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Iida R, Ueki M, Yasuda T. Identification of interacting partners of Human Mpv17-like protein with a mitigating effect of mitochondrial dysfunction through mtDNA damage. Free Radic Biol Med 2015; 87:336-45. [PMID: 26165189 DOI: 10.1016/j.freeradbiomed.2015.07.008] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2014] [Revised: 07/07/2015] [Accepted: 07/07/2015] [Indexed: 11/16/2022]
Abstract
Human Mpv17-like protein (M-LPH) has been suggested to participate in mitochondrial function. In this study, we investigated the proteins that interact with M-LPH, and identified four: H2A histone family, member X (H2AX), ribosomal protein S14 (RPS14), ribosomal protein S3 (RPS3) and B-cell receptor-associated protein 31 (Bap31). Immunofluorescence and subcellular fractionation studies revealed that M-LPH is localized predominantly in the nucleus, to some extent in a subset of mitochondria, and marginally in the cytosol. Mitochondrial M-LPH appeared as punctate foci, and these were co-localized with a subset of mitochondrial transcription factor A (TFAM) and mtDNA, indicating that M-LPH is localized in or in close proximity to mitochondrial nucleoids. RNAi-mediated knockdown of M-LPH resulted in an increase of mtDNA damage and reduced the expression of mtDNA-encoded genes. A ROS inducer, antimycin A, caused an increase in both the number and size of the mitochondrial M-LPH foci, and these foci were co-localized with two enzymes, DNA polymerase γ (POLG) and DNA ligase III (LIG3), both involved in mtDNA repair. Furthermore, knockdown of M-LPH hampered mitochondrial localization of these enzymes. Taken together, these observations suggest that M-LPH is involved in the maintenance of mtDNA and protects cells from mitochondrial dysfunction.
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Affiliation(s)
- Reiko Iida
- Division of Life Science, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan; Organization for Life Science Advancement Programs, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan.
| | - Misuzu Ueki
- Division of Medical Genetics and Biochemistry, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
| | - Toshihiro Yasuda
- Organization for Life Science Advancement Programs, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan; Division of Medical Genetics and Biochemistry, Faculty of Medical Sciences, University of Fukui, Fukui 910-1193, Japan
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Natural Compounds Modulating Mitochondrial Functions. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:527209. [PMID: 26167193 PMCID: PMC4489008 DOI: 10.1155/2015/527209] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/11/2015] [Accepted: 06/11/2015] [Indexed: 12/20/2022]
Abstract
Mitochondria are organelles responsible for several crucial cell functions, including respiration, oxidative phosphorylation, and regulation of apoptosis; they are also the main intracellular source of reactive oxygen species (ROS). In the last years, a particular interest has been devoted to studying the effects on mitochondria of natural compounds of vegetal origin, quercetin (Qu), resveratrol (RSV), and curcumin (Cur) being the most studied molecules. All these natural compounds modulate mitochondrial functions by inhibiting organelle enzymes or metabolic pathways (such as oxidative phosphorylation), by altering the production of mitochondrial ROS and by modulating the activity of transcription factors which regulate the expression of mitochondrial proteins. While Qu displays both pro- and antioxidant activities, RSV and Cur are strong antioxidant, as they efficiently scavenge mitochondrial ROS and upregulate antioxidant transcriptional programmes in cells. All the three compounds display a proapoptotic activity, mediated by the capability to directly cause the release of cytochrome c from mitochondria or indirectly by upregulating the expression of proapoptotic proteins of Bcl-2 family and downregulating antiapoptotic proteins. Interestingly, these effects are particularly evident on proliferating cancer cells and can have important therapeutic implications.
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Abstract
All living organisms require protein degradation to terminate biological processes and remove damaged proteins. One such machine is the 20S proteasome, a specialized barrel-shaped and compartmentalized multicatalytic protease. The activity of the 20S proteasome generally requires the binding of regulators/proteasome activators (PAs), which control the entrance of substrates. These include the PA700 (19S complex), which assembles with the 20S and forms the 26S proteasome and allows the efficient degradation of proteins usually labeled by ubiquitin tags, PA200 and PA28, which are involved in proteolysis through ubiquitin-independent mechanisms and PI31, which was initially identified as a 20S inhibitor in vitro. Unlike 20S proteasome, shown to be present in all Eukaryotes and Archaea, the evolutionary history of PAs remained fragmentary. Here, we made a comprehensive survey and phylogenetic analyses of the four types of regulators in 17 clades covering most of the eukaryotic supergroups. We found remarkable conservation of each PA700 subunit in all eukaryotes, indicating that the current complex PA700 structure was already set up in the last eukaryotic common ancestor (LECA). Also present in LECA, PA200, PA28, and PI31 showed a more contrasted evolutionary picture, because many lineages have subsequently lost one or two of them. The paramount conservation of PA700 composition in all eukaryotes and the dynamic evolution of PA200, PA28, and PI31 are discussed in the light of current knowledge on their physiological roles.
