13. [PMID: 28506294 PMCID: PMC5433028 DOI: 10.1186/s12867-017-0090-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2016] [Accepted: 05/05/2017] [Indexed: 01/03/2023] Open
Abstract
Background Maintenance of genome stability is critical in human cells. Mutations in or loss of genome stability pathways can lead to a number of pathologies including cancer. hSSB1 is a critical DNA repair protein functioning in the repair and signalling of stalled DNA replication forks, double strand DNA breaks and oxidised DNA lesions. The BLM helicase is central to the repair of both collapsed DNA replication forks and double strand DNA breaks by homologous recombination. Results In this study, we demonstrate that hSSB1 and BLM helicase form a complex in cells and the interaction is altered in response to ionising radiation (IR). BLM and hSSB1 also co-localised at nuclear foci following IR-induced double strand breaks and stalled replication forks. We show that hSSB1 depleted cells contain less BLM protein and that this deficiency is due to proteasome mediated degradation of BLM. Consequently, there is a defect in recruitment of BLM to chromatin in response to ionising radiation-induced DSBs and to hydroxyurea-induced stalled and collapsed replication forks. Conclusions Our data highlights that BLM helicase and hSSB1 function in a dynamic complex in cells and that this complex is likely required for BLM protein stability and function. Electronic supplementary material The online version of this article (doi:10.1186/s12867-017-0090-3) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Laura V Croft
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Nicholas W Ashton
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Nicolas Paquet
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Emma Bolderson
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Kenneth J O'Byrne
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba, QLD, 4102, Australia. .,Princess Alexandra Hospital, 199 Ipswich Road, Woolloongabba, QLD, 4102, Australia.
| | - Derek J Richard
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba, QLD, 4102, Australia.
| |
Collapse
|
8
|
Ashton NW, Paquet N, Shirran SL, Bolderson E, Kariawasam R, Touma C, Fallahbaghery A, Gamsjaeger R, Cubeddu L, Botting C, Pollock PM, O'Byrne KJ, Richard DJ. hSSB1 phosphorylation is dynamically regulated by DNA-PK and PPP-family protein phosphatases. DNA Repair (Amst) 2017; 54:30-39. [PMID: 28448822 DOI: 10.1016/j.dnarep.2017.03.006] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [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: 01/10/2017] [Revised: 02/28/2017] [Accepted: 03/24/2017] [Indexed: 11/16/2022]
Abstract
The maintenance of genomic stability is essential for cellular viability and the prevention of diseases such as cancer. Human single-stranded DNA-binding protein 1 (hSSB1) is a protein with roles in the stabilisation and restart of stalled DNA replication forks, as well as in the repair of oxidative DNA lesions and double-strand DNA breaks. In the latter process, phosphorylation of threonine 117 by the ATM kinase is required for hSSB1 stability and efficient DNA repair. The regulation of hSSB1 in other DNA repair pathways has however remained unclear. Here we report that hSSB1 is also directly phosphorylated by DNA-PK at serine residue 134. While this modification is largely suppressed in undamaged cells by PPP-family protein phosphatases, S134 phosphorylation is enhanced following the disruption of replication forks and promotes cellular survival. Together, these data thereby represent a novel mechanism for hSSB1 regulation following the inhibition of replication.
Collapse
Affiliation(s)
- Nicholas W Ashton
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba 4102, QLD, Australia.
| | - Nicolas Paquet
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba 4102, QLD, Australia.
| | - Sally L Shirran
- School of Biology, Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK.
| | - Emma Bolderson
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba 4102, QLD, Australia.
| | - Ruvini Kariawasam
- School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith 2751, NSW, Australia.
| | - Christine Touma
- School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith 2751, NSW, Australia.
| | - Azadeh Fallahbaghery
- School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith 2751, NSW, Australia.
| | - Roland Gamsjaeger
- School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith 2751, NSW, Australia.
| | - Liza Cubeddu
- School of Science and Health, University of Western Sydney, Locked Bag 1797, Penrith 2751, NSW, Australia.
| | - Catherine Botting
- School of Biology, Biomedical Sciences Research Complex, University of St Andrews, North Haugh, St Andrews, Fife KY16 9ST, UK.
| | - Pamela M Pollock
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba 4102, QLD, Australia.
| | - Kenneth J O'Byrne
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba 4102, QLD, Australia.
| | - Derek J Richard
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, 37 Kent Street, Woolloongabba 4102, QLD, Australia.
| |
Collapse
|
9
|
Ashton NW, Loo D, Paquet N, O'Byrne KJ, Richard DJ. Novel insight into the composition of human single-stranded DNA-binding protein 1 (hSSB1)-containing protein complexes. BMC Mol Biol 2016; 17:24. [PMID: 27938330 PMCID: PMC5148904 DOI: 10.1186/s12867-016-0077-5] [Citation(s) in RCA: 5] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2016] [Accepted: 12/02/2016] [Indexed: 11/10/2022] Open
Abstract
Background Single-stranded DNA-binding proteins are essential cellular components required for the protection, metabolism and processing of single-stranded DNA. Human single-stranded DNA-binding protein 1 (hSSB1) is one such protein, with described roles in genome stability maintenance and transcriptional regulation. As yet, however, the mechanisms through which hSSB1 functions and the binding partners with which it interacts remain poorly understood. Results In this work, hSSB1 was immunoprecipitated from cell lysate samples that had been enriched for non-soluble nuclear proteins and those associating with hSSB1 identified by mass spectrometry. In doing so, 334 potential hSSB1-associating proteins were identified, with known roles in a range of distinct biological processes. Unexpectedly, whilst hSSB1 has largely been studied in a genome stability context, few other DNA repair or replication proteins were detected. By contrast, a large number of proteins were identified with roles in mRNA metabolism, reflecting a currently emerging area of hSSB1 study. In addition, numerous proteins were detected that comprise various chromatin-remodelling complexes. Conclusions These findings provide new insight into the binding partners of hSSB1 and will likely function as a platform for future research. Electronic supplementary material The online version of this article (doi:10.1186/s12867-016-0077-5) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Nicholas W Ashton
- School of Biomedical Research, Institute of Health and Biomedical Innovation, Queensland University of Technology, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Dorothy Loo
- Translational Research Institute Proteomics Facility, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Nicolas Paquet
- School of Biomedical Research, Institute of Health and Biomedical Innovation, Queensland University of Technology, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Kenneth J O'Byrne
- School of Biomedical Research, Institute of Health and Biomedical Innovation, Queensland University of Technology, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD, 4102, Australia
| | - Derek J Richard
- School of Biomedical Research, Institute of Health and Biomedical Innovation, Queensland University of Technology, Translational Research Institute, 37 Kent Street, Woolloongabba, QLD, 4102, Australia.
| |
Collapse
|
10
|
Box JK, Paquet N, Adams MN, Boucher D, Bolderson E, O'Byrne KJ, Richard DJ. Nucleophosmin: from structure and function to disease development. BMC Mol Biol 2016; 17:19. [PMID: 27553022 PMCID: PMC4995807 DOI: 10.1186/s12867-016-0073-9] [Citation(s) in RCA: 155] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2016] [Accepted: 08/16/2016] [Indexed: 12/11/2022] Open
Abstract
Nucleophosmin (NPM1) is a critical cellular protein that has been implicated in a number of pathways including mRNA transport, chromatin remodeling, apoptosis and genome stability. NPM1 function is a critical requirement for normal cellular biology as is underlined in cancer where NPM1 is commonly overexpressed, mutated, rearranged and sporadically deleted. Consistent with a multifunctional role within the cell, NPM1 can function not only as a proto-oncogene but also as a tumor suppressor. The aim of this review is to look at the less well-described role of NPM1 in the DNA repair pathways as well as the role of NPM1 in the regulation of apoptosis and its mutation in cancers.
