1
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Palomino-Vizcaino G, Schuth N, Domínguez-Calva JA, Rodríguez-Meza O, Martínez-Jurado E, Serebryany E, King JA, Kroll T, Costas M, Quintanar L. Copper Reductase Activity and Free Radical Chemistry by Cataract-Associated Human Lens γ-Crystallins. J Am Chem Soc 2023; 145:6781-6797. [PMID: 36918380 DOI: 10.1021/jacs.2c13397] [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: 03/16/2023]
Abstract
Cataracts are caused by high-molecular-weight aggregates of human eye lens proteins that scatter light, causing lens opacity. Metal ions have emerged as important potential players in the etiology of cataract disease, as human lens γ-crystallins are susceptible to metal-induced aggregation. Here, the interaction of Cu2+ ions with γD-, γC-, and γS-crystallins, the three most abundant γ-crystallins in the lens, has been evaluated. Cu2+ ions induced non-amyloid aggregation in all three proteins. Solution turbidimetry, sodium dodecyl sulfate poly(acrylamide) gel electrophoresis (SDS-PAGE), circular dichroism, and differential scanning calorimetry showed that the mechanism for Cu-induced aggregation involves: (i) loss of β-sheet structure in the N-terminal domain; (ii) decreased thermal and kinetic stability; (iii) formation of metal-bridged species; and (iv) formation of disulfide-bridged dimers. Isothermal titration calorimetry (ITC) revealed distinct Cu2+ binding affinities in the γ-crystallins. Electron paramagnetic resonance (EPR) revealed two distinct Cu2+ binding sites in each protein. Spin quantitation demonstrated the reduction of γ-crystallin-bound Cu2+ ions to Cu+ under aerobic conditions, while X-ray absorption spectroscopy (XAS) confirmed the presence of linear or trigonal Cu+ binding sites in γ-crystallins. Our EPR and XAS studies revealed that γ-crystallins' Cu2+ reductase activity yields a protein-based free radical that is likely a Tyr-based species in human γD-crystallin. This unique free radical chemistry carried out by distinct redox-active Cu sites in human lens γ-crystallins likely contributes to the mechanism of copper-induced aggregation. In the context of an aging human lens, γ-crystallins could act not only as structural proteins but also as key players for metal and redox homeostasis.
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Affiliation(s)
- Giovanni Palomino-Vizcaino
- Department of Chemistry, Centro de Investigación y de Estudios Avanzados (Cinvestav), Mexico City 07360, Mexico
| | - Nils Schuth
- Department of Chemistry, Centro de Investigación y de Estudios Avanzados (Cinvestav), Mexico City 07360, Mexico
| | - José A Domínguez-Calva
- Department of Chemistry, Centro de Investigación y de Estudios Avanzados (Cinvestav), Mexico City 07360, Mexico
| | - Oscar Rodríguez-Meza
- Laboratorio de Biofisicoquímica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico
| | - Eduardo Martínez-Jurado
- Department of Chemistry, Centro de Investigación y de Estudios Avanzados (Cinvestav), Mexico City 07360, Mexico
| | - Eugene Serebryany
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02142, United States
| | - Thomas Kroll
- Stanford Synchrotron Radiation Lightsource (SSRL), SLAC National Accelerator Laboratory, Menlo Park, California 94025, United States
| | - Miguel Costas
- Laboratorio de Biofisicoquímica, Facultad de Química, Universidad Nacional Autónoma de México (UNAM), Mexico City 04510, Mexico
| | - Liliana Quintanar
- Department of Chemistry, Centro de Investigación y de Estudios Avanzados (Cinvestav), Mexico City 07360, Mexico
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2
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Abstract
CFTR modulators have dramatically changed the clinical course of CF in those fortunate enough to receive them. Inevitably, randomised controlled trials during the development of these drugs are too short to use mortality as an outcome. Evidence for their effect on life expectancy are best gained from real world registry studies specifically looking at mortality, but these are only available for ivacaftor to date. Therefore, indirect evidence must be obtained by looking at outcomes known to affect mortality and seeing the effect of these drugs on those outcomes.
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Affiliation(s)
- I M Balfour-Lynn
- Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, UK.
| | - J A King
- Department of Paediatric Respiratory Medicine, Royal Brompton Hospital, London, UK
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3
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Iannuzzi J, Leong JH, Quan J, King JA, Windsor JW, Tanyingoh D, Coward S, Forbes N, Heitman S, Buie M, Underwood F, Kaplan GG. A246 THE GLOBAL INCIDENCE OF ACUTE PANCREATITIS IS INCREASING OVER TIME: A SYSTEMATIC REVIEW AND META-ANALYSIS. J Can Assoc Gastroenterol 2021. [DOI: 10.1093/jcag/gwab002.244] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Acute pancreatitis is a common disease with significant associated morbidity and mortality. Historically, acute pancreatitis has been considered a disease with multiple etiologies and risk factors but is driven by alcohol and biliary disease. Multiple studies have shown that the incidence of acute pancreatitis is increasing globally among both adults and children.
Aims
The purpose of this study was to assess temporal trends in incidence of acute pancreatitis globally.
Methods
We performed a systematic literature search to identify population-based studies reporting the annual incidence of acute pancreatitis. Abstracts were independently assessed in duplicate to identify applicable papers for full-text review and data extraction. Joinpoint temporal trend analyses were performed to calculate the average annual percent change (AAPC) with 95% confidence intervals (CI). The AAPCs were pooled in a meta-analysis to capture the overall and regional trends in acute pancreatitis incidence over time. Temporal data were summarized in a static map and an interactive, web-based map to illustrate global differences.
Results
Forty-five studies reported the temporal incidence of acute pancreatitis (static map provided, online interactive map: https://kaplan-acute-pancreatitis-ucalgary.hub.arcgis.com/). The incidence of acute pancreatitis has increased from 1961 to 2016 (AAPC = 2.89%; 95% CI: 2.26, 3.52; n=41). Increasing incidence was observed in North America (AAPC = 2.71%; 95% CI: 1.93, 3.50; n=10) and Europe (AAPC = 2.79%; 95% CI: 1.95, 3.63; n=24). The incidence of acute pancreatitis was stable in Asia (AAPC = −0.28%; 95% CI: −5.03, 4.47; n=2).
Conclusions
This meta-analysis provides a comprehensive overview of the global incidence of acute pancreatitis over the last five decades and demonstrates a steadily rising incidence over time in most countries of the Western world. More studies are needed to better define the changing incidence of acute pancreatitis in Asia, Africa and Latin America.
Funding Agencies
None
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Affiliation(s)
- J Iannuzzi
- University of Calgary, Calgary, AB, Canada
| | - J H Leong
- University of Calgary, Calgary, AB, Canada
| | - J Quan
- University of Calgary, Calgary, AB, Canada
| | - J A King
- University of Calgary, Calgary, AB, Canada
| | - J W Windsor
- Medicine, University of Calgary, Calgary, AB, Canada
| | | | - S Coward
- University of Calgary, Calgary, AB, Canada
| | - N Forbes
- University of Calgary, Calgary, AB, Canada
| | - S Heitman
- University of Calgary, Calgary, AB, Canada
| | - M Buie
- University of Calgary, Calgary, AB, Canada
| | | | - G G Kaplan
- Medicine and Community Health Sciences, University of Calgary, Calgary, AB, Canada
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4
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Hartescu I, Morgan K, Stensel DJ, Thackray AE, King JA. 0539 Are Short Sleepers Uncoupled Sleepers? Sleep 2020. [DOI: 10.1093/sleep/zsaa056.536] [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: 11/14/2022] Open
Abstract
Abstract
Introduction
While short sleep durations (<7h/night) are associated with increased diabetes risk, there is limited evidence that increasing the habitual sleep duration of short sleepers is either feasible, or will reliably improve metabolic health outcomes. Furthermore, in the absence of insomnia disorder, it remains unclear whether habitual short sleep mainly reflects a genetic predisposition or a lifestyle choice. In a randomized controlled study we delivered a sleep extension protocol based on CBTi principles to overweight ‘short sleepers’ at increased risk of Type II diabetes.
Methods
18 male short sleepers (Mage=41.4; MBMI=29.57; baseline mean TST=5.8 h/ night) with no complaints of insomnia were randomized to the sleep extension intervention or control condition (printed sleep hygiene advice). The 6-week intervention commenced with personalized sleep re-scheduling negotiated in a 60-minute 1-to-1 session, and supported by elements of sleep hygiene, stimulus control, relaxation and cognitive strategies. Outcomes included sleep duration (actigraphy), fasting insulin, Mean Amplitude of Glycemic Excursions (MAGE) from continuous glucose monitoring, and blood pressure. Data were analyzed in linear fixed effects models including time, group and baselines values.
Results
Adherence to the 6-week protocol was high. Relative to controls (n=8), intervention participants (n = 10) showed a significant increase in TST (95%CI 46.91min, 101.64min, p<0.001; MDiff = 79.4min, p<0.001) and significant reductions in fasting insulin (95%CI -32.08 pmol/L, -.97.0 pmol/L; p=0.04; MDiff = -10.2 pmol/L, p=0.06); MAGE (95%CI -0.77, -0.08, p=0.02; MDiff -0.35, p=0.05) and diastolic (95%CI -22, -5, p=0.004; MDiff=-12, p=0.004); and systolic blood pressure (95%CI -20, -2, p=0.03; MDiff=-10, p=0.006).
Conclusion
CBTi-based sleep extension protocols offer feasible and effective lifestyle interventions in the management of metabolic health in overweight short sleepers who fit published categorization of non-complaining poor sleepers with an undeveloped insomnia identity whose subjective sleep experience and objective sleep characteristics are ‘uncoupled’.
Support
School of Sport, Exercise and Health Sciences, Loughborough University
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Affiliation(s)
- I Hartescu
- Loughborough University, Loughborough, UNITED KINGDOM
| | - K Morgan
- Loughborough University, Loughborough, UNITED KINGDOM
| | - D J Stensel
- Loughborough University, Loughborough, UNITED KINGDOM
| | - A E Thackray
- Loughborough University, Loughborough, UNITED KINGDOM
| | - J A King
- Loughborough University, Loughborough, UNITED KINGDOM
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5
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Obayemi JD, Salifu AA, Eluu SC, Uzonwanne VO, Jusu SM, Nwazojie CC, Onyekanne CE, Ojelabi O, Payne L, Moore CM, King JA, Soboyejo WO. LHRH-Conjugated Drugs as Targeted Therapeutic Agents for the Specific Targeting and Localized Treatment of Triple Negative Breast Cancer. Sci Rep 2020; 10:8212. [PMID: 32427904 PMCID: PMC7237454 DOI: 10.1038/s41598-020-64979-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [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: 04/24/2019] [Accepted: 04/22/2020] [Indexed: 02/07/2023] Open
Abstract
Bulk chemotherapy and drug release strategies for cancer treatment have been associated with lack of specificity and high drug concentrations that often result in toxic side effects. This work presents the results of an experimental study of cancer drugs (prodigiosin or paclitaxel) conjugated to Luteinizing Hormone-Releasing Hormone (LHRH) for the specific targeting and treatment of triple negative breast cancer (TNBC). Injections of LHRH-conjugated drugs (LHRH-prodigiosin or LHRH-paclitaxel) into groups of 4-week-old athymic female nude mice (induced with subcutaneous triple negative xenograft breast tumors) were found to specifically target, eliminate or shrink tumors at early, mid and late stages without any apparent cytotoxicity, as revealed by in vivo toxicity and ex vivo histopathological tests. Our results show that overexpressed LHRH receptors serve as binding sites on the breast cancer cells/tumor and the LHRH-conjugated drugs inhibited the growth of breast cells/tumor in in vitro and in vivo experiments. The inhibitions are attributed to the respective adhesive interactions between LHRH molecular recognition units on the prodigiosin (PGS) and paclitaxel (PTX) drugs and overexpressed LHRH receptors on the breast cancer cells and tumors. The implications of the results are discussed for the development of ligand-conjugated drugs for the specific targeting and treatment of TNBC.
