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Khan MF, Paul Guin J, Thampi RK, Sullivan JA, Murphy CD. Enhanced removal of perfluorooctanoic acid with sequential photocatalysis and fungal treatment. Environ Sci Pollut Res Int 2023; 30:91478-91486. [PMID: 37474853 PMCID: PMC10439853 DOI: 10.1007/s11356-023-28588-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2023] [Accepted: 06/30/2023] [Indexed: 07/22/2023]
Abstract
In this paper, we report the degradation of perfluorooctanoic acid (PFOA), which is a persistent contaminant in the environment that can severely impact human health, by exposing it to a photocatalyst, bismuth oxyiodide (BiOI), containing both Bi4O5I2 and Bi5O7I phases and a fungal biocatalyst (Cunninghamella elegans). Individually, the photocatalyst (after 3 h) and biocatalyst (after 48 h) degraded 35-40% of 100 ppm PFOA with 20-30% defluorination. There was a marked improvement in the degree of degradation (90%) and defluorination (60%) when PFOA was first photocatalytically treated, then exposed to the fungus. GC- and LC-MS analysis identified the products formed by the different treatments. Photocatalytic degradation of PFOA yielded short-chain perfluorocarboxylic acids, whereas fungal degradation yielded mainly 5:3 fluorotelomer carboxylic acid, which is a known inhibitor of cytochrome P450-catalysed degradation of PFAS in C. elegans. The combined treatment likely resulted in greater degradation because photocatalysis reduced the PFOA concentration without generating the inhibitory 5:3 fluorotelomer carboxylic acid, enabling the fungus to remove most of the remaining substrate. In addition, new fluorometabolites were identified that shed light on the initial catabolic steps involved in PFOA biodegradation.
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Affiliation(s)
- Mohd Faheem Khan
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield , Dublin 4, Ireland
| | - Jhimli Paul Guin
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Ravindranathan K Thampi
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield, Dublin 4, Ireland
| | - James A Sullivan
- School of Chemistry, University College Dublin, Belfield, Dublin 4, Ireland
| | - Cormac D Murphy
- School of Biomolecular and Biomedical Science, University College Dublin, Belfield , Dublin 4, Ireland.
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Guin JP, Sullivan JA, Muldoon J, Thampi KR. Visible light induced degradation of perfluorooctanoic acid using iodine deficient bismuth oxyiodide photocatalyst. J Hazard Mater 2023; 458:131897. [PMID: 37385096 DOI: 10.1016/j.jhazmat.2023.131897] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/10/2023] [Revised: 06/09/2023] [Accepted: 06/17/2023] [Indexed: 07/01/2023]
Abstract
A bismuth oxyiodide photocatalyst having coexistent iodine deficient phases viz. Bi4O5I2 and Bi5O7I was prepared by using a solvothermal method followed by calcination process. This has been used for the degradation of model perfluoroalkyl acids such as perfluorooctanoic acid at low concentrations (1 ppm) under simulated solar light irradiation. 94% PFOA degradation with a rate constant of 1.7 h-1 and 65% defluorination of PFOA have been achieved following 2 h of photocatalysis. The degradation of PFOA happened by the parallel direct redox reactions with high energy photoexcited electrons at the conduction band, electrons in iodine vacancies and superoxide radicals. The degradation intermediates were analyzed by electrospray ionization-mass spectrometry in the negative mode. The catalyst was converted to a more iodine deficient Bi5O7I phase during photocatalysis following creation of iodine vacancies, some of which were compensated by the fluoride ions released from degraded PFOA.
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Affiliation(s)
- Jhimli Paul Guin
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield Dublin 4, Ireland; School of Chemistry, University College Dublin, Belfield Dublin 4, Ireland.
| | - James A Sullivan
- School of Chemistry, University College Dublin, Belfield Dublin 4, Ireland.
| | - Jimmy Muldoon
- School of Chemistry, University College Dublin, Belfield Dublin 4, Ireland
| | - K Ravindranathan Thampi
- School of Chemical and Bioprocess Engineering, University College Dublin, Belfield Dublin 4, Ireland.
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Orsi AD, Wakelin EA, Plaskos C, Gupta S, Sullivan JA. Predictive Gap-balancing Reduces the Extent of Soft-tissue Adjustment Required After Bony Resection in Robot-assisted Total Knee Arthroplasty-A Comparison With Simulated Measured Resection. Arthroplast Today 2022; 16:1-8. [PMID: 35620585 PMCID: PMC9126743 DOI: 10.1016/j.artd.2022.03.025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 02/24/2022] [Accepted: 03/30/2022] [Indexed: 11/28/2022] Open
Abstract
Background To understand the extent and frequency of soft-tissue adjustment required to achieve mediolateral (ML) balance in measured resection (MR) vs gap-balancing (GB) total knee arthroplasty, this study compared ML balance and joint laxity throughout flexion between the 2 techniques. The precision of predictive GB in achieving ML balance and laxity was also assessed. Methods Two surgeons performed 95 robot-assisted GB total knee arthroplasties with predictive balancing, limiting tibial varus to 3° and adjusting femoral positioning to optimize balance. A robotic ligament tensioner measured joint laxity. Planned MR (pMR) was simulated by applying neutral tibial and femoral coronal resections and 3° of external femoral rotation. ML balance, laxity, component alignment, and resection depths were compared between planned GB (pGB) and pMR. ML balance and laxity were compared between pGB and final GB (fGB). Results The proportion of knees with >2 mm of ML imbalance in flexion or extension ranged from 3% to 18% for pGB vs 50% to 53% for pMR (P < .001). Rates of ML imbalance >3 mm ranged from 0% to 9% for pGB and 30% to 38% for MR (P < .001). The mean pMR laxity was 1.9 mm tighter medially and 1.1 mm tighter laterally than pGB throughout flexion. The mean fGB laxity was greater than the mean pGB laxity by 0.5 mm medially and 1.2 mm laterally (P < .001). Conclusion MR led to tighter joints than GB, with ML gap imbalances >3 mm in 30% of knees. GB planning improved ML balance throughout flexion but increased femoral posterior rotation variability and bone resection compared to MR. fGB laxity was likely not clinically significantly different than pGB.
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Affiliation(s)
| | | | | | - Sanjeev Gupta
- Department of Surgery, Royal Prince Alfred Hospital, Sydney, New South Wales, Australia
| | - James A. Sullivan
- Department of Surgery, Macquarie University Hospital, Sydney, New South Wales, Australia
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Morais E, O'Modhrain C, Thampi KR, Sullivan JA. RuO2/TiO2 photocatalysts prepared via a hydrothermal route: Influence of the presence of TiO2 on the reactivity of RuO2 in the artificial photosynthesis reaction. J Catal 2021. [DOI: 10.1016/j.jcat.2021.08.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Tellman B, Sullivan JA, Kuhn C, Kettner AJ, Doyle CS, Brakenridge GR, Erickson TA, Slayback DA. Satellite imaging reveals increased proportion of population exposed to floods. Nature 2021; 596:80-86. [PMID: 34349288 DOI: 10.1038/s41586-021-03695-w] [Citation(s) in RCA: 91] [Impact Index Per Article: 30.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 06/03/2021] [Indexed: 11/09/2022]
Abstract
Flooding affects more people than any other environmental hazard and hinders sustainable development1,2. Investing in flood adaptation strategies may reduce the loss of life and livelihood caused by floods3. Where and how floods occur and who is exposed are changing as a result of rapid urbanization4, flood mitigation infrastructure5 and increasing settlements in floodplains6. Previous estimates of the global flood-exposed population have been limited by a lack of observational data, relying instead on models, which have high uncertainty3,7-11. Here we use daily satellite imagery at 250-metre resolution to estimate flood extent and population exposure for 913 large flood events from 2000 to 2018. We determine a total inundation area of 2.23 million square kilometres, with 255-290 million people directly affected by floods. We estimate that the total population in locations with satellite-observed inundation grew by 58-86 million from 2000 to 2015. This represents an increase of 20 to 24 per cent in the proportion of the global population exposed to floods, ten times higher than previous estimates7. Climate change projections for 2030 indicate that the proportion of the population exposed to floods will increase further. The high spatial and temporal resolution of the satellite observations will improve our understanding of where floods are changing and how best to adapt. The global flood database generated from these observations will help to improve vulnerability assessments, the accuracy of global and local flood models, the efficacy of adaptation interventions and our understanding of the interactions between landcover change, climate and floods.