Collapse
Affiliation(s)
- Joseph K Box
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Nicolas Paquet
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.
| | - Mark N Adams
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Didier Boucher
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Emma Bolderson
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Kenneth J O'Byrne
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia
| | - Derek J Richard
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.
| |
Collapse
|
11
|
Touma C, Kariawasam R, Gimenez AX, Bernardo RE, Ashton NW, Adams MN, Paquet N, Croll TI, O'Byrne KJ, Richard DJ, Cubeddu L, Gamsjaeger R. A structural analysis of DNA binding by hSSB1 (NABP2/OBFC2B) in solution. Nucleic Acids Res 2016; 44:7963-73. [PMID: 27387285 PMCID: PMC5027503 DOI: 10.1093/nar/gkw617] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2016] [Accepted: 06/28/2016] [Indexed: 02/07/2023] Open
Abstract
Single-stranded DNA binding proteins (SSBs) play an important role in DNA processing events such as replication, recombination and repair. Human single-stranded DNA binding protein 1 (hSSB1/NABP2/OBFC2B) contains a single oligosaccharide/oligonucleotide binding (OB) domain followed by a charged C-terminus and is structurally homologous to the SSB from the hyperthermophilic crenarchaeote Sulfolobus solfataricus. Recent work has revealed that hSSB1 is critical to homologous recombination and numerous other important biological processes such as the regulation of telomeres, the maintenance of DNA replication forks and oxidative damage repair. Since the ability of hSSB1 to directly interact with single-stranded DNA (ssDNA) is paramount for all of these processes, understanding the molecular details of ssDNA recognition is essential. In this study, we have used solution-state nuclear magnetic resonance in combination with biophysical and functional experiments to structurally analyse ssDNA binding by hSSB1. We reveal that ssDNA recognition in solution is modulated by base-stacking of four key aromatic residues within the OB domain. This DNA binding mode differs significantly from the recently determined crystal structure of the SOSS1 complex containing hSSB1 and ssDNA. Our findings elucidate the detailed molecular mechanism in solution of ssDNA binding by hSSB1, a major player in the maintenance of genomic stability.
Collapse
Affiliation(s)
- Christine Touma
- School of Science and Health, Western Sydney University, Penrith, NSW 2751, Australia
| | - Ruvini Kariawasam
- School of Science and Health, Western Sydney University, Penrith, NSW 2751, Australia
| | - Adrian X Gimenez
- School of Science and Health, Western Sydney University, Penrith, NSW 2751, Australia
| | - Ray E Bernardo
- School of Science and Health, Western Sydney University, Penrith, NSW 2751, Australia
| | - Nicholas W Ashton
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Mark N Adams
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Nicolas Paquet
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Tristan I Croll
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Kenneth J O'Byrne
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Derek J Richard
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Liza Cubeddu
- School of Science and Health, Western Sydney University, Penrith, NSW 2751, Australia School of Molecular Biosciences, University of Sydney, NSW 2006, Australia
| | - Roland Gamsjaeger
- School of Science and Health, Western Sydney University, Penrith, NSW 2751, Australia School of Molecular Biosciences, University of Sydney, NSW 2006, Australia
| |
Collapse
|
12
|
Paquet N, Adams MN, Leong V, Ashton NW, Touma C, Gamsjaeger R, Cubeddu L, Beard S, Burgess JT, Bolderson E, O'Byrne KJ, Richard DJ. hSSB1 (NABP2/ OBFC2B) is required for the repair of 8-oxo-guanine by the hOGG1-mediated base excision repair pathway. Nucleic Acids Res 2015; 43:8817-29. [PMID: 26261212 PMCID: PMC4605301 DOI: 10.1093/nar/gkv790] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 07/22/2015] [Indexed: 01/03/2023] Open
Abstract
The maintenance of genome stability is essential to prevent loss of genetic information and the development of diseases such as cancer. One of the most common forms of damage to the genetic code is the oxidation of DNA by reactive oxygen species (ROS), of which 8-oxo-7,8-dihydro-guanine (8-oxoG) is the most frequent modification. Previous studies have established that human single-stranded DNA-binding protein 1 (hSSB1) is essential for the repair of double-stranded DNA breaks by the process of homologous recombination. Here we show that hSSB1 is also required following oxidative damage. Cells lacking hSSB1 are sensitive to oxidizing agents, have deficient ATM and p53 activation and cannot effectively repair 8-oxoGs. Furthermore, we demonstrate that hSSB1 forms a complex with the human oxo-guanine glycosylase 1 (hOGG1) and is important for hOGG1 localization to the damaged chromatin. In vitro, hSSB1 binds directly to DNA containing 8-oxoguanines and enhances hOGG1 activity. These results underpin the crucial role hSSB1 plays as a guardian of the genome.
Collapse
Affiliation(s)
- Nicolas Paquet
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Mark N Adams
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Vincent Leong
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Nicholas W Ashton
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Christine Touma
- School of Science and Health, University of Western Sydney, Penrith, NSW 2751 Australia
| | - Roland Gamsjaeger
- School of Science and Health, University of Western Sydney, Penrith, NSW 2751 Australia School of Molecular Bioscience, University of Sydney, Sydney, NSW 2006, Australia
| | - Liza Cubeddu
- School of Science and Health, University of Western Sydney, Penrith, NSW 2751 Australia School of Molecular Bioscience, University of Sydney, Sydney, NSW 2006, Australia
| | - Sam Beard
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Joshua T Burgess
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Emma Bolderson
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Ken J O'Byrne
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| | - Derek J Richard
- School of Biomedical Research, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Woolloongabba, QLD 4102, Australia
| |
Collapse
|
13
|
Bastide A, Paquet N, Fouquette B. Percutaneous umbilical blood sampling. Curr Stud Hematol Blood Transfus 2015:136-9. [PMID: 3280254 DOI: 10.1159/000415162] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- A Bastide
- St. François d'Assise Hospital, Laval University, Québec, Canada
| | | | | |
Collapse
|
14
|
Paquet N, Box JK, Ashton NW, Suraweera A, Croft LV, Urquhart AJ, Bolderson E, Zhang SD, O'Byrne KJ, Richard DJ. Néstor-Guillermo Progeria Syndrome: a biochemical insight into Barrier-to-Autointegration Factor 1, alanine 12 threonine mutation. BMC Mol Biol 2014; 15:27. [PMID: 25495845 PMCID: PMC4266902 DOI: 10.1186/s12867-014-0027-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2014] [Accepted: 12/02/2014] [Indexed: 12/13/2022] Open
Abstract
Background Premature aging syndromes recapitulate many aspects of natural aging and provide an insight into this phenomenon at a molecular and cellular level. The progeria syndromes appear to cause rapid aging through disruption of normal nuclear structure. Recently, a coding mutation (c.34G > A [p.A12T]) in the Barrier to Autointegration Factor 1 (BANF1) gene was identified as the genetic basis of Néstor-Guillermo Progeria syndrome (NGPS). This mutation was described to cause instability in the BANF1 protein, causing a disruption of the nuclear envelope structure. Results Here we demonstrate that the BANF1 A12T protein is indeed correctly folded, stable and that the observed phenotype, is likely due to the disruption of the DNA binding surface of the A12T mutant. We demonstrate, using biochemical assays, that the BANF1 A12T protein is impaired in its ability to bind DNA while its interaction with nuclear envelope proteins is unperturbed. Consistent with this, we demonstrate that ectopic expression of the mutant protein induces the NGPS cellular phenotype, while the protein localizes normally to the nuclear envelope. Conclusions Our study clarifies the role of the A12T mutation in NGPS patients, which will be of importance for understanding the development of the disease.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | - Derek J Richard
- School of Biomedical Science, Institute of Health and Biomedical Innovation at the Translational Research Institute, Queensland University of Technology, Brisbane, QLD, Australia.
