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Wanders RJA, Baes M, Ribeiro D, Ferdinandusse S, Waterham HR. The physiological functions of human peroxisomes. Physiol Rev 2023; 103:957-1024. [PMID: 35951481 DOI: 10.1152/physrev.00051.2021] [Citation(s) in RCA: 47] [Impact Index Per Article: 47.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Peroxisomes are subcellular organelles that play a central role in human physiology by catalyzing a range of unique metabolic functions. The importance of peroxisomes for human health is exemplified by the existence of a group of usually severe diseases caused by an impairment in one or more peroxisomal functions. Among others these include the Zellweger spectrum disorders, X-linked adrenoleukodystrophy, and Refsum disease. To fulfill their role in metabolism, peroxisomes require continued interaction with other subcellular organelles including lipid droplets, lysosomes, the endoplasmic reticulum, and mitochondria. In recent years it has become clear that the metabolic alliance between peroxisomes and other organelles requires the active participation of tethering proteins to bring the organelles physically closer together, thereby achieving efficient transfer of metabolites. This review intends to describe the current state of knowledge about the metabolic role of peroxisomes in humans, with particular emphasis on the metabolic partnership between peroxisomes and other organelles and the consequences of genetic defects in these processes. We also describe the biogenesis of peroxisomes and the consequences of the multiple genetic defects therein. In addition, we discuss the functional role of peroxisomes in different organs and tissues and include relevant information derived from model systems, notably peroxisomal mouse models. Finally, we pay particular attention to a hitherto underrated role of peroxisomes in viral infections.
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Affiliation(s)
- Ronald J A Wanders
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,United for Metabolic Diseases, Amsterdam, The Netherlands
| | - Myriam Baes
- Laboratory of Cell Metabolism, Department of Pharmaceutical and Pharmacological Sciences, KU Leuven, Leuven, Belgium
| | - Daniela Ribeiro
- Institute of Biomedicine (iBiMED) and Department of Medical Sciences, University of Aveiro, Aveiro, Portugal
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,United for Metabolic Diseases, Amsterdam, The Netherlands
| | - Hans R Waterham
- Laboratory Genetic Metabolic Diseases, Department of Clinical Chemistry, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,Department of Pediatrics, Emma Children's Hospital, Amsterdam University Medical Center, University of Amsterdam, Amsterdam, The Netherlands.,United for Metabolic Diseases, Amsterdam, The Netherlands
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2
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Zaki MS, Issa MY, Thomas MM, Elbendary HM, Rafat K, Al Menabawy NM, Selim LA, Ismail S, Abdel-Salam GM, Gleeson JG. A founder mutation in PEX12 among Egyptian patients in peroxisomal biogenesis disorder. Neurol Sci 2020; 42:2737-2745. [PMID: 33123925 DOI: 10.1007/s10072-020-04843-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2020] [Accepted: 10/17/2020] [Indexed: 10/23/2022]
Abstract
At least 14 distinctive PEX genes function in the biogenesis of peroxisomes. Biallelic alterations in the peroxisomal biogenesis factor 12 (PEX12) gene lead to Zellweger syndrome spectrum (ZSS) with variable clinical expressivity ranging from early lethality to mildly affected with long-term survival. Herein, we define 20 patients derived from 14 unrelated Egyptian families, 19 of which show a homozygous PEX12 in-frame (c.1047_1049del p.(Gln349del)) deletion. This founder mutation, reported rarely outside of Egypt, was associated with a uniformly severe phenotype. Patients showed developmental delay in early life followed by motor and mental regression, progressive hypotonia, unsteadiness, and lack of speech. Seventeen patients had sparse hair or partial alopecia, a striking feature that was not noted previously in PEX12. Neonatal cholestasis was manifested in 2 siblings. Neurodiagnostics showed consistent cerebellar atrophy and variable white matter demyelination, axonal neuropathy in about half, and cardiomyopathy in 10% of patients. A single patient with a compound heterozygous PEX12 mutation exhibited milder features with late childhood onset with gait disturbance and learning disability. Thus, the PEX12 relatively common founder mutation accounts for the majority of PEX12-related disease in Egypt and delineates a uniform clinical and radiographic phenotype.
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Affiliation(s)
- Maha S Zaki
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, El-Tahrir Street, Dokki, Cairo, 12311, Egypt.
| | - Mahmoud Y Issa
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, El-Tahrir Street, Dokki, Cairo, 12311, Egypt
| | - Manal M Thomas
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, El-Tahrir Street, Dokki, Cairo, 12311, Egypt
| | - Hasnaa M Elbendary
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, El-Tahrir Street, Dokki, Cairo, 12311, Egypt
| | - Karima Rafat
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, El-Tahrir Street, Dokki, Cairo, 12311, Egypt
| | - Nihal M Al Menabawy
- Neurology and Metabolic Division, Cairo University Children Hospital, Cairo, Egypt
| | - Laila A Selim
- Neurology and Metabolic Division, Cairo University Children Hospital, Cairo, Egypt
| | - Samira Ismail
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, El-Tahrir Street, Dokki, Cairo, 12311, Egypt
| | - Ghada M Abdel-Salam
- Clinical Genetics Department, Human Genetics and Genome Research Division, National Research Centre, El-Tahrir Street, Dokki, Cairo, 12311, Egypt
| | - Joseph G Gleeson
- Department of Neurosciences, University of California and Rady Children's Institute for Genomic Medicine, Rady Children's Hospital San Diego, La Jolla, CA, 92093, USA
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3
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Kim EH, Kim GA, Taweechaipaisankul A, Ridlo MR, Lee SH, Ra K, Ahn C, Lee BC. Phytanic acid-derived peroxisomal lipid metabolism in porcine oocytes. Theriogenology 2020; 157:276-285. [PMID: 32823023 DOI: 10.1016/j.theriogenology.2020.07.007] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 07/03/2020] [Accepted: 07/07/2020] [Indexed: 12/15/2022]
Abstract
Lipid metabolism plays an important role in oocyte maturation. The peroxisome is the fundamental mediator for this mechanism. In this study, we investigated the peroxisomal lipid metabolism in porcine oocytes. Phytanic acid (PA) was chosen as an activator of alpha-oxidation in peroxisomes. Oocyte maturation, embryo development, immunocytochemistry of peroxisomal lipid activities, and staining of mitochondrial potentials were assessed. We found that 40 μM PA not only increased porcine oocyte maturation and embryonic development, but also upregulated the expression of genes and proteins related to activities of the peroxisomal lipid metabolism (PHYH, PEX19, and PEX subfamilies) and mitochondrial potentials (NRF1 and PGC1α). Moreover, PA upregulated the lipid droplet and fatty acid content in the oocytes. Moreover, mitochondria were activated and the mitochondrial membrane potential was increased after PA treatment, resulting in the production of more ATPs in the oocytes. Our findings suggest that the degradation of PA via alpha-oxidation in the peroxisome may potentiate oocyte maturation processes, peroxisomal lipid oxidation, and mitochondria activities.
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Affiliation(s)
- Eui Hyun Kim
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Geon A Kim
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea; Department of Biomedical Laboratory Science, School of Medicine, Eulji University, Daejeon, Republic of Korea
| | - Anukul Taweechaipaisankul
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Muhammad Rosyid Ridlo
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea; Department of Bioresource Technology and Veterinary, Vocational College, Universitas Gadjah Mada, Yogyakarta, Indonesia
| | - Seok Hee Lee
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Kihae Ra
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea
| | - Curie Ahn
- Division of Nephrology, College of Medicine, Seoul National University, Seoul, Republic of Korea
| | - Byeong Chun Lee
- Department of Theriogenology and Biotechnology, Research Institute for Veterinary Science, College of Veterinary Medicine, Seoul National University, Seoul, Republic of Korea.
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4
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Abe Y, Tamura S, Honsho M, Fujiki Y. A Mouse Model System to Study Peroxisomal Roles in Neurodegeneration of Peroxisome Biogenesis Disorders. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1299:119-143. [PMID: 33417212 DOI: 10.1007/978-3-030-60204-8_10] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Fourteen PEX genes are currently identified as genes responsible for peroxisome biogenesis disorders (PBDs). Patients with PBDs manifest as neurodegenerative symptoms such as neuronal migration defect and malformation of the cerebellum. To address molecular mechanisms underlying the pathogenesis of PBDs, mouse models for the PBDs have been generated by targeted disruption of Pex genes. Pathological phenotypes and metabolic abnormalities in Pex-knockout mice well resemble those of the patients with PBDs. The mice with tissue- or cell type-specific inactivation of Pex genes have also been established by using a Cre-loxP system. The genetically modified mice reveal that pathological phenotypes of PBDs are mediated by interorgan and intercellular communications. Despite the illustrations of detailed pathological phenotypes in the mutant mice, mechanistic insights into pathogenesis of PBDs are still underway. In this chapter, we overview the phenotypes of Pex-inactivated mice and the current understanding of the pathogenesis underlying PBDs.
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Affiliation(s)
- Yuichi Abe
- Faculty of Arts and Science, Kyushu University, Fukuoka, Japan
| | | | | | - Yukio Fujiki
- Institute of Rheological Functions of Food, Fukuoka, Japan. .,Medical Institute of Bioregulation, Kyushu University, Fukuoka, Japan.
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Wang L, Zhang L, Liu C, Sun S, Liu A, Liang Y, Yu J. The roles of FgPEX2 and FgPEX12 in virulence and lipid metabolism in Fusarium graminearum. Fungal Genet Biol 2019; 135:103288. [PMID: 31704369 DOI: 10.1016/j.fgb.2019.103288] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2019] [Revised: 09/19/2019] [Accepted: 10/29/2019] [Indexed: 12/12/2022]
Abstract
Fusarium head blight (FHB) is a wheat disease with a worldwide prevalence, caused by Fusarium graminearum. Peroxisomes are ubiquitous in eukaryotic cells and are involved in various biochemical phenomena. FgPEX2 and FgPEX12 encode RING-finger peroxins PEX2 and PEX12 in F. graminearum. This study aimed to functionally characterize FgPEX2 and FgPEX12 in F. graminearum. We constructed deletion mutants of FgPEX2 and FgPEX12 via homologous recombination. The ΔPEX2 and ΔPEX12 mutants displayed defects in sexual and asexual development, virulence, cell wall integrity (CWI), and lipid metabolism. Deletion of FgPEX2 and FgPEX12 significantly decreased deoxynivalenol production. Furthermore, fluorescence microscopic analysis of the subcellular localization of GFP-PMP70 and GFP-HEX1 revealed that FgPEX2 and FgPEX12 maintain Woronin bodies. These results show that FgPEX2 and FgPEX12 are required for growth, conidiation, virulence, cell wall integrity, and lipid metabolism in F. graminearum and do not influence their peroxisomes.