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Affiliation(s)
- B Tellman
- Earth Institute, Columbia University, New York, NY, USA. .,Cloud to Street, Brooklyn, NY, USA. .,School of Geography, Development and Environment, University of Arizona, Tucson, AZ, USA.
| | - J A Sullivan
- Cloud to Street, Brooklyn, NY, USA.,School of Geography, Development and Environment, University of Arizona, Tucson, AZ, USA.,School for Environment and Sustainability, University of Michigan, Ann Arbor, MI, USA
| | - C Kuhn
- School of Environmental and Forest Sciences, University of Washington, Seattle, WA, USA
| | - A J Kettner
- INSTAAR, Dartmouth Flood Observatory, University of Colorado, Boulder, CO, USA
| | - C S Doyle
- Cloud to Street, Brooklyn, NY, USA.,Department of Geography and the Environment, University of Texas, Austin, TX, USA
| | - G R Brakenridge
- INSTAAR, Dartmouth Flood Observatory, University of Colorado, Boulder, CO, USA
| | | | - D A Slayback
- Science Systems and Applications Inc., Biospheric Sciences Lab, NASA Goddard Space Flight Center, Greenbelt, MD, USA
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Morais E, Moloney C, O'Modhrain C, McKiernan E, Brougham DF, Sullivan JA. Enhanced Stability and Emission Properties of Perylene Dyes by Surface Tethering: Preparation of Fluorescent Ru Nanoparticle Suspensions by Alkyne Linker Chemistry. Chemistry 2021; 27:1023-1030. [PMID: 33022835 DOI: 10.1002/chem.202003514] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 09/25/2020] [Indexed: 11/06/2022]
Abstract
Spherical ruthenium nanoparticles (NPs) with a narrow size distribution were synthesised in ethanol by a facile low-temperature solvothermal process without the assistance of templates, structure-directing agents or post annealing/reduction treatments. Surface passivation with a fluorescent perylene dye (EP), and with silane ligands (ETMS), both initially bearing alkyne groups and subsequently forming vinylidene linkages, provided stable suspensions of the marginally soluble free EP. Quantitative analysis of the suspension gave an estimated EP surface coverage of 15 %, corresponding to an EP/ETMS mole ratio of ≈1:6. Photophysical evaluation of the bound and free dye revealed similar absorption bands and extinction coefficients and improved properties for the bound state, including enhanced fluorescence in the visible range for the bound dye, an extended absorption range into the near-UV providing strong emission in the visible, and significantly improved photostability. The physical basis of the enhanced photophysical properties, potential routes to further improvements and the implications for applications are discussed.
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Affiliation(s)
| | - Cara Moloney
- UCD School of Chemistry, Belfield, Dublin, 4, Ireland
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Morais E, Stanley K, Thampi KR, Sullivan JA. Scope for Spherical Bi2WO6 Quazi-Perovskites in the Artificial Photosynthesis Reaction—The Effects of Surface Modification with Amine Groups. Catal Letters 2020. [DOI: 10.1007/s10562-020-03299-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Affiliation(s)
- Eduardo Morais
- School of ChemistryUniversity College Dublin Belfield, Dublin 4 Dublin Ireland
| | - K. Ravindranathan Thampi
- School of Chemical and Bioprocessing EngineeringUniversity College Dublin Belfield, Dublin 4 Dublin Ireland
| | - James A. Sullivan
- School of ChemistryUniversity College Dublin Belfield, Dublin 4 Dublin Ireland
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Almohammadi G, O’Modhrain C, Kelly S, Sullivan JA. Ti-Doped SBA-15 Catalysts Used in Phenol Oxidation Reactions. ACS Omega 2020; 5:791-798. [PMID: 31956830 PMCID: PMC6964512 DOI: 10.1021/acsomega.9b03530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Accepted: 12/05/2019] [Indexed: 06/10/2023]
Abstract
Two Ti-SBA-15 catalysts are synthesized using techniques that should either deposit Ti atoms specifically at the SBA-15 surface or allow Ti-containing species to exist at both the surface and within the bulk of SBA-15. The materials have been characterized by Fourier transform infrared (FTIR), Raman and UV visible spectroscopies, transmission electron microscopy, scanning electron microscopy/energy-dispersive X-ray spectrometry microscopies, and N2 physisorption experiments. They have been applied in the total oxidation of phenol under catalytic wet air oxidation (CWAO) conditions and using photo- and plasma promotion. The materials retain the structure of SBA-15 following the doping in both cases and Ti incorporation is confirmed. The nature of the incorporated Ti remains unclear-with evidence for anatase TiO2 (from Raman and UV vis analysis) and evidence for atomically dispersed Ti from FTIR. In terms of reactivity, the presence of Ti in the in situ-prepared catalyst improves reactivity in the photopromoted reaction (increasing conversion from 28 to 60%), while both Ti catalysts improve reactivity in the CWAO reaction (by 7% over the in situ catalyst and by 25% over the grafted material). The presence of Ti has no beneficial effect on conversion in the plasma-promoted reaction. Here, however, Ti does affect the nature of the oxidized intermediates formed during the total phenol oxidation.
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Kelly S, Sullivan JA. CO 2 Decomposition in CO 2 and CO 2 /H 2 Spark-like Plasma Discharges at Atmospheric Pressure. ChemSusChem 2019; 12:3785-3791. [PMID: 31269325 DOI: 10.1002/cssc.201901744] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2019] [Indexed: 06/09/2023]
Abstract
In this work, a spark-like plasma discharge is ignited in pure CO2 and in CO2 /H2 mixtures to investigate CO formation. Power pulsing is used to limit arc formation to sustain a high current transient "spark-like" plasma consisting of a mixed mode discharge comprising an initial current pulse ("spark") followed by a longer-lived glow mode thorough each half cycle of the applied voltage. In pure CO2 , the efficiency ranged between 20-50 % for CO2 conversions between 9-18 % for gas residence times of 100-600 ms. Adding H2 as a co-reactant was investigated for a wide range of mixture ratios. The outlet gas was found to produce O2 -free mixtures of CO/H2 /CO2 . Conversion rates in CO2 /H2 mixtures are found to be similar to pure CO2 at equivalent residence times. The primary role of H2 as a co-reactant is therefore found to be the removal of O2 formed during dissociation of CO2 . The energy cost of this dilution resulted in reduced efficiency for CO2 conversion (from 41 to 18 %), which is correlated to the efficiency drop found for pure CO2 conversion at lower flows. Opportunities for optimising this small volume "unit-cell" spark reactor are encouraged by the results presented. This approach could enable deployment of serial or parallel combinations of such reactors capable of dealing cost-effectively with the conversion of the larger CO2 and CO2 /H2 volumes required in future industry applications.