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Affiliation(s)
- J D Obayemi
- Department of Mechanical Engineering, Higgins Lab, 100 Institute Road, Worcester Polytechnic Institute (WPI), Worcester, MA, 01609, USA.,Department of Biomedical Engineering, Gateway Park Life Sciences Center, 60 Prescott Street, Worcester Polytechnic Institute (WPI), Worcester, MA, 01605, USA
| | - A A Salifu
- Department of Mechanical Engineering, Higgins Lab, 100 Institute Road, Worcester Polytechnic Institute (WPI), Worcester, MA, 01609, USA
| | - S C Eluu
- Department of Pharmaceutical Microbiology and Biotechnology, Nnamdi Azikiwe University, 420110, Ifite Awka, Anambra State, Nigeria
| | - V O Uzonwanne
- Department of Mechanical Engineering, Higgins Lab, 100 Institute Road, Worcester Polytechnic Institute (WPI), Worcester, MA, 01609, USA
| | - S M Jusu
- Department of Material Science, African University of Science and Technology, Km 10 Airport Road, Abuja, Nigeria
| | - C C Nwazojie
- Department of Material Science, African University of Science and Technology, Km 10 Airport Road, Abuja, Nigeria
| | - C E Onyekanne
- Department of Material Science, African University of Science and Technology, Km 10 Airport Road, Abuja, Nigeria
| | - O Ojelabi
- RNA Therapeutics Institute, University of Massachusetts Medical School, 368 Plantation Street, Worcester, MA, 01605, USA
| | - L Payne
- Department of Psychiatry, Center for Comparative NeuroImaging, University of Massachusetts Medical School, 303 Belmont Street, Worcester, MA, 01604, USA
| | - C M Moore
- Department of Psychiatry, Center for Comparative NeuroImaging, University of Massachusetts Medical School, 303 Belmont Street, Worcester, MA, 01604, USA
| | - J A King
- Department of Psychiatry, Center for Comparative NeuroImaging, University of Massachusetts Medical School, 303 Belmont Street, Worcester, MA, 01604, USA.,Department of Biology & Biotechnology, Gateway Park Life Sciences Center, 60 Prescott Street (Gateway Park I), Worcester Polytechnic Institute (WPI), Worcester, MA, 01605, USA
| | - W O Soboyejo
- Department of Mechanical Engineering, Higgins Lab, 100 Institute Road, Worcester Polytechnic Institute (WPI), Worcester, MA, 01609, USA. .,Department of Biomedical Engineering, Gateway Park Life Sciences Center, 60 Prescott Street, Worcester Polytechnic Institute (WPI), Worcester, MA, 01605, USA.
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6
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Windsor JW, Buie M, Coward S, Gearry R, Hansen T, King JA, Kotze P, Ma C, Ng S, Panaccione N, Panaccione R, Quan J, Seow C, Underwood F, Kaplan GG. A28 RELATIVE RATES OF ULCERATIVE COLITIS TO CROHN’S DISEASE: PARALLEL EPIDEMIOLOGIES IN NEWLY VS. HIGHLY INDUSTRIALIZED COUNTRIES. J Can Assoc Gastroenterol 2020. [DOI: 10.1093/jcag/gwz047.027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Abstract
Background
Inflammatory bowel disease (IBD) first presents in a population as cases of ulcerative colitis (UC) followed by cases of Crohn’s disease (CD). Newly industrialized countries (NIC) show a prallel epidemiology of IBD to highly industrialized countries (HIC) in the previous century; one marker of this is the relative incidence/prevalence rates of UC to CD, which approximates 1 over time.
Aims
Provide evidence for the UC:CD ratio as a proxy for disease penatrance in a population.
Methods
Systematic review of MedLine and Embase for studies reporting incidence or prevalence of UC and CD. Log-linear regression (by region and NIC/HIC [2019 United Nations definitions]) was used to calculate average annual percent change (AAPC) and associated 95% confidence intervals (CI). Data were plotted on an online, interactive map to show trends (link provided).
Results
We extracted data from 218 studies compising population-level data from 69 countries. We found negative AAPCs as the prevalence ratio of UC:CD significantly decreased over time in East Asia, West Asia, North Europe, and South Europe; 6/12 global regions displayed significantly decreasing incidence ratios. No AAPC was found to be significantly increasing (Table 1). When examing HIC/NIC, we found a significant effect of NIC on the UC:CD prevalence ratio after 2000 (AAPC:−3.83;95%CI:−6.28,−1.31) while HIC regions remained stable (AAPC:2.14;95%CI:−1.40,5.82). Looking at all available data, both HICs and NICs show significantly decreasing UC:CD prevalence ratios (HIC:AAPC:−3.72;95% CI:−4.46,−2.97; NIC:AAPC:−2.62;95%CI:−4.13,−1.08).
Conclusions
In some HICs (eg. Canada), the UC:CD incidence ratio was <1 in the earliest available data (1966), explaining the stable AAPC in North America (AAPC:−0.24;95%CI:−1.12,0.65). However, in NICs (eg. Southern Asia), the AAPC is rapidly decreasing (AAPC:−24.68;95%CI:−37.85,−8.71) as areas like Sri Lanka rapidly fall from an incidence ratio of 7.5 (2007) to 2.8 (2012), mimicking trends in IBD epidimeology of HICs in the previous century.
Funding Agencies
None
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Affiliation(s)
- J W Windsor
- Medicine, University of Calgary, Calgary, AB, Canada
| | - M Buie
- Medicine, University of Calgary, Calgary, AB, Canada
| | - S Coward
- University of Calgary, Calgary, AB, Canada
| | - R Gearry
- University of Otago, Christchurch, New Zealand
| | - T Hansen
- Medicine, University of Calgary, Calgary, AB, Canada
| | - J A King
- University of Calgary, Calgary, AB, Canada
| | - P Kotze
- Catholic University of Paraná, Curitiba, Brazil
| | - C Ma
- University of Calgary, Calgary, AB, Canada
| | - S Ng
- Chinese University of Hong Kong, Sha Tin, Hong Kong
| | - N Panaccione
- Medicine, University of Calgary, Calgary, AB, Canada
| | | | - J Quan
- Medicine, University of Calgary, Calgary, AB, Canada
| | - C Seow
- Medicine, University of Calgary, Calgary, AB, Canada
| | - F Underwood
- Medicine, University of Calgary, Calgary, AB, Canada
| | - G G Kaplan
- Medicine and Community Health Sciences, University of Calgary, Calgary, AB, Canada
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7
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Sergeeva OA, Haase-Pettingell C, King JA. Co-expression of CCT subunits hints at TRiC assembly. Cell Stress Chaperones 2019; 24:1055-1065. [PMID: 31410727 PMCID: PMC6882961 DOI: 10.1007/s12192-019-01028-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Revised: 07/05/2019] [Accepted: 07/31/2019] [Indexed: 12/18/2022] Open
Abstract
The eukaryotic cytosolic chaperonin, t-complex polypeptide 1 (TCP-1) ring complex or TRiC, is responsible for folding a tenth of the proteins in the cell. TRiC is a double-ringed barrel with each ring composed of eight different CCT (chaperonin containing TCP-1) subunits. In order for the subunits to assemble together into mature TRiC, which is believed to contain one and only one of each of these subunits per ring, they must be translated from different chromosomes, correctly folded and assembled. When expressed alone in Escherichia coli, the subunits CCT4 and CCT5, interestingly, form TRiC-like homo-oligomeric rings. To explore potential subunit-subunit interactions, we co-expressed these homo-oligomerizing CCT4 and CCT5 subunits or the archaeal chaperonin Mm-Cpn (Methanococcus maripaludis chaperonin) with CCT1-8, one at a time. We found that CCT5 shifted all of the CCT subunits, with the exception of CCT6, into double-barrel TRiC-like complexes, while CCT4 only interacted with CCT5 and CCT8 to form chaperonin rings. We hypothesize that these specific interactions may be due to the formation of hetero-oligomers in E. coli, although more work is needed for validation. We also observed the interaction of CCT5 and Mm-Cpn with smaller fragments of the CCT subunits, confirming their intrinsic chaperone activity. Based on this hetero-oligomer data, we propose that TRiC assembly relies on subunit exchange with some stable homo-oligomers, possibly CCT5, as base assembly units. Eventually, analysis of CCT arrangement in various tissues and at different developmental times is anticipated to provide additional insight on TRiC assembly and CCT subunit composition.
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Affiliation(s)
- Oksana A. Sergeeva
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA USA
- Global Health Institute, School of Life Sciences, EPFL, Lausanne, Switzerland
| | - Cameron Haase-Pettingell
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA USA
- Computer Science and Artificial Intelligence (CSAIL), Massachusetts Institute of Technology, Cambridge, MA USA
| | - Jonathan A. King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA USA
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8
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Mills-Henry IA, Thol SL, Kosinski-Collins MS, Serebryany E, King JA. Kinetic Stability of Long-Lived Human Lens γ-Crystallins and Their Isolated Double Greek Key Domains. Biophys J 2019; 117:269-280. [PMID: 31266635 DOI: 10.1016/j.bpj.2019.06.006] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2018] [Revised: 05/25/2019] [Accepted: 06/05/2019] [Indexed: 12/17/2022] Open
Abstract
The γ-crystallins of the eye lens nucleus are among the longest-lived proteins in the human body. Synthesized in utero, they must remain folded and soluble throughout adulthood to maintain lens transparency and avoid cataracts. γD- and γS-crystallin are two major monomeric crystallins of the human lens. γD-crystallin is concentrated in the oldest lens fiber cells, the lens nucleus, whereas γS-crystallin is concentrated in the younger cells of the lens cortex. The kinetic stability parameters of these two-domain proteins and their isolated domains were determined and compared. Kinetic unfolding experiments monitored by fluorescence spectroscopy in varying concentrations of guanidinium chloride were used to extrapolate unfolding rate constants and half-lives of the crystallins in the absence of the denaturant. Consistent with their long lifespans in the lens, extrapolated half-lives for the initial unfolding step were on the timescale of years. Both proteins' isolated N-terminal domains were less kinetically stable than their respective C-terminal domains at denaturant concentrations predicted to disrupt the domain interface, but at low denaturant concentrations, the relative kinetic stabilities were reversed. Cataract-associated aggregation has been shown to proceed from partially unfolded intermediates in these proteins; their extreme kinetic stability likely evolved to protect the lens from the initiation of aggregation reactions. Our findings indicate that the domain interface is the source of significant kinetic stability. The gene duplication and fusion event that produced the modern two-domain architecture of vertebrate lens crystallins may be the origin of their high kinetic as well as thermodynamic stability.
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Affiliation(s)
- Ishara A Mills-Henry
- Department of Chemistry and Food Science, Framingham State University, Framingham, Massachusetts
| | | | | | - Eugene Serebryany
- Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts.
