Mikio Nishimura

Northeast Forestry University, Charbin, Heilongjiang Sheng, China

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Publications (281)1274.81 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Functional transition of glyoxysomes to leaf peroxisomes is observed in greening cotyledons. Glyoxysomal proteins are rapidly degraded and leaf-peroxisomal proteins are transported into peroxisomes after cotyledons are exposed to light, but the molecular mechanisms underlying these processes remain unclear. We recently discovered that two degradation pathways are involved in the functional transition of peroxisomes using Arabidopsis thaliana. Lon protease 2 (LON2) is responsible for the degradation of glyoxysomal proteins inside peroxisomes, and, in parallel, autophagy eliminates damaged or obsolete peroxisomes. A double mutant defective in both the LON2- and autophagy-dependent degradation pathways accumulated glyoxysomal proteins after the cotyledons became green. Our study also demonstrated that the LON2- and autophagy-dependent pathways are interdependent, with the chaperone function of LON2 suppressing autophagic peroxisome degradation. Moreover, the peptidase domain of LON2 interferes with the suppression of autophagy, indicating that autophagy is regulated by intramolecular modulation between the proteolysis and chaperone functions of LON2.
    Plant signaling & behavior 04/2014; 9.
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    ABSTRACT: In photosynthetic cells, a large amount of hydrogen peroxide is produced in peroxisomes through photorespiration, which is a metabolic pathway related to photosynthesis. Hydrogen peroxide, a reactive oxygen species, oxidizes peroxisomal proteins and membrane lipids, resulting in a decrease in peroxisomal quality. We demonstrate that the autophagic system is responsible for the elimination of oxidized peroxisomes in plant. We isolated Arabidopsis mutants that accumulated oxidized peroxisomes, which formed large aggregates. We revealed that these mutants were defective in autophagy-related (ATG) genes and that the aggregated peroxisomes were selectively targeted by the autophagic machinery. These findings suggest that autophagy plays an important role in the quality control of peroxisomes by the selective degradation of oxidized peroxisomes. In addition, the results suggest that autophagy is also responsible for the functional transition of glyoxysomes to leaf peroxisomes.
    Autophagy 03/2014; 10(5). · 12.04 Impact Factor
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    ABSTRACT: The endoplasmic reticulum (ER) forms highly organised network structures composed of tubules and cisternae. Many plant species develop additional ER-derived structures, most of which are specific for certain groups of species. In particular, a rod-shaped structure designated as the ER body is produced by plants of the Brassicales order, which includes Arabidopsis thaliana. Genetic analyses and characterisation of A. thaliana mutants possessing a disorganised ER morphology or lacking ER bodies have provided insights into the highly organised mechanisms responsible for the formation of these unique ER structures. The accumulation of proteins specific for the ER body within the ER plays an important role in the formation of ER bodies. However, a mutant that exhibits morphological defects of both the ER and ER bodies has not been identified. This suggests that plants in the Brassicales order have evolved novel mechanisms for the development of this unique organelle, which are distinct from those used to maintain generic ER structures. In A. thaliana, ER bodies are ubiquitous in seedlings and roots, but rare in rosette leaves. Wounding of rosette leaves induces de novo formation of ER bodies, suggesting that these structures are associated with resistance against pathogens and/or herbivores. ER bodies accumulate a large amount of ß-glucosidases, which can produce substances that potentially protect against invading pests. Biochemical studies have determined that the enzymatic activities of these ß-glucosidases are enhanced during cell collapse. These results suggest that ER bodies are involved in plant immunity, although there is no direct evidence of this. In this review, we provide recent perspectives of ER and ER body formation in A. thaliana, and discuss clues for the functions of ER bodies. We highlight defence strategies against biotic stress that are unique for the Brassicales order, and discuss how ER structures could contribute to these strategies.