| |
Collapse
|
15
|
Fletcher NL, Paquet N, Dickinson EL, Dexter AF. Bioproduction of highly charged designer peptide surfactants via a chemically cleavable coiled-coil heteroconcatemer. Biotechnol Bioeng 2014; 112:242-51. [DOI: 10.1002/bit.25446] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Revised: 08/02/2014] [Accepted: 08/18/2014] [Indexed: 01/20/2023]
Affiliation(s)
- Nicholas L. Fletcher
- Australian Institute for Bioengineering and Nanotechnology; The University of Queensland; Brisbane QLD 4072 Australia
| | - Nicolas Paquet
- Australian Institute for Bioengineering and Nanotechnology; The University of Queensland; Brisbane QLD 4072 Australia
| | - Ellyce L. Dickinson
- School of Chemical Engineering; The University of Queensland; Brisbane QLD 4072 Australia
| | - Annette F. Dexter
- Australian Institute for Bioengineering and Nanotechnology; The University of Queensland; Brisbane QLD 4072 Australia
| |
Collapse
|
16
|
Lamb KL, Liu Y, Ishiguro K, Kwon Y, Paquet N, Sartorelli AC, Sung P, Rockwell S, Sweasy JB. Tumor-associated mutations in O⁶ -methylguanine DNA-methyltransferase (MGMT) reduce DNA repair functionality. Mol Carcinog 2012; 53:201-10. [PMID: 23065697 DOI: 10.1002/mc.21964] [Citation(s) in RCA: 7] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 08/27/2012] [Accepted: 08/29/2012] [Indexed: 11/10/2022]
Abstract
MGMT is the primary vehicle for cellular removal of alkyl lesions from the O-6 position of guanine and the O-4 position of thymine. While key to the maintenance of genomic integrity, MGMT also removes damage induced by alkylating chemotherapies, inhibiting the efficacy of cancer treatment. Germline variants of human MGMT are well-characterized, but somatic variants found in tumors were, prior to this work, uncharacterized. We found that MGMT G132R, from a human esophageal tumor, and MGMT G156C, from a human colorectal cancer cell line, are unable to rescue methyltransferase-deficient Escherichia coli as well as wild type (WT) human MGMT after treatment with a methylating agent. Using pre-steady state kinetics, we biochemically characterized these variants as having a reduced rate constant. G132R binds DNA containing an O⁶ -methylguanine lesion half as tightly as WT MGMT, while G156C has a 40-fold decrease in binding affinity for the same damaged DNA versus WT. Mammalian cells expressing either G132R or G156C are more sensitive to methylating agents than mammalian cells expressing WT MGMT. G132R is slightly resistant to O⁶ -benzylguanine, an inhibitor of MGMT in clinical trials, while G156C is almost completely resistant to this inhibitor. The impared functionality of expressed variants G132R and G156C suggests that the presence of somatic variants of MGMT in a tumor could impact chemotherapeutic outcomes.
Collapse
Affiliation(s)
- Kristy L Lamb
- Department of Therapeutic Radiology, Yale University School of Medicine, New Haven, Connecticut; Department of Genetics, Yale University School of Medicine, New Haven, Connecticut
| | | | | | | | | | | | | | | | | |
Collapse
|
17
|
Islam MN, Paquet N, Fox D, Dray E, Zheng XF, Klein H, Sung P, Wang W. A variant of the breast cancer type 2 susceptibility protein (BRC) repeat is essential for the RECQL5 helicase to interact with RAD51 recombinase for genome stabilization. J Biol Chem 2012; 287:23808-18. [PMID: 22645136 DOI: 10.1074/jbc.m112.375014] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The BRC repeat is a structural motif in the tumor suppressor BRCA2 (breast cancer type 2 susceptibility protein), which promotes homologous recombination (HR) by regulating RAD51 recombinase activity. To date, the BRC repeat has not been observed in other proteins, so that its role in HR is inferred only in the context of BRCA2. Here, we identified a BRC repeat variant, named BRCv, in the RECQL5 helicase, which possesses anti-recombinase activity in vitro and suppresses HR and promotes cellular resistance to camptothecin-induced replication stress in vivo. RECQL5-BRCv interacted with RAD51 through two conserved motifs similar to those in the BRCA2-BRC repeat. Mutations of either motif compromised functions of RECQL5, including association with RAD51, inhibition of RAD51-mediated D-loop formation, suppression of sister chromatid exchange, and resistance to camptothecin-induced replication stress. Potential BRCvs were also found in other HR regulatory proteins, including Srs2 and Sgs1, which possess anti-recombinase activities similar to that of RECQL5. A point mutation in the predicted Srs2-BRCv disrupted the ability of the protein to bind RAD51 and to inhibit D-loop formation. Thus, BRC is a common RAD51 interaction module that can be utilized by different proteins to either promote HR, as in the case of BRCA2, or to suppress HR, as in RECQL5.
Collapse
Affiliation(s)
- M Nurul Islam
- Laboratory of Genetics, NIA, National Institutes of Health, National Institutes of Health Biomedical Research Center, Baltimore, Maryland 21224, USA
| | | | | | | | | | | | | | | |
Collapse
|
18
|
Vivancos J, Spinner L, Mazubert C, Charlot F, Paquet N, Thareau V, Dron M, Nogué F, Charon C. The function of the RNA-binding protein TEL1 in moss reveals ancient regulatory mechanisms of shoot development. Plant Mol Biol 2012; 78:323-336. [PMID: 22170036 DOI: 10.1007/s11103-011-9867-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2011] [Accepted: 11/28/2011] [Indexed: 05/31/2023]
Abstract
The shoot represents the basic body plan in land plants. It consists of a repeated structure composed of stems and leaves. Whereas vascular plants generate a shoot in their diploid phase, non-vascular plants such as mosses form a shoot (called the gametophore) in their haploid generation. The evolution of regulatory mechanisms or genetic networks used in the development of these two kinds of shoots is unclear. TERMINAL EAR1-like genes have been involved in diploid shoot development in vascular plants. Here, we show that disruption of PpTEL1 from the moss Physcomitrella patens, causes reduced protonema growth and gametophore initiation, as well as defects in gametophore development. Leafy shoots formed on ΔTEL1 mutants exhibit shorter stems with more leaves per shoot, suggesting an accelerated leaf initiation (shortened plastochron), a phenotype shared with the Poaceae vascular plants TE1 and PLA2/LHD2 mutants. Moreover, the positive correlation between plastochron length and leaf size observed in ΔTEL1 mutants suggests a conserved compensatory mechanism correlating leaf growth and leaf initiation rate that would minimize overall changes in plant biomass. The RNA-binding protein encoded by PpTEL1 contains two N-terminus RNA-recognition motifs, and a third C-terminus non-canonical RRM, specific to TEL proteins. Removal of the PpTEL1 C-terminus (including this third RRM) or only 16-18 amino acids within it seriously impairs PpTEL1 function, suggesting a critical role for this third RRM. These results show a conserved function of the RNA-binding PpTEL1 protein in the regulation of shoot development, from early ancestors to vascular plants, that depends on the third TEL-specific RRM.
Collapse
Affiliation(s)
- Julien Vivancos
- Institut de Biologie des Plantes-CNRS (UMR8618), Université Paris-Sud 11, Saclay Plant Sciences, 91405 Orsay Cedex, France
| | | | | | | | | | | | | | | | | |
Collapse
|
19
|
Charon C, Vivancos J, Mazubert C, Paquet N, Pilate G, Dron M. Structure and vascular tissue expression of duplicated TERMINAL EAR1-like paralogues in poplar. Planta 2010; 231:525-535. [PMID: 19943172 DOI: 10.1007/s00425-009-1066-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2009] [Accepted: 10/23/2009] [Indexed: 05/28/2023]
Abstract
TERMINAL EAR1-like (TEL) genes encode putative RNA-binding proteins only found in land plants. Previous studies suggested that they may regulate tissue and organ initiation in Poaceae. Two TEL genes were identified in both Populus trichocarpa and the hybrid aspen Populus tremula x P. alba, named, respectively, PoptrTEL1-2 and PtaTEL1-2. The analysis of the organisation around the PoptrTEL genes in the P. trichocarpa genome and the estimation of the synonymous substitution rate for PtaTEL1-2 genes indicate that the paralogous link between these two Populus TEL genes probably results from the Salicoid large-scale gene-duplication event. Phylogenetic analyses confirmed their orthology link with the other TEL genes. The expression pattern of both PtaTEL genes appeared to be restricted to the mother cells of the plant body: leaf founder cells, leaf primordia, axillary buds and root differentiating tissues, as well as to mother cells of vascular tissues. Most interestingly, PtaTEL1-2 transcripts were found in differentiating cells of secondary xylem and phloem, but probably not in the cambium itself. Taken together, these results indicate specific expression of the TEL genes in differentiating cells controlling tissue and organ development in Populus (and other Angiosperm species).