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
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9
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Gallagher JM, Nephew BC, Poirier G, King JA, Bridges RS. Estrogen receptor-alpha knockouts and maternal memory in nulliparous rats. Horm Behav 2019; 110:40-45. [PMID: 30822411 DOI: 10.1016/j.yhbeh.2019.02.002] [Citation(s) in RCA: 4] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 01/29/2019] [Accepted: 02/07/2019] [Indexed: 11/17/2022]
Abstract
The current study investigated the role of estrogen receptor alpha (Esr1) in maternal memory in rats, comparing the induction and retention responses of Esr1 knockout (KO) and wild type (WT) nulliparous rats towards foster pups. Thirty days after completion of induction testing, subjects were tested for the retention of maternal care in their home cage and then for maternal behaviors in a novel cage. Both WT and Esr1 KO females displayed similar latencies to respond to foster young during the initial induction testing. Likewise, reinduction latencies to display full maternal responsiveness were similar in the Esr1 KO and WT groups during maternal memory testing in the home cage. However, in the novel cage testing WT subjects displayed modest modifications in maternal care. WT females had shorter latencies to first retrieve and mouth a test pup. These findings suggest that while Esr1 does not appear to affect the establishment of maternal care or the display of maternal memory, it may modulate aspects of pup-directed behaviors associated with the reinduction of maternal care in female rats.
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Affiliation(s)
- J M Gallagher
- Department of Biomedical Sciences, Tufts University, Cummings School of Veterinary Medicine, North Grafton, MA 01536, United States of America
| | - B C Nephew
- Department of Biomedical Sciences, Tufts University, Cummings School of Veterinary Medicine, North Grafton, MA 01536, United States of America
| | - G Poirier
- Center for Comparative NeuroImaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA 01655, United States of America
| | - J A King
- Center for Comparative NeuroImaging, Department of Psychiatry, University of Massachusetts Medical School, Worcester, MA 01655, United States of America
| | - R S Bridges
- Department of Biomedical Sciences, Tufts University, Cummings School of Veterinary Medicine, North Grafton, MA 01536, United States of America.
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10
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Azhari H, King JA, Underwood F, Coward S, shah S, Ng S, Ho G, Chan C, Kaplan GG. A258 THE GLOBAL INCIDENCE OF PEPTIC ULCER DISEASE AT THE TURN OF THE 21ST CENTURY: A STUDY OF THE ORGANIZATION FOR ECONOMIC CO-OPERATION AND DEVELOPMENT (OECD). J Can Assoc Gastroenterol 2019. [DOI: 10.1093/jcag/gwz006.257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- H Azhari
- Gastroenterology & Hepatology, University of Calgary, Calgary, AB, Canada
| | - J A King
- University of Calgary, Calgary, AB, Canada
| | - F Underwood
- Gastroenterology & Hepatology, University of Calgary, Calgary, AB, Canada
| | - S Coward
- University of Calgary, Calgary, AB, Canada
| | - S shah
- Vanderbilt University, Nashville, TN
| | - S Ng
- Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - G Ho
- Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - C Chan
- Chinese University of Hong Kong, Hong Kong, Hong Kong
| | - G G Kaplan
- Medicine and Community Health Sciences, University of Calgary, Calgary, AB, Canada
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11
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Quan J, Panaccione N, King JA, Underwood F, Windsor JW, Coward S, Gidrewicz D, Kaplan GG. A257 ASSOCIATION BETWEEN CELIAC DISEASE AND AUTISM SPECTRUM DISORDER: A SYSTEMATIC REVIEW. J Can Assoc Gastroenterol 2019. [DOI: 10.1093/jcag/gwz006.256] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- J Quan
- University of Calgary, Calgary, AB, Canada
| | | | - J A King
- University of Calgary, Calgary, AB, Canada
| | | | - J W Windsor
- Medicine, University of Calgary, Calgary, AB, Canada
| | - S Coward
- University of Calgary, Calgary, AB, Canada
| | | | - G G Kaplan
- Medicine and Community Health Sciences, University of Calgary, Calgary, AB, Canada
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12
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Iannuzzi J, Leung J, Quan J, Underwood F, King JA, Windsor JW, Kaplan GG. A256 GLOBAL INCIDENCE OF ACUTE PANCREATITIS THROUGH TIME: A SYSTEMATIC REVIEW. J Can Assoc Gastroenterol 2019. [DOI: 10.1093/jcag/gwz006.255] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
- J Iannuzzi
- Medicine, University of Calgary, Calgary, AB, Canada
| | - J Leung
- Medicine, University of Calgary, Calgary, AB, Canada
| | - J Quan
- Medicine, University of Calgary, Calgary, AB, Canada
| | | | - J A King
- University of Calgary, Calgary, AB, Canada
| | - J W Windsor
- Medicine, University of Calgary, Calgary, AB, Canada
| | - G G Kaplan
- Medicine and Community Health Sciences, University of Calgary, Calgary, AB, Canada
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13
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King JA, Jeong J, Underwood F, Quan J, Panaccione N, Windsor JW, Coward S, deBruyn J, Ronksley P, Shaheen AM, Quan H, Veldhuyzen van Zanten S, Lebwohl B, Kaplan GG. A261 INCIDENCE OF CELIAC DISEASE IS INCREASING OVER TIME: A SYSTEMATIC REVIEW AND META-ANALYSIS. J Can Assoc Gastroenterol 2019. [DOI: 10.1093/jcag/gwz006.260] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Affiliation(s)
- J A King
- University of Calgary, Calgary, AB, Canada
| | - J Jeong
- University of Calgary, Calgary, AB, Canada
| | | | - J Quan
- University of Calgary, Calgary, AB, Canada
| | | | | | - S Coward
- University of Calgary, Calgary, AB, Canada
| | - J deBruyn
- Paediatrics , University of Calgary, Calgary, AB, Canada
| | - P Ronksley
- University of Calgary, Calgary, AB, Canada
| | | | - H Quan
- University of Calgary, Calgary, AB, Canada
| | | | - B Lebwohl
- Columbia University, White Plains, NY
| | - G G Kaplan
- Medicine and Community Health Sciences, University of Calgary, Calgary, AB, Canada
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14
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Windsor JW, Buie M, Coward S, King JA, Underwood F, Quan J, Panaccione R, Seow C, Kaplan GG. A31 GLOBAL BURDEN OF HOSPITALIZATION FOR PERSONS WITH IBD IN THE 21ST CENTURY: TIME TREND ANALYSES. J Can Assoc Gastroenterol 2019. [DOI: 10.1093/jcag/gwz006.030] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Affiliation(s)
| | - M Buie
- University of Calgary, Calgary, AB, Canada
| | - S Coward
- University of Calgary, Calgary, AB, Canada
| | - J A King
- University of Calgary, Calgary, AB, Canada
| | | | - J Quan
- University of Calgary, Calgary, AB, Canada
| | | | - C Seow
- University of Calgary, Calgary, AB, Canada
| | - G G Kaplan
- University of Calgary, Calgary, AB, Canada
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15
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Abstract
Fifty years ago, on 4 March 1969, research and teaching at the Massachusetts Institute of Technology (MIT) came to a halt as students, faculty, and staff held a “research strike” for peace. The strike protested United States involvement in the Vietnam War and MIT's complicity in this engagement through its Instrumentation Laboratory (now the Draper Laboratory), a major contracting lab for the U.S. Department of Defense. The anniversary of this activism by scientists (see the Book Review on page 935) is a reminder that the scientific community must continue to recognize its social responsibilities and promote science as a benefit for all people and for a peaceful world.
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Affiliation(s)
- Jonathan A. King
- Jonathan A. King is professor in the Department of Biology at Massachusetts Institute of Technology (MIT), Cambridge, MA, USA, and is a past president of the Biophysical Society
| | - Aron Bernstein
- Aron Bernstein is an emeritus professor in the Department of Physics at MIT, Cambridge, MA, USA, and serves on the national advisory board of the Council for a Livable World, Washington, DC, USA
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16
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Mills Henry I, Kosinski-Collins M, Thol S, Serebryany E, King JA. Kinetic Stability of Long-Lived Human γ-D and γS Lens Crystallins, Derived in Part from their Domain Interfaces, May Protect against Cataract. Biophys J 2019. [DOI: 10.1016/j.bpj.2018.11.1745] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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17
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Dai W, Chen M, Myers C, Ludtke SJ, Pettitt BM, King JA, Schmid MF, Chiu W. Visualizing Individual RuBisCO and Its Assembly into Carboxysomes in Marine Cyanobacteria by Cryo-Electron Tomography. J Mol Biol 2018; 430:4156-4167. [PMID: 30138616 DOI: 10.1016/j.jmb.2018.08.013.visualizing] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/29/2018] [Accepted: 08/13/2018] [Indexed: 05/19/2023]
Abstract
Cyanobacteria are photosynthetic organisms responsible for ~25% of the organic carbon fixation on earth. A key step in carbon fixation is catalyzed by ribulose bisphosphate carboxylase/oxygenase (RuBisCO), the most abundant enzyme in the biosphere. Applying Zernike phase-contrast electron cryo-tomography and automated annotation, we identified individual RuBisCO molecules and their assembly intermediates leading to the formation of carboxysomes inside Syn5 cyanophage infected cyanobacteria Synechococcus sp. WH8109 cells. Surprisingly, more RuBisCO molecules were found to be present as cytosolic free-standing complexes or clusters than as packaged assemblies inside carboxysomes. Cytosolic RuBisCO clusters and partially assembled carboxysomes identified in the cell tomograms support a concurrent assembly model involving both the protein shell and the enclosed RuBisCO. In mature carboxysomes, RuBisCO is neither randomly nor strictly icosahedrally packed within protein shells of variable sizes. A time-averaged molecular dynamics simulation showed a semi-liquid probability distribution of the RuBisCO in carboxysomes and correlated well with carboxysome subtomogram averages. Our structural observations reveal the various stages of RuBisCO assemblies, which could be important for understanding cellular function.
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Affiliation(s)
- Wei Dai
- Department of Cell Biology and Neuroscience & Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ 08854, USA.
| | - Muyuan Chen
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christopher Myers
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Steven J Ludtke
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - B Montgomery Pettitt
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Michael F Schmid
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Wah Chiu
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA; Departments of Bioengineering and of Microbiology and Immunoplogy, James H. Clark Center, Stanford University, Stanford, CA 94305, USA.
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18
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King JA, Opachich YP, Huffman EJ, Knight R, Heeter RF, Ahmed M, Liedahl DA, Schneider MB, Thompson NB, Johns HM, Dodd E, Flippo KA, Kline JL, Lopez FE, Archuleta TN, Perry TS. Implementation of a 1-2 keV point-projection x-ray spectrometer on the National Ignition Facility. Rev Sci Instrum 2018; 89:10F101. [PMID: 30399753 DOI: 10.1063/1.5038092] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/01/2018] [Accepted: 07/12/2018] [Indexed: 06/08/2023]
Abstract
A point-projection soft X-ray Opacity Spectrometer (OpSpec) has been implemented to measure X-ray spectra from ∼1 to 2 keV on the National Ignition Facility (NIF). Measurement of such soft X-rays with open-aperture point-projection detectors is challenging because only very thin filters may be used to shield the detector from the hostile environment. OpSpec diffracts X-rays from 540 to 2100 eV off a potassium (or rubidium) acid phthalate (KAP or RbAP) crystal onto either image plates or, most recently, X-ray films. A "sacrificial front filter" strategy is used to prevent crystal damage, while 2 or 3 rear filters protect the data. Since May 2017, OpSpec has been recording X-ray transmission data for iron-magnesium plasmas on the NIF, at "Anchor 1" plasma conditions (temperature ∼150 eV, density ∼7 × 1021 e -/cm3). Upgrades improved OpSpec's performance on 6 NIF shots in August and December 2017, with reduced backgrounds and 100% data return using filter stacks as thin as 2.9 μm (total). Photometric noise is beginning to meet requirements, and further work will reduce systematic errors.