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Affiliation(s)
- Seán Kelly
- School of Chemistry, University College Dublin, Bellfield, Dublin, 4, Ireland
| | - James A Sullivan
- School of Chemistry, University College Dublin, Bellfield, Dublin, 4, Ireland
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12
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Herron R, Marchant C, Sullivan JA. Co-SBA-15 catalysts in the hydrolysis of NH3BH3 – Influences of Co precursors and catalyst pre-treatment. CATAL COMMUN 2018. [DOI: 10.1016/j.catcom.2018.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
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Derstine BA, Holcombe SA, Goulson RL, Ross BE, Wang NC, Sullivan JA, Su GL, Wang SC. Quantifying Sarcopenia Reference Values Using Lumbar and Thoracic Muscle Areas in a Healthy Population. J Nutr Health Aging 2017; 21:180-185. [PMID: 29300439 DOI: 10.1007/s12603-017-0983-3] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
BACKGROUND Sarcopenia is defined as the loss of skeletal muscle mass and function associated with aging. Muscle mass can be reliably and accurately quantified using clinical CT scans but reference measurements are lacking, particularly in healthy US populations. METHODS Two-phase CT scans from healthy kidney donors (age 18-40) at the University of Michigan between 1999-2010 were utilized. Muscle mass was quantified using two thoracic and two lumbar muscle cross-sectional area (CSA) measures. Indexed measurements were computed as area divided by height-squared. Paired analyses of non-contrast and contrast phases and different Hounsfield Unit (HU) ranges for muscle were conducted to determine their effect on CSA muscle measures. We report the means, standard deviations, and 2SD sarcopenia cutoffs from this population. RESULTS Healthy population CSA (cm2) cutoffs for N=604 males/females respectively were: 34.7/20.9 (T12 Dorsal Muscle), 91.5/55.9 (T12 Skeletal Muscle), 141.7/91.2 (L3 Skeletal Muscle), 23.5/14.3 (L4 Total Psoas Area), and 23.4/14.3 (L4 Psoas Muscle Area). Height-indexed CSA (cm2/m2) cutoffs for males/females respectively were: 10.9/7.8 (T12 Dorsal Muscle), 28.7/20.6 (T12 Skeletal Muscle), 44.6/34.0 (L3 Skeletal Muscle), 7.5/5.2 (L4 Total Psoas Area), and 7.4/5.2 (L4 Psoas Muscle Area). We confirmed that a mask of -29 to 150 HU is optimal and shows no significant difference between contrast-enhanced and non-contrast CT scan CSA measurements. CONCLUSIONS We quantified reference values for lumbar and thoracic muscle CSA measures in a healthy US population. We defined the effect of IV contrast and different HU ranges for muscle. Combined, these results facilitate the extraction of clinically valuable data from the large numbers of existing scans performed for medical indications.
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Affiliation(s)
- B A Derstine
- S.C. Wang, Morphomics Analysis Group, University of Michigan, Ann Arbor, MI, USA,
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Abstract
Historically one of the basic foundations of the genetic counseling process has been nondirectiveness; however, its definition and utility continues to be in question. There remains a need to develop genetic counseling interventions in order to qualify, quantify, measure, and enhance the genetic counseling process as well as to delineate the complex interactions of education and counseling that occur. We propose a framework for genetic counseling interventions utilizing an empowerment perspective and Lazarus and Folkman's adaptation of the theory of stress and coping. This model frames the genetic counseling process as one that promotes the autonomy of the individual by providing the individual with the tools required to make their own decisions and enhances coping and adjustment to the outcome of those decisions through control and mastery.
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Affiliation(s)
- A McConkie-Rosell
- Department of Pediatrics, Division of Medical Genetics, Duke University Medical Center, Durham, North Carolina, 27710,
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Akkaya BG, Zolnerciks JK, Ritchie TK, Bauer B, Hartz AMS, Sullivan JA, Linton KJ. The multidrug resistance pump ABCB1 is a substrate for the ubiquitin ligase NEDD4-1. Mol Membr Biol 2015; 32:39-45. [PMID: 26006083 DOI: 10.3109/09687688.2015.1023378] [Citation(s) in RCA: 18] [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: 01/26/2023]
Abstract
The ATP Binding Cassette transporter ABCB1 can export the neurotoxic peptide β-amyloid from endothelial cells that line the blood-brain barrier (BBB). This has the potential to lower cerebral levels of β-amyloid, but ABCB1 expression in the BBB appears to be progressively reduced in patients with Alzheimer's disease. The surface density of many membrane proteins is regulated by ubiquitination catalyzed by ubiquitin E3 ligases. In brain capillaries of mice challenged with β-amyloid ex vivo, we show that the level of the ubiquitin ligase Nedd4 increases concomitant with reduction in Abcb1. In vitro we show that human ABCB1 is a substrate for human NEDD4-1 ligase. Recombinant ABCB1 was purified from Sf21 insect cells and incubated with recombinant NEDD4-1 purified from Escherichia coli. The treated ABCB1 had reduced mobility on SDS-PAGE, and mass spectrometry identified eight lysine residues, K271, K272, K575, K685, K877, K885, K887 and K1062 that were ubiquitinated by NEDD4-1. Molecular modelling showed that all of the residues are exposed on the surface of the intracellular domains of ABCB1. K877, K885 and K887 in particular, are located in the intracellular loop of transmembrane helix 10 (TMH10) in close proximity, in the tertiary fold, to a putative NEDD4-1 binding site in the intracellular helix extending from TMH12 (PxY motif, residues 996-998). Transient expression of NEDD4-1 in HEK293 Flp-In cells stably expressing ABCB1 was shown to reduce the surface density of the transporter. Together, the data identify this ubiquitin ligase as a potential target for intervention in the pathophysiology of Alzheimer's disease.