Collapse
Affiliation(s)
- Céline Charon
- Institut de Biotechnologie des Plantes, CNRS (UMR8618), Université Paris-Sud 11, 91405 Orsay Cedex, France.
| | | | | | | | | | | |
Collapse
|
20
|
Garcia-Popov A, Paquet N, Lajoie Y. 163 THE EFFECT OF GYMNASTICS TRAINING ON NAVIGATION ERRORS AND ATTENTIONAL DEMAND IN A TRIANGLE COMPLETION TASK. Parkinsonism Relat Disord 2010. [DOI: 10.1016/s1353-8020(10)70164-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
21
|
Lajoie Y, Paquet N, Lafleur R. 175 ATTENTIONAL DEMANDS DURING A GOAL DIRECTED BLIND NAVIGATION TASK IN YOUNG AND OLDER ADULTS. Parkinsonism Relat Disord 2010. [DOI: 10.1016/s1353-8020(10)70176-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
22
|
Paquet N, Dannenbaum E, Hakim-Zadeh R, Fung J. Effects of fast head turns on head, trunk and pelvis motions during standing and walking in patients with unilateral vestibular deficit. J Vestib Res 2007. [DOI: 10.3233/ves-2006-16605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Patients with unilateral vestibular deficit (UVD) report difficulties with maintaining balance while executing fast head turns. Our aim was to determine whether head, trunk, and pelvis angular displacements were symmetrical in patients with UVD as they executed voluntary yaw rotation of the head towards or away from the side of the vestibular lesion, during standing and walking. Eight patients who underwent surgical resection of an acoustic neuroma stood with feet together or walked at comfortable pace across a 10-meter walkway. They turned the head as quickly and as fast as possible in the direction indicated by an illuminating arrow (left, right or none). The head angular displacement was similar towards the affected and intact sides. Acceleration tended to be larger during head rotations towards the affected versus the intact side by 13% at the head, 42% at the trunk and 37% at the pelvis (p> 0.05, NS). The pelvis rotated opposite to the head in 65% of trials towards the affected side and 56% of the trials towards the intact side during standing and 81% and 69%, respectively during walking. Overall, the UVD had only a minor influence on the symmetry of head, trunk and pelvis kinematics during fast yaw rotation of the head executed during standing and walking.
Collapse
Affiliation(s)
- N. Paquet
- School of Rehabilitation Sciences, University of Ottawa, 451 Smyth Road, Ottawa, ON, Canada K1H 8M5
- Jewish Rehabilitation Hospital site of CRIR, 3205 Place Alton-Goldbloom, Laval, PQ, Canada H7V 1R2
| | - E. Dannenbaum
- Jewish Rehabilitation Hospital site of CRIR, 3205 Place Alton-Goldbloom, Laval, PQ, Canada H7V 1R2
| | - R. Hakim-Zadeh
- Jewish Rehabilitation Hospital site of CRIR, 3205 Place Alton-Goldbloom, Laval, PQ, Canada H7V 1R2
| | - J. Fung
- Jewish Rehabilitation Hospital site of CRIR, 3205 Place Alton-Goldbloom, Laval, PQ, Canada H7V 1R2
- School of Physical and Occupational Therapy, McGill University, 3654 Promenade Sir-William-Osler, Montreal, QC, Canada H3G 1Y5
| |
Collapse
|
23
|
Raptis HA, Dannenbaum E, Paquet N, Feldman AG. Vestibular system may provide equivalent motor actions regardless of the number of body segments involved in the task. J Neurophysiol 2007; 97:4069-78. [PMID: 17428903 DOI: 10.1152/jn.00909.2006] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
The vestibulospinal system likely plays an essential role in motor equivalence--the ability to reach the desired motor goal despite intentional or imposed changes in the number of body segments involved in the task. To test this hypothesis, we compared the ability of healthy subjects and patients with unilateral vestibular lesions (surgical acoustic neuroma resection 0.6 to 6.7 yr before the study) to maintain either the same hand position or the same trajectory of within arm reach movements while flexing the trunk, in the absence of vision. In randomly selected trials, the trunk motion was prevented by an electromagnetic device. Healthy subjects were able to preserve the hand position or trajectory by modifying the elbow and shoulder joint rotations in a condition-dependent way, at a minimal latency of about 60 ms after the trunk movement onset. In contrast, six of seven patients showed deficits in the compensatory angular modifications at least in one of two tasks so that 30-100% of the trunk displacement was not compensated and thus influenced the hand position or trajectory. Results suggest that vestibular influences evoked by the head motion during trunk flexion play a major role in maintaining the consistency of arm motor actions in external space despite changes in the number of body segments involved. Our findings also suggest that despite long-term plasticity in the vestibular system and related neural structures, unilateral vestibular lesion may reduce the capacity of the nervous system to achieve motor equivalence.
Collapse
Affiliation(s)
- H A Raptis
- Neurological Science Research Center, Department of Physiology, University of Montreal and Center for Multidisciplinary Research in Rehabilitation (CRIR), Rehabilitation Institute of Montreal, Montreal., Quebec, Canada
| | | | | | | |
Collapse
|
24
|
Paquet N, Dannenbaum E, Hakim-Zadeh R, Fung J. Effects of fast head turns on head, trunk and pelvis motions during standing and walking in patients with unilateral vestibular deficit. J Vestib Res 2006; 16:279-84. [PMID: 17726281] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
Patients with unilateral vestibular deficit (UVD) report difficulties with maintaining balance while executing fast head turns. Our aim was to determine whether head, trunk, and pelvis angular displacements were symmetrical in patients with UVD as they executed voluntary yaw rotation of the head towards or away from the side of the vestibular lesion, during standing and walking. Eight patients who underwent surgical resection of an acoustic neuroma stood with feet together or walked at comfortable pace across a 10-meter walkway. They turned the head as quickly and as fast as possible in the direction indicated by an illuminating arrow (left, right or none). The head angular displacement was similar towards the affected and intact sides. Acceleration tended to be larger during head rotations towards the affected versus the intact side by 13% at the head, 42% at the trunk and 37% at the pelvis (p> 0.05, NS). The pelvis rotated opposite to the head in 65% of trials towards the affected side and 56% of the trials towards the intact side during standing and 81% and 69%, respectively during walking. Overall, the UVD had only a minor influence on the symmetry of head, trunk and pelvis kinematics during fast yaw rotation of the head executed during standing and walking.
Collapse
Affiliation(s)
- N Paquet
- School of Rehabilitation Sciences, University of Ottawa, 451 Smyth Road, Ottawa, ON, Canada K1H 8M5.
| | | | | | | |
Collapse
|
25
|
Richard O, Paquet N, Haudecoeur E, Charrier B. Organization and Expression of the GSK3/Shaggy Kinase Gene Family in the Moss Physcomitrella patens Suggest Early Gene Multiplication in Land Plants and an Ancestral Response to Osmotic Stress. J Mol Evol 2005; 61:99-113. [PMID: 16007489 DOI: 10.1007/s00239-004-0302-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2004] [Accepted: 03/02/2005] [Indexed: 10/25/2022]
Abstract
GSK3/Shaggy kinases are involved in a wide range of fundamental processes in animal development and metabolism. In angiosperm plants, these kinases are encoded by moderate-sized gene families, which appear to have a complex set of functions. Here, we present the characterization of five members of the GSK3/Shaggy gene family in the bryophyte Physcomitrella patens. The P. patens GSK3/Shaggy kinases (PpSK) are organized in a group of closely related paralogues with respect to their gene sequence and structure. Indeed, a phylogenetic analysis of the GSK3/Shaggy kinase sequences from plants and animals showed that the five PpSK proteins are monophyletic, and closer to subgroups I and IV described in angiosperms. Expression analyses performed by quantitative real-time RT-PCR on a wide range of growing conditions showed that PpSK genes responded only to either desiccation, PEG or sorbitol. As demonstrated by both inductions of marker genes and protonemal cell plasmolyses, these treatments resulted in a hyperosmotic stress. Altogether, these data suggest that (1) GSK3/Shaggy kinase gene multiplication occurred early in plant evolution, before the separation between bryophytes and vascular plants, and (2) both gene loss and duplication occurred in the ancestor of P. patens along with functional gene diversification in angiosperms. However, conservation of the transcriptional responses between Physcomitrella and Arabidopsis suggests the identification of an ancestral response of the GSK3/Shaggy kinases genes to osmotic stress.