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Affiliation(s)
- J A King
- Nevada National Security Site, Livermore, California 94550, USA
| | - Y P Opachich
- Nevada National Security Site, Livermore, California 94550, USA
| | - E J Huffman
- Nevada National Security Site, Livermore, California 94550, USA
| | - R Knight
- Nevada National Security Site, Livermore, California 94550, USA
| | - R F Heeter
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M Ahmed
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - D A Liedahl
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M B Schneider
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - N B Thompson
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - H M Johns
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - E Dodd
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - K A Flippo
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - J L Kline
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - F E Lopez
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T N Archuleta
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T S Perry
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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19
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Sargeant JA, Gray LJ, Bodicoat DH, Willis SA, Stensel DJ, Nimmo MA, Aithal GP, King JA. The effect of exercise training on intrahepatic triglyceride and hepatic insulin sensitivity: a systematic review and meta-analysis. Obes Rev 2018; 19:1446-1459. [PMID: 30092609 DOI: 10.1111/obr.12719] [Citation(s) in RCA: 60] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 05/08/2018] [Accepted: 05/09/2018] [Indexed: 12/12/2022]
Abstract
This systematic review and meta-analysis determined the impact of structured exercise training, and the influence of associated weight loss, on intrahepatic triglyceride (IHTG) in individuals with non-alcoholic fatty liver disease (NAFLD). It also examined its effect on hepatic insulin sensitivity in individuals with or at increased risk of NAFLD. Analyses were restricted to studies using magnetic resonance spectroscopy or liver biopsy for the measurement of IHTG and isotope-labelled glucose tracer for assessment of hepatic insulin sensitivity. Pooling data from 17 studies (373 exercising participants), exercise training for one to 24 weeks (mode: 12 weeks) elicits an absolute reduction in IHTG of 3.31% (95% CI: -4.41 to -2.22%). Exercise reduces IHTG independent of significant weight change (-2.16 [-2.87 to -1.44]%), but benefits are substantially greater when weight loss occurs (-4.87 [-6.64 to -3.11]%). Furthermore, meta-regression identified a positive association between percentage weight loss and absolute reduction in IHTG (β = 0.99 [0.62 to 1.36], P < 0.001). Pooling of six studies (94 participants) suggests that exercise training also improves basal hepatic insulin sensitivity (mean change in hepatic insulin sensitivity index: 0.13 [0.05 to 0.21] mg m-2 min-1 per μU mL-1 ), but available evidence is limited, and the impact of exercise on insulin-stimulated hepatic insulin sensitivity remains unclear.
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Affiliation(s)
- J A Sargeant
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,National Institute for Health Research (NIHR) Leicester Biomedical Research Centre, Leicester, UK
| | - L J Gray
- Department of Health Sciences, University of Leicester, Leicester, UK
| | - D H Bodicoat
- National Institute for Health Research (NIHR) Leicester Biomedical Research Centre, Leicester, UK.,Diabetes Research Centre, University of Leicester, Leicester, UK
| | - S A Willis
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,National Institute for Health Research (NIHR) Leicester Biomedical Research Centre, Leicester, UK
| | - D J Stensel
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,National Institute for Health Research (NIHR) Leicester Biomedical Research Centre, Leicester, UK
| | - M A Nimmo
- College of Life and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - G P Aithal
- Nottingham Digestive Diseases Centre, School of Medicine, University of Nottingham, Nottingham, UK.,National Institute for Health Research (NIHR) Nottingham Biomedical Research Centre, Nottingham University Hospitals NHS Trust and the University of Nottingham, Nottingham, UK
| | - J A King
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,National Institute for Health Research (NIHR) Leicester Biomedical Research Centre, Leicester, UK
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20
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Dai W, Chen M, Myers C, Ludtke SJ, Pettitt BM, King JA, Schmid MF, Chiu W. Visualizing Individual RuBisCO and Its Assembly into Carboxysomes in Marine Cyanobacteria by Cryo-Electron Tomography. J Mol Biol 2018; 430:4156-4167. [PMID: 30138616 DOI: 10.1016/j.jmb.2018.08.013] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 07/29/2018] [Accepted: 08/13/2018] [Indexed: 12/31/2022]
Abstract
Cyanobacteria are photosynthetic organisms responsible for ~25% of the organic carbon fixation on earth. A key step in carbon fixation is catalyzed by ribulose bisphosphate carboxylase/oxygenase (RuBisCO), the most abundant enzyme in the biosphere. Applying Zernike phase-contrast electron cryo-tomography and automated annotation, we identified individual RuBisCO molecules and their assembly intermediates leading to the formation of carboxysomes inside Syn5 cyanophage infected cyanobacteria Synechococcus sp. WH8109 cells. Surprisingly, more RuBisCO molecules were found to be present as cytosolic free-standing complexes or clusters than as packaged assemblies inside carboxysomes. Cytosolic RuBisCO clusters and partially assembled carboxysomes identified in the cell tomograms support a concurrent assembly model involving both the protein shell and the enclosed RuBisCO. In mature carboxysomes, RuBisCO is neither randomly nor strictly icosahedrally packed within protein shells of variable sizes. A time-averaged molecular dynamics simulation showed a semi-liquid probability distribution of the RuBisCO in carboxysomes and correlated well with carboxysome subtomogram averages. Our structural observations reveal the various stages of RuBisCO assemblies, which could be important for understanding cellular function.
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Affiliation(s)
- Wei Dai
- Department of Cell Biology and Neuroscience & Institute for Quantitative Biomedicine, Rutgers University, Piscataway, NJ 08854, USA.
| | - Muyuan Chen
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Christopher Myers
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Steven J Ludtke
- Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - B Montgomery Pettitt
- Department of Pharmacology and Toxicology, University of Texas Medical Branch, Galveston, TX 77555, USA; Department of Biochemistry and Molecular Biology, University of Texas Medical Branch, Galveston, TX 77555, USA; Sealy Center for Structural Biology and Molecular Biophysics, University of Texas Medical Branch, Galveston, TX 77555, USA
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
| | - Michael F Schmid
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA
| | - Wah Chiu
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA 94025, USA; Departments of Bioengineering and of Microbiology and Immunoplogy, James H. Clark Center, Stanford University, Stanford, CA 94305, USA.
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21
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Boehm I, King JA, Bernardoni F, Geisler D, Seidel M, Ritschel F, Goschke T, Haynes JD, Roessner V, Ehrlich S. Subliminal and supraliminal processing of reward-related stimuli in anorexia nervosa. Psychol Med 2018; 48:790-800. [PMID: 28832300 DOI: 10.1017/s0033291717002161] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND Previous studies have highlighted the role of the brain reward and cognitive control systems in the etiology of anorexia nervosa (AN). In an attempt to disentangle the relative contribution of these systems to the disorder, we used functional magnetic resonance imaging (fMRI) to investigate hemodynamic responses to reward-related stimuli presented both subliminally and supraliminally in acutely underweight AN patients and age-matched healthy controls (HC). METHODS fMRI data were collected from a total of 35 AN patients and 35 HC, while they passively viewed subliminally and supraliminally presented streams of food, positive social, and neutral stimuli. Activation patterns of the group × stimulation condition × stimulus type interaction were interrogated to investigate potential group differences in processing different stimulus types under the two stimulation conditions. Moreover, changes in functional connectivity were investigated using generalized psychophysiological interaction analysis. RESULTS AN patients showed a generally increased response to supraliminally presented stimuli in the inferior frontal junction (IFJ), but no alterations within the reward system. Increased activation during supraliminal stimulation with food stimuli was observed in the AN group in visual regions including superior occipital gyrus and the fusiform gyrus/parahippocampal gyrus. No group difference was found with respect to the subliminal stimulation condition and functional connectivity. CONCLUSION Increased IFJ activation in AN during supraliminal stimulation may indicate hyperactive cognitive control, which resonates with clinical presentation of excessive self-control in AN patients. Increased activation to food stimuli in visual regions may be interpreted in light of an attentional food bias in AN.
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Affiliation(s)
- I Boehm
- Division of Psychological and Social Medicine and Developmental Neurosciences,University Hospital Carl Gustav Carus, Technische Universität Dresden,Dresden,Germany
| | - J A King
- Division of Psychological and Social Medicine and Developmental Neurosciences,University Hospital Carl Gustav Carus, Technische Universität Dresden,Dresden,Germany
| | - F Bernardoni
- Division of Psychological and Social Medicine and Developmental Neurosciences,University Hospital Carl Gustav Carus, Technische Universität Dresden,Dresden,Germany
| | - D Geisler
- Division of Psychological and Social Medicine and Developmental Neurosciences,University Hospital Carl Gustav Carus, Technische Universität Dresden,Dresden,Germany
| | - M Seidel
- Division of Psychological and Social Medicine and Developmental Neurosciences,University Hospital Carl Gustav Carus, Technische Universität Dresden,Dresden,Germany
| | - F Ritschel
- Division of Psychological and Social Medicine and Developmental Neurosciences,University Hospital Carl Gustav Carus, Technische Universität Dresden,Dresden,Germany
| | - T Goschke
- Department of Psychology,Technische Universität Dresden,Dresden,Germany
| | - J-D Haynes
- Bernstein Center for Computational Neuroscience, Charité Universitäts-Medizin,Berlin,Germany
| | - V Roessner
- Department of Child and Adolescent Psychiatry,University Hospital Carl Gustav Carus, Technische Universität Dresden,Dresden,Germany
| | - S Ehrlich
- Division of Psychological and Social Medicine and Developmental Neurosciences,University Hospital Carl Gustav Carus, Technische Universität Dresden,Dresden,Germany
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22
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Radue MS, Jensen BD, Gowtham S, Klimek-McDonald DR, King JA, Odegard GM. Comparing the Mechanical Response of Di-, Tri-, and Tetra-functional Resin Epoxies with Reactive Molecular Dynamics. ACTA ACUST UNITED AC 2018; 56:255-264. [PMID: 31806922 DOI: 10.1002/polb.24539] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
The influence of monomer functionality on the mechanical properties of epoxies is studied using Molecular Dynamics (MD) with the Reax Force Field (ReaxFF). From deformation simulations, the Young's modulus, yield point, and Poisson's ratio are calculated and analyzed. The results demonstrate an increase in stiffness and yield strength with increasing resin functionality. Comparison between the network structures of distinct epoxies is further advanced by the Monomeric Degree Index (MDI). Experimental validation demonstrates the MD results correctly predict the relationship in Young's moduli. Therefore, ReaxFF is confirmed to be a useful tool for studying the mechanical behavior of epoxies.
