1
|
Martí-Andrés P, Finamor I, Torres-Cuevas I, Pérez S, Rius-Pérez S, Colino-Lage H, Guerrero-Gómez D, Morato E, Marina A, Michalska P, León R, Cheng Q, Jurányi EP, Borbényi-Galambos K, Millán I, Nagy P, Miranda-Vizuete A, Schmidt EE, Martínez-Ruiz A, Arnér ES, Sastre J. TRP14 is the rate-limiting enzyme for intracellular cystine reduction and regulates proteome cysteinylation. EMBO J 2024; 43:2789-2812. [PMID: 38811853 PMCID: PMC11217419 DOI: 10.1038/s44318-024-00117-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2023] [Revised: 04/26/2024] [Accepted: 04/26/2024] [Indexed: 05/31/2024] Open
Abstract
It has remained unknown how cells reduce cystine taken up from the extracellular space, which is a required step for further utilization of cysteine in key processes such as protein or glutathione synthesis. Here, we show that the thioredoxin-related protein of 14 kDa (TRP14, encoded by TXNDC17) is the rate-limiting enzyme for intracellular cystine reduction. When TRP14 is genetically knocked out, cysteine synthesis through the transsulfuration pathway becomes the major source of cysteine in human cells, and knockout of both pathways becomes lethal in C. elegans subjected to proteotoxic stress. TRP14 can also reduce cysteinyl moieties on proteins, rescuing their activities as here shown with cysteinylated peroxiredoxin 2. Txndc17 knockout mice were, surprisingly, protected in an acute pancreatitis model, concomitant with activation of Nrf2-driven antioxidant pathways and upregulation of transsulfuration. We conclude that TRP14 is the evolutionarily conserved enzyme principally responsible for intracellular cystine reduction in C. elegans, mice, and humans.
Collapse
Affiliation(s)
- Pablo Martí-Andrés
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Burjassot, Valencia, Spain
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE 171 77, Stockholm, Sweden
| | - Isabela Finamor
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Burjassot, Valencia, Spain
- Department of Physiology and Pharmacology, Federal University of Santa Maria, Santa Maria, Rio Grande do Sul, Brazil
| | - Isabel Torres-Cuevas
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Burjassot, Valencia, Spain
| | - Salvador Pérez
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Burjassot, Valencia, Spain
| | - Sergio Rius-Pérez
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Burjassot, Valencia, Spain
| | - Hildegard Colino-Lage
- Redox Homeostasis Group, Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - David Guerrero-Gómez
- Redox Homeostasis Group, Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Esperanza Morato
- Centro de Biología Molecular "Severo Ochoa" (CBMSO), CSIC-UAM, Madrid, Spain
| | - Anabel Marina
- Centro de Biología Molecular "Severo Ochoa" (CBMSO), CSIC-UAM, Madrid, Spain
- Unidad de Técnicas Bioanalíticas (BAT), Instituto de Investigación de Ciencias de la Alimentación (CIAL), CSIC-UAM, Madrid, Spain
| | - Patrycja Michalska
- Department of Chemistry, Molecular Sciences Research Hub, Imperial College London, London, UK
| | - Rafael León
- Institute of Medical Chemistry, CSIC, Madrid, Spain
| | - Qing Cheng
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE 171 77, Stockholm, Sweden
| | - Eszter Petra Jurányi
- Department of Molecular Immunology and Toxicology and the National Tumor Biology Laboratory, National Institute of Oncology, Budapest, Hungary
- Molecular Medicine Division, Semmelweis University Doctoral College, Budapest, Hungary
| | - Klaudia Borbényi-Galambos
- Department of Molecular Immunology and Toxicology and the National Tumor Biology Laboratory, National Institute of Oncology, Budapest, Hungary
- Kálmán Laki Doctoral School, University of Debrecen, Debrecen, Hungary
| | - Iván Millán
- Instituto Cavanilles de Biodiversidad y Biología Evolutiva, Universidad de Valencia, Paterna, Valencia, Spain
| | - Péter Nagy
- Department of Molecular Immunology and Toxicology and the National Tumor Biology Laboratory, National Institute of Oncology, Budapest, Hungary
- Department of Anatomy and Histology, HUN-REN-UVMB Laboratory of Redox Biology, University of Veterinary Medicine, Budapest, Hungary
- Chemistry Institute, University of Debrecen, Debrecen, Hungary
| | - Antonio Miranda-Vizuete
- Redox Homeostasis Group, Instituto de Biomedicina de Sevilla (IBIS), Hospital Universitario Virgen del Rocío/CSIC/Universidad de Sevilla, Seville, Spain
| | - Edward E Schmidt
- Department of Anatomy and Histology, HUN-REN-UVMB Laboratory of Redox Biology, University of Veterinary Medicine, Budapest, Hungary
- Department of Microbiology and Cell Biology, Montana State University, Bozeman, MT, USA
| | - Antonio Martínez-Ruiz
- Unidad de Investigación, Hospital Universitario Santa Cristina, Instituto de Investigación Sanitaria Princesa (IIS_IP), Madrid, Spain
| | - Elias Sj Arnér
- Division of Biochemistry, Department of Medical Biochemistry and Biophysics, Karolinska Institutet, SE 171 77, Stockholm, Sweden.