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Affiliation(s)
- Begum G Akkaya
- Blizard Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London , London , UK
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Sullivan JA, Tong JL, Wong M, Kumar A, Sarkar H, Ali S, Hussein I, Zaman I, Meredith EL, Helsby NA, Hu L, Wilkinson SR. Unravelling the role of SNM1 in the DNA repair system ofTrypanosoma brucei. Mol Microbiol 2015; 96:827-38. [DOI: 10.1111/mmi.12973] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/16/2015] [Indexed: 12/31/2022]
Affiliation(s)
- James A. Sullivan
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Jie Lun Tong
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Martin Wong
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Ambika Kumar
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Hajrah Sarkar
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Sarah Ali
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Ikran Hussein
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Iqra Zaman
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Emma Louise Meredith
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
| | - Nuala A. Helsby
- Department of Molecular Medicine and Pathology; University of Auckland; Private Bag 92019 Auckland New Zealand
| | - Longqin Hu
- Department of Medicinal Chemistry; Ernest Mario School of Pharmacy; Rutgers; The State University of New Jersey; Piscataway NJ 08854 USA
| | - Shane R. Wilkinson
- School of Biological & Chemical Sciences; Queen Mary University of London; Mile End Road London E1 4NS UK
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Sullivan JA, Sherry L. Different dispersions of group II catalysts over SBA-15 and MCM-41: Effects on transesterification reactivity. CATAL COMMUN 2015. [DOI: 10.1016/j.catcom.2014.11.016] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Sullivan JA, Burnham S. The selective oxidation of glycerol over model Au/TiO2 catalysts — The influence of glycerol purity on conversion and product selectivity. CATAL COMMUN 2014. [DOI: 10.1016/j.catcom.2014.06.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
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Burlingham W, Wilkes DS, Sullivan JA. Why is the patient out of breath? Collagen V(α1) and K-α1-tubulin take center stage in lung transplantation. Am J Transplant 2014; 14:2201-3. [PMID: 25220400 DOI: 10.1111/ajt.12910] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2014] [Revised: 06/12/2014] [Accepted: 06/25/2014] [Indexed: 01/25/2023]
Affiliation(s)
- W Burlingham
- University of Wisconsin Medical School, Madison, WI
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Sullivan JA, Neville EM, Herron R, Thampi KR, MacElroy JD. Routes to visible light active C-doped TiO2 photocatalysts using carbon atoms from the Ti precursors. J Photochem Photobiol A Chem 2014. [DOI: 10.1016/j.jphotochem.2014.05.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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Sullivan JA, Jankowska-Gan E, Shi L, Roenneburg D, Hegde S, Greenspan DS, Wilkes DS, Denlinger LC, Burlingham WJ. Differential requirement for P2X7R function in IL-17 dependent vs. IL-17 independent cellular immune responses. Am J Transplant 2014; 14:1512-22. [PMID: 24866539 PMCID: PMC4295495 DOI: 10.1111/ajt.12741] [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] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 02/24/2014] [Accepted: 03/10/2014] [Indexed: 01/25/2023]
Abstract
IL17-dependent autoimmunity to collagen type V (Col V) has been associated with lung transplant obliterative bronchiolitis. Unlike the T helper 1 (Th1)-dependent immune responses to Tetanus Toxoid (TT), the Th17 response to Col V in lung transplant patients and its Th1/17 variant observed in coronary artery disease patients requires IL-1β, tumor necrosis factor α and CD14(+) cells. Given the involvement of the P2X7 receptor (P2X7R) in monocyte IL-1β responses, we investigated its role in Th17-, Th1/17- and Th1-mediated proinflammatory responses. Transfer of antigen-pulsed peripheral blood mononucleated cells (PBMCs) from Col V-reactive patients into SCID mouse footpads along with P2X7R antagonists revealed a selective inhibition of Col V-, but not TT-specific swelling responses. P2X7R inhibitors blocked IL-1β induction from monocytes, including both Col V-α1 peptide-induced (T-dependent), as well as native Col V-induced (T-independent) responses. Significantly higher P2X7R expression was found on CXCR3(neg) CCR4(+)/6(+) CD4(+) [Th17] versus CXCR3(+)CCR4/6(neg) CD4(+) [Th1] subsets in PBMCs, suggesting that the paradigm of selective dependence on P2X7R might extend beyond Col V autoimmunity. Indeed, P2X7R inhibitors suppressed not only anti-Col V, but also Th1/17-mediated alloimmunity, in a heart transplant patient without affecting anti-viral Epstein-Barr virus responses. These results suggest that agents targeting the P2X7R might effectively treat Th17-related transplant pathologies, while maintaining Th1-immunity to infection.
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Affiliation(s)
- JA Sullivan
- Department of Surgery, University of Wisconsin, 600 Highland Avenue, Madison, WI 53792
| | - E Jankowska-Gan
- Department of Surgery, University of Wisconsin, 600 Highland Avenue, Madison, WI 53792
| | - L Shi
- Department of Medicine, University of Wisconsin, 600 Highland Avenue, Madison, WI 53792
| | - D Roenneburg
- Department of Surgery, University of Wisconsin, 600 Highland Avenue, Madison, WI 53792
| | | | - DS Greenspan
- Department of Cell & Regenerative Biology, University of Wisconsin, 600 Highland Avenue, Madison, WI 53792
| | - DS Wilkes
- Department of Medicine, University of Indiana, 340 W 10th St Suite 6200 Indianapolis, IN 46202
| | - LC Denlinger
- Department of Medicine, University of Wisconsin, 600 Highland Avenue, Madison, WI 53792
| | - WJ Burlingham
- Department of Surgery, University of Wisconsin, 600 Highland Avenue, Madison, WI 53792,To whom correspondence should be addressed: 600 Highland Avenue, Room G4/702, Madison, WI 53792. Tel: (608) 263-0119 Fax: (608) 262-6280
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Neville EM, MacElroy JD, Thampi KR, Sullivan JA. Visible light active C-doped titanate nanotubes prepared via alkaline hydrothermal treatment of C-doped nanoparticulate TiO2: Photo-electrochemical and photocatalytic properties. J Photochem Photobiol A Chem 2013. [DOI: 10.1016/j.jphotochem.2013.06.008] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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Sullivan JA, Sherry L. The Preparation of Group II Oxide Catalysts Through Acetate Calcination: The Influence of a Support on the Nature of the Final Catalyst. Catal Letters 2013. [DOI: 10.1007/s10562-013-0986-6] [Citation(s) in RCA: 2] [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: 10/27/2022]
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Sullivan JA, Walsh N, Sherry L. The Nature of Surface Deposits Following Valeric Acid Interactions with Al2O3-Supported Alkaline Earth Oxide Catalysts: Towards Cellulosic Biofuels. Catal Letters 2013. [DOI: 10.1007/s10562-013-0965-y] [Citation(s) in RCA: 2] [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: 01/05/2023]
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25
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Morgan GG, Fennell K, Kishore MJL, Sullivan JA. Tethering of Dinuclear Complexes to SBA-15 and Their Application in CO2Hydrogenation. ChemCatChem 2012. [DOI: 10.1002/cctc.201200167] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Antonio MR, Williams CW, Sullivan JA, Skanthakumar S, Hu YJ, Soderholm L. Preparation, Stability, and Structural Characterization of Plutonium(VII) in Alkaline Aqueous Solution. Inorg Chem 2012; 51:5274-81. [DOI: 10.1021/ic300205h] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Mark R. Antonio
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439,
United States
| | - C. W. Williams
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439,
United States
| | - James A. Sullivan
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439,
United States
| | - S. Skanthakumar
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439,
United States
| | - Yung-Jin Hu
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439,
United States
| | - L. Soderholm
- Chemical Sciences and Engineering Division, Argonne National Laboratory, Argonne, Illinois 60439,
United States
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Newell CA, Natesan SKA, Sullivan JA, Jouhet J, Kavanagh TA, Gray JC. Exclusion of plastid nucleoids and ribosomes from stromules in tobacco and Arabidopsis. Plant J 2012; 69:399-410. [PMID: 21951134 DOI: 10.1111/j.1365-313x.2011.04798.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Stromules are stroma-filled tubules that extend from the surface of plastids and allow the transfer of proteins as large as 550 kDa between interconnected plastids. The aim of the present study was to determine if plastid DNA or plastid ribosomes are able to enter stromules, potentially permitting the transfer of genetic information between plastids. Plastid DNA and ribosomes were marked with green fluorescent protein (GFP) fusions to LacI, the lac repressor, which binds to lacO-related sequences in plastid DNA, and to plastid ribosomal proteins Rpl1 and Rps2, respectively. Fluorescence from GFP-LacI co-localised with plastid DNA in nucleoids in all tissues of transgenic tobacco (Nicotiana tabacum L.) examined and there was no indication of its presence in stromules, not even in hypocotyl epidermal cells, which contain abundant stromules. Fluorescence from Rpl1-GFP and Rps2-GFP was also observed in a punctate pattern in chloroplasts of tobacco and Arabidopsis [Arabidopsis thaliana (L.) Heynh.], and fluorescent stromules were not detected. Rpl1-GFP was shown to assemble into ribosomes and was co-localised with plastid DNA. In contrast, in hypocotyl epidermal cells of dark-grown Arabidopsis seedlings, fluorescence from Rpl1-GFP was more evenly distributed in plastids and was observed in stromules on a total of only four plastids (<0.02% of the plastids observed). These observations indicate that plastid DNA and plastid ribosomes do not routinely move into stromules in tobacco and Arabidopsis, and suggest that transfer of genetic information by this route is likely to be a very rare event, if it occurs at all.