    Frontiers in Plant Science 02/2014; 5. · 3.60 Impact Factor
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    ABSTRACT: Balancing repair and degradation is essential for maintaining organellar and cellular homeostasis. Peroxisomes are ubiquitous organelles in eukaryotic cells that play pivotal roles in cell survival. However, the quality control mechanism used to maintain peroxisomes is unclear. Here, we demonstrate that Lon Protease 2 (LON2), which is encoded by ABERRANT PEROXISOME MORPHOLOGY 10 (APEM10), is responsible for the functional transition of peroxisomes with autophagy. The Arabidopsis apem10 mutant displayed accelerated peroxisome degradation and a dramatically reduced number of peroxisomes. LON2 deficiency caused enhanced peroxisome degradation by autophagy, and peroxisomal proteins accumulated in the cytosol due to a decrease in the number of peroxisomes. We also show the proteolytic consequence of LON2 for the degradation of peroxisomal proteins, and we demonstrated that unnecessary proteins are eliminated by LON2- and autophagy-dependent degradation pathways during the functional transition of peroxisomes. LON2 plays dual roles as an ATP-dependent protease and a chaperone. We show that the chaperone domain of LON2 is essential for the suppression of autophagy, whereas its peptidase domain interferes with this chaperone function, indicating that intramolecular modulation between the proteolysis and chaperone functions of LON2 regulates degradation of peroxisomes by autophagy.
    Plant and Cell Physiology 02/2014; · 4.98 Impact Factor
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    ABSTRACT: Peroxisomes are essential organelles 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) gene-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 by autophagy for degradation. 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 for proper plant development under natural growth conditions.
    Journal of Cell Science 01/2014; · 5.88 Impact Factor
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    ABSTRACT: The endoplasmic reticulum (ER) forms highly organized network structures composed of tubules and cisternae. Many plant species develop additional ER-derived structures, most of which are specific for certain groups of species. In particular, a rod-shaped structure designated as the ER body is produced by plants of the Brassicales order, which includes Arabidopsis thaliana. Genetic analyses and characterization of A. thaliana mutants possessing a disorganized ER morphology or lacking ER bodies have provided insights into the highly organized mechanisms responsible for the formation of these unique ER structures. The accumulation of proteins specific for the ER body within the ER plays an important role in the formation of ER bodies. However, a mutant that exhibits morphological defects of both the ER and ER bodies has not been identified. This suggests that plants in the Brassicales order have evolved novel mechanisms for the development of this unique organelle, which are distinct from those used to maintain generic ER structures. In A. thaliana, ER bodies are ubiquitous in seedlings and roots, but rare in rosette leaves. Wounding of rosette leaves induces de novo formation of ER bodies, suggesting that these structures are associated with resistance against pathogens and/or herbivores. ER bodies accumulate a large amount of β-glucosidases, which can produce substances that potentially protect against invading pests. Biochemical studies have determined that the enzymatic activities of these β-glucosidases are enhanced during cell collapse. These results suggest that ER bodies are involved in plant immunity, although there is no direct evidence of this. In this review, we provide recent perspectives of ER and ER body formation in A. thaliana, and discuss clues for the functions of ER bodies. We highlight defense strategies against biotic stress that are unique for the Brassicales order, and discuss how ER structures could contribute to these strategies.
    Frontiers in Plant Science 01/2014; 5:73. · 3.60 Impact Factor
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    ABSTRACT: The positioning of peroxisomes in a cell is a regulated process that is closely associated with their functions. Using this feature of the peroxisomal positioning as a criterion, we identified three Arabidopsis thaliana mutants (peroxisome unusual positioning1 [peup1], peup2, and peup4) that contain aggregated peroxisomes. We found that the PEUP1, PEUP2, and PEUP4 were identical to Autophagy-related2 (ATG2), ATG18a, and ATG7, respectively, which are involved in the autophagic system. The number of peroxisomes was increased and the peroxisomal proteins were highly accumulated in the peup1 mutant, suggesting that peroxisome degradation by autophagy (pexophagy) is deficient in the peup1 mutant. These aggregated peroxisomes contained high levels of inactive catalase and were more oxidative than those of the wild type, indicating that peroxisome aggregates comprise damaged peroxisomes. In addition, peroxisome aggregation was induced in wild-type plants by exogenous application of hydrogen peroxide. The cat2 mutant also contained peroxisome aggregates. These findings demonstrate that hydrogen peroxide as a result of catalase inactivation is the inducer of peroxisome aggregation. Furthermore, an autophagosome marker, ATG8, frequently colocalized with peroxisome aggregates, indicating that peroxisomes damaged by hydrogen peroxide are selectively degraded by autophagy in the wild type. Our data provide evidence that autophagy is crucial for quality control mechanisms for peroxisomes in Arabidopsis.
