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Mueller-Schuessele SJ, Leterme S, Michaud M. Plastid Transient and Stable Interactions with Other Cell Compartments. Methods Mol Biol 2024; 2776:107-134. [PMID: 38502500 DOI: 10.1007/978-1-0716-3726-5_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/21/2024]
Abstract
Plastids are organelles delineated by two envelopes playing important roles in different cellular processes such as energy production or lipid biosynthesis. To regulate their biogenesis and their function, plastids have to communicate with other cellular compartments. This communication can be mediated by metabolites, signaling molecules, and by the establishment of direct contacts between the plastid envelope and other organelles such as the endoplasmic reticulum, mitochondria, peroxisomes, plasma membrane, and the nucleus. These interactions are highly dynamic and respond to different biotic and abiotic stresses. However, the mechanisms involved in the formation of plastid-organelle contact sites and their functions are still far from being understood. In this chapter, we summarize our current knowledge about plastid contact sites and their role in the regulation of plastid biogenesis and function.
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Affiliation(s)
| | - Sébastien Leterme
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRAE, Univ. Grenoble Alpes, IRIG, CEA Grenoble, Grenoble, France
| | - Morgane Michaud
- Laboratoire de Physiologie Cellulaire et Végétale, CNRS, CEA, INRAE, Univ. Grenoble Alpes, IRIG, CEA Grenoble, Grenoble, France.
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2
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You X, Zhu S, Sheng H, Liu Z, Wang D, Wang M, Xu X, He F, Fang H, Zhang F, Wang D, Hao Z, Wang R, Xiao Y, Wan J, Wang GL, Ning Y. The rice peroxisomal receptor PEX5 negatively regulates resistance to rice blast fungus Magnaporthe oryzae. Cell Rep 2023; 42:113315. [PMID: 37862164 DOI: 10.1016/j.celrep.2023.113315] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2022] [Revised: 08/22/2023] [Accepted: 10/06/2023] [Indexed: 10/22/2023] Open
Abstract
The receptor protein PEX5, an important component of peroxisomes, regulates growth, development, and immunity in yeast and mammals. PEX5 also influences growth and development in plants, but whether it participates in plant immunity has remained unclear. Here, we report that knockdown of OsPEX5 enhances resistance to the rice blast fungus Magnaporthe oryzae. We demonstrate that OsPEX5 interacts with the E3 ubiquitin ligase APIP6, a positive regulator of plant immunity. APIP6 ubiquitinates OsPEX5 in vitro and promotes its degradation in vivo via the 26S proteasome pathway. In addition, OsPEX5 interacts with the aldehyde dehydrogenase OsALDH2B1, which functions in growth-defense trade-offs in rice. OsPEX5 stabilizes OsALDH2B1 to enhance its repression of the defense-related gene OsAOS2. Our study thus uncovers a previously unrecognized hierarchical regulatory mechanism in which an E3 ubiquitin ligase targets a peroxisome receptor protein that negatively regulates immunity in rice by stabilizing an aldehyde dehydrogenase that suppresses defense gene expression.
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Affiliation(s)
- Xiaoman You
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Shanshan Zhu
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agriculture Sciences, Beijing 100081, China
| | - Haowen Sheng
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China; College of Agronomy, Hunan Agricultural University, Changsha, China
| | - Zheng Liu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Dan Wang
- College of Agronomy, Hunan Agricultural University, Changsha, China
| | - Min Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiao Xu
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Feng He
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Hong Fang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Fan Zhang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Debao Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Zeyun Hao
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Ruyi Wang
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Yinghui Xiao
- College of Agronomy, Hunan Agricultural University, Changsha, China
| | - Jianmin Wan
- National Key Facility for Crop Gene Resources and Genetic Improvement, Institute of Crop Science, Chinese Academy of Agriculture Sciences, Beijing 100081, China
| | - Guo-Liang Wang
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, USA
| | - Yuese Ning
- State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
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3
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Akhter D, Zhang Y, Hu J, Pan R. Protein ubiquitination in plant peroxisomes. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2023; 65:371-380. [PMID: 35975710 DOI: 10.1111/jipb.13346] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Accepted: 08/11/2022] [Indexed: 06/15/2023]
Abstract
Protein ubiquitination regulates diverse cellular processes in eukaryotic organisms, from growth and development to stress response. Proteins subjected to ubiquitination can be found in virtually all subcellular locations and organelles, including peroxisomes, single-membrane and highly dynamic organelles ubiquitous in eukaryotes. Peroxisomes contain metabolic functions essential to plants and animals such as lipid catabolism, detoxification of reactive oxygen species (ROS), biosynthesis of vital hormones and cofactors, and photorespiration. Plant peroxisomes possess a complex proteome with functions varying among different tissue types and developmental stages, and during plant response to distinct environmental cues. However, how these diverse functions are regulated at the post-translational level is poorly understood, especially in plants. In this review, we summarized current knowledge of the involvement of protein ubiquitination in peroxisome protein import, remodeling, pexophagy, and metabolism, focusing on plants, and referencing discoveries from other eukaryotic systems when relevant. Based on previous ubiquitinomics studies, we compiled a list of 56 ubiquitinated Arabidopsis peroxisomal proteins whose functions are associated with all the major plant peroxisomal metabolic pathways. This discovery suggests a broad impact of protein ubiquitination on plant peroxisome functions, therefore substantiating the need to investigate this significant regulatory mechanism in peroxisomes at more depths.
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Affiliation(s)
- Delara Akhter
- State Key Laboratory of Rice Biology, Zhejiang Provincial Key Laboratory of Crop Genetic Resources, College of Agriculture and Biotechnology & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310058/311200, China
- Zhejiang Laboratory, Hangzhou, 311121, China
- Department of Genetics and Plant Breeding, Sylhet Agricultural University, Sylhet, 3100, Bangladesh
| | - Yuchan Zhang
- State Key Laboratory of Rice Biology, Zhejiang Provincial Key Laboratory of Crop Genetic Resources, College of Agriculture and Biotechnology & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310058/311200, China
- Zhejiang Laboratory, Hangzhou, 311121, China
| | - Jianping Hu
- Department of Energy Plant Research Laboratory and Plant Biology Department, Michigan State University, East Lansing,, Michigan, USA
- Department of Plant Biology, Michigan State University, East Lansing,, Michigan, USA
| | - Ronghui Pan
- State Key Laboratory of Rice Biology, Zhejiang Provincial Key Laboratory of Crop Genetic Resources, College of Agriculture and Biotechnology & ZJU-Hangzhou Global Scientific and Technological Innovation Center, Zhejiang University, Hangzhou, 310058/311200, China
- Zhejiang Laboratory, Hangzhou, 311121, China
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4
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Mano S, Hayashi Y, Hikino K, Otomo M, Kanai M, Nishimura M. Ubiquitin-conjugating activity by PEX4 is required for efficient protein transport to peroxisomes in Arabidopsis thaliana. J Biol Chem 2022; 298:102038. [PMID: 35595097 PMCID: PMC9190015 DOI: 10.1016/j.jbc.2022.102038] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2021] [Revised: 05/10/2022] [Accepted: 05/11/2022] [Indexed: 11/08/2022] Open
Abstract
Protein transport to peroxisomes requires various proteins, such as receptors in the cytosol and components of the transport machinery on peroxisomal membranes. The Arabidopsis apem (aberrant peroxisome morphology) mutant apem7 shows decreased efficiency of peroxisome targeting signal 1–dependent protein transport to peroxisomes. In apem7 mutants, peroxisome targeting signal 2–dependent protein transport is also disturbed, and plant growth is repressed. The APEM7 gene encodes a protein homologous to peroxin 4 (PEX4), which belongs to the ubiquitin-conjugating (UBC) protein family; however, the UBC activity of Arabidopsis PEX4 remains to be investigated. Here, we show using electron microscopy and immunoblot analysis using specific PEX4 antibodies and in vitro transcription/translation assay that PEX4 localizes to peroxisomal membranes and possesses UBC activity. We found that the substitution of proline with leucine by apem7 mutation alters ubiquitination of PEX4. Furthermore, substitution of the active-site cysteine residue at position 90 in PEX4, which was predicted to be a ubiquitin-conjugation site, with alanine did not restore the apem7 phenotype. Taken together, these findings indicate that abnormal ubiquitination in the apem7 mutant alters ubiquitin signaling during the process of protein transport, suggesting that the UBC activity of PEX4 is indispensable for efficient protein transport to peroxisomes.
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Affiliation(s)
- Shoji Mano
- Department of Cell Biology, National Institute for Basic Biology, Myodaiji, Okazaki, Japan; Department of Basic Biology, School of Life Science, SOKENDAI (The Graduate University for Advanced Studies), Myodaiji, Okazaki, Japan.
| | - Yasuko Hayashi
- Graduate School of Science and Technology, Niigata University, Ikarashi, Niigata, Japan
| | - Kazumi Hikino
- Department of Cell Biology, National Institute for Basic Biology, Myodaiji, Okazaki, Japan
| | - Masayoshi Otomo
- Graduate School of Science and Technology, Niigata University, Ikarashi, Niigata, Japan
| | - Masatake Kanai
- Department of Cell Biology, National Institute for Basic Biology, Myodaiji, Okazaki, Japan
| | - Mikio Nishimura
- Department of Cell Biology, National Institute for Basic Biology, Myodaiji, Okazaki, Japan
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The MFN1 and MFN2 mitofusins promote clustering between mitochondria and peroxisomes. Commun Biol 2022; 5:423. [PMID: 35523862 PMCID: PMC9076876 DOI: 10.1038/s42003-022-03377-x] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Accepted: 04/18/2022] [Indexed: 11/08/2022] Open
Abstract
Mitochondria and peroxisomes are two types of functionally close-related organelles, and both play essential roles in lipid and ROS metabolism. However, how they physically interact with each other is not well understood. In this study, we apply the proximity labeling method with peroxisomal proteins and report that mitochondrial protein mitofusins (MFNs) are in proximity to peroxisomes. Overexpression of MFNs induces not only the mitochondria clustering but also the co-clustering of peroxisomes. We also report the enrichment of MFNs at the mitochondria-peroxisome interface. Induced mitofusin expression gives rise to more mitochondria-peroxisome contacting sites. Furthermore, the tethering of peroxisomes to mitochondria can be inhibited by the expression of a truncated MFN2, which lacks the transmembrane region. Collectively, our study suggests MFNs as regulators for mitochondria-peroxisome contacts. Our findings are essential for future studies of inter-organelle metabolism regulation and signaling, and may help understand the pathogenesis of mitofusin dysfunction-related disease.