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Affiliation(s)
- M S Radue
- Michigan Technological University, Houghton, MI 49931
| | - Benjamin D Jensen
- Michigan Technological University, Houghton, MI 49931.,NASA Langley Research Center, Hampton, VA 23666
| | - S Gowtham
- Michigan Technological University, Houghton, MI 49931
| | | | - J A King
- Michigan Technological University, Houghton, MI 49931
| | - G M Odegard
- Michigan Technological University, Houghton, MI 49931
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23
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Douglas JA, King JA, Clayton DJ, Jackson AP, Sargeant JA, Thackray AE, Davies MJ, Stensel DJ. Acute effects of exercise on appetite, ad libitum energy intake and appetite-regulatory hormones in lean and overweight/obese men and women. Int J Obes (Lond) 2017; 41:1737-1744. [PMID: 28769121 PMCID: PMC5729348 DOI: 10.1038/ijo.2017.181] [Citation(s) in RCA: 54] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Revised: 07/13/2017] [Accepted: 07/14/2017] [Indexed: 02/07/2023]
Abstract
BACKGROUND Acute exercise does not elicit compensatory changes in appetite parameters in lean individuals; however, less is known about responses in overweight individuals. This study compared the acute effects of moderate-intensity exercise on appetite, energy intake and appetite-regulatory hormones in lean and overweight/obese individuals. METHODS Forty-seven healthy lean (n=22, 11 females; mean (s.d.) 37.5 (15.2) years; 22.4 (1.5) kg m-2) and overweight/obese (n=25, 11 females; 45.0 (12.4) years, 29.2 (2.9) kg m-2) individuals completed two, 8 h trials (exercise and control). In the exercise trial, participants completed 60 min treadmill exercise (59 (4)% peak oxygen uptake) at 0-1 h and rested thereafter while participants rested throughout the control trial. Appetite ratings and concentrations of acylated ghrelin, peptide YY (PYY) and glucagon-like peptide-1 (GLP-1) were measured at predetermined intervals. Standardised meals were consumed at 1.5 and 4 h and an ad libitum buffet meal was provided at 7 h. RESULTS Exercise suppressed appetite (95% confidence interval (CI) -3.1 to -0.5 mm, P=0.01), and elevated delta PYY (95% CI 10 to 17 pg ml-1, P<0.001) and GLP-1 (95% CI 7 to 10 pmol l-1, P<0.001) concentrations. Delta acylated ghrelin concentrations (95% CI -5 to 3 pg ml-1, P=0.76) and ad libitum energy intake (95% CI -391 to 346 kJ, P=0.90) were similar between trials. Subjective and hormonal appetite parameters and ad libitum energy intake were similar between lean and overweight/obese individuals (P⩾0.27). The exercise-induced elevation in delta GLP-1 was greater in overweight/obese individuals (trial-by-group interaction P=0.01), whereas lean individuals exhibited a greater exercise-induced increase in delta PYY (trial-by-group interaction P<0.001). CONCLUSIONS Acute moderate-intensity exercise transiently suppressed appetite and increased PYY and GLP-1 in the hours after exercise without stimulating compensatory changes in appetite in lean or overweight/obese individuals. These findings underscore the ability of exercise to induce a short-term energy deficit without any compensatory effects on appetite regardless of weight status.
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Affiliation(s)
- J A Douglas
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,Institute of Cancer and Genomic Sciences, University of Birmingham, Birmingham, UK
| | - J A King
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - D J Clayton
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - A P Jackson
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK.,School of Biological Sciences, University of Nottingham, Sutton Bonington, UK
| | - J A Sargeant
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - A E Thackray
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - M J Davies
- Diabetes Research Centre, University of Leicester, Leicester General Hospital, Leicester, UK
| | - D J Stensel
- National Centre for Sport and Exercise Medicine, School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
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24
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Opachich YP, Heeter RF, Barrios MA, Garcia EM, Craxton RS, King JA, Liedahl DA, McKenty PW, Schneider MB, May MJ, Zhang R, Ross PW, Kline JL, Moore AS, Weaver JL, Flippo KA, Perry TS. Capsule implosions for continuum x-ray backlighting of opacity samples at the National Ignition Facility. Phys Plasmas 2017; 24:063301. [PMID: 29104422 PMCID: PMC5648568 DOI: 10.1063/1.4985076] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/16/2017] [Accepted: 05/09/2017] [Indexed: 06/07/2023]
Abstract
Direct drive implosions of plastic capsules have been performed at the National Ignition Facility to provide a broad-spectrum (500-2000 eV) X-ray continuum source for X-ray transmission spectroscopy. The source was developed for the high-temperature plasma opacity experimental platform. Initial experiments using 2.0 mm diameter polyalpha-methyl styrene capsules with ∼20 μm thickness have been performed. X-ray yields of up to ∼1 kJ/sr have been measured using the Dante multichannel diode array. The backlighter source size was measured to be ∼100 μm FWHM, with ∼350 ps pulse duration during the peak emission stage. Results are used to simulate transmission spectra for a hypothetical iron opacity sample at 150 eV, enabling the derivation of photometrics requirements for future opacity experiments.
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Affiliation(s)
- Y P Opachich
- National Security Technologies, LLC, Livermore, California 94550, USA
| | - R F Heeter
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M A Barrios
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - E M Garcia
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - R S Craxton
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - J A King
- National Security Technologies, LLC, Livermore, California 94550, USA
| | - D A Liedahl
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - P W McKenty
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - M B Schneider
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - M J May
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - R Zhang
- Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623, USA
| | - P W Ross
- National Security Technologies, LLC, Livermore, California 94550, USA
| | - J L Kline
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - A S Moore
- Lawrence Livermore National Laboratory, Livermore, California 94550, USA
| | - J L Weaver
- Naval Research Laboratory, Washington, D.C. 20375, USA
| | - K A Flippo
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
| | - T S Perry
- Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA
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25
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Serebryany E, Woodard JC, Adkar BV, Shabab M, King JA, Shakhnovich EI. An Internal Disulfide Locks a Misfolded Aggregation-Prone Intermediate in Cataract-Linked Mutants of Human Gamma-D Crystallin. Biophys J 2017. [DOI: 10.1016/j.bpj.2016.11.923] [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] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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26
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Ross PW, Heeter RF, Ahmed MF, Dodd E, Huffman EJ, Liedahl DA, King JA, Opachich YP, Schneider MB, Perry TS. Design of the opacity spectrometer for opacity measurements at the National Ignition Facility. Rev Sci Instrum 2016; 87:11D623. [PMID: 27910379 DOI: 10.1063/1.4962819] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Recent experiments at the Sandia National Laboratory Z facility have called into question models used in calculating opacity, of importance for modeling stellar interiors. An effort is being made to reproduce these results at the National Ignition Facility (NIF). These experiments require a new X-ray opacity spectrometer (OpSpec) spanning 540 eV-2100 eV with a resolving power E/ΔE > 700. The design of the OpSpec is presented. Photometric calculations based on expected opacity data are also presented. First use on NIF is expected in September 2016.
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Affiliation(s)
- P W Ross
- National Security Technologies, LLC, 161 S. Vasco Road, Livermore, California 94550, USA
| | - R F Heeter
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - M F Ahmed
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - E Dodd
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545, USA
| | - E J Huffman
- National Security Technologies, LLC, 161 S. Vasco Road, Livermore, California 94550, USA
| | - D A Liedahl
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - J A King
- National Security Technologies, LLC, 161 S. Vasco Road, Livermore, California 94550, USA
| | - Y P Opachich
- National Security Technologies, LLC, 161 S. Vasco Road, Livermore, California 94550, USA
| | - M B Schneider
- Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, California 94550, USA
| | - T S Perry
- Los Alamos National Laboratory, P.O. Box 1663, Los Alamos, New Mexico 87545, USA
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27
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Serebryany E, Woodard JC, Adkar BV, Shabab M, King JA, Shakhnovich EI. An Internal Disulfide Locks a Misfolded Aggregation-prone Intermediate in Cataract-linked Mutants of Human γD-Crystallin. J Biol Chem 2016; 291:19172-83. [PMID: 27417136 DOI: 10.1074/jbc.m116.735977] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [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: 05/02/2016] [Indexed: 11/06/2022] Open
Abstract
Considerable mechanistic insight has been gained into amyloid aggregation; however, a large number of non-amyloid protein aggregates are considered "amorphous," and in most cases, little is known about their mechanisms. Amorphous aggregation of γ-crystallins in the eye lens causes cataract, a widespread disease of aging. We combined simulations and experiments to study the mechanism of aggregation of two γD-crystallin mutants, W42R and W42Q: the former a congenital cataract mutation, and the latter a mimic of age-related oxidative damage. We found that formation of an internal disulfide was necessary and sufficient for aggregation under physiological conditions. Two-chain all-atom simulations predicted that one non-native disulfide in particular, between Cys(32) and Cys(41), was likely to stabilize an unfolding intermediate prone to intermolecular interactions. Mass spectrometry and mutagenesis experiments confirmed the presence of this bond in the aggregates and its necessity for oxidative aggregation under physiological conditions in vitro Mining the simulation data linked formation of this disulfide to extrusion of the N-terminal β-hairpin and rearrangement of the native β-sheet topology. Specific binding between the extruded hairpin and a distal β-sheet, in an intermolecular chain reaction similar to domain swapping, is the most probable mechanism of aggregate propagation.
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Affiliation(s)
- Eugene Serebryany
- From the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 and
| | - Jaie C Woodard
- the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Bharat V Adkar
- the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
| | - Mohammed Shabab
- From the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 and
| | - Jonathan A King
- From the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 and
| | - Eugene I Shakhnovich
- the Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138
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28
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Serebryany E, Takata T, Erickson E, Schafheimer N, Wang Y, King JA. Aggregation of Trp > Glu point mutants of human gamma-D crystallin provides a model for hereditary or UV-induced cataract. Protein Sci 2016; 25:1115-28. [PMID: 26991007 DOI: 10.1002/pro.2924] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [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: 01/08/2016] [Revised: 03/09/2016] [Accepted: 03/10/2016] [Indexed: 12/21/2022]
Abstract
Numerous mutations and covalent modifications of the highly abundant, long-lived crystallins of the eye lens cause their aggregation leading to progressive opacification of the lens, cataract. The nature and biochemical mechanisms of the aggregation process are poorly understood, as neither amyloid nor native-state polymers are commonly found in opaque lenses. The βγ-crystallin fold contains four highly conserved buried tryptophans, which can be oxidized to more hydrophilic products, such as kynurenine, upon UV-B irradiation. We mimicked this class of oxidative damage using Trp→Glu point mutants of human γD-crystallin. Such substitutions may represent a model of UV-induced photodamage-introduction of a charged group into the hydrophobic core generating "denaturation from within." The effects of Trp→Glu substitutions were highly position dependent. While each was destabilizing, only the two located in the bottom of the double Greek key fold-W42E and W130E-yielded robust aggregation of partially unfolded intermediates at 37°C and pH 7. The αB-crystallin chaperone suppressed aggregation of W130E, but not W42E, indicating distinct aggregation pathways from damage in the N-terminal vs C-terminal domain. The W130E aggregates had loosely fibrillar morphology, yet were nonamyloid, noncovalent, showed little surface hydrophobicity, and formed at least 20°C below the melting temperature of the native β-sheets. These features are most consistent with domain-swapped polymerization. Aggregation of partially destabilized crystallins under physiological conditions, as occurs in this class of point mutants, could provide a simple in vitro model system for drug discovery and optimization.