- Department of Selenoprotein Research and the National Tumor Biology Laboratory, National Insitute of Oncology, Budapest, Hungary.
| | - Juan Sastre
- Department of Physiology, Faculty of Pharmacy, University of Valencia, Burjassot, Valencia, Spain.
| |
Collapse
|
2
|
Mata-Cabana A, Pérez-Nieto C, Olmedo M. Nutritional control of postembryonic development progression and arrest in Caenorhabditis elegans. ADVANCES IN GENETICS 2020; 107:33-87. [PMID: 33641748 DOI: 10.1016/bs.adgen.2020.11.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Developmental programs are under strict genetic control that favors robustness of the process. In order to guarantee the same outcome in different environmental situations, development is modulated by input pathways, which inform about external conditions. In the nematode Caenorhabditis elegans, the process of postembryonic development involves a series of stereotypic cell divisions, the progression of which is controlled by the nutritional status of the animal. C. elegans can arrest development at different larval stages, leading to cell arrest of the relevant divisions of the stage. This means that studying the nutritional control of development in C. elegans we can learn about the mechanisms controlling cell division in an in vivo model. In this work, we reviewed the current knowledge about the nutrient sensing pathways that control the progression or arrest of development in response to nutrient availability, with a special focus on the arrest at the L1 stage.
Collapse
Affiliation(s)
- Alejandro Mata-Cabana
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avd. Reina Mercedes, Sevilla, Spain
| | - Carmen Pérez-Nieto
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avd. Reina Mercedes, Sevilla, Spain
| | - María Olmedo
- Departamento de Genética, Facultad de Biología, Universidad de Sevilla, Avd. Reina Mercedes, Sevilla, Spain.
| |
Collapse
|
3
|
Zhang M, Li Z, Gao D, Gong W, Gao Y, Zhang C. Hydrogen extends Caenorhabditis elegans longevity by reducing reactive oxygen species. PLoS One 2020; 15:e0231972. [PMID: 32320994 PMCID: PMC7176462 DOI: 10.1371/journal.pone.0231972] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Accepted: 04/03/2020] [Indexed: 11/26/2022] Open
Abstract
At present, a large number of studies have reported that hydrogen has antioxidant functions and prevents oxidative stress damage. However, it is not clear whether hydrogen can prolong longevity based on these effects. Therefore, we studied and explored the antiaging potential of exogenous hydrogen and its ability to extend longevity using Caenorhabditis elegans (C. elegans) as an animal model. Our results showed that the lifespans of the N2, sod-3 and sod-5 mutant strains were extended by approximately 22.7%, 9.5%, and 8.7%, respectively, after hydrogen treatment, but hydrogen had no effect on the lifespans of the daf-2 and daf-16 mutant strains. Meanwhile, the level of reactive oxygen species (ROS) in the hydrogen treatment group was significantly lower than that in the control group. At the transcript level, the expression of age-1 and let-363 was obviously decreased, while the expression of ins-18 was increased at the same time point (14 d). Compared with the control group, paraquat (PQ) could reduce the lifespan of the N2 and sod-5 mutant strains. Importantly, the longevity of these mutant strains recovered to normal levels when the animals were treated with exogenous hydrogen. According to these results, the lifespan of C. elegans is closely related to oxidative stress and can be significantly prolonged by reducing oxidative stress damage. Taken together, our data showed that hydrogen is a valuable antioxidant that can significantly reduce the body’s ROS levels and extend the lifespan of C. elegans. This study also laid a foundation for the subsequent application of hydrogen in antiaging studies.
Collapse
Affiliation(s)
- Miao Zhang
- Institute of Radiation Medicine, Academy of Military Medical Sciences, Academy of Military Sciences, Military Cognitive and Mental Health Research Center of PLA, Beijing, China
| | - Zhihui Li
- Institute of Radiation Medicine, Academy of Military Medical Sciences, Academy of Military Sciences, Military Cognitive and Mental Health Research Center of PLA, Beijing, China
| | - Dawen Gao
- Institute of Radiation Medicine, Academy of Military Medical Sciences, Academy of Military Sciences, Military Cognitive and Mental Health Research Center of PLA, Beijing, China
| | - Wenjing Gong
- Institute of Radiation Medicine, Academy of Military Medical Sciences, Academy of Military Sciences, Military Cognitive and Mental Health Research Center of PLA, Beijing, China
- * E-mail: (CZ); (ZL)
| | - Yan Gao
- Institute of Radiation Medicine, Academy of Military Medical Sciences, Academy of Military Sciences, Military Cognitive and Mental Health Research Center of PLA, Beijing, China
| | - Chenggang Zhang
- Institute of Radiation Medicine, Academy of Military Medical Sciences, Academy of Military Sciences, Military Cognitive and Mental Health Research Center of PLA, Beijing, China
- * E-mail: (CZ); (ZL)
| |
Collapse
|
4
|
Mishra PKK, Mahawar M. PIMT-Mediated Protein Repair: Mechanism and Implications. BIOCHEMISTRY (MOSCOW) 2019; 84:453-463. [PMID: 31234761 DOI: 10.1134/s0006297919050018] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Amino acids undergo many covalent modifications, but only few amino acid repair enzymes have been identified. Protein-L-isoaspartate (D-aspartate) O-methyltransferase (PIMT), also known as L-isoaspartyl/D-aspartyl protein carboxyl methyltransferase (PCMT), methylates covalently modified isoaspartate (isoAsp) residues accumulated in proteins via Asn deamidation and Asp hydrolysis. This cytoplasmic reaction occurs through the formation of succinimide cyclical intermediate and generates either isoAsp or Asp from succinimide. Succinimide conversion into Asp is spontaneous, while isoAsp is restored by PIMT using S-adenosylmethionine as a methyl donor. PIMT transforms isoAsp into succinimide, thereby creating an opportunity for the later to be converted into Asp. Apart from normal cell physiology, formation of isoAsp in proteins is promoted by various stress conditions. The resulting isoAsp can form a kink or bend in the protein backbone thus making the protein conformationally and functionally distorted. Many PIMT-interacting proteins (proteins with isoAsp residues) have been reported in eukaryotes, but only few of them have been found in prokaryotes. Extensive studies in mice have shown the importance of PIMT in neurodegeneration. Detail elucidation of PIMT function can create a platform for addressing various disorders such as Alzheimer's disease and cancer.