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6
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Clemens S. The cell biology of zinc. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:1688-1698. [PMID: 34727160 DOI: 10.1093/jxb/erab481] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2021] [Accepted: 10/28/2021] [Indexed: 06/13/2023]
Abstract
Nearly 10% of all plant proteins belong to the zinc (Zn) proteome. They require Zn either for catalysis or as a structural element. Most of the protein-bound Zn in eukaryotic cells is found in the cytosol. The fundamental differences between transition metal cations in the stability of their complexes with organic ligands, as described by the Irving-Williams series, necessitate buffering of cytosolic Zn (the 'free Zn' pool) in the picomolar range (i.e. ~6 orders of magnitude lower than the total cellular concentration). Various metabolites and peptides, including nicotianamine, glutathione, and phytochelatins, serve as Zn buffers. They are hypothesized to supply Zn to enzymes, transporters, or the recently identified sensor proteins. Zn2+ acquisition is mediated by ZRT/IRT-like proteins. Metal tolerance proteins transport Zn2+ into vacuoles and the endoplasmic reticulum, the major Zn storage sites. Heavy metal ATPase-dependent efflux of Zn2+ is another mechanism to control cytosolic Zn. Spatially controlled Zn2+ influx or release from intracellular stores would result in dynamic modulation of cellular Zn pools, which may directly influence protein-protein interactions or the activities of enzymes involved in signaling cascades. Possible regulatory roles of such changes, as recently elucidated in mammalian cells, are discussed.
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Affiliation(s)
- Stephan Clemens
- Department of Plant Physiology and Faculty of Life Science: Food, Nutrition and Health, University of Bayreuth, Universitätsstrasse 30, D-95447 Bayreuth, Germany
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7
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Wei M, Dhanasekaran S, Yang Q, Ngolong Ngea GL, Godana EA, Zhang H. Degradation and stress response mechanism of Cryptococcus podzolicus Y3 on ochratoxin A at the transcriptional level. Lebensm Wiss Technol 2022. [DOI: 10.1016/j.lwt.2021.113061] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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8
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Traver MS, Bradford SE, Olmos JL, Wright ZJ, Miller MD, Xu W, Phillips GN, Bartel B. The Structure of the Arabidopsis PEX4-PEX22 Peroxin Complex-Insights Into Ubiquitination at the Peroxisomal Membrane. Front Cell Dev Biol 2022; 10:838923. [PMID: 35300425 PMCID: PMC8922245 DOI: 10.3389/fcell.2022.838923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2021] [Accepted: 01/28/2022] [Indexed: 01/11/2023] Open
Abstract
Peroxisomes are eukaryotic organelles that sequester critical oxidative reactions and process the resulting reactive oxygen species into less toxic byproducts. Peroxisome function and formation are coordinated by peroxins (PEX proteins) that guide peroxisome biogenesis and division and shuttle proteins into the lumen and membrane of the organelle. Despite the importance of peroxins in plant metabolism and development, no plant peroxin structures have been reported. Here we report the X-ray crystal structure of the PEX4-PEX22 peroxin complex from the reference plant Arabidopsis thaliana. PEX4 is a ubiquitin-conjugating enzyme (UBC) that ubiquitinates proteins associated with the peroxisomal membrane, and PEX22 is a peroxisomal membrane protein that anchors PEX4 to the peroxisome and facilitates PEX4 activity. We co-expressed Arabidopsis PEX4 as a translational fusion with the soluble PEX4-interacting domain of PEX22 in E. coli. The fusion was linked via a protease recognition site, allowing us to separate PEX4 and PEX22 following purification and solve the structure of the complex. We compared the structure of the PEX4-PEX22 complex to the previously published structures of yeast orthologs. Arabidopsis PEX4 displays the typical UBC structure expected from its sequence. Although Arabidopsis PEX22 lacks notable sequence identity to yeast PEX22, it maintains a similar Rossmann fold-like structure. Several salt bridges are positioned to contribute to the specificity of PEX22 for PEX4 versus other Arabidopsis UBCs, and the long unstructured PEX22 tether would allow PEX4-mediated ubiquitination of distant peroxisomal membrane targets without dissociation from PEX22. The Arabidopsis PEX4-PEX22 structure also revealed that the residue altered in pex4-1 (P123L), a mutant previously isolated via a forward-genetic screen for peroxisomal dysfunction, is near the active site cysteine of PEX4. We demonstrated in vitro UBC activity for the PEX4-PEX22 complex and found that the pex4-1 enzyme has reduced in vitro ubiquitin-conjugating activity and altered specificity compared to PEX4. Our findings illuminate the role of PEX4 and PEX22 in peroxisome structure and function and provide tools for future exploration of ubiquitination at the peroxisome surface.
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Affiliation(s)
- Melissa S. Traver
- Department of Biosciences, Rice University, Houston, TX, United States
| | - Sarah E. Bradford
- Department of Biosciences, Rice University, Houston, TX, United States
| | - Jose Luis Olmos
- Department of Biosciences, Rice University, Houston, TX, United States
| | - Zachary J. Wright
- Department of Biosciences, Rice University, Houston, TX, United States
| | | | - Weijun Xu
- Department of Biosciences, Rice University, Houston, TX, United States
| | - George N. Phillips
- Department of Biosciences, Rice University, Houston, TX, United States
- Department of Chemistry, Rice University, Houston, TX, United States
| | - Bonnie Bartel
- Department of Biosciences, Rice University, Houston, TX, United States
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9
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Meng X, Liu J, Zhao M. Genome-wide identification of RING finger genes in flax ( Linum usitatissimum) and analyses of their evolution. PeerJ 2021; 9:e12491. [PMID: 34820204 PMCID: PMC8601054 DOI: 10.7717/peerj.12491] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Accepted: 10/25/2021] [Indexed: 01/05/2023] Open
Abstract
Background Flax (Linum usitatissimum) is an important crop for its seed oil and stem fiber. Really Interesting New Gene (RING) finger genes play essential roles in growth, development, and biotic and abiotic stress responses in plants. However, little is known about these genes in flax. Methods Here, we performed a systematic genome-wide analysis to identify RING finger genes in flax. Results We identified 587 RING domains in 574 proteins and classified them into RING-H2 (292), RING-HCa (181), RING-HCb (23), RING-v (53), RING-C2 (31), RING-D (2), RING-S/T (3), and RING-G (2). These proteins were further divided into 45 groups according to domain organization. These genes were located in 15 chromosomes and clustered into three clades according to their phylogenetic relationships. A total of 312 segmental duplicated gene pairs were inferred from 411 RING finger genes, indicating a major contribution of segmental duplications to the RING finger gene family expansion. The non-synonymous/synonymous substitution ratio of the segmentally duplicated gene pairs was less than 1, suggesting that the gene family was under negative selection since duplication. Further, most RING genes in flax were differentially expressed during seed development or in the shoot apex. This study provides useful information for further functional analysis of RING finger genes in flax and to develop gene-derived molecular markers in flax breeding.
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Affiliation(s)
- Xianwen Meng
- The College of Ecological Environmental and Resources, Qinghai Provincial Key Laboratory of High Value Utilization of Characteristic Economic Plants, Qinghai Tibet Alpine Wetland Restoration Engineering Technology Research Center, Qinghai Minzu University, Xining, China
| | - Jing Liu
- The College of Ecological Environmental and Resources, Qinghai Provincial Key Laboratory of High Value Utilization of Characteristic Economic Plants, Qinghai Tibet Alpine Wetland Restoration Engineering Technology Research Center, Qinghai Minzu University, Xining, China
| | - Mingde Zhao
- The College of Ecological Environmental and Resources, Qinghai Provincial Key Laboratory of High Value Utilization of Characteristic Economic Plants, Qinghai Tibet Alpine Wetland Restoration Engineering Technology Research Center, Qinghai Minzu University, Xining, China
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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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11
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Su T, Li W, Wang P, Ma C. Dynamics of Peroxisome Homeostasis and Its Role in Stress Response and Signaling in Plants. FRONTIERS IN PLANT SCIENCE 2019; 10:705. [PMID: 31214223 PMCID: PMC6557986 DOI: 10.3389/fpls.2019.00705] [Citation(s) in RCA: 45] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2019] [Accepted: 05/13/2019] [Indexed: 05/19/2023]
Abstract
Peroxisomes play vital roles in plant growth, development, and environmental stress response. During plant development and in response to environmental stresses, the number and morphology of peroxisomes are dynamically regulated to maintain peroxisome homeostasis in cells. To execute their various functions in the cell, peroxisomes associate and communicate with other organelles. Under stress conditions, reactive oxygen species (ROS) produced in peroxisomes and other organelles activate signal transduction pathways, in a process known as retrograde signaling, to synergistically regulate defense systems. In this review, we focus on the recent advances in the plant peroxisome field to provide an overview of peroxisome biogenesis, degradation, crosstalk with other organelles, and their role in response to environmental stresses.