    The Plant Cell 12/2013; · 9.25 Impact Factor
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    ABSTRACT: Plant oxylipins derive from oxygenation of polyunsaturated fatty acids in thylakoid membranes and oxylipins such as jasmonic acid (JA) and 12-oxo-phytodienoic acid (OPDA) play important roles in adaptation to photo-oxidative stress. OPDA functions both as a JA precursor and as a biologically active signaling molecule that induces expression of a specific set of genes. These genes can be induced by OPDA in the JA-insensitive coronatine insensitive1 (coi1) mutant, suggesting that there is an alternative pathway for OPDA signaling, independent of COI1-dependent JA signaling. However, little is known about OPDA signaling in photo-oxidative stress responses. In this study, we isolated Arabidopsis mutants with constitutively enhanced expression from the OPDA-responsive HsfA2 promoter. We used deletion mapping and complementation analysis to identify one responsible gene as CATALASE2. Our results thus indicate that ROS-producing cellular metabolism links to OPDA signaling.
    Plant Physiology and Biochemistry 12/2013; · 2.78 Impact Factor
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    ABSTRACT: Plant cells face unique challenges to efficiently export cargo from the endoplasmic reticulum (ER) to mobile Golgi stacks. Coat protein complex II (COPII) components, which include two heterodimers of Secretory23/24 (Sec23/24) and Sec13/31, facilitate selective cargo export from the ER; however, little is known about the mechanisms that regulate their recruitment to the ER membrane, especially in plants. Here, we report a protein transport mutant of Arabidopsis thaliana, named maigo5 (mag5), which abnormally accumulates precursor forms of storage proteins in seeds. mag5-1 has a deletion in the putative ortholog of the Saccharomyces cerevisiae and Homo sapiens Sec16, which encodes a critical component of ER exit sites (ERESs). mag mutants developed abnormal structures (MAG bodies) within the ER and exhibited compromised ER export. A functional MAG5/SEC16A-green fluorescent protein fusion localized at Golgi-associated cup-shaped ERESs and cycled on and off these sites at a slower rate than the COPII coat. MAG5/SEC16A interacted with SEC13 and SEC31; however, in the absence of MAG5/SEC16A, recruitment of the COPII coat to ERESs was accelerated. Our results identify a key component of ER export in plants by demonstrating that MAG5/SEC16A is required for protein export at ERESs that are associated with mobile Golgi stacks, where it regulates COPII coat turnover.
    The Plant Cell 11/2013; · 9.25 Impact Factor
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    ABSTRACT: Peroxisomal matrix protein transport relies on 2 cytosolic receptors, PEX5 and PEX7, which import peroxisomal targeting signal type 1 (PTS1) and PTS2-containing proteins, respectively. To better understand the transport mechanism of PEX7, we isolated PEX7 complexes using proteomics. We identified PEX5 as well as PTS1- and PTS2-containing proteins within the complex, thereby confirming the interaction between PEX5 and PEX7 during cargo transport that had been previously characterized by biochemical approaches. In addition, a chaperone T-complex and 2 small Rab GTPases were identified. We recently reported that the RabE1c is involved in the degradation of the PEX7 when abnormal PEX7 is accumulated on the peroxisomal membrane. This study expands our knowledge on the transport machinery via PEX7 by identifying both known and novel PEX7-interacting proteins and thus is helpful for further investigation of the regulation of the peroxisomal protein receptor during its translocation.