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Affiliation(s)
- Philippe Fort
- CNRS, CRBM, UMR5237, Montpellier, France Université de Montpellier, France
| | - Andrey V Kajava
- CNRS, CRBM, UMR5237, Montpellier, France Université de Montpellier, France Institut de Biologie Computationnelle, Montpellier, France
| | - Fredéric Delsuc
- Université de Montpellier, France CNRS, IRD, Institut des Sciences de l'Evolution, UMR 5554, Montpellier, France
| | - Olivier Coux
- CNRS, CRBM, UMR5237, Montpellier, France Université de Montpellier, France
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Lin R, Liu C, Shen B, Bai M, Ling J, Chen G, Mao Z, Cheng X, Xie B. Analysis of the complete mitochondrial genome of Pochonia chlamydosporia suggests a close relationship to the invertebrate-pathogenic fungi in Hypocreales. BMC Microbiol 2015; 15:5. [PMID: 25636983 PMCID: PMC4360972 DOI: 10.1186/s12866-015-0341-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2014] [Accepted: 01/08/2015] [Indexed: 11/10/2022] Open
Abstract
Background The fungus Pochonia chlamydosporia parasitizes nematode eggs and has become one of the most promising biological control agents (BCAs) for plant-parasitic nematodes, which are major agricultural pests that cause tremendous economic losses worldwide. The complete mitochondrial (mt) genome is expected to open new avenues for understanding the phylogenetic relationships and evolution of the invertebrate-pathogenic fungi in Hypocreales. Results The complete mitogenome sequence of P. chlamydosporia is 25,615 bp in size, containing the 14 typical protein-coding genes, two ribosomal RNA genes, an intronic ORF coding for a putative ribosomal protein (rps3) and a set of 23 transfer RNA genes (trn) which recognize codons for all amino acids. Sequence similarity studies and syntenic gene analyses show that 87.02% and 58.72% of P. chlamydosporia mitogenome sequences match 90.50% of Metarhizium anisopliae sequences and 61.33% of Lecanicillium muscarium sequences with 92.38% and 86.04% identities, respectively. A phylogenetic tree inferred from 14 mt proteins in Pezizomycotina fungi supports that P. chlamydosporia is most closely related to the entomopathogenic fungus M. anisopliae. The invertebrate-pathogenic fungi in Hypocreales cluster together and clearly separate from a cluster comprising plant-pathogenic fungi (Fusarium spp.) and Hypocrea jecorina. A comparison of mitogenome sizes shows that the length of the intergenic regions or the intronic regions is the major size contributor in most of mitogenomes in Sordariomycetes. Evolutionary analysis shows that rps3 is under positive selection, leading to the display of unique evolutionary characteristics in Hypocreales. Moreover, the variability of trn distribution has a clear impact on gene order in mitogenomes. Gene rearrangement analysis shows that operation of transposition drives the rearrangement events in Pezizomycotina, and most events involve in trn position changes, but no rearrangement was found in Clavicipitaceae. Conclusions We present the complete annotated mitogenome sequence of P. chlamydosporia. Based on evolutionary and phylogenetic analyses, we have determined the relationships between the invertebrate-pathogenic fungi in Hypocreales. The invertebrate-pathogenic fungi in Hypocreales referred to in this paper form a monophyletic group sharing a most recent common ancestor. Our rps3 and trn gene order results also establish a foundation for further exploration of the evolutionary trajectory of the fungi in Hypocreales. Electronic supplementary material The online version of this article (doi:10.1186/s12866-015-0341-8) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Runmao Lin
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Chichuan Liu
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Baoming Shen
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China. .,College of Plant Protection, Hunan Agricultural University, Changsha, Hunan Province, 410128, China.
| | - Miao Bai
- Key Laboratory for Crop Germplasm Innovation and Utilization of Hunan Province, Hunan Agricultural University, Changsha, Hunan Province, 410128, China.
| | - Jian Ling
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Guohua Chen
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Zhenchuan Mao
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
| | - Xinyue Cheng
- College of Life Sciences, Beijing Normal University, Beijing, 100875, China.
| | - Bingyan Xie
- Institute of Vegetables and Flowers, Chinese Academy of Agricultural Sciences, Beijing, 100081, China.