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12
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Gao D, Smith S, Spagnuolo M, Rodriguez G, Blenner M. Dual CRISPR-Cas9 Cleavage Mediated Gene Excision and Targeted Integration in Yarrowia lipolytica. Biotechnol J 2018; 13:e1700590. [PMID: 29809313 DOI: 10.1002/biot.201700590] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 05/23/2018] [Indexed: 12/12/2022]
Abstract
CRISPR-Cas9 technology has been successfully applied in Yarrowia lipolytica for targeted genomic editing including gene disruption and integration; however, disruptions by existing methods typically result from small frameshift mutations caused by indels within the coding region, which usually resulted in unnatural protein. In this study, a dual cleavage strategy directed by paired sgRNAs is developed for gene knockout. This method allows fast and robust gene excision, demonstrated on six genes of interest. The targeted regions for excision vary in length from 0.3 kb up to 3.5 kb and contain both non-coding and coding regions. The majority of the gene excisions are repaired by perfect nonhomologous end-joining without indel. Based on this dual cleavage system, two targeted markerless integration methods are developed by providing repair templates. While both strategies are effective, homology mediated end joining (HMEJ) based method are twice as efficient as homology recombination (HR) based method. In both cases, dual cleavage leads to similar or improved gene integration efficiencies compared to gene excision without integration. This dual cleavage strategy will be useful for not only generating more predictable and robust gene knockout, but also for efficient targeted markerless integration, and simultaneous knockout and integration in Y. lipolytica.
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Affiliation(s)
- Difeng Gao
- Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina, USA
| | - Spencer Smith
- Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina, USA
| | - Michael Spagnuolo
- Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina, USA
| | - Gabriel Rodriguez
- Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina, USA
| | - Mark Blenner
- Chemical and Biomolecular Engineering, Clemson University, Clemson, South Carolina, USA
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13
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Agarwal P, Khurana P. Characterization of a novel zinc finger transcription factor (TaZnF) from wheat conferring heat stress tolerance in Arabidopsis. Cell Stress Chaperones 2018; 23:253-267. [PMID: 28889352 PMCID: PMC5823806 DOI: 10.1007/s12192-017-0838-1] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2017] [Revised: 08/08/2017] [Accepted: 08/09/2017] [Indexed: 12/26/2022] Open
Abstract
C3HC4-type zinc finger proteins are known to play important roles in various plant processes including regulation of growth and development, signaling networks, responses to abiotic stresses etc. The current study identifies and explores the involvement of TaZnF in plant stress response, mainly heat stress. TaZnF belongs to C4HC3-type zinc finger transcription factor. Phylogenetic analysis of TaZnF revealed strong sequence similarity to Brachypodium distachyon, a model system for crop species. Gene expression studies have revealed its role under diverse stress conditions including heat and cold conditions. The transcript level of TaZnF was found to be highest in seed and starts at the post anthesis period 3-5DAA, a more sensitive stage resulting in a negative influence on the yield of crop species. TaZnF possesses transcriptional activity. Overexpression of TaZnF in Arabidopsis thaliana conferred improved tolerance to both basal and high-temperature stress as observed from various assays examining their growth and development. The transgenics were recovered and showed early flowering compared to wild-type. They had larger primary roots, more lateral branching, bigger, and more numerous leaves, resulting in heavier fresh weight. Enhanced growth and early recovery resulted in bigger plants with more yield. Additionally, the overexpression Arabidopsis transgenics also showed considerable tolerance to cold and oxidative stress. These observations suggest that TaZnF acts as a positive regulator of thermal stress and thus can be of great significance in understanding and improving temperature stress tolerance in plants.
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Affiliation(s)
- Preeti Agarwal
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, 110021 India
| | - Paramjit Khurana
- Department of Plant Molecular Biology, University of Delhi South Campus, Dhaula Kuan, New Delhi, 110021 India
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14
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Kao YT, Gonzalez KL, Bartel B. Peroxisome Function, Biogenesis, and Dynamics in Plants. PLANT PHYSIOLOGY 2018; 176:162-177. [PMID: 29021223 PMCID: PMC5761812 DOI: 10.1104/pp.17.01050] [Citation(s) in RCA: 109] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 10/09/2017] [Indexed: 05/19/2023]
Abstract
Recent advances highlight understanding of the diversity of peroxisome contributions to plant biology and the mechanisms through which these essential organelles are generated.
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Affiliation(s)
- Yun-Ting Kao
- Department of Biosciences, Rice University, Houston, Texas 77005
| | - Kim L Gonzalez
- Department of Biosciences, Rice University, Houston, Texas 77005
| | - Bonnie Bartel
- Department of Biosciences, Rice University, Houston, Texas 77005
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15
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Abstract
As a laboratory animal, Drosophila melanogaster has made extensive contributions to understanding many areas of fundamental biology as well as being an effective model for human disease. Until recently, there was relatively little known about fly peroxisomes. There were early studies that examined the role of peroxisome enzymes during development of organs like the eye. However, with the advent of a well-annotated, sequenced genome, several groups have collectively determined, first by sequence homology and increasingly by functional studies, Drosophila Peroxins and related peroxisome proteins. Notably, it was shown that Drosophila peroxisome biogenesis is mediated via a well-conserved PTS1 import system. Although the fly genome encodes a Pex7 homologue, a canonical PTS2 import system does not seem to be conserved in Drosophila. Given the homology between Drosophila and Saccharomyces cerevisiae or Homo sapiens peroxisome biogenesis and function, Drosophila has emerged as an effective multicellular system to model human Peroxisome Biogenesis Disorders. Finally, Drosophila peroxisome research has recently come into its own, facilitating new discoveries into the role of peroxisomes within specific tissues, such as testes or immune cells.
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Affiliation(s)
- Matthew Anderson-Baron
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, 5-14 Medical Sciences, Edmonton, AB, T6G 2H7, Canada
| | - Andrew J Simmonds
- Department of Cell Biology, Faculty of Medicine and Dentistry, University of Alberta, 5-14 Medical Sciences, Edmonton, AB, T6G 2H7, Canada.
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16
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Mueller-Schuessele SJ, Michaud M. Plastid Transient and Stable Interactions with Other Cell Compartments. Methods Mol Biol 2018; 1829:87-109. [PMID: 29987716 DOI: 10.1007/978-1-4939-8654-5_6] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Plastids are organelles delineated by two envelopes that play important roles in different cellular processes such as energy production or lipid biosynthesis. To regulate their biogenesis and their function, plastids have to communicate with other cellular compartments. This communication can be mediated by signaling molecules and by the establishment of direct contacts between the plastid envelope and other organelles such as the endoplasmic reticulum, the mitochondria, the plasma membrane, the peroxisomes and the nucleus. These interactions are highly dynamic and respond to different biotic and abiotic stresses. However, the mechanisms involved in the formation of plastid-organelle contact sites and their functions are still enigmatic. In this chapter, we summarize our current knowledge about plastid contact sites and their role in the regulation of plastid biogenesis and function.
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Affiliation(s)
| | - Morgane Michaud
- Laboratory of Cell and Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, NIH, Bethesda, MD, USA. .,Laboratoire de Physiologie Cellulaire et Végétale, Centre National de la Recherche Scientifique, Institut National de la Recherche Agronomique, Commissariat à l'Energie Atomique et aux Energies Alternatives, CEA Grenoble, UMR5168, Université Grenoble Alpes, Grenoble, France.
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17
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Schwerter DP, Grimm I, Platta HW, Erdmann R. ATP-driven processes of peroxisomal matrix protein import. Biol Chem 2017; 398:607-624. [PMID: 27977397 DOI: 10.1515/hsz-2016-0293] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2016] [Accepted: 12/11/2016] [Indexed: 12/13/2022]
Abstract
In peroxisomal matrix protein import two processes directly depend on the binding and hydrolysis of ATP, both taking place at the late steps of the peroxisomal import cycle. First, ATP hydrolysis is required to initiate a ubiquitin-transfer cascade to modify the import (co-)receptors. These receptors display a dual localization in the cytosol and at the peroxisomal membrane, whereas only the membrane bound fraction receives the ubiquitin modification. The second ATP-dependent process of the import cycle is carried out by the two AAA+-proteins Pex1p and Pex6p. These ATPases form a heterohexameric complex, which is recruited to the peroxisomal import machinery by the membrane anchor protein Pex15p. The Pex1p/Pex6p complex recognizes the ubiquitinated import receptors, pulls them out of the membrane and releases them into the cytosol. There the deubiquitinated receptors are provided for further rounds of import. ATP binding and hydrolysis are required for Pex1p/Pex6p complex formation and receptor export. In this review, we summarize the current knowledge on the peroxisomal import cascade. In particular, we will focus on the ATP-dependent processes, which are so far best understood in the model organism Saccharomyces cerevisiae.
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Affiliation(s)
- Daniel P Schwerter
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum
| | - Immanuel Grimm
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum
| | - Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Medizinische Fakultät der Ruhr-Universität Bochum, D-44780 Bochum
| | - Ralf Erdmann
- Abteilung für Systembiochemie, Institut für Biochemie und Pathobiochemie, Medizinische Fakultät der Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum
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18
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Zang D, Wang L, Zhang Y, Zhao H, Wang Y. ThDof1.4 and ThZFP1 constitute a transcriptional regulatory cascade involved in salt or osmotic stress in Tamarix hispida. PLANT MOLECULAR BIOLOGY 2017; 94:495-507. [PMID: 28578496 DOI: 10.1007/s11103-017-0620-x] [Citation(s) in RCA: 37] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 05/24/2017] [Indexed: 05/03/2023]
Abstract
Identification of the upstream regulators of a gene is important to characterize the transcriptional pathway and the function of the gene. Previously, we found that a zinc finger protein (ThZFP1) is involved in abiotic stress tolerance of Tamarix hispida. In the present study, we further investigated the transcriptional pathway of ThZFP1. Dof motifs are abundant in the ThZFP1 promoter; therefore, we used them to screen for transcriptional regulators of ThZFP1. A Dof protein, ThDof1.4, binds to the Dof motif specifically, and was hypothesized as the upstream regulator of ThZFP1. Further study showed that overexpression of ThDof1.4 in T. hispida activated the expression of GUS controlled by the ThZFP1 promoter. In T. hispida, transient overexpression of ThDof1.4 increased the transcripts of ThZFP1; conversely, transient RNAi-silencing of ThDof1.4 reduced the expression of ThZFP1. Chromatin immunoprecipitation indicated that ThDof1.4 binds to the ThZFP1 promoter. Additionally, ThDof1.4 and ThZFP1 share similar expression patterns in response to salt or drought stress. Furthermore, like ThZFP1, ThDof1.4 could increase the proline level and enhance ROS scavenging capability to improve salt and osmotic stress tolerance. Together, these results suggested that ThDof1.4 and ThZFP1 form a transcriptional regulatory cascade involved in abiotic stress resistance in T. hispida.