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Affiliation(s)
- Christine A Newell
- Department of Plant Sciences, University of Cambridge, Cambridge CB2 3EA, UK
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Abstract
Stromules are thin stroma-filled tubules that extend from all plastid types in all multicellular plants examined. They are most easily visualised by epifluorescence or confocal microscopy of plastids containing green fluorescent protein (GFP) or other fluorescent proteins. Transient expression of gene constructs encoding plastid-targeted GFP following bombardment of whole plants or organs of Arabidopsis with gold or tungsten particles coated with plasmid DNA is a relatively rapid and simple means of producing material for observation of stromules.
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Affiliation(s)
- John C Gray
- Department of Plant Sciences, University of Cambridge, Cambridge, UK.
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Seyedarabi A, Sullivan JA, Sasakawa C, Pickersgill RW. A disulfide driven domain swap switches off the activity of Shigella IpaH9.8 E3 ligase. FEBS Lett 2010; 584:4163-8. [PMID: 20831869 DOI: 10.1016/j.febslet.2010.09.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 08/31/2010] [Accepted: 09/01/2010] [Indexed: 10/19/2022]
Abstract
We show that the monomeric form of Shigella IpaH9.8 E3 ligase catalyses the ubiquitination of human U2AF35 in vitro, providing a molecular mechanism for the observed in vivo effect. We further discover that under non-reducing conditions IpaH9.8 undergoes a domain swap driven by the formation of a disulfide bridge involving the catalytic cysteine and that this dimer is unable to catalyse the ubiquitination of U2AF35. The crystal structure of the domain-swapped dimer is presented. The redox inactivation of IpaH9.8 could be a mechanism of regulating the activity of the IpaH9.8 E3 ligase in response to cell damage so that the host cell in which the bacteria resides is maintained in a benign state suitable for bacterial survival.
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Affiliation(s)
- Arefeh Seyedarabi
- School of Biological and Chemical Sciences, Queen Mary University of London, London, United Kingdom.
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Abstract
Stromules are highly dynamic stroma-filled tubules extending from the surface of plastids and occasionally interconnecting individual plastids, allowing the movement of complex biological molecules between the interconnected plastids. Experiments with inhibitors of cytoskeleton assembly have indicated the involvement of an actin-based system in stromule movement. However, the motor protein associated with the system had not been identified. Here, we present direct evidence that myosin XI is involved in the formation and movement of stromules in tobacco leaves. Application of 2,3-butanedione 2-monoxime, an inhibitor of myosin ATPase activity, resulted in the loss of stromules from tobacco leaf epidermal cells. Transient RNA interference of myosin XI in leaves of Nicotiana benthamiana also resulted in the loss of stromules from epidermal cells, without any effect on transcripts for actin or myosin VIII. Transient expression of a GFP-tagged myosin XI tail domain in tobacco leaf epidermal cells showed that the fusion protein localized to the chloroplast envelope, as well as to mitochondria and other organelles. Our findings identify myosin XI as a key protein involved in the formation and movement of stromules.
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Affiliation(s)
- Senthil Kumar A Natesan
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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Yu JW, Rubio V, Lee NY, Bai S, Lee SY, Kim SS, Liu L, Zhang Y, Irigoyen ML, Sullivan JA, Zhang Y, Lee I, Xie Q, Paek NC, Deng XW. COP1 and ELF3 control circadian function and photoperiodic flowering by regulating GI stability. Mol Cell 2009; 32:617-30. [PMID: 19061637 DOI: 10.1016/j.molcel.2008.09.026] [Citation(s) in RCA: 291] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2008] [Revised: 07/18/2008] [Accepted: 09/11/2008] [Indexed: 12/25/2022]
Abstract
Seasonal changes in day length are perceived by plant photoreceptors and transmitted to the circadian clock to modulate developmental responses such as flowering time. Blue-light-sensing cryptochromes, the E3 ubiquitin-ligase COP1, and clock-associated proteins ELF3 and GI regulate this process, although the regulatory link between them is unclear. Here we present data showing that COP1 acts with ELF3 to mediate day length signaling from CRY2 to GI within the photoperiod flowering pathway. We found that COP1 and ELF3 interact in vivo and show that ELF3 allows COP1 to interact with GI in vivo, leading to GI degradation in planta. Accordingly, mutation of COP1 or ELF3 disturbs the pattern of GI cyclic accumulation. We propose a model in which ELF3 acts as a substrate adaptor, enabling COP1 to modulate light input signal to the circadian clock through targeted destabilization of GI.
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Affiliation(s)
- Jae-Woong Yu
- Department of Plant Science and Research Institute for Agriculture and Life Sciences, Seoul National University, Seoul 151-921, Korea
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Nikko E, Sullivan JA, Pelham HRB. Arrestin-like proteins mediate ubiquitination and endocytosis of the yeast metal transporter Smf1. EMBO Rep 2008; 9:1216-21. [PMID: 18953286 PMCID: PMC2575832 DOI: 10.1038/embor.2008.199] [Citation(s) in RCA: 140] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2008] [Revised: 09/25/2008] [Accepted: 09/25/2008] [Indexed: 01/09/2023] Open
Abstract
Many plasma membrane proteins in yeast are ubiquitinated and endocytosed, but how they are recognized for modification has remained unknown. Here, we show that the manganese transporter Smf1 is endocytosed when cells are exposed to cadmium ions, that this endocytosis depends on Rsp5-dependent ubiquitination of specific lysines and that it also requires phosphorylation at nearby sites. This phosphorylation is, however, constitutive rather than stress-induced. Efficient ubiquitination requires Ecm21 or Csr2, two members of a family of arrestin-like yeast proteins that contain several PY motifs and bind to Rsp5. Ecm21 also binds to phosphorylated Smf1, providing a link between Rsp5 and its substrate. PY motif-containing arrestin-like proteins are found in many species, including humans, and might have a general role as ubiquitin ligase adaptors.