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Affiliation(s)
- Eugene Serebryany
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139
| | - Takumi Takata
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139
| | - Erika Erickson
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139
| | - Nathaniel Schafheimer
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139
| | - Yongting Wang
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139
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29
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Dominguez-Calva JA, Serebryany E, Haase-Pettingell C, King JA, Quintanar L. Elucidating the Coordination Features Associated to Copper and Zinc Induced Aggregation of Human γ-D Crystallin. Biophys J 2016. [DOI: 10.1016/j.bpj.2015.11.2095] [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] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
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30
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Quintanar L, Domínguez-Calva JA, Serebryany E, Rivillas-Acevedo L, Haase-Pettingell C, Amero C, King JA. Copper and Zinc Ions Specifically Promote Nonamyloid Aggregation of the Highly Stable Human γ-D Crystallin. ACS Chem Biol 2016; 11:263-72. [PMID: 26579725 DOI: 10.1021/acschembio.5b00919] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Cataract is the leading cause of blindness in the world. It results from aggregation of eye lens proteins into high-molecular-weight complexes, causing light scattering and lens opacity. Copper and zinc concentrations in cataractous lens are increased significantly relative to a healthy lens, and a variety of experimental and epidemiological studies implicate metals as potential etiological agents for cataract. The natively monomeric, β-sheet rich human γD (HγD) crystallin is one of the more abundant proteins in the core of the lens. It is also one of the most thermodynamically stable proteins in the human body. Surprisingly, we found that both Cu(II) and Zn(II) ions induced rapid, nonamyloid aggregation of HγD, forming high-molecular-weight light-scattering aggregates. Unlike Zn(II), Cu(II) also substantially decreased the thermal stability of HγD and promoted the formation of disulfide-bridged dimers, suggesting distinct aggregation mechanisms. In both cases, however, metal-induced aggregation depended strongly on temperature and was suppressed by the human lens chaperone αB-crystallin (HαB), implicating partially folded intermediates in the aggregation process. Consistently, distinct site-specific interactions of Cu(II) and Zn(II) ions with the protein and conformational changes in specific hinge regions were identified by nuclear magnetic resonance. This study provides insights into the mechanisms of metal-induced aggregation of one of the more stable proteins in the human body, and it reveals a novel and unexplored bioinorganic facet of cataract disease.
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Affiliation(s)
- Liliana Quintanar
- Departamento
de Química, Centro de Investigación y de Estudios Avanzados (Cinvestav), 07360 Mexico City, México
| | - José A. Domínguez-Calva
- Departamento
de Química, Centro de Investigación y de Estudios Avanzados (Cinvestav), 07360 Mexico City, México
| | - Eugene Serebryany
- Department
of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Lina Rivillas-Acevedo
- Centro
de Investigaciones Químicas, Instituto de Investigación
en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, 62209 Cuernavaca, México
| | - Cameron Haase-Pettingell
- Department
of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
| | - Carlos Amero
- Centro
de Investigaciones Químicas, Instituto de Investigación
en Ciencias Básicas y Aplicadas, Universidad Autónoma del Estado de Morelos, 62209 Cuernavaca, México
| | - Jonathan A. King
- Department
of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, United States
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31
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Pintilie G, Chen DH, Haase-Pettingell CA, King JA, Chiu W. Resolution and Probabilistic Models of Components in CryoEM Maps of Mature P22 Bacteriophage. Biophys J 2015; 110:827-39. [PMID: 26743049 DOI: 10.1016/j.bpj.2015.11.3522] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2015] [Revised: 10/14/2015] [Accepted: 11/11/2015] [Indexed: 01/08/2023] Open
Abstract
CryoEM continues to produce density maps of larger and more complex assemblies with multiple protein components of mixed symmetries. Resolution is not always uniform throughout a cryoEM map, and it can be useful to estimate the resolution in specific molecular components of a large assembly. In this study, we present procedures to 1) estimate the resolution in subcomponents by gold-standard Fourier shell correlation (FSC); 2) validate modeling procedures, particularly at medium resolutions, which can include loop modeling and flexible fitting; and 3) build probabilistic models that combine high-accuracy priors (such as crystallographic structures) with medium-resolution cryoEM densities. As an example, we apply these methods to new cryoEM maps of the mature bacteriophage P22, reconstructed without imposing icosahedral symmetry. Resolution estimates based on gold-standard FSC show the highest resolution in the coat region (7.6 Å), whereas other components are at slightly lower resolutions: portal (9.2 Å), hub (8.5 Å), tailspike (10.9 Å), and needle (10.5 Å). These differences are indicative of inherent structural heterogeneity and/or reconstruction accuracy in different subcomponents of the map. Probabilistic models for these subcomponents provide new insights, to our knowledge, and structural information when taking into account uncertainty given the limitations of the observed density.
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Affiliation(s)
- Grigore Pintilie
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas.
| | - Dong-Hua Chen
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas
| | | | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts
| | - Wah Chiu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas
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32
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Jelleyman C, Yates T, O'Donovan G, Gray LJ, King JA, Khunti K, Davies MJ. The effects of high-intensity interval training on glucose regulation and insulin resistance: a meta-analysis. Obes Rev 2015; 16:942-61. [PMID: 26481101 DOI: 10.1111/obr.12317] [Citation(s) in RCA: 320] [Impact Index Per Article: 35.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/06/2015] [Accepted: 08/06/2015] [Indexed: 12/26/2022]
Abstract
The aim of this meta-analysis was to quantify the effects of high-intensity interval training (HIIT) on markers of glucose regulation and insulin resistance compared with control conditions (CON) or continuous training (CT). Databases were searched for HIIT interventions based upon the inclusion criteria: training ≥2 weeks, adult participants and outcome measurements that included insulin resistance, fasting glucose, HbA1c or fasting insulin. Dual interventions and participants with type 1 diabetes were excluded. Fifty studies were included. There was a reduction in insulin resistance following HIIT compared with both CON and CT (HIIT vs. CON: standardized mean difference [SMD] = -0.49, confidence intervals [CIs] -0.87 to -0.12, P = 0.009; CT: SMD = -0.35, -0.68 to -0.02, P = 0.036). Compared with CON, HbA1c decreased by 0.19% (-0.36 to -0.03, P = 0.021) and body weight decreased by 1.3 kg (-1.9 to -0.7, P < 0.001). There were no statistically significant differences between groups in other outcomes overall. However, participants at risk of or with type 2 diabetes experienced reductions in fasting glucose (-0.92 mmol L(-1), -1.22 to -0.62, P < 0.001) compared with CON. HIIT appears effective at improving metabolic health, particularly in those at risk of or with type 2 diabetes. Larger randomized controlled trials of longer duration than those included in this meta-analysis are required to confirm these results.
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Affiliation(s)
- C Jelleyman
- Diabetes Research Centre, University of Leicester, Leicester, UK.,NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity Biomedical Research Unit, Leicester & Loughborough, UK
| | - T Yates
- Diabetes Research Centre, University of Leicester, Leicester, UK.,NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity Biomedical Research Unit, Leicester & Loughborough, UK
| | - G O'Donovan
- Diabetes Research Centre, University of Leicester, Leicester, UK
| | - L J Gray
- Department of Health Sciences, University of Leicester, Leicester, UK
| | - J A King
- NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity Biomedical Research Unit, Leicester & Loughborough, UK.,School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, UK
| | - K Khunti
- Diabetes Research Centre, University of Leicester, Leicester, UK.,NIHR Collaboration for Leadership in Applied Health Research and Care - East Midlands (NIHR CLAHRC - EM), Leicester, UK
| | - M J Davies
- Diabetes Research Centre, University of Leicester, Leicester, UK.,NIHR Leicester-Loughborough Diet, Lifestyle and Physical Activity Biomedical Research Unit, Leicester & Loughborough, UK
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33
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Darrow MC, Sergeeva OA, Isas JM, Galaz-Montoya JG, King JA, Langen R, Schmid MF, Chiu W. Structural Mechanisms of Mutant Huntingtin Aggregation Suppression by the Synthetic Chaperonin-like CCT5 Complex Explained by Cryoelectron Tomography. J Biol Chem 2015; 290:17451-61. [PMID: 25995452 DOI: 10.1074/jbc.m115.655373] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [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: 03/27/2015] [Indexed: 11/06/2022] Open
Abstract
Huntington disease, a neurodegenerative disorder characterized by functional deficits and loss of striatal neurons, is linked to an expanded and unstable CAG trinucleotide repeat in the huntingtin gene (HTT). This DNA sequence translates to a polyglutamine repeat in the protein product, leading to mutant huntingtin (mHTT) protein aggregation. The aggregation of mHTT is inhibited in vitro and in vivo by the TCP-1 ring complex (TRiC) chaperonin. Recently, a novel complex comprised of a single type of TRiC subunit has been reported to inhibit mHTT aggregation. Specifically, the purified CCT5 homo-oligomer complex, when compared with TRiC, has a similar structure, ATP use, and substrate refolding activity, and, importantly, it also inhibits mHTT aggregation. Using an aggregation suppression assay and cryoelectron tomography coupled with a novel computational classification method, we uncover the interactions between the synthetic CCT5 complex (∼ 1 MDa) and aggregates of mutant huntingtin exon 1 containing 46 glutamines (mHTTQ46-Ex1). We find that, in a similar fashion to TRiC, synthetic CCT5 complex caps mHTT fibrils at their tips and encapsulates mHTT oligomers, providing a structural description of the inhibition of mHTTQ46-Ex1 by CCT5 complex and a shared mechanism of mHTT inhibition between TRiC chaperonin and the CCT5 complex: cap and contain.
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Affiliation(s)
- Michele C Darrow
- From the National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Oksana A Sergeeva
- the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and
| | - Jose M Isas
- the Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Jesús G Galaz-Montoya
- From the National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Jonathan A King
- the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, and
| | - Ralf Langen
- the Zilkha Neurogenetic Institute, Keck School of Medicine, University of Southern California, Los Angeles, California 90033
| | - Michael F Schmid
- From the National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030
| | - Wah Chiu
- From the National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030,
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Ritschel F, King JA, Geisler D, Flohr L, Neidel F, Boehm I, Seidel M, Zwipp J, Ripke S, Smolka MN, Roessner V, Ehrlich S. Temporal delay discounting in acutely ill and weight-recovered patients with anorexia nervosa. Psychol Med 2015; 45:1229-1239. [PMID: 25579471 DOI: 10.1017/s0033291714002311] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
BACKGROUND Patients with anorexia nervosa (AN) are characterized by a very low body weight but readily give up immediate rewards (food) for long-term goals (slim figure), which might indicate an unusual level of self-control. This everyday clinical observation may be quantifiable in the framework of the anticipation-discounting dilemma. METHOD Using a cross-sectional design, this study compared the capacity to delay reward in 34 patients suffering from acute AN (acAN), 33 weight-recovered AN patients (recAN) and 54 healthy controls. We also used a longitudinal study to reassess 21 acAN patients after short-term weight restoration. A validated intertemporal choice task and a hyperbolic model were used to estimate temporal discounting rates. RESULTS Confirming the validity of the task used, decreased delay discounting was associated with age and low self-reported impulsivity. However, no group differences in key measures of temporal discounting of monetary rewards were found. CONCLUSIONS Increased cognitive control, which has been suggested as a key characteristic of AN, does not seem to extend the capacity to wait for delayed monetary rewards. Differences between our study and the only previous study reporting decreased delay discounting in adult AN patients may be explained by the different age range and chronicity of acute patients, but the fact that weight recovery was not associated with changes in discount rates suggests that discounting behavior is not a trait marker in AN. Future studies using paradigms with disorder-specific stimuli may help to clarify the role of delay discounting in AN.