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Affiliation(s)
- Dandan Zang
- State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Lina Wang
- State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Yiming Zhang
- State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Huimin Zhao
- State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China
| | - Yucheng Wang
- State Key Laboratory of Forest Genetics and Tree Breeding, Northeast Forestry University, 26 Hexing Road, Harbin, 150040, China.
- Key Laboratory of Biogeography and Bioresource in Arid Land, Xinjiang Institute of Ecology and Geography, Chinese Academy of Sciences, Ürümqi, 830011, Xinjiang, China.
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19
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Genome-wide identification, evolution and expression analysis of RING finger protein genes in Brassica rapa. Sci Rep 2017; 7:40690. [PMID: 28094809 PMCID: PMC5240574 DOI: 10.1038/srep40690] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2016] [Accepted: 12/08/2016] [Indexed: 12/31/2022] Open
Abstract
More and more RING finger genes were found to be implicated in various important biological processes. In the present study, a total of 731 RING domains in 715 predicted proteins were identified in Brassica rapa genome (AA, 2n = 20), which were further divided into eight types: RING-H2 (371), RING-HCa (215), RING-HCb (47), RING-v (44), RING-C2 (38), RING-D (10), RING-S/T (5) and RING-G (1). The 715 RING finger proteins were further classified into 51 groups according to the presence of additional domains. 700 RING finger protein genes were mapped to the 10 chromosomes of B. rapa with a range of 47 to 111 genes for each chromosome. 667 RING finger protein genes were expressed in at least one of the six tissues examined, indicating their involvement in various physiological and developmental processes in B. rapa. Hierarchical clustering analysis of RNA-seq data divided them into seven major groups, one of which includes 231 members preferentially expressed in leaf, and constitutes then a panel of gene candidates for studying the genetic and molecular mechanisms of leafy head traits in Brassica crops. Our results lay the foundation for further studies on the classification, evolution and putative functions of RING finger protein genes in Brassica species.
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20
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Integrating Information in Biological Ontologies and Molecular Networks to Infer Novel Terms. Sci Rep 2016; 6:39237. [PMID: 27976738 PMCID: PMC5157009 DOI: 10.1038/srep39237] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Accepted: 11/21/2016] [Indexed: 12/24/2022] Open
Abstract
Currently most terms and term-term relationships in Gene Ontology (GO) are defined manually, which creates cost, consistency and completeness issues. Recent studies have demonstrated the feasibility of inferring GO automatically from biological networks, which represents an important complementary approach to GO construction. These methods (NeXO and CliXO) are unsupervised, which means 1) they cannot use the information contained in existing GO, 2) the way they integrate biological networks may not optimize the accuracy, and 3) they are not customized to infer the three different sub-ontologies of GO. Here we present a semi-supervised method called Unicorn that extends these previous methods to tackle the three problems. Unicorn uses a sub-tree of an existing GO sub-ontology as training part to learn parameters in integrating multiple networks. Cross-validation results show that Unicorn reliably inferred the left-out parts of each specific GO sub-ontology. In addition, by training Unicorn with an old version of GO together with biological networks, it successfully re-discovered some terms and term-term relationships present only in a new version of GO. Unicorn also successfully inferred some novel terms that were not contained in GO but have biological meanings well-supported by the literature.Availability: Source code of Unicorn is available at http://yiplab.cse.cuhk.edu.hk/unicorn/.
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21
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Reumann S, Bartel B. Plant peroxisomes: recent discoveries in functional complexity, organelle homeostasis, and morphological dynamics. CURRENT OPINION IN PLANT BIOLOGY 2016; 34:17-26. [PMID: 27500947 PMCID: PMC5161562 DOI: 10.1016/j.pbi.2016.07.008] [Citation(s) in RCA: 61] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/29/2016] [Revised: 07/15/2016] [Accepted: 07/20/2016] [Indexed: 05/20/2023]
Abstract
Peroxisomes are essential for life in plants. These organelles house a variety of metabolic processes that generate and inactivate reactive oxygen species. Our knowledge of pathways and mechanisms that depend on peroxisomes and their constituent enzymes continues to grow, and in this review we highlight recent advances in understanding the identity and biological functions of peroxisomal enzymes and metabolic processes. We also review how peroxisomal matrix and membrane proteins enter the organelle from their sites of synthesis. Peroxisome homeostasis is regulated by specific degradation mechanisms, and we discuss the contributions of specialized autophagy and a peroxisomal protease to the degradation of entire peroxisomes and peroxisomal enzymes that are damaged or superfluous. Finally, we review how peroxisomes can flexibly change their morphology to facilitate inter-organellar contacts.
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Affiliation(s)
- Sigrun Reumann
- Department of Plant Biochemistry and Infection Biology, Biocentre Klein Flottbek, University of Hamburg, D-22609 Hamburg, Germany; Centre for Organelle Research, Faculty of Science and Technology, University of Stavanger, N-4036 Stavanger, Norway
| | - Bonnie Bartel
- Department of BioSciences, Rice University, Houston, TX 77005, USA.
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22
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Affiliation(s)
| | - Maria Daniela D'Agostino
- McGill University Department of Human Genetics and McGill University Health Center, Department of Medical Genetics, Montreal, QC, Canada
| | - Nancy Braverman
- McGill University Department of Human Genetics and Pediatrics, and The Research Institute of the McGill University Health Centre, Montreal, QC, Canada
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23
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Kao YT, Fleming WA, Ventura MJ, Bartel B. Genetic Interactions between PEROXIN12 and Other Peroxisome-Associated Ubiquitination Components. PLANT PHYSIOLOGY 2016; 172:1643-1656. [PMID: 27650450 PMCID: PMC5100787 DOI: 10.1104/pp.16.01211] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/02/2016] [Accepted: 09/15/2016] [Indexed: 05/28/2023]
Abstract
Most eukaryotic cells require peroxisomes, organelles housing fatty acid β-oxidation and other critical metabolic reactions. Peroxisomal matrix proteins carry peroxisome-targeting signals that are recognized by one of two receptors, PEX5 or PEX7, in the cytosol. After delivering the matrix proteins to the organelle, these receptors are removed from the peroxisomal membrane or matrix. Receptor retrotranslocation not only facilitates further rounds of matrix protein import but also prevents deleterious PEX5 retention in the membrane. Three peroxisome-associated ubiquitin-protein ligases in the Really Interesting New Gene (RING) family, PEX2, PEX10, and PEX12, facilitate PEX5 retrotranslocation. However, the detailed mechanism of receptor retrotranslocation remains unclear in plants. We identified an Arabidopsis (Arabidopsis thaliana) pex12 Glu-to-Lys missense allele that conferred severe peroxisomal defects, including impaired β-oxidation, inefficient matrix protein import, and decreased growth. We compared this pex12-1 mutant to other peroxisome-associated ubiquitination-related mutants and found that RING peroxin mutants displayed elevated PEX5 and PEX7 levels, supporting the involvement of RING peroxins in receptor ubiquitination in Arabidopsis. Also, we observed that disruption of any Arabidopsis RING peroxin led to decreased PEX10 levels, as seen in yeast and mammals. Peroxisomal defects were exacerbated in RING peroxin double mutants, suggesting distinct roles of individual RING peroxins. Finally, reducing function of the peroxisome-associated ubiquitin-conjugating enzyme PEX4 restored PEX10 levels and partially ameliorated the other molecular and physiological defects of the pex12-1 mutant. Future biochemical analyses will be needed to determine whether destabilization of the RING peroxin complex observed in pex12-1 stems from PEX4-dependent ubiquitination on the pex12-1 ectopic Lys residue.
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Affiliation(s)
- Yun-Ting Kao
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, Texas 77005 (Y.-T.K., W.A.F., M.J.V., B.B.)
| | - Wendell A Fleming
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, Texas 77005 (Y.-T.K., W.A.F., M.J.V., B.B.)
| | - Meredith J Ventura
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, Texas 77005 (Y.-T.K., W.A.F., M.J.V., B.B.)
| | - Bonnie Bartel
- Biochemistry and Cell Biology Program, Department of BioSciences, Rice University, Houston, Texas 77005 (Y.-T.K., W.A.F., M.J.V., B.B.)
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24
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Sargent G, van Zutphen T, Shatseva T, Zhang L, Di Giovanni V, Bandsma R, Kim PK. PEX2 is the E3 ubiquitin ligase required for pexophagy during starvation. J Cell Biol 2016; 214:677-90. [PMID: 27597759 PMCID: PMC5021090 DOI: 10.1083/jcb.201511034] [Citation(s) in RCA: 127] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2015] [Accepted: 08/01/2016] [Indexed: 12/31/2022] Open
Abstract
Sargent et al. identify the E3 ubiquitin ligase PEX2 as the causative agent of mammalian pexophagy. During amino acid starvation, PEX2 expression increases to ubiquitinate peroxisomal membrane proteins and signal peroxisome degradation by autophagy. Peroxisomes are metabolic organelles necessary for anabolic and catabolic lipid reactions whose numbers are highly dynamic based on the metabolic need of the cells. One mechanism to regulate peroxisome numbers is through an autophagic process called pexophagy. In mammalian cells, ubiquitination of peroxisomal membrane proteins signals pexophagy; however, the E3 ligase responsible for mediating ubiquitination is not known. Here, we report that the peroxisomal E3 ubiquitin ligase peroxin 2 (PEX2) is the causative agent for mammalian pexophagy. Expression of PEX2 leads to gross ubiquitination of peroxisomes and degradation of peroxisomes in an NBR1-dependent autophagic process. We identify PEX5 and PMP70 as substrates of PEX2 that are ubiquitinated during amino acid starvation. We also find that PEX2 expression is up-regulated during both amino acid starvation and rapamycin treatment, suggesting that the mTORC1 pathway regulates pexophagy by regulating PEX2 expression levels. Finally, we validate our findings in vivo using an animal model.