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Affiliation(s)
- Elina Nikko
- MRC Laboratory of Molecular Biology, Hills Road, Cambridge CB2 0QH, UK
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Choy MK, Sullivan JA, Theobald JC, Davies WJ, Gray JC. An Arabidopsis mutant able to green after extended dark periods shows decreased transcripts of seed protein genes and altered sensitivity to abscisic acid. J Exp Bot 2008; 59:3869-84. [PMID: 18931353 PMCID: PMC2576634 DOI: 10.1093/jxb/ern227] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [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] [Received: 06/12/2008] [Revised: 08/10/2008] [Accepted: 08/11/2008] [Indexed: 05/20/2023]
Abstract
An Arabidopsis mutant showing an altered ability to green on illumination after extended periods of darkness has been isolated in a screen for genomes uncoupled (gun) mutants. Following illumination for 24 h, 10-day-old dark-grown mutant seedlings accumulated five times more chlorophyll than wild-type seedlings and this was correlated with differences in plastid morphology observed by transmission electron microscopy. The mutant has been named greening after extended darkness 1 (ged1). Microarray analysis showed much lower amounts of transcripts of genes encoding seed storage proteins, oleosins, and late embryogenesis abundant (LEA) proteins in 7-day-old seedlings of ged1 compared with the wild type. RNA gel-blot analyses confirmed very low levels of transcripts of seed protein genes in ged1 seedlings grown for 2-10 d in the dark, and showed higher amounts of transcripts of photosynthesis-related genes in illuminated 10-day-old dark-grown ged1 seedlings compared with the wild type. Consensus elements similar to abscisic acid (ABA) response elements (ABREs) were detected in the upstream regions of all genes highly affected in ged1. Germination of ged1 seeds was hypersensitive to ABA, although no differences in ABA content were detected in 7-day-old seedlings. This suggests the mutant may have an altered responsiveness to ABA, affecting expression of ABA-responsive genes and plastid development during extended darkness.
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Affiliation(s)
- Mun-Kit Choy
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - James A. Sullivan
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
| | - Julian C. Theobald
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - William J. Davies
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, UK
| | - John C. Gray
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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Puthiyaveetil S, Kavanagh TA, Cain P, Sullivan JA, Newell CA, Gray JC, Robinson C, van der Giezen M, Rogers MB, Allen JF. The ancestral symbiont sensor kinase CSK links photosynthesis with gene expression in chloroplasts. Proc Natl Acad Sci U S A 2008; 105:10061-6. [PMID: 18632566 PMCID: PMC2474565 DOI: 10.1073/pnas.0803928105] [Citation(s) in RCA: 137] [Impact Index Per Article: 8.6] [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: 02/15/2008] [Indexed: 11/18/2022] Open
Abstract
We describe a novel, typically prokaryotic, sensor kinase in chloroplasts of green plants. The gene for this chloroplast sensor kinase (CSK) is found in cyanobacteria, prokaryotes from which chloroplasts evolved. The CSK gene has moved, during evolution, from the ancestral chloroplast to the nuclear genomes of eukaryotic algae and green plants. The CSK protein is now synthesised in the cytosol of photosynthetic eukaryotes and imported into their chloroplasts as a protein precursor. In the model higher plant Arabidopsis thaliana, CSK is autophosphorylated and required for control of transcription of chloroplast genes by the redox state of an electron carrier connecting photosystems I and II. CSK therefore provides a redox regulatory mechanism that couples photosynthesis to gene expression. This mechanism is inherited directly from the cyanobacterial ancestor of chloroplasts, is intrinsic to chloroplasts, and is targeted to chloroplast genes.
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Affiliation(s)
- Sujith Puthiyaveetil
- *School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom
| | | | - Peter Cain
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - James A. Sullivan
- *School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom
| | - Christine A. Newell
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, United Kingdom; and
| | - John C. Gray
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, United Kingdom; and
| | - Colin Robinson
- Department of Biological Sciences, University of Warwick, Coventry CV4 7AL, United Kingdom
| | - Mark van der Giezen
- Centre for Eukaryotic Evolutionary Microbiology, School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - Matthew B. Rogers
- Centre for Eukaryotic Evolutionary Microbiology, School of Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom
| | - John F. Allen
- *School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London E1 4NS, United Kingdom
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Flanagan KA, Sullivan JA, Müeller-Bunz H. Preparation and characterization of 4-dimethylaminopyridine-stabilized palladium nanoparticles. Langmuir 2007; 23:12508-12520. [PMID: 17985937 DOI: 10.1021/la7015897] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
4-Dimethylaminopyridine (DMAP)-stabilized palladium nanoparticles with a mean diameter of 3.4 +/- 0.5 nm are prepared from the aqueous phase reduction of Na2PdCl4 using NaBH4 in the presence of DMAP. TEM and UV-vis spectroscopy characterization of the nanoparticle dispersion shows no obvious change in the nanoparticles several months after preparation. 1H NMR spectroscopy of the nanoparticles shows that the nanoparticle dispersion also contains a boron/DMAP complex and two palladium/DMAP complexes. One of the palladium complexes crystallizes out of the dispersion and is identified as Pd(DMAP)4(OH)2 by X-ray crystallography. Following extensive analysis, it is believed that the palladium/DMAP complexes are formed following the oxidation of the palladium nanoparticles. The prepared nanoparticle dispersion promotes selective hydrogen/deuterium (H/D) exchange on the carbon atoms alpha to the endocyclic nitrogen atom on the DMAP-stabilizing ligands through reaction with D2O. This activity is attributed to the presence of the nanoparticles rather than to the presence of the oxidized palladium/DMAP complexes.
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Affiliation(s)
- Keith A Flanagan
- School of Chemistry and Chemical Biology, University College Dublin, Belfield, Dublin 4, Ireland
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Sullivan JA, Lewis MJ, Nikko E, Pelham HR. Multiple interactions drive adaptor-mediated recruitment of the ubiquitin ligase rsp5 to membrane proteins in vivo and in vitro. Mol Biol Cell 2007; 18:2429-40. [PMID: 17429078 PMCID: PMC1924809 DOI: 10.1091/mbc.e07-01-0011] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Recognition of membrane proteins by the Nedd4/Rsp5 ubiquitin ligase family is a critical step in their targeting to the multivesicular body pathway. Some substrates contain "PY" motifs (PPxY), which bind to WW domains in the ligase. Others lack PY motifs and instead rely on adaptors that recruit the ligase to them. To investigate the mechanism of adaptor-mediated ubiquitination, we have characterized the interactions between the adaptor Bsd2, the ubiquitin ligase Rsp5, and the membrane proteins Cps1, Tre1, and Smf1 from Saccharomyces cerevisiae. We have reconstituted adaptor-mediated modification of Cps1 and Tre1 in vitro, and we show that two PY motifs in Bsd2 and two WW domains (WW2 and WW3) in Rsp5 are crucial for this. The binding of a weak noncanonical DMAPSY motif in Bsd2 to WW3 is an absolute requirement for Bsd2 adaptor function. We show that sorting of the manganese transporter Smf1, which requires both Bsd2 and Tre1, depends upon two PY motifs in Bsd2 and one motif in Tre1 but only two WW domains in Rsp5. We suggest that sequential assembly of first a Bsd2/Rsp5 complex, then a Tre1/Bsd2/Rsp5 complex followed by a rearrangement of PY-WW interactions is required for the ubiquitination of Smf1.