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Affiliation(s)
- F Ritschel
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
| | - J A King
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
| | - D Geisler
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
| | - L Flohr
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
| | - F Neidel
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
| | - I Boehm
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
| | - M Seidel
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
| | - J Zwipp
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
| | - S Ripke
- Department of Psychiatry and Neuroimaging Center,Technische Universität Dresden,Dresden,Germany
| | - M N Smolka
- Department of Psychiatry and Neuroimaging Center,Technische Universität Dresden,Dresden,Germany
| | - V Roessner
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
| | - S Ehrlich
- Department of Child and Adolescent Psychiatry,Faculty of Medicine Carl Gustav Carus of the Technische Universität Dresden,Dresden,Germany
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Serebryany E, King JA. Wild-type human γD-crystallin promotes aggregation of its oxidation-mimicking, misfolding-prone W42Q mutant. J Biol Chem 2015; 290:11491-503. [PMID: 25787081 DOI: 10.1074/jbc.m114.621581] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [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: 10/27/2014] [Indexed: 11/06/2022] Open
Abstract
Non-native protein conformers generated by mutation or chemical damage template aggregation of wild-type, undamaged polypeptides in diseases ranging from amyotrophic lateral sclerosis to cancer. We tested for such interactions in the natively monomeric human eye lens protein γd-crystallin, whose aggregation leads to cataract disease. The oxidation-mimicking W42Q mutant of γd-crystallin formed non-native polymers starting from a native-like state under physiological conditions. Aggregation occurred in the temperature range 35-45 °C, in which the mutant protein began to lose the native conformation of its N-terminal domain. Surprisingly, wild-type γd-crystallin promoted W42Q polymerization in a catalytic manner, even at mutant concentrations too low for homogeneous nucleation to occur. The presence of wild-type protein also downshifted the temperature range of W42Q aggregation. W42Q aggregation required formation of a non-native intramolecular disulfide bond but not intermolecular cross-linking. Transient WT/W42Q binding may catalyze this oxidative misfolding event in the mutant. That a more stable variant in a mixture can specifically promote aggregation of a less stable one rationalizes how extensive aggregation of rare damaged polypeptides can occur during the course of aging.
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Affiliation(s)
- Eugene Serebryany
- From the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Jonathan A King
- From the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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Quintanar L, Serebryany E, Domínguez-Calva JA, Haasse-Pettingell C, King JA. Copper and Zinc Binding Specifically Induce the Aggregation of Human γ-D Crystallin. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.2749] [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] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
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King JA, Sergeeva O, Knee KM. How Do Group Ii Chaperonins Distinguish their Partially Folded Substrates from the Native States? Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.319] [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] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Knee KM, Patel D, Sergeeva O, Kelly JJ, Janz JM, King JA, Yue W, Bulawa C. CCT5: A Model Protein Folding Machine. Biophys J 2015. [DOI: 10.1016/j.bpj.2014.11.318] [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] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
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Saini A, Faulkner SH, Moir H, Warwick P, King JA, Nimmo MA. Interleukin-6 in combination with the interleukin-6 receptor stimulates glucose uptake in resting human skeletal muscle independently of insulin action. Diabetes Obes Metab 2014; 16:931-6. [PMID: 24702712 DOI: 10.1111/dom.12299] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/06/2013] [Revised: 02/26/2014] [Accepted: 03/31/2014] [Indexed: 11/26/2022]
Abstract
AIM To examine if the physiological concentrations of both interleukin-6 (IL-6), in combination with IL-6 receptor (IL-6R), are able to stimulate glucose uptake in human skeletal muscle and to identify the associated signalling pathways. METHODS Skeletal muscle tissue (~60 mg) obtained from healthy female volunteers via muscle biopsy was subjected to incubation in the absence or presence of insulin (60 µU/ml), recombinant human IL-6 (rhIL-6) (4 ng/ml) or a combination of rhIL-6 (4 ng/ml) and rhIL-6R (100 ng/ml) for 30 min, with glucose transport measured for each incubation. Western blot analysis was conducted on key signalling proteins, protein kinase B (PKB/Akt), adenosine monophosphate kinase (AMPK) and mammalian target of rapamycin (mTOR) to gain an early insight into any differing transport mechanisms. RESULTS Human skeletal muscle exhibited increased glucose uptake with insulin (1.85-fold; p < 0.05) and stimulated phosphorylation of PKB/Akt and AMPK (0.98 ± 0.23 and 1.49 ± 0.13, respectively, phosphorylated: total; p < 0.05). IL-6/IL-6R increased phosphorylation of mTOR (fourfold, p < 0.05) compared to insulin, IL-6 alone and basal control. IL-6 did not stimulate glucose uptake but combined with IL-6R, induced 1.5-fold increase in glucose uptake (p < 0.05) and phosphorylation of AMPK (0.95 ± 0.19; phosphorylated: total, p < 0.05). CONCLUSIONS IL-6 in combination with IL-6R and not IL-6 alone increased glucose uptake in human skeletal muscle. IL-6/IL-6R-mediated glucose uptake occurred independently of PKB/Akt phosphorylation, showing that IL-6/IL-6R-induced glucose uptake is dependent on a divergent pathway.
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Affiliation(s)
- A Saini
- School of Sport, Exercise & Health Sciences, Loughborough University, Loughborough, UK
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Sergeeva OA, Tran MT, Haase-Pettingell C, King JA. Biochemical characterization of mutants in chaperonin proteins CCT4 and CCT5 associated with hereditary sensory neuropathy. J Biol Chem 2014; 289:27470-80. [PMID: 25124038 DOI: 10.1074/jbc.m114.576033] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Hereditary sensory neuropathies are a class of disorders marked by degeneration of the nerve fibers in the sensory periphery neurons. Recently, two mutations were identified in the subunits of the eukaryotic cytosolic chaperonin TRiC, a protein machine responsible for folding actin and tubulin in the cell. C450Y CCT4 was identified in a stock of Sprague-Dawley rats, whereas H147R CCT5 was found in a human Moroccan family. As with many genetically identified mutations associated with neuropathies, the underlying molecular basis of the mutants was not defined. We investigated the biochemical properties of these mutants using an expression system in Escherichia coli that produces homo-oligomeric rings of CCT4 and CCT5. Full-length versions of both mutant protein chains were expressed in E. coli at levels approaching that of the WT chains. Sucrose gradient centrifugation revealed chaperonin-sized complexes of both WT and mutant chaperonins, but with reduced recovery of C450Y CCT4 soluble subunits. Electron microscopy of negatively stained samples of C450Y CCT4 revealed few ring-shaped species, whereas WT CCT4, H147R CCT5, and WT CCT5 revealed similar ring structures. CCT5 complexes were assayed for their ability to suppress aggregation of and refold the model substrate γd-crystallin, suppress aggregation of mutant huntingtin, and refold the physiological substrate β-actin in vitro. H147R CCT5 was not as efficient in chaperoning these substrates as WT CCT5. The subtle effects of these mutations are consistent with the homozygous disease phenotype, in which most functions are carried out during development and adulthood, but some selective function is lost or reduced.
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Affiliation(s)
- Oksana A Sergeeva
- From the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Meme T Tran
- From the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Cameron Haase-Pettingell
- From the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | - Jonathan A King
- From the Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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Gipson P, Baker ML, Raytcheva D, Haase-Pettingell C, Piret J, King JA, Chiu W. Protruding knob-like proteins violate local symmetries in an icosahedral marine virus. Nat Commun 2014; 5:4278. [PMID: 24985522 PMCID: PMC4102127 DOI: 10.1038/ncomms5278] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [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: 12/20/2013] [Accepted: 06/03/2014] [Indexed: 02/02/2023] Open
Abstract
Marine viruses play crucial roles in shaping the dynamics of oceanic microbial communities and in the carbon cycle on Earth. Here we report a 4.7-Å structure of a cyanobacterial virus, Syn5, by electron cryo-microscopy and modelling. A Cα backbone trace of the major capsid protein (gp39) reveals a classic phage protein fold. In addition, two knob-like proteins protruding from the capsid surface are also observed. Using bioinformatics and structure analysis tools, these proteins are identified to correspond to gp55 and gp58 (each with two copies per asymmetric unit). The non 1:1 stoichiometric distribution of gp55/58 to gp39 breaks all expected local symmetries and leads to non-quasi-equivalence of the capsid subunits, suggesting a role in capsid stabilization. Such a structural arrangement has not yet been observed in any known virus structures.
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Affiliation(s)
- Preeti Gipson
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Matthew L Baker
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
| | - Desislava Raytcheva
- 1] Department of Microbiology, Northeastern University, Boston, Massachusetts 02115, USA [2] Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Cameron Haase-Pettingell
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Jacqueline Piret
- Department of Microbiology, Northeastern University, Boston, Massachusetts 02115, USA
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
| | - Wah Chiu
- Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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Serebryany E, King JA. The βγ-crystallins: native state stability and pathways to aggregation. Prog Biophys Mol Biol 2014; 115:32-41. [PMID: 24835736 DOI: 10.1016/j.pbiomolbio.2014.05.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2014] [Revised: 04/30/2014] [Accepted: 05/02/2014] [Indexed: 01/26/2023]
Abstract
The βγ-crystallins are among the most stable and long-lived proteins in the human body. With increasing age, however, they transform to high molecular weight light-scattering aggregates, resulting in cataracts. This occurs despite the presence in the lens of high concentrations of the a-crystallin chaperones. Aggregation of crystallins can be induced in vitro by a variety of stresses, including acidic pH, ultraviolet light, oxidative damage, heating or freezing, and specific amino acid substitutions. Accumulating evidence points to the existence of specific biochemical pathways of protein: protein interaction and polymerization. We review the methods used for studying crystallin stability and aggregation and discuss the sometimes counterintuitive relationships between factors that favor native state stability and those that favor non-native aggregation. We discuss the behavior of βγ-crystallins in mixtures and their chaperone ability; the consequences of missense mutations and covalent damage to the side-chains; and the evolutionary strategies that have shaped these proteins. Efforts are ongoing to reveal the nature of cataractous crystallin aggregates and understand the mechanisms of aggregation in the context of key models of protein polymerization: amyloid, native-state, and domain-swapped. Such mechanistic understanding is likely to be of value for the development of therapeutic interventions and draw attention to unanswered questions about the relationship between a protein's native state stability and its transformation to an aggregated state.
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Affiliation(s)
- Eugene Serebryany
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA, United States.
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Sergeeva OA, Yang J, King JA, Knee KM. Group II archaeal chaperonin recognition of partially folded human γD-crystallin mutants. Protein Sci 2014; 23:693-702. [PMID: 24615724 DOI: 10.1002/pro.2452] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [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: 12/04/2013] [Revised: 02/24/2014] [Accepted: 03/04/2014] [Indexed: 11/12/2022]
Abstract
The features in partially folded intermediates that allow the group II chaperonins to distinguish partially folded from native states remain unclear. The archaeal group II chaperonin from Methanococcus Mauripaludis (Mm-Cpn) assists the in vitro refolding of the well-characterized β-sheet lens protein human γD-crystallin (HγD-Crys). The domain interface and buried cores of this Greek key conformation include side chains, which might be exposed in partially folded intermediates. We sought to assess whether particular features buried in the native state, but absent from the native protein surface, might serve as recognition signals. The features tested were (a) paired aromatic side chains, (b) side chains in the interface between the duplicated domains of HγD-Crys, and (c) side chains in the buried core which result in congenital cataract when substituted. We tested the Mm-Cpn suppression of aggregation of these HγD-Crys mutants upon dilution out of denaturant. Mm-Cpn was capable of suppressing the off-pathway aggregation of the three classes of mutants indicating that the buried residues were not recognition signals. In fact, Mm-Cpn recognized the HγD-Crys mutants better than (wild-type) WT and refolded most mutant HγD-Crys to levels twice that of WT HγD-Crys. This presumably represents the increased population or longer lifetimes of the partially folded intermediates of the mutant proteins. The results suggest that Mm-Cpn does not recognize the features of HγD-Crys tested-paired aromatics, exposed domain interface, or destabilized core-but rather recognizes other features of the partially folded β-sheet conformation that are absent or inaccessible in the native state of HγD-Crys.