    Plant signaling & behavior 10/2013; 9(1).
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    ABSTRACT: In Arabidopsis thaliana, MAIGO 2 (MAG2) is involved in protein transport between the endoplasmic reticulum (ER) and Golgi apparatus via its association with the ER-localized t-SNARE components, SYP81/AtUfe1 and SEC20. To characterize the molecular machinery of MAG2-mediated protein transport, we explored MAG2-interacting proteins using transgenic A. thaliana plants expressing tandem-affinity purification (TAP)-tagged MAG2. We identified three proteins, which were designated as MAG2 INTERACTING PROTEIN 1 (MIP1, At2g32900), MIP2 (At5g24350), and MIP3 (At2g42700). Both MIP1 and MAG2 were localized to the ER membrane. All mutants of mag2, mip1, mip2, and mip3 exhibited a defect in storage protein maturation and developed abnormal storage proteins body structures (MAG bodies) in the ER of seed cells. These observations suggest that MIPs are closely associated with MAG2 and function in protein transport between the ER and Golgi apparatus. MIP1 and MIP2 had a Zeste-White 10 (ZW10) domain and a Sec39 domain, respectively, although they had low sequence identities (21% and 23%) with respective human orthologues. These results suggest that the plant complex of MAG2-MIP1-MIP2 is a counterpart to the triple-subunit tethering complexes in yeast (Tip20p-Dsl1p-Sec39p) and humans (RINT1-ZW10-NAG). Surprisingly, the plant complex also contained a fourth member (MIP3) with a Sec1 domain. There is no report to date showing that a Sec1-containing protein is a subunit of ER-localized tethering complexes. Our results suggest that MAG2 and three MIP proteins form a unique complex on the ER that is responsible for efficient transport of seed storage proteins. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    The Plant Journal 10/2013; · 6.58 Impact Factor
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    ABSTRACT: The Plant Organelles Database 2 (PODB2), which was first launched in 2006 as PODB, provides static image and movie data of plant organelles, protocols for plant organelle research and external links to relevant websites. PODB2 has facilitated plant organellar research and the understanding of plant organelle dynamics. To provide comprehensive information on plant organelles in more detail, PODB2 was updated to the PODB3 (http://podb.nibb.ac.jp/Organellome/). PODB3 contains two additional components: the electron micrograph database and the perceptive organelles database. Through the electron micrograph database, users can examine the subcellular and/or suborganellar structures in various organs of wild-type and mutant plants. The perceptive organelles database provides information on organelle dynamics in response to external stimuli. In addition to the extra components, the user interface for access has been enhanced in PODB3. The data in PODB3 are directly submitted by plant researchers and can be freely downloaded for use in further analysis. PODB3 contains all the information included in PODB2, and the volume of data and protocols deposited in the PODB3 continue to grow steadily. We welcome contributions of data from all plant researchers to enhance the utility and comprehensiveness of PODB3.
    Plant and Cell Physiology 10/2013; · 4.98 Impact Factor
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    ABSTRACT: The cell nucleus communicates with the cytoplasm through a nucleocytoplasmic linker that maintains the shape of the nucleus and mediates its migration. In contrast to animal nuclei, which are moved by motor proteins (kinesins and dyneins) along the microtubule cytoskeleton [1, 2], plant nuclei move rapidly and farther along an actin filament cytoskeleton [3]. This implies that plants use a distinct nucleocytoplasmic linker for nuclear dynamics, although its molecular identity is unknown. Here, we describe a new type of nucleocytoplasmic linker consisting of a myosin motor and nuclear membrane proteins. In the Arabidopsis thaliana mutant kaku1, nuclear movement was impaired and the nuclear envelope was abnormally invaginated. The responsible gene was identified as myosin XI-i, which encodes a plant-specific myosin. Myosin XI-i is specifically localized on the nuclear membrane, where it physically interacts with the outer-nuclear-membrane proteins WIT1 and WIT2. Both WIT proteins are required for anchoring myosin XI-i to the nuclear membrane and for nuclear movement. A striking feature of plant cells is dark-induced nuclear positioning in mesophyll cells. A deficiency of either myosin XI-i or WIT proteins diminished dark-induced nuclear positioning. The unique nucleocytoplasmic linkage in plants might enable rapid nuclear positioning in response to environmental stimuli.