Collapse
Affiliation(s)
- P K K Mishra
- Division of Biochemistry, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India.
| | - M Mahawar
- Division of Biochemistry, Indian Veterinary Research Institute, Izatnagar, Bareilly, Uttar Pradesh, 243122, India.
| |
Collapse
|
5
|
Pesingi PK, Kumawat M, Behera P, Dixit SK, Agarwal RK, Goswami TK, Mahawar M. Protein-L-Isoaspartyl Methyltransferase (PIMT) Is Required for Survival of Salmonella Typhimurium at 42°C and Contributes to the Virulence in Poultry. Front Microbiol 2017; 8:361. [PMID: 28326072 PMCID: PMC5339242 DOI: 10.3389/fmicb.2017.00361] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 02/21/2017] [Indexed: 01/07/2023] Open
Abstract
Poultry birds are asymptomatic reservoir of Salmonella Typhimurium (S. Typhimurium) but act as source of human infection for this bacterium. Inside the poultry, S. Typhimurium experiences several stresses, 42°C body temperature of birds is one of them. Proteins are highly susceptible to temperature mediated damage. Conversion of protein bound aspartate (Asp) residues to iso-aspartate (iso-Asp) is one of such modifications that occur at elevated temperature. Iso-Asp formation has been linked to protein inactivation and compromised cellular survival. Protein-L-isoaspartyl methyltransferase (PIMT) can repair iso-Asp back to Asp, thus enhances the cellular survival at elevated temperature. Here, we show that the pimt gene deletion strain of S. Typhimurium (Δpimt mutant strain) is hypersensitive to 42°C in vitro. The hypersusceptibility of Δpimt strain is partially reversed by plasmid based complementation (trans-complementation) of Δpimt strain. Following oral inoculation, Δpimt strain showed defective colonization in poultry caecum, and compromised dissemination to spleen and liver. Interestingly, we have observed three and half folds induction of the PIMT protein following exposure of S. Typhimurium to 42°C. Our data suggest a novel role of pimt gene in the survival of S. Typhimurium at elevated temperature and virulence.
Collapse
Affiliation(s)
- Pavan K Pesingi
- Division of Veterinary Public Health, Indian Veterinary Research Institute Izatnagar, India
| | - Manoj Kumawat
- Division of Biochemistry, Indian Veterinary Research Institute Izatnagar, India
| | - Pranatee Behera
- Division of Biochemistry, Indian Veterinary Research Institute Izatnagar, India
| | - Sunil K Dixit
- Division of Immunology, Indian Veterinary Research Institute Izatnagar, India
| | - Rajesh K Agarwal
- Division of Bacteriology and Mycology, Indian Veterinary Research Institute Izatnagar, India
| | - Tapas K Goswami
- Division of Immunology, Indian Veterinary Research Institute Izatnagar, India
| | - Manish Mahawar
- Division of Biochemistry, Indian Veterinary Research Institute Izatnagar, India
| |
Collapse
|
6
|
Gourgou E, Chronis N. Chemically induced oxidative stress affects ASH neuronal function and behavior in C. elegans. Sci Rep 2016; 6:38147. [PMID: 27922032 PMCID: PMC5138595 DOI: 10.1038/srep38147] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Accepted: 10/27/2016] [Indexed: 11/08/2022] Open
Abstract
Oxidative stress (OS) impact on a single neuron's function in vivo remains obscure. Using C. elegans as a model organism, we report the effect of paraquat (PQ)-induced OS on wild type worms on the function of the ASH polymodal neuron. By calcium (Ca2+) imaging, we quantified ASH activation upon stimulus delivery. PQ-treated worms displayed higher maximum depolarization (peak of the Ca2+ transients) compared to untreated animals. PQ had a similar effect on the ASH neuron response time (rising slope of the Ca2+ transients), except in very young worms. OS effect on ASH was partially abolished in vitamin C-treated worms. We performed octanol and osmotic avoidance tests, to investigate the OS effect on ASH-dependent behaviors. PQ-treated worms have enhanced avoidance behavior compared to untreated ones, suggesting that elevated ASH Ca2+ transients result in enhanced ASH-mediated behavior. The above findings suggest a possible hormetic effect of PQ, as a factor inducing mild oxidative stress. We also quantified locomotion parameters (velocity, bending amplitude), which are not mediated by ASH activation. Bending amplitude did not differ significantly between treated and untreated worms; velocity in older adults decreased. The differential effect of OS on behavioral patterns may mirror a selective impact on the organism's neurons.