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Affiliation(s)
- Oksana A Sergeeva
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts, 02139
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Abstract
Advances in electron cryo-tomography open up a new avenue to visualize the 3-D
internal structure of a single bacterium before and after its infection by
bacteriophages in its native environment, without using chemical fixatives,
fluorescent dyes or negative stains. Such direct observation reveals the
presence of assembly intermediates of the bacteriophage and thus allows us to
map out the maturation pathway of the bacteriophage inside its host.
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Affiliation(s)
- Wei Dai
- National Center for Macromolecular Imaging, Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030 USA
| | - Michael F Schmid
- National Center for Macromolecular Imaging, Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030 USA
| | - Jonathan A King
- Department of Biology, Massachusetts Institute of Technology, Cambridge, MA 02139 USA
| | - Wah Chiu
- National Center for Macromolecular Imaging, Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030 USA
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Yang Z, Xia Z, Huynh T, King JA, Zhou R. Dissecting the contributions of β-hairpin tyrosine pairs to the folding and stability of long-lived human γD-crystallins. Nanoscale 2014; 6:1797-807. [PMID: 24352614 PMCID: PMC3976203 DOI: 10.1039/c3nr03782g] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/15/2023]
Abstract
Ultraviolet-radiation-induced damage to and aggregation of human lens crystallin proteins are thought to be a significant pathway to age-related cataract. The aromatic residues within the duplicated Greek key domains of γ- and β-crystallins are the main ultraviolet absorbers and are susceptible to direct and indirect ultraviolet damage. The previous site-directed mutagenesis studies have revealed a striking difference for two highly conserved homologous β-hairpin Tyr pairs, at the N-terminal domain (N-td) and C-terminal domain (C-td), respectively, in their contribution to the overall stability of HγD-Crys, but why they behave so differently still remains a mystery. In this paper, we systematically investigated the underlying molecular mechanism and detailed contributions of these two Tyr pairs with large scale molecular dynamics simulations. A series of different tyrosine-to-alanine pair(s) substitutions were performed in either the N-td, the C-td, or both. Our results suggest that the Y45A/Y50A pair substitution in the N-td mainly affects the stability of the N-td itself, while the Y133A/Y138A pair substitution in the C-td leads to a more cooperative unfolding of both N-td and C-td. The stability of motif 2 in the N-td is mainly determined by the interdomain interface, while motif 1 in the N-td or motifs 3 and 4 in the C-td are mainly stabilized by the intradomain hydrophobic core. The damage to any tyrosine pair(s) can directly introduce some apparent water leakage to the hydrophobic core at the interface, which in turn causes a serious loss in the stability of the N-td. However, for the C-td substitutions, it may further impair the stable "sandwich-like" Y133-R167-Y138 cluster (through cation-π interactions) in the wild-type, thus causing the loop regions near the residue A138 to undergo large fluctuations, which in turn results in the intrusion of water into the hydrophobic core of the C-td and induces the C-td to lose its stability. These findings help resolve the "mystery" on why these two Tyr pairs display such a striking difference in their contributions to the overall protein stability despite their highly homologous nature.
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Affiliation(s)
- Zaixing Yang
- Institute of Quantitative Biology and Medicine, SRMP and RAD-X & Collaborative Innovation Center of Suzhou Nano Science and Technology, Jiangsu Provincial Key Laboratory of Radiation Medicine and Protection, Soochow University, Suzhou 215123, China.
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Dai W, Fu C, Raytcheva D, Flanagan J, Khant HA, Liu X, Rochat RH, Haase-Pettingell C, Piret J, Ludtke SJ, Nagayama K, Schmid MF, King JA, Chiu W. Visualizing virus assembly intermediates inside marine cyanobacteria. Nature 2013; 502:707-10. [PMID: 24107993 PMCID: PMC3984937 DOI: 10.1038/nature12604] [Citation(s) in RCA: 103] [Impact Index Per Article: 9.4] [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: 05/31/2013] [Accepted: 08/27/2013] [Indexed: 12/31/2022]
Abstract
Cyanobacteria are photosynthetic organisms responsible for ~25% of organic carbon fixation on earth. These bacteria began to convert solar energy and carbon dioxide into bioenergy and oxygen billions of years ago. Cyanophages, which infect these bacteria, play an important role in regulating the marine ecosystem by controlling cyanobacteria community organization and mediating lateral gene transfer. Here we visualize the maturation process of cyanophage Syn5 inside its host cell, Synechococcus, using Zernike Phase Contrast (ZPC) electron cryo-tomography (cryoET)1,2. This imaging modality yields significant enhancement of image contrast over conventional cryoET and thus facilitates the direct identification of subcellular components, including thylakoid membranes, carboxysomes and polyribosomes, as well as phages, inside the congested cytosol of the infected cell. By correlating the structural features and relative abundance of viral progeny within cells at different stages of infection, we identified distinct Syn5 assembly intermediates. Our results suggest that the procapsid releases scaffolding proteins and expands its volume at an early stage of genome packaging. Later in assembly, we detected full particles with a tail either with or without an additional horn. The morphogenetic pathway we describe herein is highly conserved and was probably established long before that of double stranded DNA (dsDNA) viruses infecting higher life forms.
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Affiliation(s)
- Wei Dai
- National Center for Macromolecular Imaging, Verna and Marrs Mclean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, USA
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Abstract
Being physically active and undertaking exercise on a regular basis are critical lifestyle behaviours which protect against the development of numerous chronic metabolic conditions. One of the key mechanisms by which physical activity exerts favourable health effects appears to be due to its capacity to reduce chronic low-grade inflammation. Single bouts of exercise have a potent anti-inflammatory influence with recent advances describing important effects of acute exercise on inflammatory mediators produced within skeletal muscle (myokines), adipose tissue (adipokines) and leucocytes. The accumulated effects of physical activity or exercise training on systemic inflammation have been studied widely within epidemiological research; however, information from intervention trials is still emerging. Current data suggest that the most marked improvements in the inflammatory profile are conferred with exercise performed at higher intensities, with combined aerobic and resistance exercise training potentially providing the greatest benefit. The purpose of this review is to describe recent advances in our understanding surrounding the acute and chronic effects of physical activity on key mediators of inflammation. Within this, particular attention is given to the interleukin-6 system owing to its apparent centrality in mediating the anti-inflammatory effects of exercise.
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Affiliation(s)
- M A Nimmo
- School of Sport, Exercise and Health Sciences, Loughborough University, Loughborough, Leicestershire, UK.
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48
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Sergeeva OA, Chen B, Haase-Pettingell C, Ludtke SJ, Chiu W, King JA. Human CCT4 and CCT5 chaperonin subunits expressed in Escherichia coli form biologically active homo-oligomers. J Biol Chem 2013; 288:17734-44. [PMID: 23612981 DOI: 10.1074/jbc.m112.443929] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chaperonins are a family of chaperones that encapsulate their substrates and assist their folding in an ATP-dependent manner. The ubiquitous eukaryotic chaperonin, TCP-1 ring complex (TRiC), is a hetero-oligomeric complex composed of two rings, each formed from eight different CCT (chaperonin containing TCP-1) subunits. Each CCT subunit may have distinct substrate recognition and ATP hydrolysis properties. We have expressed each human CCT subunit individually in Escherichia coli to investigate whether they form chaperonin-like double ring complexes. CCT4 and CCT5, but not the other six CCT subunits, formed high molecular weight complexes within the E. coli cells that sedimented about 20S in sucrose gradients. When CCT4 and CCT5 were purified, they were both organized as two back-to-back rings of eight subunits each, as seen by negative stain and cryo-electron microscopy. This morphology is consistent with that of the hetero-oligomeric double-ring TRiC purified from bovine testes and HeLa cells. Both CCT4 and CCT5 homo-oligomers hydrolyzed ATP at a rate similar to human TRiC and were active as assayed by luciferase refolding and human γD-crystallin aggregation suppression and refolding. Thus, both CCT4 and CCT5 homo-oligomers have the property of forming 8-fold double rings absent the other subunits, and these complexes carry out chaperonin reactions without other partner subunits.
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Affiliation(s)
- Oksana A Sergeeva
- Department of Biology, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA
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49
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Knee KM, Sergeeva OA, King JA. Human TRiC complex purified from HeLa cells contains all eight CCT subunits and is active in vitro. Cell Stress Chaperones 2013; 18:137-44. [PMID: 23011926 PMCID: PMC3581623 DOI: 10.1007/s12192-012-0357-z] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2012] [Revised: 07/10/2012] [Accepted: 07/13/2012] [Indexed: 10/28/2022] Open
Abstract
Archaeal and eukaryotic cytosols contain group II chaperonins, which have a double-barrel structure and fold proteins inside a cavity in an ATP-dependent manner. The most complex of the chaperonins, the eukaryotic TCP-1 ring complex (TRiC), has eight different subunits, chaperone containing TCP-1 (CCT1-8), that are arranged so that there is one of each subunit per ring. Aspects of the structure and function of the bovine and yeast TRiC have been characterized, but studies of human TRiC have been limited. We have isolated and purified endogenous human TRiC from HeLa suspension cells. This purified human TRiC contained all eight CCT subunits organized into double-barrel rings, consistent with what has been found for bovine and yeast TRiC. The purified human TRiC is active as demonstrated by the luciferase refolding assay. As a more stringent test, the ability of human TRiC to suppress the aggregation of human γD-crystallin was examined. In addition to suppressing off-pathway aggregation, TRiC was able to assist the refolding of the crystallin molecules, an activity not found with the lens chaperone, α-crystallin. Additionally, we show that human TRiC from HeLa cell lysate is associated with the heat shock protein 70 and heat shock protein 90 chaperones. Purification of human endogenous TRiC from HeLa cells will enable further characterization of this key chaperonin, required for the reproduction of all human cells.
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Affiliation(s)
- Kelly M. Knee
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Ave., 68-330, Cambridge, MA 02139 USA
| | - Oksana A. Sergeeva
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Ave., 68-330, Cambridge, MA 02139 USA
| | - Jonathan A. King
- Department of Biology, Massachusetts Institute of Technology, 77 Massachusetts Ave., 68-330, Cambridge, MA 02139 USA
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Abstract
A single subunit DNA-dependent RNA polymerase was identified and purified to apparent homogeneity from cyanophage Syn5 that infects the marine cyanobacteria Synechococcus. Syn5 is homologous to bacteriophage T7 that infects Escherichia coli. Using the purified enzyme its promoter has been identified by examining transcription of segments of Syn5 DNA and sequencing the 5'-termini of the transcripts. Only two Syn5 RNAP promoters, having the sequence 5'-ATTGGGCACCCGTAA-3', are found within the Syn5 genome. One promoter is located within the Syn5 RNA polymerase gene and the other is located close to the right genetic end of the genome. The purified enzyme and its promoter have enabled a determination of the requirements for transcription. Unlike the salt-sensitive bacteriophage T7 RNA polymerase, this marine RNA polymerase requires 160 mm potassium for maximal activity. The optimal temperature for Syn5 RNA polymerase is 24 °C, much lower than that for T7 RNA polymerase. Magnesium is required as a cofactor although some activity is observed with ferrous ions. Syn5 RNA polymerase is more efficient in utilizing low concentrations of ribonucleotides than T7 RNA polymerase.
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Affiliation(s)
- Bin Zhu
- Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, Massachusetts 02115, USA.
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