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Affiliation(s)
- Lina Wang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Li Zhang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Chunjie Liu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Shaohua Sun
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Aixin Liu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Yuancun Liang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China
| | - Jinfeng Yu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an 271018, China.
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6
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A Mechanistic Perspective on PEX1 and PEX6, Two AAA+ Proteins of the Peroxisomal Protein Import Machinery. Int J Mol Sci 2019; 20:ijms20215246. [PMID: 31652724 PMCID: PMC6862443 DOI: 10.3390/ijms20215246] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2019] [Revised: 10/18/2019] [Accepted: 10/21/2019] [Indexed: 12/11/2022] Open
Abstract
In contrast to many protein translocases that use ATP or GTP hydrolysis as the driving force to transport proteins across biological membranes, the peroxisomal matrix protein import machinery relies on a regulated self-assembly mechanism for this purpose and uses ATP hydrolysis only to reset its components. The ATP-dependent protein complex in charge of resetting this machinery—the Receptor Export Module (REM)—comprises two members of the “ATPases Associated with diverse cellular Activities” (AAA+) family, PEX1 and PEX6, and a membrane protein that anchors the ATPases to the organelle membrane. In recent years, a large amount of data on the structure/function of the REM complex has become available. Here, we discuss the main findings and their mechanistic implications.
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7
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Zhang L, Liu C, Wang L, Sun S, Liu A, Liang Y, Yu J, Dong H. FgPEX1 and FgPEX10 are required for the maintenance of Woronin bodies and full virulence of Fusarium graminearum. Curr Genet 2019; 65:1383-1396. [PMID: 31111312 DOI: 10.1007/s00294-019-00994-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2019] [Revised: 05/08/2019] [Accepted: 05/13/2019] [Indexed: 01/08/2023]
Abstract
Peroxisomes are ubiquitous single-membrane-bound organelles that perform a variety of biochemical functions in eukaryotic cells. Proteins involved in peroxisomal biogenesis are collectively called peroxins. Currently, functions of most peroxins in phytopathogenic fungi are poorly understood. Here, we report identification of PEX1 and PEX10 in the phytopathogenic fungus, Fusarium graminearum, namely FgPEX1 and FgPEX10, the orthologs of yeast ScPEX1 and ScPEX10. To functionally characterize FgPEX1 and FgPEX10, we constructed deletion mutants of FgPEX1 and FgPEX10 (ΔPEX1 and ΔPEX10) by targeting gene-replacement strategies. Our data demonstrate that both mutants displayed reduced mycelial growth, conidiation, and production of perithecia. Deletion of FgPEX1 and FgPEX10 resulted in a shortage of acetyl-CoA, which is an important reason for the reduced deoxynivalenol production and inhibited virulence of F. graminearum. Moreover, ΔPEX1 and ΔPEX10 showed an increased accumulation of lipid droplets and endogenous reactive oxygen species. In addition, FgPEX1 and FgPEX10 were found to be involved in the maintenance of cell wall integrity and Woronin bodies.
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Affiliation(s)
- Li Zhang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
| | - Chunjie Liu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
| | - Lina Wang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
| | - Shaohua Sun
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
| | - Aixin Liu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
| | - Yuancun Liang
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
| | - Jinfeng Yu
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China.
| | - Hansong Dong
- Key Laboratory of Agricultural Microbiology, College of Plant Protection, Shandong Agricultural University, Tai'an, 271018, China
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8
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Barros-Barbosa A, Rodrigues TA, Ferreira MJ, Pedrosa AG, Teixeira NR, Francisco T, Azevedo JE. The intrinsically disordered nature of the peroxisomal protein translocation machinery. FEBS J 2018; 286:24-38. [PMID: 30443986 DOI: 10.1111/febs.14704] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Accepted: 11/14/2018] [Indexed: 12/18/2022]
Abstract
Despite having a membrane that is impermeable to all but the smallest of metabolites, peroxisomes acquire their newly synthesized (cytosolic) matrix proteins in an already folded conformation. In some cases, even oligomeric proteins have been reported to translocate the organelle membrane. The protein sorting machinery that accomplishes this feat must be rather flexible and, unsurprisingly, several of its key components have large intrinsically disordered domains. Here, we provide an overview on these domains and their interactions trying to infer their functional roles in this protein sorting pathway.
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Affiliation(s)
- Aurora Barros-Barbosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Portugal
| | - Tony A Rodrigues
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Portugal
| | - Maria J Ferreira
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Portugal
| | - Ana G Pedrosa
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Portugal
| | - Nélson R Teixeira
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Portugal
| | - Tânia Francisco
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Portugal
| | - Jorge E Azevedo
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, Portugal.,Instituto de Biologia Molecular e Celular (IBMC), Universidade do Porto, Portugal.,Instituto de Ciências Biomédicas de Abel Salazar (ICBAS), Universidade do Porto, Portugal
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Peroxisomes and cancer: The role of a metabolic specialist in a disease of aberrant metabolism. Biochim Biophys Acta Rev Cancer 2018; 1870:103-121. [PMID: 30012421 DOI: 10.1016/j.bbcan.2018.07.004] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 05/30/2018] [Accepted: 07/10/2018] [Indexed: 01/02/2023]
Abstract
Cancer is irrevocably linked to aberrant metabolic processes. While once considered a vestigial organelle, we now know that peroxisomes play a central role in the metabolism of reactive oxygen species, bile acids, ether phospholipids (e.g. plasmalogens), very-long chain, and branched-chain fatty acids. Immune system evasion is a hallmark of cancer, and peroxisomes have an emerging role in the regulation of cellular immune responses. Investigations of individual peroxisome proteins and metabolites support their pro-tumorigenic functions. However, a significant knowledge gap remains regarding how individual functions of proteins and metabolites of the peroxisome orchestrate its potential role as a pro-tumorigenic organelle. This review highlights new advances in our understanding of biogenesis, enzymatic functions, and autophagic degradation of peroxisomes (pexophagy), and provides evidence linking these activities to tumorigenesis. Finally, we propose avenues that may be exploited to target peroxisome-related processes as a mode of combatting cancer.
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Renaud M, Guissart C, Mallaret M, Ferdinandusse S, Cheillan D, Drouot N, Muller J, Claustres M, Tranchant C, Anheim M, Koenig M. Expanding the spectrum of PEX10-related peroxisomal biogenesis disorders: slowly progressive recessive ataxia. J Neurol 2016; 263:1552-8. [PMID: 27230853 DOI: 10.1007/s00415-016-8167-3] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/09/2016] [Accepted: 05/09/2016] [Indexed: 11/24/2022]
Abstract
Peroxisomal biogenesis disorders (PBDs) consist of a heterogeneous group of autosomal recessive diseases, in which peroxisome assembly and proliferation are impaired leading to severe multisystem disease and early death. PBDs include Zellweger spectrum disorders (ZSDs) with a relatively mild clinical phenotype caused by PEX1, (MIM# 602136), PEX2 (MIM# 170993), PEX6 (MIM# 601498), PEX10 (MIM# 602859), PEX12 (MIM# 601758), and PEX16 (MIM# 603360) mutations. Three adult patients are reported belonging to a non-consanguineous French family affected with slowly progressive cerebellar ataxia, axonal neuropathy, and pyramidal signs. Mental retardation and diabetes mellitus were optional. The age at onset was in childhood or in adolescence (3-15 years). Brain MRI showed marked cerebellar atrophy. Biochemical blood analyses suggested a mild peroxisomal defect. With whole exome sequencing, two mutations in PEX10 were found in the three patients: c.827G>T (novel) causing the missense change p.Cys276Phe and c.932G>A causing the missense change p.Arg311Gln. The phenotypic spectrum related to PEX10 mutations includes slowly progressive, syndromic recessive ataxia.
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Affiliation(s)
- Mathilde Renaud
- Département de Neurologie, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, 67098, Strasbourg Cedex, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, 67404, Illkirch, France.,Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Claire Guissart
- Laboratoire de Génétique de Maladies Rares, Institut Universitaire de Recherche Clinique, EA7402, Université de Montpellier, CHU Montpellier, 641 Avenue du Doyen Gaston Giraud, 34093, Montpellier Cedex 5, France
| | - Martial Mallaret
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, 67404, Illkirch, France.,Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France.,Service de Neurologie, Centre Hospitalier de Haguenau, 67500, Haguenau, France
| | - Sacha Ferdinandusse
- Laboratory Genetic Metabolic Diseases, Academic Medical Center, 1105 AZ, Amsterdam, The Netherlands
| | - David Cheillan
- Hospices Civils de Lyon: Service des Maladies Héréditaires du Métabolisme et Dépistage Néonatal, INSERM U.1060: Laboratoire de Recherche en Cardiovasculaire, Métabolisme, Diabétologie et Nutrition, Lyon, France
| | - Nathalie Drouot
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, 67404, Illkirch, France
| | - Jean Muller
- Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, 67404, Illkirch, France.,Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France.,Laboratoire de Génétique Médicale, UMR_S INSERM U1112, IGMA, Faculté de Médecine FMTS, Université de Strasbourg, Strasbourg, France.,Laboratoire de Diagnostic Génétique, Hôpitaux Universitaires de Strasbourg, Strasbourg, France
| | - Mireille Claustres
- Laboratoire de Génétique de Maladies Rares, Institut Universitaire de Recherche Clinique, EA7402, Université de Montpellier, CHU Montpellier, 641 Avenue du Doyen Gaston Giraud, 34093, Montpellier Cedex 5, France
| | - Christine Tranchant
- Département de Neurologie, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, 67098, Strasbourg Cedex, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, 67404, Illkirch, France.,Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Mathieu Anheim
- Département de Neurologie, Hôpitaux Universitaires de Strasbourg, Hôpital de Hautepierre, 67098, Strasbourg Cedex, France.,Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), INSERM-U964/CNRS-UMR7104/Université de Strasbourg, 67404, Illkirch, France.,Fédération de Médecine Translationnelle de Strasbourg (FMTS), Université de Strasbourg, Strasbourg, France
| | - Michel Koenig
- Laboratoire de Génétique de Maladies Rares, Institut Universitaire de Recherche Clinique, EA7402, Université de Montpellier, CHU Montpellier, 641 Avenue du Doyen Gaston Giraud, 34093, Montpellier Cedex 5, France.