Collapse
Affiliation(s)
- Eleni Gourgou
- Department of Mechanical Engineering, University of Michigan, 2350 Hayward Str., Ann Arbor, MI, 48109, USA
- Department of Internal Medicine, Division of Geriatric Medicine, Medical School, University of Michigan, 109 Zina Pitcher Place, Ann Arbor, MI, 48109, USA
| | - Nikos Chronis
- Department of Mechanical Engineering, University of Michigan, 2350 Hayward Str., Ann Arbor, MI, 48109, USA
- Department of Biomedical Engineering, University of Michigan, 2200 Bonisteel Blvd., Ann Arbor, MI, 48109, USA
| |
Collapse
|
7
|
Kumawat M, Pesingi PK, Agarwal RK, Goswami TK, Mahawar M. Contribution of protein isoaspartate methyl transferase (PIMT) in the survival of Salmonella Typhimurium under oxidative stress and virulence. Int J Med Microbiol 2016; 306:222-30. [DOI: 10.1016/j.ijmm.2016.04.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Revised: 04/07/2016] [Accepted: 04/26/2016] [Indexed: 12/22/2022] Open
|
8
|
Ouazia D, Levros LC, Rassart É, Desrosiers R. The protein l-isoaspartyl (d-aspartyl) methyltransferase protects against dopamine-induced apoptosis in neuroblastoma SH-SY5Y cells. Neuroscience 2015; 295:139-50. [DOI: 10.1016/j.neuroscience.2015.03.026] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 03/10/2015] [Accepted: 03/14/2015] [Indexed: 11/15/2022]
|
9
|
Carter WG, Vigneswara V, Newlaczyl A, Wayne D, Ahmed B, Saddington S, Brewer C, Raut N, Gerdes HK, Erdozain AM, Tooth D, Bolt EL, Osna NA, Tuma DJ, Kharbanda KK. Isoaspartate, carbamoyl phosphate synthase-1, and carbonic anhydrase-III as biomarkers of liver injury. Biochem Biophys Res Commun 2015; 458:626-631. [PMID: 25684186 PMCID: PMC4355035 DOI: 10.1016/j.bbrc.2015.01.158] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2015] [Accepted: 01/28/2015] [Indexed: 02/08/2023]
Abstract
We had previously shown that alcohol consumption can induce cellular isoaspartate protein damage via an impairment of the activity of protein isoaspartyl methyltransferase (PIMT), an enzyme that triggers repair of isoaspartate protein damage. To further investigate the mechanism of isoaspartate accumulation, hepatocytes cultured from control or 4-week ethanol-fed rats were incubated in vitro with tubercidin or adenosine. Both these agents, known to elevate intracellular S-adenosylhomocysteine levels, increased cellular isoaspartate damage over that recorded following ethanol consumption in vivo. Increased isoaspartate damage was attenuated by treatment with betaine. To characterize isoaspartate-damaged proteins that accumulate after ethanol administration, rat liver cytosolic proteins were methylated using exogenous PIMT and (3)H-S-adenosylmethionine and proteins resolved by gel electrophoresis. Three major protein bands of ∼ 75-80 kDa, ∼ 95-100 kDa, and ∼ 155-160 kDa were identified by autoradiography. Column chromatography used to enrich isoaspartate-damaged proteins indicated that damaged proteins from ethanol-fed rats were similar to those that accrued in the livers of PIMT knockout (KO) mice. Carbamoyl phosphate synthase-1 (CPS-1) was partially purified and identified as the ∼ 160 kDa protein target of PIMT in ethanol-fed rats and in PIMT KO mice. Analysis of the liver proteome of 4-week ethanol-fed rats and PIMT KO mice demonstrated elevated cytosolic CPS-1 and betaine homocysteine S-methyltransferase-1 when compared to their respective controls, and a significant reduction of carbonic anhydrase-III (CA-III) evident only in ethanol-fed rats. Ethanol feeding of rats for 8 weeks resulted in a larger (∼ 2.3-fold) increase in CPS-1 levels compared to 4-week ethanol feeding indicating that CPS-1 accumulation correlated with the duration of ethanol consumption. Collectively, our results suggest that elevated isoaspartate and CPS-1, and reduced CA-III levels could serve as biomarkers of hepatocellular injury.
Collapse
Affiliation(s)
- Wayne G Carter
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK.
| | - Vasanthy Vigneswara
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Anna Newlaczyl
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Declan Wayne
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Bilal Ahmed
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Stephen Saddington
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Charlotte Brewer
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Nikhilesh Raut
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Henry K Gerdes
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK
| | - Amaia M Erdozain
- School of Medicine, University of Nottingham, Royal Derby Hospital Centre, Derby, DE22 3DT, UK; Department of Pharmacology, University of the Basque Country, and Centro de Investigación Biomédica en Red de Salud Mental, Spain
| | - David Tooth
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Edward L Bolt
- School of Life Sciences, University of Nottingham, Queen's Medical Centre, Nottingham, UK
| | - Natalie A Osna
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry, University of Nebraska Medical Center, Omaha, NE, USA
| | - Dean J Tuma
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry, University of Nebraska Medical Center, Omaha, NE, USA
| | - Kusum K Kharbanda
- Research Service, Veterans Affairs Nebraska-Western Iowa Health Care System, Omaha, NE, USA; Department of Internal Medicine, University of Nebraska Medical Center, Omaha, NE, USA; Department of Biochemistry, University of Nebraska Medical Center, Omaha, NE, USA
| |
Collapse
|
10
|
Patananan AN, Budenholzer LM, Pedraza ME, Torres ER, Adler LN, Clarke SG. The invertebrate Caenorhabditis elegans biosynthesizes ascorbate. Arch Biochem Biophys 2015; 569:32-44. [PMID: 25668719 PMCID: PMC4357563 DOI: 10.1016/j.abb.2015.02.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2014] [Revised: 01/28/2015] [Accepted: 02/01/2015] [Indexed: 01/01/2023]
Abstract
L-ascorbate, commonly known as vitamin C, serves as an antioxidant and cofactor essential for many biological processes. Distinct ascorbate biosynthetic pathways have been established for animals and plants, but little is known about the presence or synthesis of this molecule in invertebrate species. We have investigated ascorbate metabolism in the nematode Caenorhabditis elegans, where this molecule would be expected to play roles in oxidative stress resistance and as cofactor in collagen and neurotransmitter synthesis. Using high-performance liquid chromatography and gas-chromatography mass spectrometry, we determined that ascorbate is present at low amounts in the egg stage, L1 larvae, and mixed animal populations, with the egg stage containing the highest concentrations. Incubating C. elegans with precursor molecules necessary for ascorbate synthesis in plants and animals did not significantly alter ascorbate levels. Furthermore, bioinformatic analyses did not support the presence in C. elegans of either the plant or the animal biosynthetic pathway. However, we observed the complete 13C-labeling of ascorbate when C. elegans was grown with 13C-labeled Escherichia coli as a food source. These results support the hypothesis that ascorbate biosynthesis in invertebrates may proceed by a novel pathway and lay the foundation for a broader understanding of its biological role.