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Affiliation(s)
- Graeme Sargent
- Cell Biology Department, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada Biochemistry Department, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Tim van Zutphen
- Department of Pediatrics, Center for Liver, Digestive and Metabolic Diseases, University of Groningen, University Medical Center Groningen, 9700 AD Groningen, Netherlands
| | - Tatiana Shatseva
- Biochemistry Department, University of Toronto, Toronto, ON M5S 1A8, Canada
| | - Ling Zhang
- Physiology and Experimental Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Valeria Di Giovanni
- Physiology and Experimental Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Robert Bandsma
- Department of Paediatric Laboratory Medicine, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada Physiology and Experimental Medicine Program, Research Institute, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada Division of Gastroenterology, Hepatology and Nutrition, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada Centre for Global Child Health, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Peter Kijun Kim
- Cell Biology Department, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada Biochemistry Department, University of Toronto, Toronto, ON M5S 1A8, Canada
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25
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Cross LL, Ebeed HT, Baker A. Peroxisome biogenesis, protein targeting mechanisms and PEX gene functions in plants. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1863:850-62. [DOI: 10.1016/j.bbamcr.2015.09.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/15/2015] [Revised: 09/15/2015] [Accepted: 09/21/2015] [Indexed: 12/16/2022]
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26
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Xie Q, Tzfadia O, Levy M, Weithorn E, Peled-Zehavi H, Van Parys T, Van de Peer Y, Galili G. hfAIM: A reliable bioinformatics approach for in silico genome-wide identification of autophagy-associated Atg8-interacting motifs in various organisms. Autophagy 2016; 12:876-87. [PMID: 27071037 DOI: 10.1080/15548627.2016.1147668] [Citation(s) in RCA: 59] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
Most of the proteins that are specifically turned over by selective autophagy are recognized by the presence of short Atg8 interacting motifs (AIMs) that facilitate their association with the autophagy apparatus. Such AIMs can be identified by bioinformatics methods based on their defined degenerate consensus F/W/Y-X-X-L/I/V sequences in which X represents any amino acid. Achieving reliability and/or fidelity of the prediction of such AIMs on a genome-wide scale represents a major challenge. Here, we present a bioinformatics approach, high fidelity AIM (hfAIM), which uses additional sequence requirements-the presence of acidic amino acids and the absence of positively charged amino acids in certain positions-to reliably identify AIMs in proteins. We demonstrate that the use of the hfAIM method allows for in silico high fidelity prediction of AIMs in AIM-containing proteins (ACPs) on a genome-wide scale in various organisms. Furthermore, by using hfAIM to identify putative AIMs in the Arabidopsis proteome, we illustrate a potential contribution of selective autophagy to various biological processes. More specifically, we identified 9 peroxisomal PEX proteins that contain hfAIM motifs, among which AtPEX1, AtPEX6 and AtPEX10 possess evolutionary-conserved AIMs. Bimolecular fluorescence complementation (BiFC) results verified that AtPEX6 and AtPEX10 indeed interact with Atg8 in planta. In addition, we show that mutations occurring within or nearby hfAIMs in PEX1, PEX6 and PEX10 caused defects in the growth and development of various organisms. Taken together, the above results suggest that the hfAIM tool can be used to effectively perform genome-wide in silico screens of proteins that are potentially regulated by selective autophagy. The hfAIM system is a web tool that can be accessed at link: http://bioinformatics.psb.ugent.be/hfAIM/.
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Affiliation(s)
- Qingjun Xie
- a Department of Plant and Environmental Science , Weizmann Institute of Science , Rehovotx , Israel
| | - Oren Tzfadia
- a Department of Plant and Environmental Science , Weizmann Institute of Science , Rehovotx , Israel.,b Department of Plant Systems Biology , VIB , Ghent , Belgium.,c Department of Plant Biotechnology and Bioinformatics , Ghent University , Ghent , Belgium.,d Bioinformatics Institute Ghent, Ghent University , Ghent , Belgium
| | - Matan Levy
- a Department of Plant and Environmental Science , Weizmann Institute of Science , Rehovotx , Israel
| | - Efrat Weithorn
- a Department of Plant and Environmental Science , Weizmann Institute of Science , Rehovotx , Israel
| | - Hadas Peled-Zehavi
- a Department of Plant and Environmental Science , Weizmann Institute of Science , Rehovotx , Israel
| | - Thomas Van Parys
- b Department of Plant Systems Biology , VIB , Ghent , Belgium.,c Department of Plant Biotechnology and Bioinformatics , Ghent University , Ghent , Belgium.,d Bioinformatics Institute Ghent, Ghent University , Ghent , Belgium
| | - Yves Van de Peer
- b Department of Plant Systems Biology , VIB , Ghent , Belgium.,c Department of Plant Biotechnology and Bioinformatics , Ghent University , Ghent , Belgium.,d Bioinformatics Institute Ghent, Ghent University , Ghent , Belgium.,e Genomics Research Institute (GRI), University of Pretoria , Pretoria , South Africa
| | - Gad Galili
- a Department of Plant and Environmental Science , Weizmann Institute of Science , Rehovotx , Israel
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27
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Gao H, Metz J, Teanby NA, Ward AD, Botchway SW, Coles B, Pollard MR, Sparkes I. In Vivo Quantification of Peroxisome Tethering to Chloroplasts in Tobacco Epidermal Cells Using Optical Tweezers. PLANT PHYSIOLOGY 2016; 170:263-72. [PMID: 26518344 PMCID: PMC4704594 DOI: 10.1104/pp.15.01529] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Accepted: 10/24/2015] [Indexed: 05/19/2023]
Abstract
Peroxisomes are highly motile organelles that display a range of motions within a short time frame. In static snapshots, they can be juxtaposed to chloroplasts, which has led to the hypothesis that they are physically interacting. Here, using optical tweezers, we tested the dynamic physical interaction in vivo. Using near-infrared optical tweezers combined with TIRF microscopy, we were able to trap peroxisomes and approximate the forces involved in chloroplast association in vivo in tobacco (Nicotiana tabacum) and observed weaker tethering to additional unknown structures within the cell. We show that chloroplasts and peroxisomes are physically tethered through peroxules, a poorly described structure in plant cells. We suggest that peroxules have a novel role in maintaining peroxisome-organelle interactions in the dynamic environment. This could be important for fatty acid mobilization and photorespiration through the interaction with oil bodies and chloroplasts, highlighting a fundamentally important role for organelle interactions for essential biochemistry and physiological processes.
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Affiliation(s)
- Hongbo Gao
- Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom (H.G., J.M., I.S.);School of Earth Sciences, University of Bristol, Clifton, Bristol BS8 1RJ, United Kingdom (N.A.T.); andCentral Laser Facility, Science and Technology Facilities Council, Didcot, Oxon OX11 0FA, United Kingdom (A.D.W., S.W.B., B.C., M.R.P.)
| | - Jeremy Metz
- Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom (H.G., J.M., I.S.);School of Earth Sciences, University of Bristol, Clifton, Bristol BS8 1RJ, United Kingdom (N.A.T.); andCentral Laser Facility, Science and Technology Facilities Council, Didcot, Oxon OX11 0FA, United Kingdom (A.D.W., S.W.B., B.C., M.R.P.)
| | - Nick A Teanby
- Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom (H.G., J.M., I.S.);School of Earth Sciences, University of Bristol, Clifton, Bristol BS8 1RJ, United Kingdom (N.A.T.); andCentral Laser Facility, Science and Technology Facilities Council, Didcot, Oxon OX11 0FA, United Kingdom (A.D.W., S.W.B., B.C., M.R.P.)
| | - Andy D Ward
- Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom (H.G., J.M., I.S.);School of Earth Sciences, University of Bristol, Clifton, Bristol BS8 1RJ, United Kingdom (N.A.T.); andCentral Laser Facility, Science and Technology Facilities Council, Didcot, Oxon OX11 0FA, United Kingdom (A.D.W., S.W.B., B.C., M.R.P.)
| | - Stanley W Botchway
- Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom (H.G., J.M., I.S.);School of Earth Sciences, University of Bristol, Clifton, Bristol BS8 1RJ, United Kingdom (N.A.T.); andCentral Laser Facility, Science and Technology Facilities Council, Didcot, Oxon OX11 0FA, United Kingdom (A.D.W., S.W.B., B.C., M.R.P.)
| | - Benjamin Coles
- Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom (H.G., J.M., I.S.);School of Earth Sciences, University of Bristol, Clifton, Bristol BS8 1RJ, United Kingdom (N.A.T.); andCentral Laser Facility, Science and Technology Facilities Council, Didcot, Oxon OX11 0FA, United Kingdom (A.D.W., S.W.B., B.C., M.R.P.)
| | - Mark R Pollard
- Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom (H.G., J.M., I.S.);School of Earth Sciences, University of Bristol, Clifton, Bristol BS8 1RJ, United Kingdom (N.A.T.); andCentral Laser Facility, Science and Technology Facilities Council, Didcot, Oxon OX11 0FA, United Kingdom (A.D.W., S.W.B., B.C., M.R.P.)
| | - Imogen Sparkes
- Biosciences, University of Exeter, Exeter EX4 4QD, United Kingdom (H.G., J.M., I.S.);School of Earth Sciences, University of Bristol, Clifton, Bristol BS8 1RJ, United Kingdom (N.A.T.); andCentral Laser Facility, Science and Technology Facilities Council, Didcot, Oxon OX11 0FA, United Kingdom (A.D.W., S.W.B., B.C., M.R.P.)