    Current biology: CB 08/2013; · 10.99 Impact Factor
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    ABSTRACT: The maintenance and reformation of gene expression domains are the basis for the morphogenic processes of multicellular systems. In a leaf primordium of Arabidopsis thaliana, the expression of FILAMENTOUS FLOWER (FIL) and the activity of the microRNA miR165/166 are specific to the abaxial side. This miR165/166 activity restricts the target gene expression to the adaxial side. The adaxial and abaxial specific gene expressions are crucial for the wide expansion of leaf lamina. The FIL-expression and the miR165/166-free domains are almost mutually exclusive, and they have been considered to be maintained during leaf development. However, we found here that the position of the boundary between the two domains gradually shifts from the adaxial side to the abaxial side. The cell lineage analysis revealed that this boundary shifting was associated with a sequential gene expression switch from the FIL-expressing (miR165/166 active) to the miR165/166-free (non-FIL-expressing) states. Our genetic analyses using the enlarged fil expression domain2 (enf2) mutant and chemical treatment experiments revealed that impairment in the plastid (chloroplast) gene expression machinery retards this boundary shifting and inhibits the lamina expansion. Furthermore, these developmental effects caused by the abnormal plastids were not observed in the genomes uncoupled1 (gun1) mutant background. This study characterizes the dynamic nature of the adaxial-abaxial specification process in leaf primordia and reveals that the dynamic process is affected by the GUN1-dependent retrograde signal in response to the failure of plastid gene expression. These findings advance our understanding on the molecular mechanism linking the plastid function to the leaf morphogenic processes.
    PLoS Genetics 07/2013; 9(7):e1003655. · 8.52 Impact Factor
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    ABSTRACT: Plants accumulate large amounts of storage products in seeds to provide an energy reserve and to supply nutrients for germination and post-germinative growth. Arabidopsis thaliana belongs to the Brassica family, and oil is the main storage product in Arabidopsis seeds. To elucidate the regulatory mechanisms of oil biosynthesis in seeds, we screened for high density seeds (heavy seed) that have a low oil content. HS3 (heavy seed 3) encodes the DEAD-box RNA helicase 22 that is localized to plastids. The triacylglycerol (TAG) content of hs3-1 seeds was 10% lower than that of WT seeds, while the protein content was unchanged. The hs3-1 plants displayed a pale-green phenotype in developing seeds and seedlings, but not in adult leaves. The HS3 expression level was high in developing seeds and seedlings, but was low in stems, rosette leaves and flowers. The plastid gene expression profile of WT developing seeds and seedlings differed from that of hs3-1 developing seeds and seedlings. The expression of several genes was reduced in developing hs3-1 seeds, including accD, a gene that encodes the β subunit of carboxyltransferase, which is one component of acetyl-CoA carboxylase in plastids. By contrast, no differences were observed between the expression profiles of WT and hs3-1 rosette leaves. These results show that HS3 is essential for proper mRNA accumulation of plastid genes during seed development and seedling growth, and suggest that HS3 ensures seed oil biosynthesis by maintaining plastid mRNA levels.