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11
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Human disorders of peroxisome metabolism and biogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:922-33. [DOI: 10.1016/j.bbamcr.2015.11.015] [Citation(s) in RCA: 230] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2015] [Revised: 11/16/2015] [Accepted: 11/17/2015] [Indexed: 12/22/2022]
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12
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Žárský V, Tachezy J. Evolutionary loss of peroxisomes--not limited to parasites. Biol Direct 2015; 10:74. [PMID: 26700421 PMCID: PMC4690255 DOI: 10.1186/s13062-015-0101-6] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 12/14/2015] [Indexed: 11/26/2022] Open
Abstract
Background Peroxisomes are ubiquitous eukaryotic organelles that compartmentalize a variety of metabolic pathways that are primarily related to the oxidative metabolism of lipids and the detoxification of reactive oxygen species. The importance of peroxisomes is underscored by serious human diseases, which are caused by disorders in peroxisomal functions. Some eukaryotic lineages, however, lost peroxisomes. These organisms are mainly anaerobic protists and some parasitic lineages including Plasmodium and parasitic platyhelminths. Here we performed a systematic in-silico analysis of peroxisomal markers among metazoans to assess presence of peroxisomes and peroxisomal enzymes. Results Our analyses reveal an obvious loss of peroxisomes in all tested flukes, tapeworms, and parasitic roundworms of the order Trichocephalida. Intriguingly, peroxisomal markers are absent from the genome of the free-living tunicate Oikopleura dioica, which inhabits oxygen-containing niches of sea waters. We further map the presence and predicted subcellular localization of putative peroxisomal enzymes, showing that in organisms without the peroxisomal markers the set of these enzymes is highly reduced and none of them contains a predicted peroxisomal targeting signal. Conclusions We have shown that several lineages of metazoans independently lost peroxisomes and that the loss of peroxisomes was not exclusively associated with adaptation to anaerobic habitats and a parasitic lifestyle. Although the reason for the loss of peroxisomes from O. dioica is unclear, organisms lacking peroxisomes, including the free-living O. dioica, share certain typical r-selected traits: high fecundity, limited ontogenesis and relatively low complexity of the gene content. We hypothesize that peroxisomes are generally the first compartment to be lost during evolutionary reductions of the eukaryotic cell. Reviewers This article was reviewed by Michael Gray and Nick Lane. Electronic supplementary material The online version of this article (doi:10.1186/s13062-015-0101-6) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Vojtěch Žárský
- Department of Parasitology, Faculty of Science, Charles University in Prague, Viničná 7, 128 44, Prague, Czech Republic.
| | - Jan Tachezy
- Department of Parasitology, Faculty of Science, Charles University in Prague, Viničná 7, 128 44, Prague, Czech Republic.
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Konkoľová J, Petrovič R, Chandoga J, Halasová E, Jungová P, Böhmer D. A novel mutation in the PEX12 gene causing a peroxisomal biogenesis disorder. Mol Biol Rep 2015; 42:1359-63. [PMID: 26094004 DOI: 10.1007/s11033-015-3885-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2015] [Accepted: 06/17/2015] [Indexed: 11/24/2022]
Abstract
The peroxisomal biogenesis disorders are autosomal recessive diseases morphologically characterised by lacking peroxisomes, biochemically by generalised deficiency of peroxisomal constituent and clinically manifested by serious health problems. Genes involved in the peroxisomal biogenesis are defined as the PEX genes encoding proteins called the peroxins. These peroxins are required for function in assembly of the peroxisomal membrane or in import of the enzymes into the peroxisomes. In this study we present a full overview of the clinical presentation, biochemical and molecular data of patient with Zellweger syndrome from Slovakia. We investigated biochemical metabolites using gas chromatography/mass spectrometry. The presence of causal ins/del mutations we identified by a Sanger sequencing and RFLP. We reported that the patient was a compound heterozygote for mutations in the gene PEX12: a 2-bp insertion (c.767_768dupAT) and a 2-bp deletion (c.887_888delTC). The first one mentioned is a novel mutation, which has not been reported before. Both mutations create a frameshift of the open reading frame which result a premature STOP codon and generate a complete loss of the C-terminal RING finger domain that is crucial for the correct import of proteins into peroxisomes. We found causal mutations responsible for a severe phenotype, and moreover we noted a novel mutation c.767_768dupAT that has not been reported before. The presence of mutations was studied in all family members, and the resulting data were successfully utilized for prenatal diagnosis.
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Affiliation(s)
- Jana Konkoľová
- Institute of Medical Biology, Genetics and Clinical Genetics, Faculty of Medicine & University Hospital Bratislava, Comenius University, Sasinkova 4, 811 08, Bratislava, Slovakia,
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14
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Peripheral nervous system defects in a mouse model for peroxisomal biogenesis disorders. Dev Biol 2014; 395:84-95. [PMID: 25176044 DOI: 10.1016/j.ydbio.2014.08.026] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Revised: 08/19/2014] [Accepted: 08/20/2014] [Indexed: 12/19/2022]
Abstract
Peroxisome biogenesis disorders (PBD) are autosomal recessive disorders in humans characterized by skeletal, eye and brain abnormalities. Despite the fact that neurological deficits, including peripheral nervous system (PNS) defects, can be observed at birth in some PBD patients including those with PEX10 mutations, the embryological basis of the PNS defects is unclear. Using a forward genetic screen, we identified a mouse model for Pex10 deficiency that exhibits neurological abnormalities during fetal development. Homozygous Pex10 mutant mouse embryos display biochemical abnormalities related to a PBD deficiency. During late embryogenesis, Pex10 homozygous mutant mice experience progressive loss of movement and at birth they become cyanotic and die shortly thereafter. Homozygous Pex10 mutant fetuses display decreased integrity of axons and synapses, over-extension of axons in the diaphragm and decreased Schwann cell numbers. Our neuropathological, molecular and electrophysiological studies provide new insights into the embryological basis of the PNS deficits in a PBD model. Our findings identify PEX10 function, and likely other PEX proteins, as an essential component of the spinal locomotor circuit.
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15
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Tamura S, Matsumoto N, Takeba R, Fujiki Y. AAA peroxins and their recruiter Pex26p modulate the interactions of peroxins involved in peroxisomal protein import. J Biol Chem 2014; 289:24336-46. [PMID: 25016021 DOI: 10.1074/jbc.m114.588038] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Pex1p and Pex6p are required for the relocation of the import receptor Pex5p from the peroxisomal membrane to the cytosol. We herein show that mammalian Pex26p directly binds to Pex14p, the initial docking receptor of Pex5p, and interacts with Pex5p via Pex14p. The binding affinity of Pex26p to Pex14p is altered by Pex5p. Further evidence suggests that the N-terminal region in Pex26p acts as a scaffold protein to recruit Pex14p·Pex5p complex together with Pex1p·Pex6p complexes on peroxisomes. Pex26p binding to Pex14p was suppressed by overexpression of Pex1p and Pex6p in an ATP-dependent manner, whereas Pex14p was not competed out by Pex1p and Pex6p from Pex26p mutant defective in peroxisomal matrix protein import. These results suggested that peroxisome biogenesis requires Pex1p- and Pex6p-regulated dissociation of Pex14p from Pex26p. Pex1p homo-oligomer directly binds to Pex5p as assessed by a surface plasmon resonance-based assay. Moreover, cytosolic Pex1p is likely to maintain the functional oligomer of Pex5p. Taken together, in the peroxisomal protein import, AAA peroxins modulate the interaction between Pex26p and Pex14p on peroxisome membrane as well as Pex5p oligomer in the cytosol.
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Affiliation(s)
- Shigehiko Tamura
- Faculty of Arts and Science, Kyushu University, Fukuoka 812-8581, Japan and Graduate School of Systems Life Sciences, Kyushu University Graduate School, Fukuoka 812-8581, Japan
| | - Naomi Matsumoto
- Graduate School of Systems Life Sciences, Kyushu University Graduate School, Fukuoka 812-8581, Japan
| | - Ryota Takeba
- Graduate School of Systems Life Sciences, Kyushu University Graduate School, Fukuoka 812-8581, Japan
| | - Yukio Fujiki
- From the Department of Biology, Faculty of Sciences, and
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16
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Okumoto K, Noda H, Fujiki Y. Distinct modes of ubiquitination of peroxisome-targeting signal type 1 (PTS1) receptor Pex5p regulate PTS1 protein import. J Biol Chem 2014; 289:14089-108. [PMID: 24662292 DOI: 10.1074/jbc.m113.527937] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Peroxisome targeting signal type-1 (PTS1) receptor, Pex5p, is a key player in peroxisomal matrix protein import. Pex5p recognizes PTS1 cargoes in the cytosol, targets peroxisomes, translocates across the membrane, unloads the cargoes, and shuttles back to the cytosol. Ubiquitination of Pex5p at a conserved cysteine is required for the exit from peroxisomes. However, any potential ubiquitin ligase (E3) remains unidentified in mammals. Here, we establish an in vitro ubiquitination assay system and demonstrate that RING finger Pex10p functions as an E3 with an E2, UbcH5C. The E3 activity of Pex10p is essential for its peroxisome-restoring activity, being enhanced by another RING peroxin, Pex12p. The Pex10p·Pex12p complex catalyzes monoubiquitination of Pex5p at one of multiple lysine residues in vitro, following the dissociation of Pex5p from Pex14p and the PTS1 cargo. Several lines of evidence with lysine-to-arginine mutants of Pex5p demonstrate that Pex10p RING E3-mediated ubiquitination of Pex5p is required for its efficient export from peroxisomes to the cytosol and peroxisomal matrix protein import. RING peroxins are required for both modes of Pex5p ubiquitination, thus playing a pivotal role in Pex5p shuttling.