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Gao Y, Li MY, Zhao J, Zhang YC, Xie QJ, Chen DH. Genome-wide analysis of RING finger proteins in the smallest free-living photosynthetic eukaryote Ostreococus tauri. Mar Genomics 2015; 26:51-61. [PMID: 26751716 DOI: 10.1016/j.margen.2015.12.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Revised: 12/21/2015] [Accepted: 12/22/2015] [Indexed: 11/19/2022]
Abstract
RING finger proteins and ubiquitination marks are widely involved in diverse aspects of growth and development, biological processes, and stress or environmental responses. As the smallest free-living photosynthetic eukaryote known so far, the green alga Ostreococus tauri has become an excellent model for investigating the origin of different gene families in the green lineage. Here, 65 RING domains in 65 predicted proteins were identified from O. tauri and on the basis of one or more substitutions at the metal ligand positions and spacing between them they were divided into eight canonical or modified types (RING-CH, -H2, -v, -C2, -C3HCHC2, -C2HC5, -C3GC3S, and -C2SHC4), in which the latter four were newly identified and might represent the intermediate states between RING domain and other similar domains, respectively. RING finger proteins were classified into eight classes based on the presence of additional domains, including RING-Only, -Plus, -C3H1, -PHD, -WD40, -PEX, -TM, and -DEXDc classes. These RING family genes usually lack introns and are distributed over 17 chromosomes. In addition, 29 RING-finger proteins in O. tauri share different degrees of homology with those in the model flowering plant Arabidopsis, indicating they might be necessary for the basic survival of free-living eukaryotes. Therefore, our results provide new insight into the general classification and evolutionary conservation of RING domain-containing proteins in O. tauri.
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Affiliation(s)
- Yan Gao
- Key Laboratory of Education Department of Hunan Province on Plant Genetics and Molecular Biology, Hunan Agricultural University, Changsha 410128, China
| | - Ming-Yi Li
- Key Laboratory of Education Department of Hunan Province on Plant Genetics and Molecular Biology, Hunan Agricultural University, Changsha 410128, China
| | - Jing Zhao
- Key Laboratory of Education Department of Hunan Province on Plant Genetics and Molecular Biology, Hunan Agricultural University, Changsha 410128, China
| | - Yan-Cui Zhang
- Key Laboratory of Education Department of Hunan Province on Plant Genetics and Molecular Biology, Hunan Agricultural University, Changsha 410128, China
| | - Qiu-Jiao Xie
- Key Laboratory of Education Department of Hunan Province on Plant Genetics and Molecular Biology, Hunan Agricultural University, Changsha 410128, China
| | - Dong-Hong Chen
- Key Laboratory of Education Department of Hunan Province on Plant Genetics and Molecular Biology, Hunan Agricultural University, Changsha 410128, China; College of Bioscience and Biotechnology, International Associated Laboratory of CNRS-Fudan-HUNAU on Plant Epigenome Research, Hunan Agricultural University, Changsha 410128, China.
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29
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Platta HW, Brinkmeier R, Reidick C, Galiani S, Clausen MP, Eggeling C. Regulation of peroxisomal matrix protein import by ubiquitination. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:838-49. [PMID: 26367801 DOI: 10.1016/j.bbamcr.2015.09.010] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Revised: 09/09/2015] [Accepted: 09/10/2015] [Indexed: 02/02/2023]
Abstract
Peroxisomes are organelles that play an important role in many cellular tasks. The functionality of peroxisomes depends on the proper import of their matrix proteins. Peroxisomal matrix proteins are imported posttranslationally in a folded, sometimes even oligomeric state. They harbor a peroxisomal targeting sequence (PTS), which is recognized by dynamic PTS-receptors in the cytosol. The PTS-receptors ferry the cargo to the peroxisomal membrane, where they become part of a transient import pore and then release the cargo into the peroxisomal lumen. Subsequentially, the PTS-receptors are ubiquitinated in order to mark them for the export-machinery, which releases them back to the cytosol. Upon deubiquitination, the PTS-receptors can facilitate further rounds of cargo import. Because the ubiquitination of the receptors is an essential step in the import cycle, it also represents a central regulatory element that governs peroxisomal dynamics. In this review we want to give an introduction to the functional role played by ubiquitination during peroxisomal protein import and highlight the mechanistic concepts that have emerged based on data derived from different species since the discovery of the first ubiquitinated peroxin 15years ago. Moreover, we discuss future tasks and the potential of using advanced technologies for investigating further details of peroxisomal protein transport.
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Affiliation(s)
- Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44780 Bochum, Germany.
| | - Rebecca Brinkmeier
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Christina Reidick
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, 44780 Bochum, Germany
| | - Silvia Galiani
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Mathias P Clausen
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom
| | - Christian Eggeling
- MRC Human Immunology Unit, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford OX3 9DS, United Kingdom.
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Burkhart SE, Kao YT, Bartel B. Peroxisomal ubiquitin-protein ligases peroxin2 and peroxin10 have distinct but synergistic roles in matrix protein import and peroxin5 retrotranslocation in Arabidopsis. PLANT PHYSIOLOGY 2014; 166:1329-44. [PMID: 25214533 PMCID: PMC4226347 DOI: 10.1104/pp.114.247148] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2014] [Accepted: 09/11/2014] [Indexed: 05/20/2023]
Abstract
Peroxisomal matrix proteins carry peroxisomal targeting signals (PTSs), PTS1 or PTS2, and are imported into the organelle with the assistance of peroxin (PEX) proteins. From a microscopy-based screen to identify Arabidopsis (Arabidopsis thaliana) mutants defective in matrix protein degradation, we isolated unique mutations in PEX2 and PEX10, which encode ubiquitin-protein ligases anchored in the peroxisomal membrane. In yeast (Saccharomyces cerevisiae), PEX2, PEX10, and a third ligase, PEX12, ubiquitinate a peroxisome matrix protein receptor, PEX5, allowing the PEX1 and PEX6 ATP-hydrolyzing enzymes to retrotranslocate PEX5 out of the membrane after cargo delivery. We found that the pex2-1 and pex10-2 Arabidopsis mutants exhibited defects in peroxisomal physiology and matrix protein import. Moreover, the pex2-1 pex10-2 double mutant exhibited severely impaired growth and synergistic physiological defects, suggesting that PEX2 and PEX10 function cooperatively in the wild type. The pex2-1 lesion restored the unusually low PEX5 levels in the pex6-1 mutant, implicating PEX2 in PEX5 degradation when retrotranslocation is impaired. PEX5 overexpression altered pex10-2 but not pex2-1 defects, suggesting that PEX10 facilitates PEX5 retrotranslocation from the peroxisomal membrane. Although the pex2-1 pex10-2 double mutant displayed severe import defects of both PTS1 and PTS2 proteins into peroxisomes, both pex2-1 and pex10-2 single mutants exhibited clear import defects of PTS1 proteins but apparently normal PTS2 import. A similar PTS1-specific pattern was observed in the pex4-1 ubiquitin-conjugating enzyme mutant. Our results indicate that Arabidopsis PEX2 and PEX10 cooperate to support import of matrix proteins into plant peroxisomes and suggest that some PTS2 import can still occur when PEX5 retrotranslocation is slowed.
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Affiliation(s)
- Sarah E Burkhart
- Department of BioSciences, Rice University, Houston, Texas 77005
| | - Yun-Ting Kao
- Department of BioSciences, Rice University, Houston, Texas 77005
| | - Bonnie Bartel
- Department of BioSciences, Rice University, Houston, Texas 77005
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31
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Metabolic engineering of microorganisms to produce omega-3 very long-chain polyunsaturated fatty acids. Prog Lipid Res 2014; 56:19-35. [PMID: 25107699 DOI: 10.1016/j.plipres.2014.07.001] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2014] [Accepted: 07/14/2014] [Indexed: 12/28/2022]
Abstract
Omega-3 long-chain polyunsaturated fatty acids (LC-PUFAs) have received growing attention due to their significant roles in human health. Currently the main source of these nutritionally and medically important fatty acids is marine fish, which has not met ever-increasing global demand. Microorganisms are an important alternative source also being explored. Although many microorganisms accumulate omega-3 LC-PUFAs naturally, metabolic engineering might still be necessary for significantly improving their yields. Here, we review recent research involving the engineering of microorganisms for production of omega-3 LC-PUFAs, including eicospentaenoic acid and docosohexaenoic acid. Both reconstitution of omega-3 LC-PUFA biosynthetic pathways and modification of existing pathways in microorganisms have demonstrated the potential to produce high levels of omega-3 LC-PUFAs. However, the yields of omega-3 LC-PUFAs in host systems have been substantially limited by potential metabolic bottlenecks, which might be caused partly by inefficient flux of fatty acid intermediates between the acyl-CoA and different lipid class pools. Although fatty acid flux in both native and heterologous microbial hosts might be controlled by several acyltransferases, evidence has suggested that genetic manipulation of one acyltransferase alone could significantly increase the accumulation of LC-PUFAs. The number of oleaginous microorganisms that can be genetically transformed is increasing, which will advance engineering efforts to maximize LC-PUFA yields in microbial strains.