    Plant and Cell Physiology 06/2013; · 4.98 Impact Factor
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    ABSTRACT: The epidermal cells of the Arabidopsis thaliana seed coat, which correspond to the second layer of the outer integument (oi2), contain large quantities of a pectic polysaccharide called mucilage within the apoplastic space beneath the outer periclinal cell wall. Immediately after seed imbibition, the mucilage is extruded and completely envelops the seed in a gel-like capsule. We found that a class III peroxidase family protein, PEROXIDASE36 (PER36), functions as a mucilage extrusion factor. Expression of PER36 occurred only in oi2 cells for a few days around the torpedo stage. A PER36-green fluorescent protein fusion was secreted into the outer cell wall in a polarized manner. per36 mutants were defective in mucilage extrusion after seed imbibition due to the failure of outer cell wall rupture, although the mutants exhibited normal monosaccharide composition of the mucilage. This abnormal phenotype of per36 was rescued by pectin solubilization, which promoted cell wall loosening. These results suggest that PER36 regulates the degradation of the outer cell wall. Taken together, this work indicates that polarized secretion of PER36 in a developmental stage-dependent manner plays a role in cell wall modification of oi2 cells.
    The Plant Cell 04/2013; · 9.25 Impact Factor
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    ABSTRACT: The biogenesis of peroxisomes is mediated by peroxins (PEXs). PEX7 is a cytosolic receptor that imports peroxisomal targeting signal type 2 (PTS2)-containing proteins. Although PEX7 is important for protein transport, the mechanisms that mediate its function are unknown. In this study, we performed proteomic analysis to identify PEX7-binding proteins using transgenic Arabidopsis expressing green fluorescent protein (GFP)-tagged PEX7. Our analysis identified RabE1c, a small GTPase, as a PEX7 binding partner. In vivo analysis revealed that GTP-bound RabE1c binds to PEX7, and that a subset of RabE1c localizes to peroxisomes and interacts with PEX7 on the peroxisome membrane. Unlike endogenous PEX7, which is predominantly localized to the cytosol, GFP-PEX7 accumulates abnormally on the peroxisomal membrane and induces degradation of endogenous PEX7, concomitant with a reduction in import of PTS2-containing proteins and decreased peroxisomal β-oxidation activity. Thus, GFP-PEX7 on the peroxisomal membrane exerts a dominant-negative effect. Mutation of RabE1c restored endogenous PEX7 protein expression and import of PTS2-containing proteins, as well as peroxisomal β-oxidation activity. Treatment with proteasome inhibitors also restored endogenous PEX7 protein levels in GFP-PEX7-expressing seedlings. Based on these findings, we conclude that RabE1c binds PEX7 and facilitates PEX7 degradation in the presence of immobile GFP-PEX7 accumulated at the membrane.
    Journal of Biological Chemistry 01/2013; · 4.65 Impact Factor
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    ABSTRACT: The endoplasmic reticulum (ER) body, a large compartment specific to the Brassicales, accumulates β-glucosidase and possibly plays a role in the defense against pathogens and herbivores. Although the ER body is a subdomain of ER, it is unclear whether any ER body-specific membrane protein exists. In this study, we identified two integral membrane proteins of ER body in Arabidopsis, and termed them MEMBRANE PROTEIN OF ER BODY 1 (MEB1) and MEB2. In Arabidopsis, a basic-helix-loop-helix transcription factor NAI1 and an ER body component NAI2 regulate the ER body formation. The expression profiles of MEB1 and MEB2 are similar to those of NAI1, NAI2 and ER body β-glucosidase PYK10 in Arabidopsis. The expression of MEB1 and MEB2 was reduced in the nai1 mutant, indicating that NAI1 regulates the expression of MEB1 and MEB2 genes. MEB1 and MEB2 proteins localize to the ER body membrane but not to the ER network, suggesting that these proteins are specifically recruited to the ER body membrane. MEB1 and MEB2 physically interacted with ER body component NAI2, and they were diffused throughout the ER network in the nai2 mutant, which has no ER body. Heterologous expression of MEB1 and MEB2 in yeast suppresses iron and manganese toxicity, suggesting that MEB1 and MEB2 are metal transporters. These results indicate that the membrane of ER bodies has specific membrane proteins, and suggest that the ER body is involved in defense against metal stress as well as pathogens and herbivores.