Collapse
Affiliation(s)
- Odile Richard
- Institut de Biotechnologie des Plantes, Bât. 630, UMR CNRS 8618, Université Paris-Sud, 91405, Orsay Cedex, France
| | | | | | | |
Collapse
|
26
|
Paquet N, Bernadet M, Morin H, Traas J, Dron M, Charon C. Expression patterns of TEL genes in Poaceae suggest a conserved association with cell differentiation. J Exp Bot 2005; 56:1605-1614. [PMID: 15837706 DOI: 10.1093/jxb/eri155] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Poaceae species present a conserved distichous phyllotaxy (leaf position along the stem) and share common properties with respect to leaf initiation. The goal of this work was to determine if these common traits imply common genes. Therefore, homologues of the maize TERMINAL EAR1 gene in Poaceae were studied. This gene encodes an RNA-binding motif (RRM) protein, that is suggested to regulate leaf initiation. Using degenerate primers, one unique tel (terminal ear1-like) gene from seven Poaceae members, covering almost all the phylogenetic tree of the family, was identified by PCR. These genes present a very high degree of similarity, a much conserved exon-intron structure, and the three RRMs and TEL characteristic motifs. The evolution of tel sequences in Poaceae strongly correlates with the known phylogenetic tree of this family. RT-PCR gene expression analyses show conserved tel expression in the shoot apex in all species, suggesting functional orthology between these genes. In addition, in situ hybridization experiments with specific antisense probes show tel transcript accumulation in all differentiating cells of the leaf, from the recruitment of leaf founder cells to leaf margins cells. Tel expression is not restricted to initiating leaves as it is also found in pro-vascular tissues, root meristems, and immature inflorescences. Therefore, these results suggest that TEL is not only associated with leaf initiation but more generally with cell differentiation in Poaceae.
Collapse
Affiliation(s)
- Nicolas Paquet
- Institut de Biotechnologie des Plantes (UMR8618), University of Paris XI, F-91405 Orsay Cedex, France
| | | | | | | | | | | |
Collapse
|
27
|
LoMonaco EA, Paquet N, Hui-Chan CWY. Responses to whole head-and-body tilts with and without passive ankle dorsiflexion in the absence of visual feedback. Clin Biomech (Bristol, Avon) 2004; 19:648-52. [PMID: 15234490 DOI: 10.1016/j.clinbiomech.2004.03.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2003] [Accepted: 03/17/2004] [Indexed: 02/07/2023]
Abstract
OBJECTIVES We have investigated lower limb responses in seven blindfolded healthy subjects to well controlled tilts in the standing position. Our aims were (1) to determine the effect of head acceleration magnitude on responses evoked by whole head-and-body tilts, and (2) to establish whether tilt-evoked responses are modifiable by passive ankle dorsiflexion. Whole head-and-body tilts evoked responses in the biceps femoris, medial gastrocnemius and tibialis anterior muscles. METHODS Seven young healthy subjects stood on a spring-activated tilting apparatus and underwent sudden whole head-and-body tilts of about 15 degrees from the vertical position, with or without passive ankle dorsiflexion. Head acceleration was recorded with a linear accelerometer and ankle angular displacement with a potentiometer. Surface EMG signals were recorded in the right biceps femoris, medial gastrocnemius and tibialis anterior muscles. RESULTS As the peak of head acceleration was increased from 0.5 g to 1.8 g, the frequency of occurrence of tilt-evoked responses increased from 7% to 60% of trials in the biceps femoris muscle during whole head-and-body tilts. In general, the more proximal muscle (biceps femoris) was activated before the more distal muscle (medial gastrocnemius) during whole head-and-body tilts, while the opposite pattern was found during tilt with dorsiflexion. CONCLUSIONS Our results indicate that the occurrence of tilt-evoked responses increases with an increase in the amplitude of tilting acceleration. This suggests that tilt-evoked responses are dependent, at least in part, on vestibular stimulation. In addition, the spatio-temporal pattern of biceps femoris and medial gastrocnemius muscle activation was opposite during whole head-and-body tilts and tilts with dorsiflexion. This finding suggests that foot/ankle somatosensory inputs can modify tilt-evoked responses.
Collapse
Affiliation(s)
- E A LoMonaco
- School of Physical and Occupational Therapy, McGill University, Canada
| | | | | |
Collapse
|
28
|
Abstract
PURPOSE To explore the interrater reliability of the Advanced Mobility and Balance Scale (AMBS) and to determine its discriminative capacity in stroke patients. METHODS Twelve hemiparetic patients and six healthy elderly volunteers were videotaped while: (1) executing rapid head motions during standing and walking; and (2) standing and walking on a slope. Five physical therapists viewed the videotapes to establish interrater reliability. RESULTS Interrater reliability: Intraclass correlation ratios ranged from 0.93-0.97 for the AMBS global as well as slope and head turn subscores. Construct validity: One-way ANOVAs and post-hoc pairwise comparisons were performed to determine whether there was a difference in scores between high (HFL) and low functional-level (LFL) stroke patients (based on gait speed) and healthy subjects. Mean (+/-SD) global scores were 45 +/- 3 for healthy subjects, 40 +/- 9 for HFL stroke patients and 25 +/- 1 for LFL stroke patients (p < 0.05 for HFL versus LFL patients and LFL patients versus healthy subjects). The AMBS slope subscores were 22 +/- 2, 19 +/- 5, 9 +/- 7 for healthy, HFL and LFL subjects respectively (p < 0.05 for HFL versus LFL patients and LFL patients versus healthy subjects). CONCLUSION The AMBS has excellent interrater reliability and good discriminative capacities.
Collapse
Affiliation(s)
- D Kairy
- Jewish Rehabilitation Hospital Research Centre, Laval, Quebec, Canada
| | | | | |
Collapse
|
29
|
Paquet N, Watt DG, Lefebvre L. Rhythmical eye-head-torso rotation alters fore-aft head stabilization during treadmill locomotion in humans. J Vestib Res 2000; 10:41-9. [PMID: 10798832] [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] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
A repetitive manoeuvre called torso rotation (TR) is known to temporarily reduce the gain of the horizontal vestibulo-ocular reflex by 10-15% in healthy humans. TR consists of a series of rhythmical rotations of the eyes, head and upper body executed continuously for 30 minutes while standing. Our aim was to investigate whether TR affects the ability to hold the head in a fixed fore-aft position relative to space while walking on a treadmill with eyes closed. Ten healthy subjects stood in a carefully standardized position on a stationary treadmill. The treadmill started unexpectedly and ran for 4 s at 29 cm/s. The test stimulus was a linear acceleration in the fore-aft direction at the moment of treadmill start-up. Linear head position (i.e., ability to stabilize the head) was measured during and following the stimulus. A mechanical system prevented head rotation. Two series of 60 trials were performed before TR (control 1 and control 2 series) and one after TR. Before TR, subjects drifted rearward at an average drift velocity +/- S.D. = 3.1 +/- 0.9 cm/s. This drift was reasonably stable over time within and between the two control series. After TR, head holding ability was further impaired, with subjects having more difficulty to stabilize their head after treadmill start-up. In the first 10 trials after the arrest of TR, the average drift velocity was significantly larger than before TR(6.1 +/- 1.5 cm/sec, p < 0.01). Recovery to control values followed a roughly exponential time course, with 67% recovery occurring in the first 3.4 minutes after TR. Our results indicate that TR impairs the ability to sense and/or respond to fore-aft linear accelerations of the head following treadmill start-up in the absence of vision.
Collapse
Affiliation(s)
- N Paquet
- Aerospace Medical Research Unit, McGill University, Montreal, Quebec, Canada.
| | | | | |
Collapse
|
30
|
Abstract
We have demonstrated that lower limb extensor muscle response to tibial nerve stimulation is significantly facilitated by whole head-and-body tilt in the forward direction. Our aim was to examine whether this reflex interaction is influenced by age. Reflexes were elicited in lower limb muscles by electrical stimulation (ES) of the right tibial nerve. We compared reflexes during supported stance (ESalone) and sudden forward tilting of the whole head-and-body (Tilt+ES) between 10 healthy subjects aged 66 ± 4 years and 13 subjects aged 27 ± 3 years. In young subjects the area of response evoked in the ipsilateral vastus lateralis (iVL) was significantly increased by 74% during Tilt+ES as compared with ESalone (p < 0.05). Moreover, the latency of contralateral VL and soleus muscle responses (cVL and/or cSO) was significantly shorter by 61 ms during Tilt+ES than ESalone (p < 0.01). In contrast, older subjects showed no significant increase in the excitability of iVL muscle response and cVL and/or cSO muscle responses during Tilt+ES as compared with ESalone despite the application of similar intensity of ES and head acceleration as in young subjects. Our findings showed that the interaction between ES-evoked and tilt-evoked responses in lower limb extensor muscles is modified with age, which suggests modifications of sensorimotor integration involved in balance control.