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Li XR, Li HJ, Yuan L, Liu M, Shi DQ, Liu J, Yang WC. Arabidopsis DAYU/ABERRANT PEROXISOME MORPHOLOGY9 is a key regulator of peroxisome biogenesis and plays critical roles during pollen maturation and germination in planta. THE PLANT CELL 2014; 26:619-35. [PMID: 24510720 PMCID: PMC3967029 DOI: 10.1105/tpc.113.121087] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/23/2013] [Revised: 01/13/2014] [Accepted: 01/20/2014] [Indexed: 05/20/2023]
Abstract
Pollen undergo a maturation process to sustain pollen viability and prepare them for germination. Molecular mechanisms controlling these processes remain largely unknown. Here, we report an Arabidopsis thaliana mutant, dayu (dau), which impairs pollen maturation and in vivo germination. Molecular analysis indicated that DAU encodes the peroxisomal membrane protein ABERRANT PEROXISOME MORPHOLOGY9 (APEM9). DAU is transiently expressed from bicellular pollen to mature pollen during male gametogenesis. DAU interacts with peroxisomal membrane proteins PEROXIN13 (PEX13) and PEX16 in planta. Consistently, both peroxisome biogenesis and peroxisome protein import are impaired in dau pollen. In addition, the jasmonic acid (JA) level is significantly decreased in dau pollen, and the dau mutant phenotype is partially rescued by exogenous application of JA, indicating that the male sterility is mainly due to JA deficiency. In addition, the phenotypic survey of peroxin mutants indicates that the PEXs most likely play different roles in pollen germination. Taken together, these data indicate that DAU/APEM9 plays critical roles in peroxisome biogenesis and function, which is essential for JA production and pollen maturation and germination.
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Affiliation(s)
- Xin-Ran Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Hong-Ju Li
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Li Yuan
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Man Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Dong-Qiao Shi
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jie Liu
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
| | - Wei-Cai Yang
- State Key Laboratory of Molecular Developmental Biology, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing 100101, China
- Address correspondence to
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Yoshimoto K, Shibata M, Kondo M, Oikawa K, Sato M, Toyooka K, Shirasu K, Nishimura M, Ohsumi Y. Organ-specific quality control of plant peroxisomes is mediated by autophagy. J Cell Sci 2014; 127:1161-8. [PMID: 24463818 DOI: 10.1242/jcs.139709] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023] Open
Abstract
Peroxisomes are essential organelles that are characterized by the possession of enzymes that produce hydrogen peroxide (H2O2) as part of their normal catalytic cycle. During the metabolic process, peroxisomal proteins are inevitably damaged by H2O2 and the integrity of the peroxisomes is impaired. Here, we show that autophagy, an intracellular process for vacuolar degradation, selectively degrades dysfunctional peroxisomes. Marked accumulation of peroxisomes was observed in the leaves but not roots of autophagy-related (ATG)-knockout Arabidopsis thaliana mutants. The peroxisomes in leaf cells contained markedly increased levels of catalase in an insoluble and inactive aggregate form. The chemically inducible complementation system in ATG5-knockout Arabidopsis provided the evidence that these accumulated peroxisomes were delivered to vacuoles for degradation by autophagy. Interestingly, autophagosomal membrane structures specifically recognized the abnormal peroxisomes at the site of the aggregates. Thus, autophagy is essential for the quality control of peroxisomes in leaves and for proper plant development under natural growth conditions.
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Affiliation(s)
- Kohki Yoshimoto
- RIKEN Plant Science Center, Tsurumi-ku, Yokohama 230-0045, Japan
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34
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Platta HW, Hagen S, Reidick C, Erdmann R. The peroxisomal receptor dislocation pathway: to the exportomer and beyond. Biochimie 2013; 98:16-28. [PMID: 24345375 DOI: 10.1016/j.biochi.2013.12.009] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2013] [Accepted: 12/05/2013] [Indexed: 12/29/2022]
Abstract
The biogenesis of peroxisomes is an ubiquitin-dependent process. In particular, the import of matrix proteins into the peroxisomal lumen requires the modification of import receptors with ubiquitin. The matrix proteins are synthesized on free polyribosomes in the cytosol and are recognized by import receptors via a peroxisomal targeting sequence (PTS). Subsequent to the transport of the receptor/cargo-complex to the peroxisomal membrane and the release of the cargo into the peroxisomal lumen, the PTS-receptors are exported back to the cytosol for further rounds of matrix protein import. The exportomer represents the molecular machinery required for the retrotranslocation of the PTS-receptors. It comprises enzymes for the ubiquitination as well as for the ATP-dependent extraction of the PTS-receptors from the peroxisomal membrane. Furthermore, recent evidence indicates a mechanistic interconnection of the ATP-dependent removal of the PTS-receptors with the translocation of the matrix protein into the organellar lumen. Interestingly, the components of the peroxisomal exportomer seem also to be involved in cellular tasks that are distinct from the ubiquitination and dislocation of the peroxisomal PTS-receptors. This includes work that indicates a central function of this machinery in the export of peroxisomal matrix proteins in plants, while a subset of exportomer components is involved in the meiocyte formation in some fungi, the peroxisome-chloroplast contact during photorespiration in plants and possibly even the selective degradation of peroxisomes via pexophagy. In this review, we want to discuss the central role of the exportomer during matrix protein import, but also highlight distinct roles of exportomer constituents in additional cellular processes. This article is part of a Special Issue entitled: Peroxisomes: biogenesis, functions and diseases.
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Affiliation(s)
- Harald W Platta
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
| | - Stefanie Hagen
- Systembiochemie, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Christina Reidick
- Biochemie Intrazellulärer Transportprozesse, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany
| | - Ralf Erdmann
- Systembiochemie, Ruhr-Universität Bochum, Universitätsstr. 150, D-44780 Bochum, Germany.
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35
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Dolze E, Chigri F, Höwing T, Hierl G, Isono E, Vothknecht UC, Gietl C. Calmodulin-like protein AtCML3 mediates dimerization of peroxisomal processing protease AtDEG15 and contributes to normal peroxisome metabolism. PLANT MOLECULAR BIOLOGY 2013; 83:607-24. [PMID: 23943091 PMCID: PMC3830196 DOI: 10.1007/s11103-013-0112-6] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 07/17/2013] [Indexed: 05/22/2023]
Abstract
Matrix enzymes are imported into peroxisomes and glyoxysomes, a subclass of peroxisomes involved in lipid mobilization. Two peroxisomal targeting signals (PTS), the C-terminal PTS1 and the N-terminal PTS2, mediate the translocation of proteins into the organelle. PTS2 processing upon import is conserved in higher eukaryotes, and in watermelon the glyoxysomal processing protease (GPP) was shown to catalyse PTS2 processing. GPP and its ortholog, the peroxisomal DEG protease from Arabidopsis thaliana (AtDEG15), belong to the Deg/HtrA family of ATP-independent serine proteases with Escherichia coli DegP as their prototype. GPP existes in monomeric and dimeric forms. Their equilibrium is shifted towards the monomer upon Ca(2+)-removal and towards the dimer upon Ca(2+)-addition, which is accompanied by a change in substrate specificity from a general protease (monomer) to the specific cleavage of the PTS2 (dimer). We describe the Ca(2+)/calmodulin (CaM) mediated dimerization of AtDEG15. Dimerization is mediated by the CaM-like protein AtCML3 as shown by yeast two and three hybrid analyses. The binding of AtCML3 occurs within the first 25 N-terminal amino acids of AtDEG15, a domain containing a predicted CaM-binding motif. Biochemical analysis of AtDEG15 deletion constructs in planta support the requirement of the CaM-binding domain for PTS2 processing. Phylogenetic analyses indicate that the CaM-binding site is conserved in peroxisomal processing proteases of higher plants (dicots, monocots) but not present in orthologs of animals or cellular slime molds. Despite normal PTS2 processing activity, an atcml3 mutant exhibited reduced 2,4-DB sensitivity, a phenotype previously reported for the atdeg15 mutant, indicating similarly impaired peroxisome metabolism.
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Affiliation(s)
- Esther Dolze
- Institute of Botany, Center of Life and Food Sciences Weihenstephan, TU Munich, Emil-Ramann-Str. 4, 85350 Freising, Germany
| | - Fatima Chigri
- Department of Biology, Center of Integrated Protein Science, LMU Munich, 82152 Martinsried, Germany
| | - Timo Höwing
- Institute of Botany, Center of Life and Food Sciences Weihenstephan, TU Munich, Emil-Ramann-Str. 4, 85350 Freising, Germany
| | - Georg Hierl
- Institute of Botany, Center of Life and Food Sciences Weihenstephan, TU Munich, Emil-Ramann-Str. 4, 85350 Freising, Germany
| | - Erika Isono
- Department of Plant Systems Biology, Center of Life and Food Sciences Weihenstephan, TU Munich, 85350 Freising, Germany
| | - Ute C. Vothknecht
- Department of Biology, Center of Integrated Protein Science, LMU Munich, 82152 Martinsried, Germany
| | - Christine Gietl
- Institute of Botany, Center of Life and Food Sciences Weihenstephan, TU Munich, Emil-Ramann-Str. 4, 85350 Freising, Germany
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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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37
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Production of omega-3 eicosapentaenoic acid by metabolic engineering of Yarrowia lipolytica. Nat Biotechnol 2013; 31:734-40. [DOI: 10.1038/nbt.2622] [Citation(s) in RCA: 395] [Impact Index Per Article: 35.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2012] [Accepted: 05/29/2013] [Indexed: 01/09/2023]
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38
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Braverman NE, D'Agostino MD, MacLean GE. Peroxisome biogenesis disorders: Biological, clinical and pathophysiological perspectives. ACTA ACUST UNITED AC 2013; 17:187-96. [DOI: 10.1002/ddrr.1113] [Citation(s) in RCA: 101] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2012] [Accepted: 05/17/2012] [Indexed: 01/08/2023]
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39
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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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40
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Jung YJ, Lee IH, Nou IS, Lee KD, Rashotte AM, Kang KK. BrRZFP1 a Brassica rapa C3HC4-type RING zinc finger protein involved in cold, salt and dehydration stress. PLANT BIOLOGY (STUTTGART, GERMANY) 2013; 15:274-83. [PMID: 22726580 DOI: 10.1111/j.1438-8677.2012.00631.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
C3HC4-type RING zinc finger proteins are known to be essential in the regulation of plant processes, including responses to abiotic stress. Here, we identify, clone and examine the first C3HC4-type RING zinc finger protein (BrRZFP1) from Brassica rapa under stress conditions. Phylogenetic analysis of BrRZFP1 revealed strong sequence similarity to C3HC4-type zinc finger proteins from Arabidopsis that are induced by abiotic stresses. Diverse environmental stresses, including salt and cold, were found to induce BrRZFP1 transcripts greater than eightfold in B. rapa. Additional strong induction was shown of the stress hormone abscisic acid, together suggesting that BrRZFP1 could play a role as a general stress modulator. Similar profiles of induction for each of these stresses was found in both root and shoot tissues, although at much higher levels in roots. Constitutive expression of BrRZFP1 in Nicotiana tabacum was conducted to further analyse how changes in gene expression levels would affect plant stress responses. BrRZFP1 overexpression conferred increased tolerance to cold, salt and dehydration stresses. This was observed in several assays examining growth status throughout development, including increased germination, fresh weight and length of shoots and roots, as well as enhanced chlorophyll retention. These results suggest that the transcription factor BrRZFP1 is an important determinant of stress response in plants and that changes in its expression level in plants could increase stress tolerance.