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DNA damage stress induces the expression of ribosomal protein S27a gene in a p53-dependent manner. Gene 2015; 559:44-51. [PMID: 25592822 DOI: 10.1016/j.gene.2015.01.014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2014] [Revised: 12/28/2014] [Accepted: 01/08/2015] [Indexed: 12/28/2022]
Abstract
The small ribosomal protein RPS27a is known to play a role in the activation of cellular checkpoints via p53 which links ribosome biogenesis to cell cycle progression. Here, we show that RPS27a gene is a direct transcriptional target of p53 and is overexpressed in response to DNA damage. Elevated RPS27a level was associated with increased expression of p53 and its target p21(Waf1) gene. The RPS27a activity was specifically inhibited in the presence of a dominant negative mutant of p53. Down-regulation of ectopically expressed RPS27a by RNA interference blocked the activation of p21(waf1) in response to DNA damage. Thus, RPS27a appears to be a novel stress sensor in the cell which amplifies p53 response to arrest cell cycle.
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You Y, Wen R, Pathak R, Li A, Li W, St Clair D, Hauer-Jensen M, Zhou D, Liang Y. Latexin sensitizes leukemogenic cells to gamma-irradiation-induced cell-cycle arrest and cell death through Rps3 pathway. Cell Death Dis 2014; 5:e1493. [PMID: 25341047 PMCID: PMC4237263 DOI: 10.1038/cddis.2014.443] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 09/04/2014] [Accepted: 09/08/2014] [Indexed: 11/09/2022]
Abstract
Leukemia is a leading cause of cancer death. Recently, the latexin (Lxn) gene was identified as a potential tumor suppressor in several types of solid tumors and lymphoma, and Lxn expression was found to be absent or downregulated in leukemic cells. Whether Lxn functions as a tumor suppressor in leukemia and what molecular and cellular mechanisms are involved are unknown. In this study, the myeloid leukemogenic FDC-P1 cell line was used as a model system and Lxn was ectopically expressed in these cells. Using the protein pull-down assay and mass spectrometry, ribosomal protein subunit 3 (Rps3) was identified as a novel Lxn binding protein. Ectopic expression of Lxn inhibited FDC-P1 growth in vitro. More surprisingly, Lxn enhanced gamma irradiation-induced DNA damages and induced cell-cycle arrest and massive necrosis, leading to depletion of FDC-P1 cells. Mechanistically, Lxn inhibited the nuclear translocation of Rps3 upon radiation, resulting in abnormal mitotic spindle formation and chromosome instability. Rps3 knockdown increased the radiation sensitivity of FDC-P1, confirming that the mechanism of action of Lxn is mediated by Rps3 pathway. Moreover, Lxn enhanced the cytotoxicity of chemotherapeutic agent, VP-16, on FDC-P1 cells. Our study suggests that Lxn itself not only suppresses leukemic cell growth but also potentiates the cytotoxic effect of radio- and chemotherapy on cancer cells. Lxn could be a novel molecular target that improves the efficacy of anti-cancer therapy.
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Affiliation(s)
- Y You
- Department of Internal Medicine, University of Kentucky, Lexington, KY 40536, USA
| | - R Wen
- Department of Internal Medicine, University of Kentucky, Lexington, KY 40536, USA
| | - R Pathak
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - A Li
- Department of Pathology, Harvard Medical School, Boston, MA 02115, USA
| | - W Li
- Department of Internal Medicine, University of Kentucky, Lexington, KY 40536, USA
| | - D St Clair
- Gratuate Center for Toxicology, University of Kentucky, Lexington, KY 40536, USA
| | - M Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - D Zhou
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, USA
| | - Y Liang
- 1] Department of Internal Medicine, University of Kentucky, Lexington, KY 40536, USA [2] Gratuate Center for Toxicology, University of Kentucky, Lexington, KY 40536, USA
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Kim Y, Kim HD, Youn B, Park YG, Kim J. Ribosomal protein S3 is secreted as a homodimer in cancer cells. Biochem Biophys Res Commun 2013; 441:805-8. [PMID: 24211576 DOI: 10.1016/j.bbrc.2013.10.132] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2013] [Accepted: 10/25/2013] [Indexed: 11/19/2022]
Abstract
Protein secretion is a general phenomenon by which cells communicate with the extracellular environment. Secretory proteins, including hormones, enzymes, toxins, and antimicrobial peptides have various functions in extracellular environments. Here, we determined that ribosomal protein S3 (rpS3) is homodimerized and secreted in several cancer cell lines such as HT1080 (human fibrosarcoma) and MPC11 (mouse plasmacytoma). Moreover, we found that the secreted rpS3 protein increased in doxorubicin-resistant MPC11 cells compared to that in MPC11 cells. In addition, we also detected that the level of secreted rpS3 increased in more malignant cells, which were established with continuous exposure of cigarette smoke condensate. These findings suggest that the secreted rpS3 protein is an indicator of malignant tumors.
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Affiliation(s)
- YongJoong Kim
- Laboratory of Biochemistry, Division of Life Sciences, Korea University, Seoul 136-701, Republic of Korea
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