Collapse
Affiliation(s)
- Alexander N Patananan
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA
| | - Lauren M Budenholzer
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA
| | - Maria E Pedraza
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA
| | - Eric R Torres
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA
| | - Lital N Adler
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA
| | - Steven G Clarke
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA.
| |
Collapse
|
11
|
Qin Z, Dimitrijevic A, Aswad DW. Accelerated protein damage in brains of PIMT+/- mice; a possible model for the variability of cognitive decline in human aging. Neurobiol Aging 2014; 36:1029-36. [PMID: 25465735 DOI: 10.1016/j.neurobiolaging.2014.10.036] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2014] [Revised: 10/14/2014] [Accepted: 10/27/2014] [Indexed: 12/18/2022]
Abstract
Isoaspartate formation is a common type of protein damage normally kept in check by the repair enzyme protein-L-isoaspartyl methyltransferase (PIMT). Mice with a knockout of the gene (Pcmt1) for this enzyme (KO, -/-) exhibit a pronounced neuropathology with fatal epileptic seizures at 30-60 days. Heterozygous (HZ, +/-) mice have 50% of the PIMT activity found in wild-type (WT, +/+) mice, but appear normal. To see if HZ mice exhibit accelerated aging at the molecular level, we compared brain extracts from HZ and WT mice at 8 months and 2 years with regard to PIMT activity, isoaspartate levels, and activity of an endogenous PIMT substrate, creatine kinase B. PIMT activity declined modestly with age in both genotypes. Isoaspartate was significantly higher in HZ than WT mice at 8 months and more so at 2 years, rising 5× faster in HZ males and 3× faster in females. Creatine kinase activity decreased with age and was always lower in the HZ mice. These findings suggest the individual variation of human PIMT levels may significantly influence the course of age-related central nervous system dysfunction.
Collapse
Affiliation(s)
- Zhenxia Qin
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, USA
| | - Aleksandra Dimitrijevic
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, USA
| | - Dana W Aswad
- Department of Molecular Biology & Biochemistry, University of California, Irvine, Irvine, CA, USA.
| |
Collapse
|
12
|
Dimitrijevic A, Qin Z, Aswad DW. Isoaspartyl formation in creatine kinase B is associated with loss of enzymatic activity; implications for the linkage of isoaspartate accumulation and neurological dysfunction in the PIMT knockout mouse. PLoS One 2014; 9:e100622. [PMID: 24955845 PMCID: PMC4067349 DOI: 10.1371/journal.pone.0100622] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2014] [Accepted: 05/29/2014] [Indexed: 01/12/2023] Open
Abstract
Isoaspartate (isoAsp) formation is a common type of spontaneous protein damage that is normally kept in check by the repair enzyme protein-L-isoaspartyl methyltransferase (PIMT). PIMT-KO (knockout) mice exhibit a pronounced neuropathology highlighted by death from an epileptic seizure at 30 to 60 days after birth. The mechanisms by which isoaspartyl damage disrupts normal brain function are incompletely understood. Proteomic analysis of the PIMT-KO mouse brain has shown that a number of key neuronal proteins accumulate high levels of isoAsp, but the extent to which their cellular functions is altered has yet to be determined. One of the major neuronal targets of PIMT is creatine kinase B (CKB), a well-characterized enzyme whose activity is relatively easy to assay. We show here that (1) the specific activity of CKB is significantly reduced in the brains of PIMT-deficient mice, (2) that in vitro aging of recombinant CKB results in significant accumulation of isoAsp sites with concomitant loss of enzymatic activity, and (3) that incubation of in vitro aged CKB with PIMT and its methyl donor S-adenosyl-L-methionine substantially repairs the aged CKB with regard to both its isoAsp content and its enzymatic activity. These results, combined with similarity in phenotypes of PIMT-KO and CKB-KO mice, suggests that loss of normal CKB structure and function contributes to the mechanisms by which isoAsp accumulation leads to CNS dysfunction in the PIMT-KO mouse.