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Affiliation(s)
- Y J Jung
- Department of Horticulture, Hankyong National University, Ansung City, Gyeonggi-do, South Korea
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Kaur N, Zhao Q, Xie Q, Hu J. Arabidopsis RING peroxins are E3 ubiquitin ligases that interact with two homologous ubiquitin receptor proteins(F). JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2013; 55:108-20. [PMID: 23336935 DOI: 10.1111/jipb.12014] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
Peroxisomes are essential eukaryotic organelles that mediate various metabolic processes. Peroxisome import depends on a group of peroxisome biogenesis factors called peroxins, many of which are evolutionarily conserved. PEX2, PEX10, and PEX12 are three RING-finger-domain-containing integral membrane peroxins crucial for protein import. In yeast (Saccharomyces cerevisae), RING peroxins act as E3 ligases, facilitating the recycling of the peroxisome import receptor protein PEX5 through ubiquitination. In plants, RING peroxins are essential to plant vitality. To elucidate the mode of action of the plant RING peroxins, we employed in vitro assays to show that the Arabidopsis RING peroxins also have E3 ligase activities. We also identified a PEX2-interacting protein, DSK2b, which is a member of the ubiquitin receptor family known to function as shuttle factors ferrying polyubiquitinated substrates to the proteasome for degradation. DSK2b and its tandem duplicate DSK2a are localized in the cytosol and the nucleus, and both interact with the RING domain of PEX2 and PEX12. DSK2 artificial microRNA lines did not display obvious defects in plant growth or peroxisomal processes, indicating functional redundancies among Arabidopsis ubiquitin receptor proteins. Our results suggest that Arabidopsis RING peroxins can function as E3 ligases and act together with the ubiquitin receptor protein DSK2 in the peroxisomal membrane-associated protein degradation system.
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Affiliation(s)
- Navneet Kaur
- MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA
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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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Hu J, Baker A, Bartel B, Linka N, Mullen RT, Reumann S, Zolman BK. Plant peroxisomes: biogenesis and function. THE PLANT CELL 2012; 24:2279-303. [PMID: 22669882 PMCID: PMC3406917 DOI: 10.1105/tpc.112.096586] [Citation(s) in RCA: 296] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Abstract
Peroxisomes are eukaryotic organelles that are highly dynamic both in morphology and metabolism. Plant peroxisomes are involved in numerous processes, including primary and secondary metabolism, development, and responses to abiotic and biotic stresses. Considerable progress has been made in the identification of factors involved in peroxisomal biogenesis, revealing mechanisms that are both shared with and diverged from non-plant systems. Furthermore, recent advances have begun to reveal an unexpectedly large plant peroxisomal proteome and have increased our understanding of metabolic pathways in peroxisomes. Coordination of the biosynthesis, import, biochemical activity, and degradation of peroxisomal proteins allows for highly dynamic responses of peroxisomal metabolism to meet the needs of a plant. Knowledge gained from plant peroxisomal research will be instrumental to fully understanding the organelle's dynamic behavior and defining peroxisomal metabolic networks, thus allowing the development of molecular strategies for rational engineering of plant metabolism, biomass production, stress tolerance, and pathogen defense.
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Affiliation(s)
- Jianping Hu
- Michigan State University-Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824, USA.
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Sun H, Zhang A, Wang X. Potential role of metabolomic approaches for Chinese medicine syndromes and herbal medicine. Phytother Res 2012; 26:1466-71. [PMID: 22422429 DOI: 10.1002/ptr.4613] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 12/13/2011] [Accepted: 12/19/2011] [Indexed: 12/21/2022]
Abstract
Systems biology has significantly increased in recent years. Its method and design resemble those of traditional Chinese medicine (TCM), which is a unique medical system that assisted the ancient Chinese in dealing with disease. The technology platforms of systems biology, especially metabolomics, could provide more rapid, direct, concise and effective methods for disease research. In particular, metabolomics could provide useful tools for exploring the essence of Chinese medicine syndromes (CMS) disease, facilitating personalized TCM. Moreover, metabolomics has the potential to enable mapping of early biochemical changes in disease and hence provide an opportunity to develop predictive biomarkers that can trigger earlier interventions. A future hope for the metabonomic approach is the identification of biomarkers that are able to highlight individuals likely to suffer from disease and enable early diagnosis of the disease or the identification of those at risk, and it will help to understand CMS and modernize TCM. In this review, we focus on the key role of robust metabolomic approaches as an aid for traditional herbal medicine; particular attention will be paid to the past successes in applications of metabonomics to contribute to low-molecular-weight metabolites (biomarkers) discovery in TCM research.
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Affiliation(s)
- Hui Sun
- National TCM Key Laboratory of Serum Pharmacochemistry, Heilongjiang University of Chinese Medicine, Harbin, China
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Peraza-Reyes L, Arnaise S, Zickler D, Coppin E, Debuchy R, Berteaux-Lecellier V. The importomer peroxins are differentially required for peroxisome assembly and meiotic development in Podospora anserina: insights into a new peroxisome import pathway. Mol Microbiol 2011; 82:365-77. [PMID: 21895788 DOI: 10.1111/j.1365-2958.2011.07816.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Peroxisome biogenesis relies on two known peroxisome matrix protein import pathways that are mediated by the receptors PEX5 and PEX7. These pathways converge at the importomer, a peroxisome-membrane complex that is required for protein translocation into peroxisomes and consists of docking and RING-finger subcomplexes. In the fungus Podospora anserina, the RING-finger peroxins are crucial for meiocyte formation, while PEX5, PEX7 or the docking peroxin PEX14 are not. Here we show that PEX14 and the PEX14-related protein PEX14/17 are differentially involved in peroxisome import during development. PEX14/17 activity does not compensate for loss of PEX14 function, and elimination of both proteins has no effect on meiocyte differentiation. In contrast, the docking peroxin PEX13, and the peroxins implicated in peroxisome membrane biogenesis PEX3 and PEX19, are required for meiocyte formation. Remarkably, the PTS2 coreceptor PEX20 is also essential for meiocyte differentiation and this function does not require PEX5 or PEX7. This finding suggests that PEX20 can mediate the import receptor activity of specific peroxisome matrix proteins. Our results suggest a new pathway for peroxisome import, which relies on PEX20 as import receptor and which seems critically required for specific developmental processes, like meiocyte differentiation in P. anserina.
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Affiliation(s)
- Leonardo Peraza-Reyes
- Institut de Génétique et Microbiologie, Univ. Paris-Sud, UMR8621, F-91405 Orsay, France.
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Kaur N, Hu J. Defining the plant peroxisomal proteome: from Arabidopsis to rice. FRONTIERS IN PLANT SCIENCE 2011; 2:103. [PMID: 22645559 PMCID: PMC3355810 DOI: 10.3389/fpls.2011.00103] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2011] [Accepted: 12/08/2011] [Indexed: 05/08/2023]
Abstract
Peroxisomes are small subcellular organelles mediating a multitude of processes in plants. Proteomics studies over the last several years have yielded much needed information on the composition of plant peroxisomes. In this review, the status of peroxisome proteomics studies in Arabidopsis and other plant species and the cumulative advances made through these studies are summarized. A reference Arabidopsis peroxisome proteome is generated, and some unique aspects of Arabidopsis peroxisomes that were uncovered through proteomics studies and hint at unanticipated peroxisomal functions are also highlighted. Knowledge gained from Arabidopsis was utilized to compile a tentative list of peroxisome proteins for the model monocot plant, rice. Differences in the peroxisomal proteome between these two model plants were drawn, and novel facets in rice were expounded upon. Finally, we discuss about the current limitations of experimental proteomics in decoding the complete and dynamic makeup of peroxisomes, and complementary and integrated approaches that would be beneficial to defining the peroxisomal metabolic and regulatory roadmaps. The synteny of genomes in the grass family makes rice an ideal model to study peroxisomes in cereal crops, in which these organelles have received much less attention, with the ultimate goal to improve crop yield.
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Affiliation(s)
- Navneet Kaur
- MSU-DOE Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
| | - Jianping Hu
- MSU-DOE Plant Research Laboratory, Michigan State UniversityEast Lansing, MI, USA
- Plant Biology Department, Michigan State UniversityEast Lansing, MI, USA
- *Correspondence: Jianping Hu, MSU-DOE Plant Research Laboratory, Michigan State University, East Lansing, MI 48824, USA. e-mail:
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