Collapse
Affiliation(s)
- N Paquet
- School of Physical and Occupational Therapy, Faculty of Medicine, McGill University, 3654 Drummond street, Montreal, Québec, Canada H3G 1Y5.
| | | |
Collapse
|
31
|
Paquet N, Hui-Chan CW. Human soleus H-reflex excitability is decreased by dynamic head-and-body tilts. J Vestib Res 1999; 9:379-83. [PMID: 10544376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/14/2023]
Abstract
The modulation of soleus (SO) H-reflex excitability during dynamic whole head-and-body tilts (WHBT) was investigated in normal healthy subjects. Between 30 and 70 ms, and 151 and 190 ms after head acceleration onset, the H-reflex amplitude was smaller than during quiet standing by 7.6% (p < 0.01) and 15.4% (p = 0.06) respectively. This finding suggested that dynamic WHBT reduced the excitability of the predominantly monosynaptic stretch reflex are in the majority of the subjects studied.
Collapse
Affiliation(s)
- N Paquet
- School of Physical and Occupational Therapy, Faculty of Medicine, McGill University, Montreal, Québec, Canada.
| | | |
Collapse
|
32
|
Abstract
BACKGROUND Previous studies demonstrated that destabilizing responses to slow perturbations were enhanced in patients with Parkinson's disease (PD). Our objectives were to investigate the influence of PD on responses to faster whole head-and-body tilts in the standing position, and to establish whether any modification of tilt-evoked responses in PD patients was related to possible changes in the modulation of soleus (SO) H-reflex. METHODS Ten PD patients and 10 age-matched normal subjects assumed a standing position on an L-shaped tilting apparatus. Their head and shoulders were firmly attached to the back support of the apparatus, while their feet were fixated to the standing platform. With their vision occluded, the subjects's whole head-and-body was suddenly tilted forward to 20 degrees, at a peak head acceleration of 0.7 g +/- 0.1 g. Tilt-evoked responses were recorded from the lower limb muscles bilaterally. In addition, 40 H-reflexes were elicited in the SO muscle at 30-190 ms intervals after the onset of head acceleration. The M response amplitude was kept within +/- 15% of its control value. RESULTS PD patients demonstrated an abnormally high responsiveness to whole head-and-body tilts in comparison with age-matched normal subjects. This was shown by the significantly larger proportion of PD patients manifesting responses in the SO, biceps femoris and vastus lateralis muscles (p < 0.05), as well as their significantly larger SO response area (413%; p < 0.01). In contrast, the amplitude of the SO H-reflex was significantly increased by only 14% (p < 0.05) in these patients, and only at 30-70 ms after head acceleration onset. CONCLUSIONS The overexcitable tilt-evoked responses of PD patients could originate from a reduced ability to suppress responses when the body is supported. This enhanced excitability of tilt-evoked responses was probably not due to motoneuronal hyperexcitability or decreased presynaptic inhibition of the group Ia terminals involved in the mainly monosynaptic H-reflex pathway. Thus, we hypothesize that the control of spinal interneurons involved in the tilt-evoked responses may be defective in PD.
Collapse
Affiliation(s)
- N Paquet
- School of Physical and Occupational Therapy, Faculty of Medicine, McGill University, Montreal, Quebec, Canada
| | | |
Collapse
|
33
|
Abstract
We studied the interaction between muscle responses evoked in standing by electrical stimulation (ES) of the tibial nerve and dynamic tilts of the head-and-body in 13 young healthy subjects. Subjects were attached to an L-shaped tilting apparatus and underwent sudden forward tilting of their head-and-body as a whole, without ankle rotation. During such tilts, the area of response evoked in the ipsilateral vastus lateralis (iVL) muscle by the ES was significantly increased by 74% as compared to quiet supported stance (P = 0.01). The response latency of the contralateral VL and soleus muscles i.e. the crossed extension reflex, was significantly shorter during tilt (54 +/- 22 ms) than during quiet supported stance (115 +/- 13 ms, P < 0.01). The increased excitability of extensor muscles activated by ES during tilt seems appropriate to maintain stance during a forward perturbation of the body.
Collapse
Affiliation(s)
- N Paquet
- School of Physical and Occupational Therapy and Physiology Department, Faculty of Medicine, McGill University, Montreal, Québec, Canada
| | | |
Collapse
|
34
|
Abstract
The effects of body position on the electrically evoked flexion (FR) and crossed extension reflexes (CER) were investigated in humans. The FR area in the ipsilateral tibialis anterior muscle was significantly smaller during sitting than supported stance by 36% (P < 0.01). In contrast, the excitability of extensor muscles on both sides was enhanced in standing. For instance, twice as many subjects manifested a response in the ipsilateral vastus lateralis (VL) and the contralateral VL and/or soleus muscles (i.e. the CER) in standing than sitting. The FR and CER modulation observed seems to be dictated by the difference in functional demand between sitting and supported stance.
Collapse
Affiliation(s)
- N Paquet
- School of Physical and Occupational Therapy and Physiology Department, Faculty of Medicine, McGill University, Montreal, Québec, Canada
| | | | | |
Collapse
|
35
|
Paquet N, Verreault J, Lepage S, Bénard F. False-positive 201thallium study in Wolff-Parkinson-White syndrome. Can J Cardiol 1996; 12:499-502. [PMID: 8640596] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Wolff-Parkinson-White syndrome (WPW) is known to cause abnormal rest electrocardiogram and stress tests. Consequently, the diagnosis of coronary artery disease (CAD) may be difficult in patients with WPW. Previous reports have described false positive stress 201thallium studies in WPW, but the absence of CAD has rarely been confirmed by coronary angiography. A case of false positive stress 201thallium scintigraphy confirmed by angiography is presented. Left ventricular contractile asynchrony can explain the defects observed in myocardial perfusion scintigraphy. The importance of the defects relates to the length of the delta wave.
Collapse
Affiliation(s)
- N Paquet
- Department of Nuclear Medicine, Centre Hospitalier Universitaire de Sherbrooke, Québec
| | | | | | | |
Collapse
|
36
|
Falquet L, Paquet N, Frutiger S, Hughes GJ, Hoang-Van K, Jaton JC. cDNA cloning of a human 100 kDa de-ubiquitinating enzyme: the 100 kDa human de-ubiquitinase belongs to the ubiquitin C-terminal hydrolase family 2 (UCH2). FEBS Lett 1995; 376:233-7. [PMID: 7498549 DOI: 10.1016/0014-5793(95)01287-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The full length cDNA encoding a 100 kDa human de-ubiquitinating enzyme, referred to as de-ubiquitinase was obtained using one clone selected from a randomly sequenced human brain cDNA library and specific primers. The sequence of 18 peptides generated from the de-ubiquitinase isolated from out-dated human erythrocytes matched perfectly with the predicted amino acid sequence, which would encode a protein containing 858 amino acids (calculated M(r) = 95,743 Da). Homology search disclosed that the protein is a member of a large family of ubiquitin C-terminal hydrolases (UCH2), that was defined on the basis of the presence of two specific patterns, 'the Cys- and His-domains', which are likely to be involved in the de-ubiquitinating activity [7]. An additional conserved region, 'the aspartic acid domain', was also identified, the functional role of which is unknown.
Collapse
Affiliation(s)
- L Falquet
- Department of Medical Biochemistry, Faculty of Medicine, University of Geneva, Medical Center, Switzerland
| | | | | | | | | | | |
Collapse
|
37
|
Luu-The V, Dufort I, Paquet N, Reimnitz G, Labrie F. Structural characterization and expression of the human dehydroepiandrosterone sulfotransferase gene. DNA Cell Biol 1995; 14:511-8. [PMID: 7598806 DOI: 10.1089/dna.1995.14.511] [Citation(s) in RCA: 39] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023] Open
Abstract
Dehydroepiandrosterone sulfotransferase catalyzes the transformation of dehydroepiandrosterone to dehydroepiandrosterone sulfate, the most abundant steroid in circulation in the human and primate. Dehydroepiandrosterone sulfate serves as precursor for the formation of active androgens and estrogens in peripheral target tissues. In addition, blockade at the dehydroepiandrosterone level could give raise to high level of DHEA and thus disorders due to mild excess of androgen. Recently, the cDNA encoding dehydroepiandrosterone sulfotransferase has been isolated from a human liver cDNA library. To study the regulation and expression, as well as the possible defect linked to DHEA sulfotransferase gene, we have isolated and characterized its structure by screening a lambda EMBL3 library of human leukocyte genomic DNA using human dehydroepiandrosterone sulfotransferase cDNA as a probe. Sequencing of the gene shows that it is included in approximately 17 kb and contains six exons separated by five introns. Northern blot analysis shows a strong signal in the adrenals and liver, whereas no signal was detected in the spleen, thymus, prostate, testis, ovary, small intestine, colon, peripheral blood leukocytes, heart, brain, placenta, lung, skeletal muscle, kidney, or pancreas. Using primer extension analysis, the transcription start site is located at nucleotide 98 upstream from the ATG initiating codon. Putative TATA and CAAT boxes are situated at positions 72 and 96 upstream from the transcription start site, respectively. Using DNA from a panel of human/rodent somatic cell hybrids, and amplification of the gene by the polymerase chain reaction, the human dehydroepiandrosterone sulfotransferase gene has been assigned to chromosome 19.