    Plant physiology 11/2012; · 6.56 Impact Factor
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    ABSTRACT: The galactolipids monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG) are the predominant lipids in thylakoid membranes indispensable for photosynthesis. Among the three isoforms that catalyze MGDG synthesis in Arabidopsis thaliana, MGD1 is responsible for most galactolipid synthesis in chloroplasts, whereas MGD2 and MGD3 are required for DGDG accumulation during phosphate (Pi) starvation. A null mutant of Arabidopsis MGD1 (mgd1-2), which lacks both galactolipids and shows a severe defect in chloroplast biogenesis under nutrient-sufficient conditions, accumulated large amounts of DGDG with a strong induction of MGD2/3 expression during Pi starvation. In plastids of the Pi-starved mgd1-2 leaves, biogenesis of thylakoid-like internal membranes, which was occasionally associated with invagination of the inner envelope, was observed with chlorophyll accumulation. Moreover, the mutant accumulated photosynthetic membrane proteins upon Pi starvation, indicating a compensation of MGD1 deficiency by the Pi stress-induced galactolipid biosynthesis. In the mutant, however, photosynthetic activity was still abolished and light-harvesting/photosystem core complexes were improperly formed, suggesting a requirement for MGDG for the proper assembly of these complexes. During Pi starvation, distribution of plastid nucleoids changed concomitantly with internal membrane biogenesis in mgd1-2. Moreover, reduced expression of nuclear- and plastid-encoded photosynthetic genes observed in Pi-sufficient mgd1-2 was restored after Pi starvation. In contrast, Pi starvation showed no such positive effects in mutants lacking chlorophyll biosynthesis. These observations demonstrate that galactolipid biosynthesis and subsequent membrane biogenesis inside the plastid strongly influence nucleoid distribution and the expression of both plastid- and nuclear-encoded photosynthetic genes independently of photosynthesis. © 2012 The Authors. The Plant Journal © 2012 Blackwell Publishing Ltd.
    The Plant Journal 09/2012; · 6.58 Impact Factor

Publication Stats

8k Citations
1,274.81 Total Impact Points

Institutions

  • 2013
    • Northeast Forestry University
      Charbin, Heilongjiang Sheng, China
  • 2001–2013
    • Kyoto University
      • • Department of Botany
      • • Graduate School of Science / Faculty of Science
      Kyoto, Kyoto-fu, Japan
    • Tokyo Metropolitan University
      • Department of Biological Sciences
      Edo, Tōkyō, Japan
  • 1990–2013
    • National Institute for Basic Biology
      Okazaki, Aichi, Japan
  • 2007–2011
    • Tokyo Institute of Technology
      • • Center for Biological Resources and Informatics
      • • Graduate School of Bioscience and Biotechnology
      Tokyo, Tokyo-to, Japan
  • 1992–2009
    • Japanese Red Cross
      Edo, Tōkyō, Japan
  • 1982–2009
    • Nagoya University
      • • Graduate School of Information Science
      • • Radioisotope Research Center
      Nagoya-shi, Aichi-ken, Japan
  • 2002
    • Okayama University
      • Faculty of Agriculture
      Okayama, Okayama, Japan
  • 1997
    • Red Cross
      Washington, Washington, D.C., United States
    • Hiroshima University
      • Faculty of Applied Biological Science
      Hiroshima-shi, Hiroshima-ken, Japan
    • Shinshu University
      • Division of Applied Biology
      Shonai, Nagano, Japan
  • 1995–1997
    • The Graduate University for Advanced Studies
      • School of Life Science
      Miura, Kanagawa-ken, Japan
  • 1996
    • The University of Tokyo
      Edo, Tōkyō, Japan
  • 1994–1995
    • Jagiellonian University
      • Department of Plant Physiology and Biochemistry
      Kraków, Lesser Poland Voivodeship, Poland
    • Osaka University
      • Department of Biological Sciences
      Ōsaka-shi, Osaka-fu, Japan
  • 1991
    • Kobe University
      • Department of Biology
      Kōbe, Hyōgo, Japan
  • 1986–1987
    • French National Centre for Scientific Research
      Lutetia Parisorum, Île-de-France, France