Collapse
Affiliation(s)
- Aleksandra Dimitrijevic
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Zhenxia Qin
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
| | - Dana W Aswad
- Department of Molecular Biology & Biochemistry, University of California Irvine, Irvine, California, United States of America
| |
Collapse
|
13
|
Patananan AN, Capri J, Whitelegge JP, Clarke SG. Non-repair pathways for minimizing protein isoaspartyl damage in the yeast Saccharomyces cerevisiae. J Biol Chem 2014; 289:16936-53. [PMID: 24764295 DOI: 10.1074/jbc.m114.564385] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The spontaneous degradation of asparaginyl and aspartyl residues to isoaspartyl residues is a common type of protein damage in aging organisms. Although the protein-l-isoaspartyl (d-aspartyl) O-methyltransferase (EC 2.1.1.77) can initiate the repair of l-isoaspartyl residues to l-aspartyl residues in most organisms, no gene homolog or enzymatic activity is present in the budding yeast Saccharomyces cerevisiae. Therefore, we used biochemical approaches to elucidate how proteins containing isoaspartyl residues are metabolized in this organism. Surprisingly, the level of isoaspartyl residues in yeast proteins (50-300 pmol of isoaspartyl residues/mg of protein extract) is comparable with organisms with protein-l-isoaspartyl (d-aspartyl) O-methyltransferase, suggesting a novel regulatory pathway. Interfering with common protein quality control mechanisms by mutating and inhibiting the proteasomal and autophagic pathways in vivo did not increase isoaspartyl residue levels compared with wild type or uninhibited cells. However, the inhibition of metalloproteases in in vitro aging experiments by EDTA resulted in an ∼3-fold increase in the level of isoaspartyl-containing peptides. Characterization by mass spectrometry of these peptides identified several proteins involved in metabolism as targets of isoaspartyl damage. Further analysis of these peptides revealed that many have an N-terminal isoaspartyl site and originate from proteins with short half-lives. These results suggest that one or more metalloproteases participate in limiting isoaspartyl formation by robust proteolysis.
Collapse
Affiliation(s)
- Alexander N Patananan
- From the Department of Chemistry and Biochemistry and the Molecular Biology Institute and
| | - Joseph Capri
- the Pasarow Mass Spectrometry Laboratory, Neuropsychiatric Institute-Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, California 90095
| | - Julian P Whitelegge
- the Pasarow Mass Spectrometry Laboratory, Neuropsychiatric Institute-Semel Institute for Neuroscience and Human Behavior, UCLA, Los Angeles, California 90095
| | - Steven G Clarke
- From the Department of Chemistry and Biochemistry and the Molecular Biology Institute and
| |
Collapse
|
14
|
Qin Z, Yang J, Klassen HJ, Aswad DW. Isoaspartyl protein damage and repair in mouse retina. Invest Ophthalmol Vis Sci 2014; 55:1572-9. [PMID: 24550364 DOI: 10.1167/iovs.13-13668] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022] Open
Abstract
PURPOSE To determine the propensity of retinal proteins for spontaneous damage via formation of isoaspartyl sites, a common type of protein damage that could contribute to retinal disease. METHODS Tissue extracts were obtained from retinas and brains of control mice and from mice in which the gene for protein L-isoaspartate O-methyltransferase (PIMT; an enzyme that repairs isoaspartyl protein damage) was knocked out. PIMT expression in these extracts was measured by Western blot, and its specific activity was assayed by monitoring the rate of [(3)H]methyl transfer from S-adenosyl-[methyl-(3)H]L-methionine to γ-globulin. Isoaspartate levels in extracts were measured by their capacity to accept [(3)H]methyl groups via the PIMT-catalyzed methylation reaction. To compare molecular weight distributions of isoaspartyl-rich proteins in retina versus brain, proteins from PIMT knockout (KO) and control mice were separated by SDS-PAGE and transferred to polyvinylidene difluoride (PVDF). Isoaspartyl proteins were (3)H-labeled on-blot using a PIMT overlay and imaged by autoradiography. RESULTS When normalized to the β-actin content of each tissue, retina was found to be nearly identical to brain with regard to expression and activity of PIMT and its propensity to accumulate isoaspartyl sites when PIMT is absent. The two tissues show distinct differences in the molecular weight distribution of isoaspartyl proteins. CONCLUSIONS The retina is rich in PIMT activity and contains a wide range of proteins that are highly susceptible to this type of protein damage. Recoverin may be one such protein. Isoaspartate formation, along with oxidation, should be considered as a potential source of protein dysfunction and autoimmunity in retinal disease.
Collapse
Affiliation(s)
- Zhenxia Qin
- Department of Molecular Biology and Biochemistry, University of California, Irvine, California
| | | | | | | |
Collapse
|
15
|
Ouazia D, Levros LC, Rassart E, Desrosiers RR. Dopamine down-regulation of protein L-isoaspartyl methyltransferase is dependent on reactive oxygen species in SH-SY5Y cells. Neuroscience 2014; 267:263-76. [PMID: 24631677 DOI: 10.1016/j.neuroscience.2014.03.001] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2013] [Revised: 02/18/2014] [Accepted: 03/02/2014] [Indexed: 12/21/2022]
Abstract
Parkinson's disease (PD) is a chronic and progressive neurological disorder that is characterized by the loss of dopaminergic neurons in the substantia nigra. Dopamine, via the oxidative stress that it generates in the cytosol, could contribute to the selective loss of neurons observed in PD. Protein L-isoaspartyl methyltransferase (PIMT) is an enzyme that repairs L-isoaspartyl-containing proteins and possesses anti-apoptotic properties. PIMT expression has been shown to decrease with age. Together, these observations prompted us to investigate whether dopamine can regulate PIMT expression in SH-SY5Y neuroblastoma cells. Here, we report that dopamine down-regulated PIMT at both gene and protein levels. The same inhibition of PIMT protein level was caused by the electron transport chain inhibitor, rotenone, which was accompanied, in both cases, by an increase in cell death and reactive oxygen species (ROS) production. In fact, pre-treatment with the antioxidant N-acetyl cysteine blocked PIMT dopamine-associated down-regulation. PCMT1 promoter mapping experiments allowed the identification of two regions that showed different sensitivity to DA action. A first region localized between 61 and 94bp upstream of transcription start site was very sensitive to dopamine inhibition while a second region between 41 and 61bp appeared more resistant to dopamine inhibitory effect. The inhibition of PCMT1 promoter activity was mediated by dopamine-induced ROS since it was prevented by the hydroxyl radical scavenger N,N'-dimethylthiourea. Conversely, H2O2 inhibited in a dose-dependent manner the transcriptional activity of PCMT1 promoter. Therefore, our findings identified new molecular mechanisms, cytosolic dopamine and its resulting ROS, as inhibitors of PIMT expression. This suggests that ROS generated from cytosolic dopamine could reduce both the PCMT1 gene promoter activity and the PIMT protein level thus decreasing its capacity to repair proteins involved in apoptosis and could contribute to neuronal cell death observed in PD.