Collapse
Affiliation(s)
- V Luu-The
- Medical Research Council Group in Molecular Endocrinology, CHUL Research Center, Quebec, Canada
| | | | | | | | | |
Collapse
|
38
|
Abstract
A tilting apparatus has been designed and constructed to produce fore-aft whole head-and-body tilt (WHBT) alone, or in combination with ankle dorsiflexion of standing subjects, about an axis colinear with the ankle joint. The apparatus is composed of a vertical tilting structure attached to a supporting base. Mechanical rotation of the vertical tilting structure is achieved by a spring activating system mounted on its base. Subjects are secured to the vertical structure by a body harness system with the head fixed, and the feet secured to the standing platform. Simultaneous dynamic WHBT and ankle joint displacement are induced by rotating the vertical support; whereas WHBT alone is achieved by concurrent rotation of both the vertical support and standing platform. Tilts are triggered manually, and data acquisition precedes head acceleration onset by 50-100 ms to provide suitable baseline values. This tilting apparatus has been successfully used to apply forward WHBT in 34 subjects with height ranging from 1.55 to 1.87 m and weights from 42 to 95 kg, and at magnitudes of peak head acceleration varying from 0.4 to 2.2 g as measured by a linear accelerometer mounted on a dental bite. These acceleration rates can be reproduced with minor variation in the same subjects. Moreover, the area under the head acceleration traces was reproducible within 15% between subjects. Tilts can be delivered with concomitant ankle dorsiflexion. These features make the low-cost tilting apparatus a very useful tool for the study of human tilting reactions in both laboratories and clinical settings.
Collapse
Affiliation(s)
- E A Lo Monaco
- School of Physical and Occupational Therapy, Faculty of Medicine, McGill University, Montreal, Canada
| | | | | |
Collapse
|
39
|
Lette J, Carini G, Tatum JL, Paquet N, Bisson G, Picard M, Bom HS, Lusa AM, Labanti G, Teitelbaum J. Safety of dipyridamole testing in patients with cerebrovascular disease. Am J Cardiol 1995; 75:535-7. [PMID: 7864009 DOI: 10.1016/s0002-9149(99)80602-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- J Lette
- Maisonneuve Hospital, Montreal Heart Institute, Canada
| | | | | | | | | | | | | | | | | | | |
Collapse
|
40
|
Falquet L, Paquet N, Frutiger S, Hughes GJ, Hoang-Van K, Jaton JC. A human de-ubiquitinating enzyme with both isopeptidase and peptidase activities in vitro. FEBS Lett 1995; 359:73-7. [PMID: 7851534 DOI: 10.1016/0014-5793(94)01451-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Some enzymatic and physicochemical properties of a human ubiquitin-specific isopeptidase are reported. The enzyme was purified to homogeneity from red blood cells and its specificity towards polymeric ubiquitin substrates suggests a de-ubiquitinating activity capable of cleaving 'head-to-tail' polyUb chains as well as isoamide 'branched' Ub dimers. KM values show a 10 fold preference for the cleavage of branched Ub dimers over head-to-tail Ub dimers. The enzymatic activity can be strongly inhibited by various peptides containing either of the cleavage site sequences found in Ub polymers, but not by unrelated peptides. The enzyme is monomeric under reducing conditions and exhibits a globular shape with an average diameter of 9 nm, an S20,w value of 5.2 S and a molar mass of 110 kDa +/- 10%. Because the enzyme cleaves both peptide-linked and isopeptide-linked Ub moieties from substrates, we propose to name it de-ubiquitinase rather than isopeptidase.
Collapse
Affiliation(s)
- L Falquet
- Department of Medical Biochemistry, Faculty of Medicine, University of Geneva, Switzerland
| | | | | | | | | | | |
Collapse
|
41
|
Tissot JD, Schifferli JA, Hochstrasser DF, Pasquali C, Spertini F, Clément F, Frutiger S, Paquet N, Hughes GJ, Schneider P. Two-dimensional polyacrylamide gel electrophoresis analysis of cryoglobulins and identification of an IgM-associated peptide. J Immunol Methods 1994; 173:63-75. [PMID: 8034987 DOI: 10.1016/0022-1759(94)90284-4] [Citation(s) in RCA: 58] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The clonality of immunoglobulins (Igs) in cryoprecipitates (n = 41) was studied by two-dimensional polyacrylamide gel electrophoresis (2-D PAGE). Our series included 24 cryoglobulins characterized by immunofixation electrophoresis (IF), 12 'trace amount' cryoglobulins, defined by a protein content in the precipitate of less than 0.05 mg/ml of serum, and five cryoglobulins of undetermined protein composition by IF. 2-D PAGE analysis showed polyclonal IgG associated either with monoclonal Igs (type II cryoglobulins; n = 14) or with polyclonal IgM (type III cryoglobulins; n = 14). In ten cryoprecipitates (two 'trace amount' cryoglobulins as well as seven of 19 type II and as one of five type III cryoglobulins by IF) polyclonal IgG were associated with a mixture of polyclonal and monoclonal IgM. These cryoglobulins were tentatively named type II-III cryoglobulins. A monoclonal IgM was observed in one cryoprecipitate (type I cryoglobulins). Two cryoglobulins presented unexpected 2-D patterns, characterized by the presence of oligoclonal IgM, with trace amounts of Igs of different isotypes (tentatively named type II-III(variant) cryoglobulins). A peptide of 44 kDa with a pI of 5.45 was observed in all cryoglobulins containing IgM (n = 40). This peptide was also present in purified monoclonal or polyclonal IgM fractions. N-terminal microsequencing (12 amino acid residues) revealed that this IgM-associated peptide was an unknown protein. Our results highlight the role of 2-D PAGE as an aid in the analysis of cryoglobulins.
Collapse
Affiliation(s)
- J D Tissot
- Fondation Centre de Transfusion Sanguine de la Croix-Rouge suisse, Lausanne, Switzerland
| | | | | | | | | | | | | | | | | | | |
Collapse
|
42
|
Abstract
Profiles of hip-spine movement interaction and muscle activations were characterized in 10 low back pain patients and in 10 normal subjects during trunk forward bending and extension. Electrogoniometric recordings showed that patients performed the movements significantly more slowly than normal subjects when asked to choose a comfortable cadence. For movements performed at the same velocity and amplitude, only the movement profiles at the spine and activation patterns of the erector spinae (ES) muscle during flexion were found to be significantly different between the two groups. A detailed analysis revealed that a subgroup of six patients (SG2) with an abnormal hip-spine movement interaction showed a significant (P < 0.01) lack of relaxation in ES muscle at the end of flexion. Patients from SG2 had pain for a longer time (P < 0.01) compared to patients from SG1 with normal movement and electromyographic profiles. Given the small sample size, these results are not conclusive, but they suggest that the lack of relaxation of the ES muscle may be associated with perturbation of movement patterns and the duration of the symptoms.
Collapse
Affiliation(s)
- N Paquet
- Department of Physiotherapy, Faculty of Medicine, Laval University, Quebec City, P.Q., Canada
| | | | | |
Collapse
|
43
|
Bjellqvist B, Sanchez JC, Pasquali C, Ravier F, Paquet N, Frutiger S, Hughes GJ, Hochstrasser D. Micropreparative two-dimensional electrophoresis allowing the separation of samples containing milligram amounts of proteins. Electrophoresis 1993; 14:1375-8. [PMID: 8137805 DOI: 10.1002/elps.11501401212] [Citation(s) in RCA: 151] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
We describe some simple modifications to the micropreparative two-dimensional (2-D) electrophoresis procedure using immobilized pH gradients in the first dimension and sodium dodecyl sulfate-electrophoresis in the second dimension. The geometry of the immobilized pH gradient strips has been changed to allow the use of large sample application cups that can accommodate greater sample volumes. The use of narrow range immobilized pH gradients with a large sample loading volume allows an efficient resolubilization of polypeptides after the first dimension. As a result, the vertical streaking caused by too high a protein concentration is eliminated in the second dimension. Protein identification by N-terminal sequencing is facilitated by the large protein load (1-15 mg) which can be employed using this modification. Spots not normally detectable on conventional analytical 2-D maps, even with sensitive silver staining, are observed. Results for plasma and liver proteins are shown.