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Affiliation(s)
- Kanji Okumoto
- From the Department of Biology, Faculty of Sciences, and the Graduate School of Systems Life Sciences, Kyushu University Graduate School, Fukuoka 812-8581, Japan
| | - Hiromi Noda
- From the Department of Biology, Faculty of Sciences, and
| | - Yukio Fujiki
- From the Department of Biology, Faculty of Sciences, and
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17
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El Magraoui F, Brinkmeier R, Schrötter A, Girzalsky W, Müller T, Marcus K, Meyer HE, Erdmann R, Platta HW. Distinct Ubiquitination Cascades Act on the Peroxisomal Targeting Signal Type 2 Co-receptor Pex18p. Traffic 2013; 14:1290-301. [DOI: 10.1111/tra.12120] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2013] [Revised: 09/09/2013] [Accepted: 09/11/2013] [Indexed: 01/29/2023]
Affiliation(s)
- Fouzi El Magraoui
- Biochemie Intrazellulärer Transportprozesse; Ruhr-Universität Bochum; Bochum 44780 Germany
- Systembiochemie; Ruhr-Universität Bochum; Bochum 44780 Germany
- Medizinische Proteomik/Bioanalytik, AG Neuro Proteomics; Medizinisches Proteom-Center; Bochum 44801 Germany
| | - Rebecca Brinkmeier
- Biochemie Intrazellulärer Transportprozesse; Ruhr-Universität Bochum; Bochum 44780 Germany
| | - Andreas Schrötter
- Medizinische Proteomik/Bioanalytik, AG Neuro Proteomics; Medizinisches Proteom-Center; Bochum 44801 Germany
| | | | - Thorsten Müller
- Funktionelle Proteomik; Medizinisches Proteom-Center; Bochum 44801 Germany
| | - Katrin Marcus
- Funktionelle Proteomik; Medizinisches Proteom-Center; Bochum 44801 Germany
| | - Helmut E. Meyer
- Medizinische Proteomik/Bioanalytik; Medizinisches Proteom-Center; Bochum 44801 Germany
| | - Ralf Erdmann
- Systembiochemie; Ruhr-Universität Bochum; Bochum 44780 Germany
| | - Harald W. Platta
- Biochemie Intrazellulärer Transportprozesse; Ruhr-Universität Bochum; Bochum 44780 Germany
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18
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Francisco T, Rodrigues TA, Pinto MP, Carvalho AF, Azevedo JE, Grou CP. Ubiquitin in the peroxisomal protein import pathway. Biochimie 2013; 98:29-35. [PMID: 23954799 DOI: 10.1016/j.biochi.2013.08.003] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2013] [Accepted: 08/05/2013] [Indexed: 10/26/2022]
Abstract
PEX5 is the shuttling receptor for newly synthesized peroxisomal matrix proteins. Alone, or with the help of an adaptor protein, this receptor binds peroxisomal matrix proteins in the cytosol and transports them to the peroxisomal membrane docking/translocation module (DTM). The interaction between cargo-loaded PEX5 and the DTM ultimately results in its insertion into the DTM with the concomitant translocation of the cargo protein across the organelle membrane. PEX5 is not consumed in this event; rather it is dislocated back into the cytosol so that it can promote additional rounds of protein transportation. Remarkably, the data collected in recent years indicate that dislocation is preceded by monoubiquitination of PEX5 at a conserved cysteine residue. This mandatory modification is not the only type of ubiquitination occurring at the DTM. Indeed, several findings suggest that defective receptors jamming the DTM are polyubiquitinated and targeted to the proteasome for degradation.
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Affiliation(s)
- Tânia Francisco
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, R. do Campo Alegre, 823, 4150-180 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Tony A Rodrigues
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, R. do Campo Alegre, 823, 4150-180 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal
| | - Manuel P Pinto
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, R. do Campo Alegre, 823, 4150-180 Porto, Portugal
| | - Andreia F Carvalho
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, R. do Campo Alegre, 823, 4150-180 Porto, Portugal
| | - Jorge E Azevedo
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, R. do Campo Alegre, 823, 4150-180 Porto, Portugal; Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. de Jorge Viterbo Ferreira, 228, 4050-313 Porto, Portugal.
| | - Cláudia P Grou
- Organelle Biogenesis and Function Group, Instituto de Biologia Celular e Molecular (IBMC), Universidade do Porto, R. do Campo Alegre, 823, 4150-180 Porto, Portugal.
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19
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Platta HW, Hagen S, Erdmann R. The exportomer: the peroxisomal receptor export machinery. Cell Mol Life Sci 2013; 70:1393-411. [PMID: 22983384 PMCID: PMC11113987 DOI: 10.1007/s00018-012-1136-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2012] [Revised: 07/30/2012] [Accepted: 08/13/2012] [Indexed: 12/21/2022]
Abstract
Peroxisomes constitute a dynamic compartment of almost all eukaryotic cells. Depending on environmental changes and cellular demands peroxisomes can acquire diverse metabolic roles. The compartmentalization of peroxisomal matrix enzymes is a prerequisite to carry out their physiologic function. The matrix proteins are synthesized on free ribosomes in the cytosol and are ferried to the peroxisomal membrane by specific soluble receptors. Subsequent to cargo release into the peroxisomal matrix, the receptors are exported back to the cytosol to facilitate further rounds of matrix protein import. This dislocation step is accomplished by a remarkable machinery, which comprises enzymes required for the ubiquitination as well as the ATP-dependent extraction of the receptor from the membrane. Interestingly, receptor ubiquitination and dislocation are the only known energy-dependent steps in the peroxisomal matrix protein import process. The current view is that the export machinery of the receptors might function as molecular motor not only in the dislocation of the receptors but also in the import step of peroxisomal matrix protein by coupling ATP-dependent removal of the peroxisomal import receptor with cargo translocation into the organelle. In this review we will focus on the architecture and function of the peroxisomal receptor export machinery, the peroxisomal exportomer.
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Affiliation(s)
- Harald W. Platta
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum, Germany
| | - Stefanie Hagen
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum, Germany
| | - Ralf Erdmann
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Ruhr-Universität Bochum, Universitätsstr. 150, 44780 Bochum, Germany
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20
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Abstract
Peroxisomes are remarkably versatile cell organelles whose size, shape, number, and protein content can vary greatly depending on the organism, the developmental stage of the organism’s life cycle, and the environment in which the organism lives. The main functions usually associated with peroxisomes include the metabolism of lipids and reactive oxygen species. However, in recent years, it has become clear that these organelles may also act as intracellular signaling platforms that mediate developmental decisions by modulating extraperoxisomal concentrations of several second messengers. To fulfill their functions, peroxisomes physically and functionally interact with other cell organelles, including mitochondria and the endoplasmic reticulum. Defects in peroxisome dynamics can lead to organelle dysfunction and have been associated with various human disorders. The purpose of this paper is to thoroughly summarize and discuss the current concepts underlying peroxisome formation, multiplication, and degradation. In addition, this paper will briefly highlight what is known about the interplay between peroxisomes and other cell organelles and explore the physiological and pathological implications of this interorganellar crosstalk.
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Affiliation(s)
- Marc Fransen
- Department of Cellular and Molecular Medicine, KU Leuven, Herestraat 49, P.O. Box 601, 3000 Leuven, Belgium
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21
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El Magraoui F, Bäumer BE, Platta HW, Baumann JS, Girzalsky W, Erdmann R. The RING-type ubiquitin ligases Pex2p, Pex10p and Pex12p form a heteromeric complex that displays enhanced activity in an ubiquitin conjugating enzyme-selective manner. FEBS J 2012; 279:2060-70. [PMID: 22471590 DOI: 10.1111/j.1742-4658.2012.08591.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
The RING finger peroxins Pex2p, Pex10p and Pex12p are central components of the peroxisomal matrix protein import machinery. The RING domain enables each of these proteins to exhibit ubiquitin-protein ligase activity, which has been linked to ubiquitin-dependent regulation of the peroxisomal import receptor Pex5p. The RING peroxins are considered to form a heteromeric complex in vivo, although the elucidation of the structural assembly, as well as the functional interplay of the RING domains, has remained elusive. Using in vitro approaches, we show that the RING domains form a heteromeric complex with Pex10p(RING) as a central component that directly binds the Pex2p(RING) and Pex12p(RING). The RING domains proved to function as heteromeric pairs that display an Pex10p-dependent enhanced ligase activity in an ubiquitin conjugating enzyme-selective manner.
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Affiliation(s)
- Fouzi El Magraoui
- Abteilung für Systembiochemie, Institut für Physiologische Chemie, Medizinische Fakultät, Ruhr-Universität Bochum, Germany
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22
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Waterham HR, Ebberink MS. Genetics and molecular basis of human peroxisome biogenesis disorders. Biochim Biophys Acta Mol Basis Dis 2012; 1822:1430-41. [PMID: 22871920 DOI: 10.1016/j.bbadis.2012.04.006] [Citation(s) in RCA: 160] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Revised: 03/30/2012] [Accepted: 04/11/2012] [Indexed: 10/28/2022]
Abstract
Human peroxisome biogenesis disorders (PBDs) are a heterogeneous group of autosomal recessive disorders comprised of two clinically distinct subtypes: the Zellweger syndrome spectrum (ZSS) disorders and rhizomelic chondrodysplasia punctata (RCDP) type 1. PBDs are caused by defects in any of at least 14 different PEX genes, which encode proteins involved in peroxisome assembly and proliferation. Thirteen of these genes are associated with ZSS disorders. The genetic heterogeneity among PBDs and the inability to predict from the biochemical and clinical phenotype of a patient with ZSS which of the currently known 13 PEX genes is defective, has fostered the development of different strategies to identify the causative gene defects. These include PEX cDNA transfection complementation assays followed by sequencing of the thus identified PEX genes, and a PEX gene screen in which the most frequently mutated exons of the different PEX genes are analyzed. The benefits of DNA testing for PBDs include carrier testing of relatives, early prenatal testing or preimplantation genetic diagnosis in families with a recurrence risk for ZSS disorders, and insight in genotype-phenotype correlations, which may eventually assist to improve patient management. In this review we describe the current status of genetic analysis and the molecular basis of PBDs.