Collapse
Affiliation(s)
- D Ouazia
- Université du Québec à Montréal, Département de chimie, C.P. 8888, Succursale Centre-Ville, Montréal, Québec H3C 3P8, Canada
| | - L-C Levros
- Laboratoire de Biologie Moléculaire, Département des Sciences Biologiques, Centre BioMed, Université du Québec à Montréal, Montréal, Québec H3C 3P8, Canada
| | - E Rassart
- Laboratoire de Biologie Moléculaire, Département des Sciences Biologiques, Centre BioMed, Université du Québec à Montréal, Montréal, Québec H3C 3P8, Canada
| | - R R Desrosiers
- Université du Québec à Montréal, Département de chimie, C.P. 8888, Succursale Centre-Ville, Montréal, Québec H3C 3P8, Canada.
| |
Collapse
|
16
|
Chakraborty S, Bornhorst J, Nguyen TT, Aschner M. Oxidative stress mechanisms underlying Parkinson's disease-associated neurodegeneration in C. elegans. Int J Mol Sci 2013; 14:23103-28. [PMID: 24284401 PMCID: PMC3856108 DOI: 10.3390/ijms141123103] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Revised: 10/08/2013] [Accepted: 10/16/2013] [Indexed: 12/11/2022] Open
Abstract
Oxidative stress is thought to play a significant role in the development and progression of neurodegenerative diseases. Although it is currently considered a hallmark of such processes, the interweaving of a multitude of signaling cascades hinders complete understanding of the direct role of oxidative stress in neurodegeneration. In addition to its extensive use as an aging model, some researchers have turned to the invertebrate model Caenorhabditis elegans (C. elegans) in order to further investigate molecular mediators that either exacerbate or protect against reactive oxygen species (ROS)-mediated neurodegeneration. Due to their fully characterized genome and short life cycle, rapid generation of C. elegans genetic models can be useful to study upstream markers of oxidative stress within interconnected signaling pathways. This report will focus on the roles of C. elegans homologs for the oxidative stress-associated transcription factor Nrf2, as well as the autosomal recessive, early-onset Parkinson’s disease (PD)-associated proteins Parkin, DJ-1, and PINK1, in neurodegenerative processes.
Collapse
Affiliation(s)
- Sudipta Chakraborty
- Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mail:
- Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mail:
| | - Julia Bornhorst
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mail:
| | - Thuy T. Nguyen
- Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mail:
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Michael Aschner
- Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mail:
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA; E-Mail:
- Department of Pharmacology, Vanderbilt University Medical Center, Nashville, TN 37232, USA
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +1-718-430-2317
| |
Collapse
|
17
|
Gomez F, Monsalve GC, Tse V, Saiki R, Weng E, Lee L, Srinivasan C, Frand AR, Clarke CF. Delayed accumulation of intestinal coliform bacteria enhances life span and stress resistance in Caenorhabditis elegans fed respiratory deficient E. coli. BMC Microbiol 2012; 12:300. [PMID: 23256533 PMCID: PMC3548685 DOI: 10.1186/1471-2180-12-300] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 12/14/2012] [Indexed: 11/24/2022] Open
Abstract
Background Studies with the nematode model Caenorhabditis elegans have identified conserved biochemical pathways that act to modulate life span. Life span can also be influenced by the composition of the intestinal microbiome, and C. elegans life span can be dramatically influenced by its diet of Escherichia coli. Although C. elegans is typically fed the standard OP50 strain of E. coli, nematodes fed E. coli strains rendered respiratory deficient, either due to a lack coenzyme Q or the absence of ATP synthase, show significant life span extension. Here we explore the mechanisms accounting for the enhanced nematode life span in response to these diets. Results The intestinal load of E. coli was monitored by determination of worm-associated colony forming units (cfu/worm or coliform counts) as a function of age. The presence of GFP-expressing E. coli in the worm intestine was also monitored by fluorescence microscopy. Worms fed the standard OP50 E. coli strain have high cfu and GFP-labeled bacteria in their guts at the L4 larval stage, and show saturated coliform counts by day five of adulthood. In contrast, nematodes fed diets of respiratory deficient E. coli lacking coenzyme Q lived significantly longer and failed to accumulate bacteria within the lumen at early ages. Animals fed bacteria deficient in complex V showed intermediate coliform numbers and were not quite as long-lived. The results indicate that respiratory deficient Q-less E. coli are effectively degraded in the early adult worm, either at the pharynx or within the intestine, and do not accumulate in the intestinal tract until day ten of adulthood. Conclusions The findings of this study suggest that the nematodes fed the respiratory deficient E. coli diet live longer because the delay in bacterial colonization of the gut subjects the worms to less stress compared to worms fed the OP50 E. coli diet. This work suggests that bacterial respiration can act as a virulence factor, influencing the ability of bacteria to colonize and subsequently harm the animal host. Respiratory deficient bacteria may pose a useful model for probing probiotic relationships within the gut microbiome in higher organisms.