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Affiliation(s)
- James A. Sullivan
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH, United Kingdom
| | - Michael J. Lewis
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH, United Kingdom
| | - Elina Nikko
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH, United Kingdom
| | - Hugh R.B. Pelham
- Medical Research Council Laboratory of Molecular Biology, Cambridge CB2 2QH, United Kingdom
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Brown NJ, Sullivan JA, Gray JC. Light and plastid signals regulate the expression of the pea plastocyanin gene through a common region at the 5' end of the coding region. Plant J 2005; 43:541-52. [PMID: 16098108 DOI: 10.1111/j.1365-313x.2005.02474.x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/04/2023]
Abstract
Expression of the pea plastocyanin gene (PetE) is regulated by light and plastid signals. Previous work indicated that light and plastid regulation of pea PetE operates post-transcriptionally in transgenic tobacco, and requires the correct 5' terminus of the PetE transcript and the PetE-coding region. The post-transcriptional light and plastid regulation of pea PetE has now been demonstrated to operate in transgenic Arabidopsis, where in contrast the endogenous PETE gene is regulated transcriptionally. Transgenic tobacco seedlings containing constructs with progressive 3' deletions of the PetE-coding region fused to the luciferase (Luc) reporter gene demonstrate that the first 60 nucleotides of the coding region are sufficient for regulated accumulation of Luc transcripts by light and plastid signalling pathways affected by treatment with norflurazon and lincomycin. PetE constructs containing premature stop codons were generated to investigate whether translation has a role in light or plastid regulation. Insertion of a stop codon in place of the second codon of the PetE-coding region diminished both light and plastid regulation of PetE transcripts, whereas stop codons inserted later in the transcript had no effect on light or plastid regulation. These experiments indicate that the 5' end of the plastocyanin-coding region contains sequences important for regulation by light and plastid signals.
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Affiliation(s)
- Naomi J Brown
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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Sullivan JA, Keane O, Maguire L. The influence of SO42- on the catalytic combustion of soot using O2 and NO/O2 mixtures over Na-promoted Al2O3 catalysts. CATAL COMMUN 2005. [DOI: 10.1016/j.catcom.2005.04.008] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
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Boettner DR, Huston CD, Sullivan JA, Petri WA. Entamoeba histolytica and Entamoeba dispar utilize externalized phosphatidylserine for recognition and phagocytosis of erythrocytes. Infect Immun 2005; 73:3422-30. [PMID: 15908370 PMCID: PMC1111853 DOI: 10.1128/iai.73.6.3422-3430.2005] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Amebic erythrophagocytosis is characteristic of invasive amebiasis, and mutants deficient in erythrocyte ingestion are avirulent. We sought to understand the molecular mechanisms underlying erythrocyte phagocytosis by Entamoeba histolytica. Following adherence to amebae, erythrocytes became round and crenulated, and phosphatidylserine (PS) was exposed on their outer membrane leaflets. These changes were similar to the effects of calcium treatment on erythrocytes, which we utilized to separate ameba-induced exposure of erythrocyte PS from the process of phagocytosis. The adherence and phagocytosis of calcium-treated erythrocytes were less inhibited by galactose than were those of healthy erythrocytes, suggesting the existence of an amebic coreceptor specific for PS. To test whether PS was recognized by amebae, calcium-treated cells were incubated with annexin V prior to adherence to or ingestion by E. histolytica. Annexin V blocked both adherence (50% +/- 12% inhibition; P < 0.05) and phagocytosis (65% +/- 10%; P < 0.05), providing evidence that at least one galactose-independent coreceptor was involved in the adherence and ingestion of red blood cells. The coreceptor was inhibited by phospho-l-serine and to a lesser extent by phospho-d-serine but not by phospho-l-threonine, which is consistent with the coreceptor functioning in the adherence and ingestion of erythrocytes via recognition of PS. We expanded our investigations to the highly related but noninvasive parasite Entamoeba dispar and demonstrated that it was deficient in red-blood-cell adherence, induction of PS exposure, and phagocytosis. These findings establish phosphatidylserine involvement in erythrophagocytosis by amebae and suggest the existence of a PS receptor on the surfaces of both E. histolytica and E. dispar.
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Affiliation(s)
- Douglas R Boettner
- Division of Infectious Diseases and International Health, P. O. Box 801340, Rm. 2115, MR4 Building, University of Virginia Health System, Charlottesville, VA 22908-1340, USA
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Abstract
Stromules (stroma-filled tubules) are highly dynamic structures extending from the surface of all plastid types examined so far, including proplastids, chloroplasts, etioplasts, leucoplasts, amyloplasts, and chromoplasts. Stromules are usually 0.35-0.85 microm in diameter and of variable length, from short beak-like projections to linear or branched structures up to 220 mum long. They are enclosed by the inner and outer plastid envelope membranes and enable the transfer of molecules as large as Rubisco (approximately 560 kDa) between interconnected plastids. Stromules occur in all cell types, but stromule morphology and the proportion of plastids with stromules vary from tissue to tissue and at different stages of plant development. In general, stromules are more abundant in tissues containing non-green plastids, and in cells containing smaller plastids. The primary function of stromules is still unresolved, although the presence of stromules markedly increases the plastid surface area, potentially increasing transport to and from the cytosol. Other functions of stromules, such as transfer of macromolecules between plastids and starch granule formation in cereal endosperm, may be restricted to particular tissues and cell types.
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Affiliation(s)
- Senthil Kumar A Natesan
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, UK
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Su N, Sullivan JA, Deng XW. Modulation of F1 hybrid stature without altering parent plants through trans-activated expression of a mutated rice GAI homologue. Plant Biotechnol J 2005; 3:157-64. [PMID: 17173616 DOI: 10.1111/j.1467-7652.2004.00107.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Hybrid breeding, by taking advantage of heterosis, brings about many superior properties to the F1 progeny. However, some properties, such as increased plant height, are not desirable for agronomic purposes. To specifically counter the height increase associated with hybrid progeny, we employed an Arabidopsis model and tested a trans-activation system for specifically expressing a mutated GAI gene only in the F1 hybrid plants to reduce plant stature. A transcriptional activator, the Gal4 DNA-binding domain fused to the acidic activation domain of herpes simplex virus VP16 protein, driven by a maize ubiquitin promoter, was introduced in one parental line. A rice GAI homologue with an N-terminal deletion of the DELLA domain, driven by a promoter that is responsive to the transcriptional activator, was transferred into another parental line. After genetic crossing, trans-activation of the GAI mutant gene resulted in a dwarf phenotype. Over 50 pair-wise crosses between the parental lines were performed, and analyses suggested that the percentage of F1 progeny exhibiting dwarfism ranged from about 25% to 100%. Furthermore, the dwarfism trait introduced in F1 progeny did not seem to affect total seed yield. Our result suggests the feasibility of manipulating F1 hybrid progeny traits without affecting parent plants or the agronomic property of the progeny.