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Ebberink MS, Mooijer PAW, Gootjes J, Koster J, Wanders RJA, Waterham HR. Genetic classification and mutational spectrum of more than 600 patients with a Zellweger syndrome spectrum disorder. Hum Mutat 2011; 32:59-69. [PMID: 21031596 DOI: 10.1002/humu.21388] [Citation(s) in RCA: 102] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The autosomal recessive Zellweger syndrome spectrum (ZSS) disorders comprise a main subgroup of the peroxisome biogenesis disorders and can be caused by mutations in any of 12 different currently identified PEX genes resulting in severe multisystemic disorders. To get insight into the spectrum of PEX gene defects among ZSS disorders and to investigate if additional human PEX genes are required for functional peroxisome biogenesis, we assigned over 600 ZSS fibroblast cell lines to different genetic complementation groups. These fibroblast cell lines were subjected to a complementation assay involving fusion by means of polyethylene glycol or a PEX cDNA transfection assay specifically developed for this purpose. In a majority of the cell lines we subsequently determined the underlying mutations by sequence analysis of the implicated PEX genes. The PEX cDNA transfection assay allows for the rapid identification of PEX genes defective in ZSS patients. The assignment of over 600 fibroblast cell lines to different genetic complementation groups provides the most comprehensive and representative overview of the frequency distribution of the different PEX gene defects. We did not identify any novel genetic complementation group, suggesting that all PEX gene defects resulting in peroxisome deficiency are currently known.
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Affiliation(s)
- Merel S Ebberink
- Academic Medical Centre at the University of Amsterdam, The Netherlands
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Martín JF, Ullán RV, García-Estrada C. Role of peroxisomes in the biosynthesis and secretion of β-lactams and other secondary metabolites. J Ind Microbiol Biotechnol 2011; 39:367-82. [PMID: 22160272 DOI: 10.1007/s10295-011-1063-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2011] [Accepted: 11/16/2011] [Indexed: 12/01/2022]
Abstract
Peroxisomes are eukaryotic organelles surrounded by a single bilayer membrane, containing a variety of proteins depending on the organism; they mainly perform degradation reactions of toxic metabolites (detoxification), catabolism of linear and branched-chain fatty acids, and removal of H(2)O(2) (formed in some oxidative processes) by catalase. Proteins named peroxins are involved in recruiting, transporting, and introducing the peroxisomal matrix proteins into the peroxisomes. The matrix proteins contain the peroxisomal targeting signals PTS1 and/or PTS2 that are recognized by the peroxins Pex5 and Pex7, respectively. Initial evidence indicated that the penicillin biosynthetic enzyme isopenicillin N acyltransferase (IAT) of Penicillium chrysogenum is located inside peroxisomes. There is now solid evidence (based on electron microscopy and/or biochemical data) confirming that IAT and the phenylacetic acid- and fatty acid-activating enzymes are also located in peroxisomes. Similarly, the Acremonium chrysogenum CefD1 and CefD2 proteins that perform the central reactions (activation and epimerization of isopenicillin N) of the cephalosporin pathway are targeted to peroxisomes. Growing evidence supports the conclusion that some enzymes involved in the biosynthesis of mycotoxins (e.g., AK-toxin), and the biosynthesis of signaling molecules in plants (e.g., jasmonic acid or auxins) occur in peroxisomes. The high concentration of substrates (in many cases toxic to the cytoplasm) and enzymes inside the peroxisomes allows efficient synthesis of metabolites with interesting biological or pharmacological activities. This compartmentalization poses additional challenges to the cell due to the need to import the substrates into the peroxisomes and to export the final products; the transporters involved in these processes are still very poorly known. This article focuses on new aspects of the metabolic processes occurring in peroxisomes, namely the degradation and detoxification processes that lead to the biosynthesis and secretion of secondary metabolites.
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Affiliation(s)
- Juan-Francisco Martín
- Área de Microbiología, Departamento de Biología Molecular, Universidad de León, León, Spain.
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Miyata N, Okumoto K, Mukai S, Noguchi M, Fujiki Y. AWP1/ZFAND6 functions in Pex5 export by interacting with cys-monoubiquitinated Pex5 and Pex6 AAA ATPase. Traffic 2011; 13:168-83. [PMID: 21980954 DOI: 10.1111/j.1600-0854.2011.01298.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
During biogenesis of the peroxisome, a subcellular organelle, the peroxisomal-targeting signal 1 (PTS1) receptor Pex5 functions as a shuttling receptor for PTS1-containing peroxisomal matrix proteins. However, the precise mechanism of receptor shuttling between peroxisomes and cytosol remains elusive despite the identification of numerous peroxins involved in this process. Herein, a new factor was isolated by a combination of biochemical fractionation and an in vitro Pex5 export assay, and was identified as AWP1/ZFAND6, a ubiquitin-binding NF-κB modulator. In the in vitro Pex5 export assay, recombinant AWP1 stimulated Pex5 export and an anti-AWP1 antibody interfered with Pex5 export. AWP1 interacted with Pex6 AAA ATPase, but not with Pex1-Pex6 complexes. Preferential binding of AWP1 to the cysteine-ubiquitinated form of Pex5 rather than to unmodified Pex5 was mediated by the AWP1 A20 zinc-finger domain. Inhibition of AWP1 by RNA interference had a significant effect on PTS1-protein import into peroxisomes. Furthermore, in AWP1 knock-down cells, Pex5 stability was decreased, similar to fibroblasts from patients defective in Pex1, Pex6 and Pex26, all of which are required for Pex5 export. Taken together, these results identify AWP1 as a novel cofactor of Pex6 involved in the regulation of Pex5 export during peroxisome biogenesis.
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Affiliation(s)
- Non Miyata
- Department of Biology, Faculty of Sciences, Kyushu University, Fukuoka, Japan
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Different functions of the C3HC4 zinc RING finger peroxins PEX10, PEX2, and PEX12 in peroxisome formation and matrix protein import. Proc Natl Acad Sci U S A 2010; 107:14915-20. [PMID: 20679226 DOI: 10.1073/pnas.1009174107] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The integral peroxisomal membrane proteins PEX10, PEX2, and PEX12 contain a zinc RING finger close to the C terminus. Loss of function of these peroxins causes embryo lethality at the heart stage in Arabidopsis. Preventing the coordination of Zn(2+) ions by amino acid substitutions in PEX10, PEX2, and PEX12 and overexpressing the resulting conditional sublethal mutations in WT uncovered additional functions of PEX10. Plants overexpressing DeltaZn-mutant PEX10 display deformed peroxisomal shapes causing diminished contact with chloroplasts and possibly with mitochondria. These changes correlated with impaired metabolite transfer and, at high CO(2), recoverable defective photorespiration plus dwarfish phenotype. The N-terminal PEX10 domain is critical for peroxisome biogenesis and plant development. A point mutation in the highly conserved TLGEEY motif results in vermiform peroxisome shape without impairing organelle contact. Addition of an N-terminal T7 tag to WT PEX0 resulted in partially recoverable reduced growth and defective inflorescences persisting under high CO(2). In contrast, plants overexpressing PEX2-DeltaZn-T7 grow like WT in normal atmosphere, contain normal-shaped peroxisomes, but display impaired peroxisomal matrix protein import. PEX12-DeltaZn-T7 mutants exhibit unimpaired import of matrix protein and normal-shaped peroxisomes when grown in normal atmosphere. During seed germination, glyoxysomes form a reticulum around the lipid bodies for mobilization of storage oil. The formation of this glyoxysomal reticulum seemed to be impaired in PEX10-DeltaZn but not in PEX2-DeltaZn-T7 or PEX12-DeltaZn-T7 plants. Both cytosolic PEX10 domains seem essential for peroxisome structure but differ in metabolic function, suggesting a role for this plant peroxin in addition to the import of matrix protein via ubiquitination of PEX5.
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Williams CP, Stanley WA. Peroxin 5: a cycling receptor for protein translocation into peroxisomes. Int J Biochem Cell Biol 2010; 42:1771-4. [PMID: 20633695 DOI: 10.1016/j.biocel.2010.07.004] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2010] [Revised: 07/05/2010] [Accepted: 07/06/2010] [Indexed: 11/26/2022]
Abstract
Peroxins are proteins that regulate the biogenesis of peroxisomes-small vesicular subcellular organelles essential for human life and health. A key peroxin - to date the best studied - is peroxin 5. Structurally, peroxin 5 is a bi-domain protein of about 70 kDa containing both globular and non-globular segments and displaying conformational flexibility. Functionally, it is a cycling receptor for importing essential enzymes into the peroxisome lumen, facilitated by highly promiscuous interactions with numerous proteins and possibly lipids. Peroxin 5 has medical significance in that (i) congenital defects can lead to fatal peroxisome biogenesis disorders, (ii) inefficient peroxisome targeting is linked to disease and aging and (iii) differences between human peroxin 5 and homologues in pathogens may be exploited in the development of therapeutics.
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Affiliation(s)
- Chris P Williams
- European Molecular Biology Laboratory, c/o DESY, Hamburg, Germany
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28
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Getting a camel through the eye of a needle: the import of folded proteins by peroxisomes. Biol Cell 2010; 102:245-63. [PMID: 20146669 DOI: 10.1042/bc20090159] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Peroxisomes are a family of organelles which have many unusual features. They can arise de novo from the endoplasmic reticulum by a still poorly characterized process, yet possess a unique machinery for the import of their matrix proteins. As peroxisomes lack DNA, their function, which is highly variable and dependent on developmental and/or environmental conditions, is determined by the post-translational import of specific metabolic enzymes in folded or oligomeric states. The two classes of matrix targeting signals for peroxisomal proteins [PTS1 (peroxisomal targeting signal 1) and PTS2] are recognized by cytosolic receptors [PEX5 (peroxin 5) and PEX7 respectively] which escort their cargo proteins to, or possibly across, the peroxisome membrane. Although the membrane translocation mechanism remains unclear, it appears to be driven by thermodynamically favourable binding interactions. Recycling of the receptors from the peroxisome membrane requires ATP hydrolysis for two linked processes: ubiquitination of PEX5 (and the PEX7 co-receptors in yeast) and the function of two peroxisome-associated AAA (ATPase associated with various cellular activities) ATPases, which play a role in recycling or turnover of the ubiquitinated receptors. This review summarizes and integrates recent findings on peroxisome matrix protein import from yeast, plant and mammalian model systems, and discusses some of the gaps in our understanding of this remarkable protein transport system.