Collapse
Affiliation(s)
- Fernando Gomez
- Molecular Biology Institute, University of California, Los Angeles, CA 90095, USA
| | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Dutta T, Banerjee S, Soren D, Lahiri S, Sengupta S, Rasquinha JA, Ghosh AK. Regulation of Enzymatic Activity by Deamidation and Their Subsequent Repair by Protein l-isoaspartyl Methyl Transferase. Appl Biochem Biotechnol 2012; 168:2358-75. [DOI: 10.1007/s12010-012-9942-y] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2012] [Accepted: 10/05/2012] [Indexed: 01/19/2023]
|
19
|
Novel structural arrangement of nematode cystathionine β-synthases: characterization of Caenorhabditis elegans CBS-1. Biochem J 2012; 443:535-47. [PMID: 22240119 PMCID: PMC3316156 DOI: 10.1042/bj20111478] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
CBSs (cystathionine β-synthases) are eukaryotic PLP (pyridoxal 5 *-phosphate)-dependent proteins that maintain cellular homocysteine homoeostasis and produce cystathionine and hydrogen sulfide. In the present study, we describe a novel structural arrangement of the CBS enzyme encoded by the cbs-1 gene of the nematode Caenorhabditis elegans. The CBS-1 protein contains a unique tandem repeat of two evolutionarily conserved catalytic regions in a single polypeptide chain. These repeats include a catalytically active C-terminal module containing a PLP-binding site and a less conserved N-terminal module that is unable to bind the PLP cofactor and cannot catalyse CBS reactions, as demonstrated by analysis of truncated variants and active-site mutant proteins. In contrast with other metazoan enzymes, CBS-1 lacks the haem and regulatory Bateman domain essential for activation by AdoMet (S-adenosylmethionine) and only forms monomers. We determined the tissue and subcellular distribution of CBS-1 and showed that cbs-1 knockdown by RNA interference leads to delayed development and to an approximately 10-fold elevation of homocysteine concentrations in nematode extracts. The present study provides the first insight into the metabolism of sulfur amino acids and hydrogen sulfide in C. elegans and shows that nematode CBSs possess a structural feature that is unique among CBS proteins.
Collapse
|
20
|
The interplay between protein L-isoaspartyl methyltransferase activity and insulin-like signaling to extend lifespan in Caenorhabditis elegans. PLoS One 2011; 6:e20850. [PMID: 21695191 PMCID: PMC3113807 DOI: 10.1371/journal.pone.0020850] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2011] [Accepted: 05/11/2011] [Indexed: 12/22/2022] Open
Abstract
The protein L-isoaspartyl-O-methyltransferase functions to initiate the repair of isomerized aspartyl and asparaginyl residues that spontaneously accumulate with age in a variety of organisms. Caenorhabditis elegans nematodes lacking the pcm-1 gene encoding this enzyme display a normal lifespan and phenotype under standard laboratory growth conditions. However, significant defects in development, egg laying, dauer survival, and autophagy have been observed in pcm-1 mutant nematodes when deprived of food and when exposed to oxidative stress. Interestingly, overexpression of this repair enzyme in both Drosophila and C. elegans extends adult lifespan under thermal stress. In this work, we show the involvement of the insulin/insulin-like growth factor-1 signaling (IIS) pathway in PCM-1-dependent lifespan extension in C. elegans. We demonstrate that reducing the levels of the DAF-16 downstream transcriptional effector of the IIS pathway by RNA interference reduces the lifespan extension resulting from PCM-1 overexpression. Using quantitative real-time PCR analysis, we show the up-regulation of DAF-16-dependent stress response genes in the PCM-1 overexpressor animals compared to wild-type and pcm-1 mutant nematodes under mild thermal stress conditions. Additionally, similar to other long-lived C. elegans mutants in the IIS pathway, including daf-2 and age-1 mutants, PCM-1 overexpressor adult animals display increased resistance to severe thermal stress, whereas pcm-1 mutant animals survive less long under these conditions. Although we observe a higher accumulation of damaged proteins in pcm-1 mutant nematodes, the basal level of isoaspartyl residues detected in wild-type animals was not reduced by PCM-1 overexpression. Our results support a signaling role for the protein L-isoaspartyl methyltransferase in lifespan extension that involves the IIS pathway, but that may be independent of its function in overall protein repair.
Collapse
|
21
|
A high-throughput method for assessing chemical toxicity using a Caenorhabditis elegans reproduction assay. Toxicol Appl Pharmacol 2010; 245:153-9. [PMID: 20206647 DOI: 10.1016/j.taap.2010.02.014] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2009] [Revised: 02/19/2010] [Accepted: 02/23/2010] [Indexed: 02/06/2023]
Abstract
The National Research Council has outlined the need for non-mammalian toxicological models to test the potential health effects of a large number of chemicals while also reducing the use of traditional animal models. The nematode Caenorhabditis elegans is an attractive alternative model because of its well-characterized and evolutionarily conserved biology, low cost, and ability to be used in high-throughput screening. A high-throughput method is described for quantifying the reproductive capacity of C. elegans exposed to chemicals for 48 h from the last larval stage (L4) to adulthood using a COPAS Biosort. Initially, the effects of exposure conditions that could influence reproduction were defined. Concentrations of DMSO vehicle <or=1% did not affect reproduction. Previous studies indicated that C. elegans may be influenced by exposure to low pH conditions. At pHs greater than 4.5, C. elegans reproduction was not affected; however below this pH there was a significant decrease in the number of offspring. Cadmium chloride was chosen as a model toxicant to verify that automated measurements were comparable to those of traditional observational studies. EC(50) values for cadmium for automated measurements (176-192 microM) were comparable to those previously reported for a 72-h exposure using manual counting (151 microM). The toxicity of seven test toxicants on C. elegans reproduction was highly correlative with rodent lethality suggesting that this assay may be useful in predicting the potential toxicity of chemicals in other organisms.
Collapse
|