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Affiliation(s)
- Ning Su
- Peking-Yale Joint Center of Plant Molecular Genetics and Agrobiotechnology, College of Life Sciences, Peking University, Beijing 100871, China
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45
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Yanagawa Y, Sullivan JA, Komatsu S, Gusmaroli G, Suzuki G, Yin J, Ishibashi T, Saijo Y, Rubio V, Kimura S, Wang J, Deng XW. Arabidopsis COP10 forms a complex with DDB1 and DET1 in vivo and enhances the activity of ubiquitin conjugating enzymes. Genes Dev 2004; 18:2172-81. [PMID: 15342494 PMCID: PMC515294 DOI: 10.1101/gad.1229504] [Citation(s) in RCA: 150] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
COP10 is a ubiquitin-conjugating enzyme variant (UEV), which is thought to act together with COP1, DET1, and the COP9 signalosome (CSN) in Arabidopsis to repress photomorphogenesis. Here, we demonstrate that COP10 interacts with ubiquitin-conjugating enzymes (E2s) in vivo, and can enhance their activity in vitro, an activity distinct from previous characterized UEVs such as MMS2 and UEV1. Furthermore, we show that COP10 forms a complex with UV-damaged DNA-binding protein 1a (DDB1a) and de-etiolated 1 (DET1), and physically interacts with COP1 and the CSN. Purified CDD (COP10, DDB1, DET1) complex also shows enhancement of E2 activity (UEA) similar to that observed with COP10 itself. Our data suggests that COP10, along with COP1 and the CSN, promotes the degradation of positive regulators of photomorphogenesis, such as the transcription factor HY5, via the ubiquitin/26S proteasome system. Thus, the CDD complex may act as a ubiquitylation-promoting factor to regulate photomorphogenesis.
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Affiliation(s)
- Yuki Yanagawa
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104, USA
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Feng S, Shen Y, Sullivan JA, Rubio V, Xiong Y, Sun TP, Deng XW. Arabidopsis CAND1, an unmodified CUL1-interacting protein, is involved in multiple developmental pathways controlled by ubiquitin/proteasome-mediated protein Degradation. Plant Cell 2004; 16:1870-82. [PMID: 15208391 PMCID: PMC514167 DOI: 10.1105/tpc.021949] [Citation(s) in RCA: 104] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2004] [Accepted: 04/30/2004] [Indexed: 05/10/2023]
Abstract
Ubiquitin/proteasome-mediated protein degradation controls various developmental pathways in eukaryotes. Cullin-containing complexes are both versatile and abundant groups of RING family ubiquitin E3 ligases, whose activities are subject to control by RUB/Nedd8 (for related to ubiquitin/neural precursor cell-expressed developmentally downregulated 8) modification of their cullin subunits. Here, we report the identification of an Arabidopsis thaliana counterpart of human CAND1 (cullin-associated and neddylation-dissociated) and demonstrate that it can preferentially interact with unmodified CUL1. The Arabidopsis cand1-1 null mutant displays distinct phenotypes, including late flowering, aerial rosettes, floral organ defects, low fertility, dwarfism, loss of apical dominance, and altered responses to multiple plant hormones. Molecular analyses show that many of these defects are because of compromised activity of CUL1-containing ubiquitin E3 ligases, indicating that CAND1 is required for their optimal activity. Furthermore, the cand1-1 mutant displays a partial constitutive photomorphogenic phenotype and has defects in HY5 degradation in the absence of light, a process mediated by a different RING family E3, COP1. Thus, our data provides genetic support for a critical role of CAND1 in regulating various ubiquitin E3 ligases and their targeted cellular and developmental pathways.
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Affiliation(s)
- Suhua Feng
- Department of Molecular, Cellular, and Developmental Biology, Yale University, New Haven, Conecticut 06520-8104, USA
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47
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Abstract
A tightly regulated and highly specific system for the degradation of individual proteins is essential for the survival of all organisms. In eukaryotes, this is achieved by the tagging of proteins with ubiquitin and their subsequent recognition and degradation by the 26S proteasome. In plants, genetic analysis has identified many genes that regulate developmental pathways. Subsequent analysis of these genes has implicated ubiquitin and the 26S proteasome in the control of diverse developmental processes, and indicates that proteolysis is a crucial regulatory step throughout the life cycle of plants.
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Affiliation(s)
- James A Sullivan
- Deptartment of Molecular, Cellular and Developmental Biology, Yale University, PO Box 208104, 165 Prospect Street, New Haven, Connecticut 06520-8104, USA
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48
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Abstract
OBJECTIVES Composite arterial grafts for coronary artery bypass grafting surgery allow complete arterial revascularization but are limited by the inflow of a single internal thoracic artery supplying all the grafted vessels. We reviewed the safety of composite arterial grafts using either bilateral internal thoracic arteries or a single internal thoracic artery and radial artery. METHODS From January 1999 to July 2002, 402 consecutive patients receiving composite grafts only were compared to a control group of patients (n = 542) undergoing coronary artery bypass grafting with internal thoracic artery and saphenous veins operated upon by the same surgeons. Two different statistical approaches were used to compare groups in this retrospective analysis. First, propensity score analysis with greedy matching technique was used to match patients from each group. Second, a multivariate analysis was performed looking at a combined patient outcome of death, intra-aortic balloon counterpulsation utilization, myocardial infarction, stroke, and prolonged ventilation on all patients in both groups. RESULTS After matching by propensity score, the major clinical outcomes in composite arterial (n = 249) and control (n = 249) groups were found to be similar. The in-hospital mortality in the composite group was 1.2% as compared with 0.4% in matched patients (P =.62). However, patients in the composite group were found to have a significantly longer pump time (P <.0001), longer clamp time (P <.0001), increased incidence of prolonged mechanical ventilation (12.8% vs 4.8%; P =.002), and higher incidence of combined morbidity outcome (13.6% vs 6.4%; P =.007) as compared with matched patients. Multivariable analysis showed that composite arterial grafting was an independent predictor of the combined morbidity outcome with an odds ratio of 2.1 (1.2-3.7). CONCLUSIONS These findings suggest that composite arterial grafting may be associated with an increase in risk-adjusted patient morbidity when compared with a conventional coronary artery bypass grafting group, although a mortality difference was not demonstrable.
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Affiliation(s)
- J F Légaré
- Dalhousie University, Halifax, Nova Scotia, Canada
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Hanna R, McDonald MT, Sullivan JA, Mackey JF, Krishnamurthy V, Kishnani PS. Diagnostic and treatment challenges of neuronopathic Gaucher disease: two cases with an intermediate phenotype. J Inherit Metab Dis 2004; 27:687-90. [PMID: 15669686 DOI: 10.1023/b:boli.0000043027.80328.75] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Gaucher disease (GD) is a lysosomal storage disorder with a broad, overlapping clinical spectrum. The presented two case reports highlight the clinical evaluation required in neuronopathic GD to assist with medical management and genetic counselling.
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Affiliation(s)
- R Hanna
- Division of Medical Genetics, Department of Pediatrics, Duke University Medical Center, Durham, North Carolina, USA
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50
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Saijo Y, Sullivan JA, Wang H, Yang J, Shen Y, Rubio V, Ma L, Hoecker U, Deng XW. The COP1-SPA1 interaction defines a critical step in phytochrome A-mediated regulation of HY5 activity. Genes Dev 2003; 17:2642-7. [PMID: 14597662 PMCID: PMC280614 DOI: 10.1101/gad.1122903] [Citation(s) in RCA: 326] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Arabidopsis COP1 is a constitutive repressor of photomorphogenesis that interacts with photomorphogenesis-promoting factors such as HY5 to promote their proteasome-mediated degradation. SPA1 is a repressor of phytochrome A-mediated responses to far-red light. Here we report that COP1 acts as part of a large protein complex and interacts with SPA1 in a light-dependent manner. We further demonstrate the E3 ubiquitin ligase activity of COP1 on HY5 in vitro and the alteration of that activity by SPA1. Thus, the COP1-SPA1 interaction defines a critical step in coordinating COP1-mediated ubiquitination and subsequent degradation of HY5 with PHYA signaling.
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Affiliation(s)
- Yusuke Saijo
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520, USA
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