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Chen H, Liu Z, Huang X. Drosophila models of peroxisomal biogenesis disorder: peroxins are required for spermatogenesis and very-long-chain fatty acid metabolism. Hum Mol Genet 2009; 19:494-505. [DOI: 10.1093/hmg/ddp518] [Citation(s) in RCA: 53] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Singh T, Hayashi M, Mano S, Arai Y, Goto S, Nishimura M. Molecular components required for the targeting of PEX7 to peroxisomes in Arabidopsis thaliana. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2009; 60:488-98. [PMID: 19594707 DOI: 10.1111/j.1365-313x.2009.03970.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/09/2023]
Abstract
PEX7 is a soluble import receptor that recognizes peroxisomal targeting signal type 2 (PTS2)-containing proteins. In the present study, using a green fluorescent protein (GFP) fusion protein of PEX7 (GFP-PEX7), we analyzed the molecular function and subcellular localization of PEX7 in Arabidopsis thaliana. The overexpression of GFP-PEX7 resulted in defective glyoxysomal fatty acid beta-oxidation, but had no significant effect on leaf peroxisomal function. Analysis of the subcellular localization of GFP-PEX7 in transgenic Arabidopsis showed that GFP-PEX7 localizes primarily to the peroxisome. Transient expression of a C- or N-terminal fusion protein of PEX7 and yellow fluorescent protein (YFP) (PEX7-YFP and YFP-PEX7, respectively) in leek epidermal cells, using the particle bombardment technique, confirmed that fluorescent protein-tagged PEX7 localizes to peroxisomes in Arabidopsis. Immunoblot analysis revealed that GFP-PEX7 accumulates primarily in peroxisomal membrane fractions, whereas endogenous PEX7 was distributed evenly in cytosolic and peroxisomal membrane fractions, which indicated that both endogenous PEX7 and GFP-PEX7 are properly targeted to peroxisomal membranes. The results of bimolecular fluorescence complementation (BiFC) and yeast two-hybrid analyses showed that PEX7 binds directly to PTS2-containing proteins and PEX12 in the peroxisomal membrane. We used red fluorescent protein (tdTomato) fusion protein of PEX7 (tdTomato-PEX7) in several Arabidopsis pex mutants to identify proteins required for the targeting of PEX7 to peroxisomes in planta. The results demonstrated that pex14, pex13 and pex12 mutations disrupt the proper targeting of PEX7 to peroxisomes. Overall, our results suggest that the targeting of PEX7 to peroxisomes requires four proteins: a PTS2-containing protein, PEX14, PEX13 and PEX12.
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Affiliation(s)
- Tanuja Singh
- Department of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan
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Pex2 and pex12 function as protein-ubiquitin ligases in peroxisomal protein import. Mol Cell Biol 2009; 29:5505-16. [PMID: 19687296 DOI: 10.1128/mcb.00388-09] [Citation(s) in RCA: 152] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The PTS1-dependent peroxisomal matrix protein import is facilitated by the receptor protein Pex5 and can be divided into cargo recognition in the cytosol, membrane docking of the cargo-receptor complex, cargo release, and recycling of the receptor. The final step is controlled by the ubiquitination status of Pex5. While polyubiquitinated Pex5 is degraded by the proteasome, monoubiquitinated Pex5 is destined for a new round of the receptor cycle. Recently, the ubiquitin-conjugating enzymes involved in Pex5 ubiquitination were identified as Ubc4 and Pex4 (Ubc10), whereas the identity of the corresponding protein-ubiquitin ligases remained unknown. Here we report on the identification of the protein-ubiquitin ligases that are responsible for the ubiquitination of the peroxisomal protein import receptor Pex5. It is demonstrated that each of the three RING peroxins Pex2, Pex10, and Pex12 exhibits ubiquitin-protein isopeptide ligase activity. Our results show that Pex2 mediates the Ubc4-dependent polyubiquitination whereas Pex12 facilitates the Pex4-dependent monoubiquitination of Pex5.
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Yik WY, Steinberg SJ, Moser AB, Moser HW, Hacia JG. Identification of novel mutations and sequence variation in the Zellweger syndrome spectrum of peroxisome biogenesis disorders. Hum Mutat 2009; 30:E467-80. [PMID: 19105186 DOI: 10.1002/humu.20932] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Peroxisome biogenesis disorders (PBD) are a heterogeneous group of autosomal recessive neurodegenerative disorders that affect multiple organ systems. Approximately 80% of PBD patients are classified in the Zellweger syndrome spectrum (PBD-ZSS). Mutations in the PEX1, PEX6, PEX10, PEX12, or PEX26 genes are found in approximately 90% of PBD-ZSS patients. Here, we sequenced the coding regions and splice junctions of these five genes in 58 PBD-ZSS cases previously subjected to targeted sequencing of a limited number of PEX gene exons. In our cohort, 71 unique sequence variants were identified, including 18 novel mutations predicted to disrupt protein function and 2 novel silent variants. We identified 4 patients who had two deleterious mutations in one PEX gene and a third deleterious mutation in a second PEX gene. For two such patients, we conducted cell fusion complementation analyses to identify the defective gene responsible for aberrant peroxisome assembly. Overall, we provide empirical data to estimate the relative fraction of disease-causing alleles that occur in the coding and splice junction sequences of these five PEX genes and the frequency of cases where mutations occur in multiple PEX genes. This information is beneficial for efforts aimed at establishing rapid and sensitive clinical diagnostics for PBD-ZSS patients and interpreting the results from these genetic tests.
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Affiliation(s)
- Wing Yan Yik
- Department of Biochemistry and Molecular Biology, University of Southern California, Los Angeles, California, USA
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Miyata N, Hosoi KI, Mukai S, Fujiki Y. In vitro import of peroxisome-targeting signal type 2 (PTS2) receptor Pex7p into peroxisomes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2009; 1793:860-70. [DOI: 10.1016/j.bbamcr.2009.02.007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2008] [Revised: 02/10/2009] [Accepted: 02/19/2009] [Indexed: 11/25/2022]
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Ito R, Morita M, Takahashi N, Shimozawa N, Usuda N, Imanaka T, Ito M. Identification of Pex5pM, and retarded maturation of 3-ketoacyl-CoA thiolase and acyl-CoA oxidase in CHO cells expressing mutant Pex5p isoforms. J Biochem 2009; 138:781-90. [PMID: 16428307 DOI: 10.1093/jb/mvi175] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recently, we isolated CHO cells, termed SK32 cells, that express mutant Pex5p (G432R), and showed mislocalization of catalase in the cytosol, but peroxisomal localization of 3-ketoacyl-CoA thiolase (thiolase) in the mutant cells [Ito, R. et al. (2001) Biochem. Biophys. Res. Commun. 288, 321-327]. While analyzing the mutant cells, we found a novel Pex5p isoform (Pex5pM), which was shorter by seven amino acids than Pex5pL and longer by 30 amino acids than Pex5pS. Similar levels of mRNA syntheses for the PEX5 gene were observed in both the wild type and mutant cells, but the protein levels of Pex5p isoforms were markedly reduced in the mutant cells cultured at 37 degrees C and only slightly discernible at 30 degrees C, suggesting that they could be rapidly degraded. Furthermore, we characterized the peroxisomal localization of thiolase and acyl-CoA oxidase (Aox) in SK32 cells. The proteins in the organelle fraction were protected from proteinase K-digestion in the mutant cells, indicating that they were translocated inside peroxisomes. However, the conversion of Aox from component A to components B and C was completely prevented at both 30 and 37 degrees C, and the precursor form of thiolase was partially processed to the mature one in a temperature-sensitive manner. Transformed SK32 cells stably expressing one of the wild type Pex5p isoforms were isolated, and then the maturation steps for thiolase and Aox were examined. Pex5pM and S restored the processing of the two enzymes, but Pex5pL did not. In addition, Pex5pL prevented the maturation of thiolase observed at 30 degrees C. These results indicate that (i) the novel Pex5pM is functional and (ii) a seven amino acids-insertion, which is present in the L isoform but absent in the M isoform, plays some role in the process of maturation of thiolase and Aox.
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Affiliation(s)
- Ritsu Ito
- Division of Molecular Cell Biology, Saga University Faculty of Medicine, Nabeshima 5-1-1, Saga 849-8501
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Brown LA, Baker A. Shuttles and cycles: transport of proteins into the peroxisome matrix (review). Mol Membr Biol 2008; 25:363-75. [PMID: 18651315 DOI: 10.1080/09687680802130583] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Peroxisomes are organelles that carry out diverse biochemical processes in eukaryotic cells, including the core pathways of beta-oxidation of lipid molecules and detoxification of reactive oxygen species. In multicellular organisms defects in peroxisome assembly result in multiple biochemical and developmental abnormalities. As peroxisomes do not contain genetic material, their protein content, and therefore function, is determined by the import of nuclearly encoded proteins from the cytosol and, presumably, removal of damaged or obsolete proteins. Import of matrix proteins can be broken down into four steps: targeting signal recognition by the cycling import receptors; receptor-cargo docking at the peroxisome membrane; translocation and cargo unloading; and receptor recycling. Import is mediated by a set of evolutionarily conserved proteins called peroxins that have been identified primarily via genetic screens, but knowledge of their biochemical activities remains largely unresolved. Recent studies have filled in some of the blanks regarding receptor recycling and the role of ubiquitination but outstanding questions remain concerning the nature of the translocon and its ability to accommodate folded, even oligomeric proteins, and the mechanism of cargo unloading and turnover of peroxisomal proteins. This review seeks to integrate recent findings from yeast, mammalian and plant systems to present an up to date account of how proteins enter the peroxisome matrix.
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Peraza-Reyes L, Zickler D, Berteaux-Lecellier V. The peroxisome RING-finger complex is required for meiocyte formation in the fungus Podospora anserina. Traffic 2008; 9:1998-2009. [PMID: 18785921 DOI: 10.1111/j.1600-0854.2008.00812.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Peroxisomes are involved in a variety of metabolic pathways and developmental processes. In the filamentous fungus Podospora anserina, absence of different peroxins implicated in peroxisome matrix protein import leads to different developmental defects. Lack of the RING-finger complex peroxin PEX2 blocks sexual development at the dikaryotic stage, while in absence of both receptors, PEX5 and PEX7, karyogamy and meiosis can proceed and sexual spores are formed. This suggests a complex role for PEX2 that prompted us to study the developmental involvement of the RING-finger complex. We show that, like PEX2, the two other proteins of the complex, PEX10 and PEX12, are equally implicated in peroxisome biogenesis and that absence of each or all these proteins lead to the same developmental defect. Moreover, we demonstrate that peroxisome localization of PEX2 is not drastically affected in the absence of PEX10 and PEX12 and that the upregulation of these latter RING-finger peroxins does not compensate for the lack of a second one, suggesting that the three proteins work together in development but independent of their function in peroxisome biogenesis.