Collapse
Affiliation(s)
- B Bjellqvist
- Department of Medicine and Biochemistry, University of Geneva, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
44
|
Hughes GJ, Frutiger S, Paquet N, Pasquali C, Sanchez JC, Tissot JD, Bairoch A, Appel RD, Hochstrasser DF. Human liver protein map: update 1993. Electrophoresis 1993; 14:1216-22. [PMID: 8313870 DOI: 10.1002/elps.11501401181] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This publication updates the reference human liver protein map. By microsequencing, 27 spots or 34 polypeptide chains were identified. The most abundant polypeptides detected on the silver stained liver map were key elements in major hepatic biochemical pathways. The new polypeptides and previously known proteins are listed in a table and/or labeled on the protein map, thus providing the 1993 reference human liver SWISS-2DPAGE database. SWISS-2DPAGE and the SWISS-PROT protein sequence databases are closely linked together through the use of common accession numbers.
Collapse
Affiliation(s)
- G J Hughes
- Medical Biochemistry Department, Geneva University
| | | | | | | | | | | | | | | | | |
Collapse
|
45
|
Golaz O, Hughes GJ, Frutiger S, Paquet N, Bairoch A, Pasquali C, Sanchez JC, Tissot JD, Appel RD, Walzer C. Plasma and red blood cell protein maps: update 1993. Electrophoresis 1993; 14:1223-31. [PMID: 8313871 DOI: 10.1002/elps.11501401183] [Citation(s) in RCA: 109] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
This publication updates the reference plasma and red blood cell protein maps obtained with immobilized pH gradients. Seventeen polypeptide spots or chains were partially characterized by direct N-terminal sequencing or by sequencing of peptides obtained from enzymatic digestion. Additional new polypeptides and previously known proteins are listed in a table and/or labeled on the protein maps, thus providing the 1993 update of the human plasma and red blood cell two-dimensional gel SWISS-2DPAGE database. SWISS-2DPAGE and the SWISS-PROT protein sequence databases are closely linked together through the use of common accession numbers.
Collapse
Affiliation(s)
- O Golaz
- Medicine Department, Geneva University
| | | | | | | | | | | | | | | | | | | |
Collapse
|
46
|
Bjellqvist B, Hughes GJ, Pasquali C, Paquet N, Ravier F, Sanchez JC, Frutiger S, Hochstrasser D. The focusing positions of polypeptides in immobilized pH gradients can be predicted from their amino acid sequences. Electrophoresis 1993; 14:1023-31. [PMID: 8125050 DOI: 10.1002/elps.11501401163] [Citation(s) in RCA: 694] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
The focusing positions in narrow range immobilized pH gradients of 29 polypeptides of known amino acid sequence were determined under denaturing conditions. The isoelectric points of the proteins calculated from their amino acid sequences matched with good accuracy the experimentally determined pI values. We show the advantages of being able to predict the position of a protein of known structure within a two-dimensional gel.
Collapse
Affiliation(s)
- B Bjellqvist
- Department of Medicine, University of Geneva, Switzerland
| | | | | | | | | | | | | | | |
Collapse
|
47
|
Michéa-Hamzehpour M, Sanchez JC, Epp SF, Paquet N, Hughes GJ, Hochstrasser D, Pechère JC. Two-dimensional polyacrylamide gel electrophoresis isolation and microsequencing of Pseudomonas aeruginosa proteins. Enzyme Protein 1993; 47:1-8. [PMID: 8012497 DOI: 10.1159/000468649] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Outer membrane (OM) proteins of beta-lactam-susceptible and -resistant strains of Pseudomonas aeruginosa were analyzed by 2-D polyacrylamide gel electrophoresis. Carrier ampholytes, pH 4-8, and immobilized pH gradient (IPG), pH 3.5-10.0, procedures were used. An acidic-protein spot (pI = 5.2) detected in susceptible but not in an imipenem-resistant strain was sequenced and twenty-five N-terminal amino acids had total homology with the OM protein D, the imipenem-specific porin of P. aeruginosa. A basic-protein spot (pI = 9.0) detected in ceftazidime-resistant, but not in a susceptible strain was sequenced and fourteen N-terminal amino acids had homology with a beta-lactamase encoded by the ampC gene of P. aeruginosa. The IPG procedure allows identification of more than one hundred proteins of the OM fraction from a single gel. Detection of beta-lactamase in OM fractions might reflect a periplasmic contamination, but its anchorage within the OM cannot be ruled out.
Collapse
Affiliation(s)
- M Michéa-Hamzehpour
- Département de Génétique et Microbiologie, Centre Médical Universitaire, Genève, Suisse
| | | | | | | | | | | | | |
Collapse
|
48
|
Frutiger S, Hughes GJ, Paquet N, Lüthy R, Jaton JC. Disulfide bond assignment in human J chain and its covalent pairing with immunoglobulin M. Biochemistry 1992; 31:12643-7. [PMID: 1472500 DOI: 10.1021/bi00165a014] [Citation(s) in RCA: 55] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The assignment of disulfide bonds in human J chain and its covalent pairing with immunoglobulin M was determined under conditions which minimize disulfide bond interchange. We show that in J chain the three intradisulfide bridges are formed between Cys 12 and 100, Cys 71 and 91, and Cys 108 and 133. Previous reports [reviewed by Koshland, M. E. (1985) Annu. Rev. Immunol. 3, 425-453] have proposed that cysteines 12, 14, or 68 were linked to the penultimate cysteine 575 of two mu chain tails. In this work, we demonstrate that cysteines 14 and 68 are disulfide-bridged to mu chains. A revised, albeit putative, model of J chain folding is presented which takes into account the correct disulfide pairing and the predictive secondary structure assignment.
Collapse
Affiliation(s)
- S Frutiger
- Department of Medical Biochemistry, University of Geneva Medical Center, Switzerland
| | | | | | | | | |
Collapse
|
49
|
Hochstrasser DF, Frutiger S, Paquet N, Bairoch A, Ravier F, Pasquali C, Sanchez JC, Tissot JD, Bjellqvist B, Vargas R. Human liver protein map: a reference database established by microsequencing and gel comparison. Electrophoresis 1992; 13:992-1001. [PMID: 1286669 DOI: 10.1002/elps.11501301201] [Citation(s) in RCA: 113] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
This publication establishes a reference human liver protein map obtained with immobilized pH gradients. By microsequencing, 57 spots or 42 polypeptide chains were identified. By protein map comparison and matching (liver, red blood cell and plasma sample maps), 8 additional proteins were identified. The new polypeptides and previously known proteins are listed in a table and/or labeled on the protein map, thus providing a human liver two-dimensional gel database. This reference map can be used to identify protein spots on other samples such as rectal cancer biopsies.
Collapse
|
50
|
Toussi A, Paquet N, Huber O, Frutiger S, Tissot JD, Hughes GJ, Hochstrasser DF. Polypeptide marker and disease patterns found while mapping proteins in ascitis. J Chromatogr 1992; 582:87-92. [PMID: 1491063 DOI: 10.1016/0378-4347(92)80306-b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
To assess the protein composition of ascitis, 28 samples of ascitic fluid were obtained from patients admitted to Geneva University Hospital. The samples were analysed randomly and blindly by high-resolution two-dimensional polyacrylamide gel electrophoresis. The final visual evaluation was compared with the discharged summary and diagnosis. The protein pattern of ascitis was, as expected, very similar to normal or diseased plasma, with the exception of two spots which were present in ascitic fluids but not in the 200 plasma samples analyzed in parallel. After microsequencing, they proved to be beta-fibrinogen fragments. Several diseases showed distinct patterns, especially acute pancreatitis. A group of intense spots with an apparent molecular mass between those of alpha 1-antitrypsin and beta-haptoglobin were found in all ascitic fluid from pancreatitis cases (six patients). These spots had isoelectric points similar to those of alpha 1-antitrypsin and beta-haptoglobin and microsequencing revealed that they were three different fragments of alpha 1-antitrypsin.
Collapse
Affiliation(s)
- A Toussi
- Medicine Department, Geneva University Hospital, Switzerland
| | | | | | | | | | | | | |
Collapse
|