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Affiliation(s)
- Leonardo Peraza-Reyes
- Univ. Paris-Sud, CNRS UMR8621, Institut de Génétique et Microbiologie, 91405 Orsay, France
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Pex10p functions as an E3 ligase for the Ubc4p-dependent ubiquitination of Pex5p. Biochem Biophys Res Commun 2008; 374:620-4. [PMID: 18644345 DOI: 10.1016/j.bbrc.2008.07.054] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Accepted: 07/14/2008] [Indexed: 01/06/2023]
Abstract
The Saccharomyces cerevisiae (Sc) PTS1 import receptor Pex5p is modified by ubiquitin, both in an Ubc4p-dependent and a Pex4p (Ubc10p)-dependent manner. Both of these modifications require the RING domain-containing protein Pex10p in vivo, but the actual role this protein plays in the ubiquitination of Pex5p has so far, remained enigmatic. Here, we report that the RING domain of Pex10p exhibits E(3) ligase activity in vitro, in combination with the human E(2) enzyme UbcH5a, a homologue of ScUbc4p, but not when ScPex4p was used as an E(2) enzyme in the reaction. We have further characterised Pex10p's E(3) ligase activity using mutants designed to disturb this activity and show that Pex10p acts as the E(3) ligase for Ubc4p-dependent ubiquitination of Pex5p but not Pex4p-dependent ubiquitination in vivo. These data imply that the two distinct Pex5p modifications require different E(3) ligases, as well as different E(2) enzymes.
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Koellensperger G, Daubert S, Erdmann R, Hann S, Rottensteiner H. Characterisation of zinc-binding domains of peroxisomal RING finger proteins using size exclusion chromatography/inductively coupled plasma-mass spectrometry. Biol Chem 2008; 388:1209-14. [PMID: 17976014 DOI: 10.1515/bc.2007.125] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
We determined the zinc binding stoichiometry of peroxisomal RING finger proteins by measuring sulfur/metal ratios using inductively coupled plasma-mass spectrometry coupled to size exclusion chromatography, a strategy that provides a fast and quantitative overview on the binding of metals in proteins. As a quality control, liquid chromatography-electrospray ionisation-time of flight-mass spectrometry was used to measure the molar masses of the intact proteins. The RING fingers of Pex2p, Pex10p, and Pex12p showed a stoichiometry of 2.0, 2.1, and 1.2 mol zinc/mol protein, respectively. Thus, Pex2p and Pex10p possess a typical RING domain with two coordinated zinc atoms, whereas that of Pex12p coordinates only a single zinc atom.
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Affiliation(s)
- Gunda Koellensperger
- Abteilung für Analytische Chemie, Universität für Bodenkultur Wien, A-1190, Wien, Austria
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Williams C, van den Berg M, Sprenger RR, Distel B. A Conserved Cysteine Is Essential for Pex4p-dependent Ubiquitination of the Peroxisomal Import Receptor Pex5p. J Biol Chem 2007; 282:22534-43. [PMID: 17550898 DOI: 10.1074/jbc.m702038200] [Citation(s) in RCA: 164] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The peroxisomal protein import receptor Pex5p is modified by ubiquitin, both in an Ubc4p-dependent and -independent manner. Here we show that the two types of ubiquitination target different residues in the NH(2)-terminal region of Pex5p and we identify Pex4p (Ubc10p) as the ubiquitin-conjugating enzyme required for Ubc4p-independent ubiquitination. Whereas Ubc4p-dependent ubiquitination occurs on two lysine residues, Pex4p-dependent ubiquitination neither requires lysine residues nor the NH(2)-terminal alpha-NH(2) group. Instead, a conserved cysteine residue appears to be essential for both the Pex4p-dependent ubiquitination and the overall function of Pex5p. In addition, we show that this form of ubiquitinated Pex5p is susceptible to the reducing agent beta-mercaptoethanol, a compound that is unable to break ubiquitin-NH(2) group linkages. Together, our results strongly suggest that Pex4p-dependent ubiquitination of Pex5p occurs on a cysteine residue.
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Affiliation(s)
- Chris Williams
- Department of Medical Biochemistry, Academic Medical Center, Meibergdreef 15, 1105 AZ Amsterdam, The Netherlands
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Zeharia A, Ebberink MS, Wanders RJA, Waterham HR, Gutman A, Nissenkorn A, Korman SH. A novel PEX12 mutation identified as the cause of a peroxisomal biogenesis disorder with mild clinical phenotype, mild biochemical abnormalities in fibroblasts and a mosaic catalase immunofluorescence pattern, even at 40 degrees C. J Hum Genet 2007; 52:599-606. [PMID: 17534573 DOI: 10.1007/s10038-007-0157-y] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2006] [Accepted: 05/07/2007] [Indexed: 10/23/2022]
Abstract
Mutations in 12 different PEX genes can cause a generalized peroxisomal biogenesis disorder with clinical phenotypes ranging from Zellweger syndrome to infantile Refsum disease. To identify the specific PEX gene to be sequenced, complementation analysis is first performed in fibroblasts using catalase immunofluorescence. A patient with a relatively mild phenotype of infantile cholestasis, hypotonia and motor delay had elevated plasma very long-chain fatty acids and bile acid precursors, but fibroblast studies revealed normal or only mildly abnormal peroxisomal parameters and mosaic catalase immunofluorescence. This mosaicism persisted even when the incubation temperature was increased from 37 degrees C to 40 degrees C, a maneuver previously shown to abolish mosaicism by exacerbating peroxisomal dysfunction. As mosaicism precludes complementation analysis, a candidate gene approach was employed. After PEX1 sequencing was unrewarding, PEX12 sequencing revealed homozygosity for a novel c.102A>T (p.R34S) missense mutation affecting a partially conserved residue in the N-terminal region important for localization to peroxisomes. Transfection of patient fibroblasts with wild-type PEX12 cDNA confirmed that a PEX12 defect was the basis for the PBD. Homozygosity for c.102A>T was identified in a second patient of similar ethnic origin also presenting with a mild phenotype. PEX12 is a highly probable candidate gene for direct sequencing in the context of a mild clinical phenotype with mosaicism and minimally abnormal peroxisomal parameters in fibroblasts.
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Affiliation(s)
- Avraham Zeharia
- Day Hospitalization Unit, Schneider Children's Medical Center of Israel, Sackler School of Medicine, Tel Aviv University, Petach Tikvah, Israel
| | - Merel S Ebberink
- Departments of Clinical Chemistry and Pediatrics, Academic Medical Centre, Emma Children's Hospital, University of Amsterdam, Amsterdam, The Netherlands
| | - Ronald J A Wanders
- Departments of Clinical Chemistry and Pediatrics, Academic Medical Centre, Emma Children's Hospital, University of Amsterdam, Amsterdam, The Netherlands
| | - Hans R Waterham
- Departments of Clinical Chemistry and Pediatrics, Academic Medical Centre, Emma Children's Hospital, University of Amsterdam, Amsterdam, The Netherlands
| | - Alisa Gutman
- Department of Clinical Biochemistry, Hadassah-Hebrew University Medical Center, Jerusalem, Israel
| | - Andreea Nissenkorn
- Pediatric Neurology Unit, Safra Children's Hosptial, Sheba Medical Center and Sackler School of Medicine, Tel Aviv University, Tel Hashomer, Israel
| | - Stanley H Korman
- Department of Clinical Biochemistry, Hadassah-Hebrew University Medical Center, Jerusalem, Israel.
- Metabolic Diseases Unit, Division of Pediatrics, Hadassah-Hebrew University Medical Center, POB 12000, Jerusalem, Israel.
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Platta HW, Erdmann R. The peroxisomal protein import machinery. FEBS Lett 2007; 581:2811-9. [PMID: 17445803 DOI: 10.1016/j.febslet.2007.04.001] [Citation(s) in RCA: 71] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2007] [Revised: 03/27/2007] [Accepted: 04/02/2007] [Indexed: 11/19/2022]
Abstract
Peroxisomes are unique organelles whose physiological functions vary depending on the cellular environment or metabolic and developmental state of the organism. These changes in enzyme content are accomplished by the dynamically operating membrane and matrix protein import machineries of peroxisomes that rely on the concerted function of at least 20 peroxins. The import of folded matrix proteins is mediated by cycling receptors that shuttle between the cytosol and peroxisomal lumen. Receptor release back to the cytosol represents the ATP-dependent step of peroxisomal matrix protein import, which consists of two energy-consuming reactions: receptor ubiquitination and dislocation.
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Affiliation(s)
- Harald W Platta
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum, Germany
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Saveria T, Kessler P, Jensen BC, Parsons M. Characterization of glycosomal RING finger proteins of trypanosomatids. Exp Parasitol 2006; 116:14-24. [PMID: 17188680 PMCID: PMC1976121 DOI: 10.1016/j.exppara.2006.11.004] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2006] [Revised: 10/10/2006] [Accepted: 11/07/2006] [Indexed: 11/30/2022]
Abstract
The glycosomes of trypanosomatids are essential organelles that are evolutionarily related to peroxisomes of other eukaryotes. The peroxisomal RING proteins-PEX2, PEX10 and PEX12-comprise a network of integral membrane proteins that function in the matrix protein import cycle. Here, we describe PEX10 and PEX12 in Trypanosoma brucei, Leishmania major, and Trypanosoma cruzi. We expressed GFP fusions of each T. brucei coding region in procyclic form T. brucei, where they localized to glycosomes and behaved as integral membrane proteins. Despite the weak transmembrane predictions for TbPEX12, protease protection assays demonstrated that both the N and C termini are cytosolic, similar to mammalian PEX12. GFP fusions of T. cruzi PEX10 and L. major PEX12 also localized to glycosomes in T. brucei indicating that glycosomal membrane protein targeting is conserved across trypanosomatids.
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Affiliation(s)
- Tracy Saveria
- Seattle Biomedical Research Institute, 307 Westlake Avenue N., Seattle, WA 98109, USA
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Thoms S, Erdmann R. Peroxisomal matrix protein receptor ubiquitination and recycling. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1620-8. [PMID: 17028012 DOI: 10.1016/j.bbamcr.2006.08.046] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/10/2006] [Revised: 08/15/2006] [Accepted: 08/23/2006] [Indexed: 11/22/2022]
Abstract
The peroxisomal targeting signal type1 (PTS1) receptor Pex5 is required for the peroxisomal targeting of most matrix proteins. Pex5 recognises target proteins in the cytosol and directs them to the peroxisomal membrane where cargo is released into the matrix, and the receptor shuttles back to the cytosol. Recently, it has become evident that the membrane-bound Pex5 can be modified by mono- and polyubiquitination. This review summarises recent results on Pex5 ubiquitination and on the role of the AAA peroxins Pex1 and Pex6 as dislocases required for the release of Pex5 from the membrane to the cytosol where the receptor is either degraded by proteasomes or made available for another round of protein import into peroxisomes.
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Affiliation(s)
- Sven Thoms
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum, Germany
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Steinberg SJ, Dodt G, Raymond GV, Braverman NE, Moser AB, Moser HW. Peroxisome biogenesis disorders. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1733-48. [PMID: 17055079 DOI: 10.1016/j.bbamcr.2006.09.010] [Citation(s) in RCA: 338] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/25/2006] [Revised: 09/05/2006] [Accepted: 09/06/2006] [Indexed: 01/02/2023]
Abstract
Defects in PEX genes impair peroxisome assembly and multiple metabolic pathways confined to this organelle, thus providing the biochemical and molecular bases of the peroxisome biogenesis disorders (PBD). PBD are divided into two types--Zellweger syndrome spectrum (ZSS) and rhizomelic chondrodysplasia punctata (RCDP). Biochemical studies performed in blood and urine are used to screen for the PBD. DNA testing is possible for all of the disorders, but is more challenging for the ZSS since 12 PEX genes are known to be associated with this spectrum of PBD. In contrast, PBD-RCDP is associated with defects in the PEX7 gene alone. Studies of the cellular and molecular defects in PBD patients have contributed significantly to our understanding of the role of each PEX gene in peroxisome assembly.
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Affiliation(s)
- Steven J Steinberg
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Saleem RA, Smith JJ, Aitchison JD. Proteomics of the peroxisome. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1541-51. [PMID: 17050007 PMCID: PMC1858641 DOI: 10.1016/j.bbamcr.2006.09.005] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/21/2006] [Revised: 09/01/2006] [Accepted: 09/06/2006] [Indexed: 10/24/2022]
Abstract
Genomes provide us with a blue print for the potential of a cell. However, the activity of a cell is expressed in its proteome. Full understanding of the complexity of cells demands a comprehensive view of the proteome; its interactions, activity states and organization. Comprehensive proteomic approaches applied to peroxisomes have yielded new insights into the organelle and its dynamic interplay with other cellular structures. As technologies and methodologies improve, proteomics hold the promise for new discoveries of peroxisome function and a full description of this dynamic organelle.
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Affiliation(s)
| | | | - JD Aitchison
- * Corresponding author: JD Aitchison, Institute for Systems Biology, 1441 N 34 Street, Seattle, Washington, USA, 98103,
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Rayapuram N, Subramani S. The importomer--a peroxisomal membrane complex involved in protein translocation into the peroxisome matrix. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1613-9. [PMID: 17027097 DOI: 10.1016/j.bbamcr.2006.08.035] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2006] [Revised: 08/18/2006] [Accepted: 08/23/2006] [Indexed: 12/01/2022]
Abstract
The import of proteins into the peroxisome matrix is an essential step in peroxisome biogenesis, which is critical for normal functioning of most eukaryotic cells. The translocation of proteins across the peroxisome membrane and the dynamic behavior of the import receptors during the import cycle is facilitated by several peroxisome-membrane-associated protein complexes, one of which is called the importomer complex [B. Agne, N.M. Meindl, K. Niederhoff, H. Einwachter, P. Rehling, A. Sickmann, H.E. Meyer, W. Girzalsky, W.H. Kunau, Pex8p: an intraperoxisomal organizer of the peroxisomal import machinery, Mol. Cell 11 (2003) 635-646; P.P. Hazra, I. Suriapranata, W.B. Snyder, S. Subramani, Peroxisome remnants in pex3Delta cells and the requirement of Pex3p for interactions between the peroxisomal docking and translocation subcomplexes, Traffic 3 (2002) 560-574. ]. We provide below a brief historical perspective regarding the importomer and its role in peroxisome biogenesis. We also identify areas in which further work is needed to uncover the physiological role of the importomer.
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Affiliation(s)
- Naganand Rayapuram
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, Room 3230 Bonner Hall, 9500 Gilman Drive, UC San Diego, La Jolla, CA 92093-0322, USA
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Léon S, Goodman JM, Subramani S. Uniqueness of the mechanism of protein import into the peroxisome matrix: transport of folded, co-factor-bound and oligomeric proteins by shuttling receptors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2006; 1763:1552-64. [PMID: 17011644 DOI: 10.1016/j.bbamcr.2006.08.037] [Citation(s) in RCA: 96] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/19/2006] [Revised: 08/18/2006] [Accepted: 08/23/2006] [Indexed: 11/30/2022]
Abstract
Based on earlier suggestions that peroxisomes may have arisen from endosymbionts that later lost their DNA, it was expected that protein transport into this organelle would have parallels to systems found in other organelles of endosymbiont origin, such as mitochondria and chloroplasts. This review highlights three features of peroxisomal matrix protein import that make it unique in comparison with these other subcellular compartments - the ability of this organelle to transport folded, co-factor-bound and oligomeric proteins, the dynamics of the import receptors during the matrix protein import cycle and the existence of a peroxisomal quality-control pathway, which insures that the peroxisome membrane is cleared of cargo-free receptors.
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Affiliation(s)
- Sébastien Léon
- Section of Molecular Biology, Division of Biological Sciences, University California, Room 3230 Bonner Hall, 9500 Gilman Drive, UC San Diego, La Jolla, CA 92093-0322, USA
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Rosenkranz K, Birschmann I, Grunau S, Girzalsky W, Kunau WH, Erdmann R. Functional association of the AAA complex and the peroxisomal importomer. FEBS J 2006; 273:3804-15. [PMID: 16911527 DOI: 10.1111/j.1742-4658.2006.05388.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The AAA peroxins, Pex1p and Pex6p, are components of the peroxisomal protein import machinery required for the relocation of the import receptor Pex5p from the peroxisomal membrane to the cytosol. We demonstrate that Pex1p and Pex6p form a stable complex in the cytosol, which associates at the peroxisomal membrane with their membrane anchor Pex15p and the peroxisomal importomer. The interconnection of Pex15p with the components of the importomer was independent of Pex1p and Pex6p, indicating that Pex15p is an incorporated component of the assembly. Further evidence suggests that the AAA peroxins shuttle between cytosol and peroxisome with proper binding of the Pex15p-AAA complex to the importomer and release of the AAA peroxins from the peroxisomal membrane depending on an operative peroxisomal protein import mechanism. Pex4p-deficient cells exhibit a wild-type-like assembly of the importomer, which differs in that it is associated with increased amounts of Pex1p and Pex6p, in agreement with a function for Pex4p in the release of AAA peroxins from the peroxisomal membrane.
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Affiliation(s)
- Katja Rosenkranz
- Abteilung für Systembiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Germany
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Mano S, Nakamori C, Nito K, Kondo M, Nishimura M. The Arabidopsis pex12 and pex13 mutants are defective in both PTS1- and PTS2-dependent protein transport to peroxisomes. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2006; 47:604-18. [PMID: 16813573 DOI: 10.1111/j.1365-313x.2006.02809.x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Peroxisome biogenesis requires various complex processes including organelle division, enlargement and protein transport. We have been studying a number of Arabidopsis apm mutants that display aberrant peroxisome morphology. Two of these mutants, apm2 and apm4, showed green fluorescent protein fluorescence in the cytosol as well as in peroxisomes, indicating a decrease of efficiency of peroxisome targeting signal 1 (PTS1)-dependent protein transport to peroxisomes. Interestingly, both mutants were defective in PTS2-dependent protein transport. Plant growth was more inhibited in apm4 than apm2 mutants, apparently because protein transport was more severely decreased in apm4 than in apm2 mutants. APM2 and APM4 were found to encode proteins homologous to the peroxins PEX13 and PEX12, respectively, which are thought to be involved in transporting matrix proteins into peroxisomes in yeasts and mammals. We show that APM2/PEX13 and APM4/PEX12 are localized on peroxisomal membranes, and that APM2/PEX13 interacts with PEX7, a cytosolic PTS2 receptor. Additionally, a PTS1 receptor, PEX5, was found to stall on peroxisomal membranes in both mutants, suggesting that PEX12 and PEX13 are components that are involved in protein transport on peroxisomal membranes in higher plants. Proteins homologous to PEX12 and PEX13 have previously been found in Arabidopsis but it is not known whether they are involved in protein transport to peroxisomes. Our findings reveal that APM2/PEX13 and APM4/PEX12 are responsible for matrix protein import to peroxisomes in planta.
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Affiliation(s)
- Shoji Mano
- Department of Cell Biology, National Institute for Basic Biology, Okazaki 444-8585, Japan
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Léon S, Zhang L, McDonald WH, Yates J, Cregg JM, Subramani S. Dynamics of the peroxisomal import cycle of PpPex20p: ubiquitin-dependent localization and regulation. ACTA ACUST UNITED AC 2006; 172:67-78. [PMID: 16390998 PMCID: PMC2063535 DOI: 10.1083/jcb.200508096] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We characterize the peroxin PpPex20p from Pichia pastoris and show its requirement for translocation of PTS2 cargoes into peroxisomes. PpPex20p docks at the peroxisomal membrane and translocates into peroxisomes. Its peroxisomal localization requires the docking peroxin Pex14p but not the peroxins Pex2p, Pex10p, and Pex12p, whose absence causes peroxisomal accumulation of Pex20p. Similarities between Pex5p and Pex20p were noted in their protein interactions and dynamics during import, and both contain a conserved NH2-terminal domain. In the absence of the E2-like Pex4p or the AAA proteins Pex1p and Pex6p, Pex20p is degraded via polyubiquitylation of residue K19, and the K19R mutation causes accumulation of Pex20p in peroxisome remnants. Finally, either interference with K48-branched polyubiquitylation or removal of the conserved NH2-terminal domain causes accumulation of Pex20p in peroxisomes, mimicking a defect in its recycling to the cytosol. Our data are consistent with a model in which Pex20p enters peroxisomes and recycles back to the cytosol in an ubiquitin-dependent manner.
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Affiliation(s)
- Sébastien Léon
- Section of Molecular Biology, Division of Biological Sciences, University of California, San Diego, La Jolla, CA 92093
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