1
|
Sáiz-Bonilla M, Martín-Merchán A, Pallás V, Navarro JA. A viral protein targets mitochondria and chloroplasts by subverting general import pathways and specific receptors. J Virol 2023; 97:e0112423. [PMID: 37792002 PMCID: PMC10617419 DOI: 10.1128/jvi.01124-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2023] [Accepted: 08/15/2023] [Indexed: 10/05/2023] Open
Abstract
IMPORTANCE Many plant proteins and some proteins from plant pathogens are dually targeted to chloroplasts and mitochondria, and are supposed to be transported along the general pathways for organellar protein import, but this issue has not been explored yet. Moreover, organellar translocon receptors exist as families of several members whose functional specialization in different cargos is supposed but not thoroughly studied. This article provides novel insights into such topics showing for the first time that an exogenous protein, the melon necrotic spot virus coat protein, exploits the common Toc/Tom import systems to enter both mitochondria and chloroplasts while identifying the involved specific receptors.
Collapse
Affiliation(s)
- María Sáiz-Bonilla
- Laboratory of Plant Molecular Virology, Department of Molecular and Evolutionary Plant Virology, Institute for Plant Molecular and Cell Biology, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, Valencia, Spain
| | - Andrea Martín-Merchán
- Laboratory of Plant Molecular Virology, Department of Molecular and Evolutionary Plant Virology, Institute for Plant Molecular and Cell Biology, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, Valencia, Spain
| | - Vicente Pallás
- Laboratory of Plant Molecular Virology, Department of Molecular and Evolutionary Plant Virology, Institute for Plant Molecular and Cell Biology, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, Valencia, Spain
| | - Jose Antonio Navarro
- Laboratory of Plant Molecular Virology, Department of Molecular and Evolutionary Plant Virology, Institute for Plant Molecular and Cell Biology, Consejo Superior de Investigaciones Científicas-Universitat Politècnica de València, Valencia, Spain
| |
Collapse
|
2
|
Sáiz-Bonilla M, Martín Merchán A, Pallás V, Navarro JA. Molecular characterization, targeting and expression analysis of chloroplast and mitochondrion protein import components in Nicotiana benthamiana. FRONTIERS IN PLANT SCIENCE 2022; 13:1040688. [PMID: 36388587 PMCID: PMC9643744 DOI: 10.3389/fpls.2022.1040688] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 10/10/2022] [Indexed: 06/16/2023]
Abstract
Improved bioinformatics tools for annotating gene function are becoming increasingly available, but such information must be considered theoretical until further experimental evidence proves it. In the work reported here, the genes for the main components of the translocons of the outer membrane of chloroplasts (Toc) and mitochondria (Tom), including preprotein receptors and protein-conducting channels of N. benthamiana, were identified. Sequence identity searches and phylogenetic relationships with functionally annotated sequences such as those of A. thaliana revealed that N. benthamiana orthologs mainly exist as recently duplicated loci. Only a Toc34 ortholog was found (NbToc34), while Toc159 receptor family was composed of four orthologs but somewhat different from those of A. thaliana. Except for NbToc90, the rest (NbToc120, NbToc159A and NbToc159B) had a molecular weight of about 150 kDa and an acidic domain similar in length. Only two orthologs of the Tom20 receptors, NbTom20-1 and NbTom20-2, were found. The number of the Toc and Tom receptor isoforms in N. benthamiana was comparable to that previously reported in tomato and what we found in BLAST searches in other species in the genera Nicotiana and Solanum. After cloning, the subcellular localization of N. benthamiana orthologs was studied, resulting to be identical to that of A. thaliana receptors. Phenotype analysis after silencing together with relative expression analysis in roots, stems and leaves revealed that, except for the Toc and Tom channel-forming components (NbToc75 and NbTom40) and NbToc34, functional redundancy could be observed either among Toc159 or mitochondrial receptors. Finally, heterodimer formation between NbToc34 and the NbToc159 family receptors was confirmed by two alternative techniques indicating that different Toc complexes could be assembled. Additional work needs to be addressed to know if this results in a functional specialization of each Toc complex.
Collapse
Affiliation(s)
| | | | - Vicente Pallás
- *Correspondence: Vicente Pallas, ; Jose Antonio Navarro,
| | | |
Collapse
|
3
|
New Insights into the Chloroplast Outer Membrane Proteome and Associated Targeting Pathways. Int J Mol Sci 2022; 23:ijms23031571. [PMID: 35163495 PMCID: PMC8836251 DOI: 10.3390/ijms23031571] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Revised: 01/24/2022] [Accepted: 01/27/2022] [Indexed: 12/04/2022] Open
Abstract
Plastids are a dynamic class of organelle in plant cells that arose from an ancient cyanobacterial endosymbiont. Over the course of evolution, most genes encoding plastid proteins were transferred to the nuclear genome. In parallel, eukaryotic cells evolved a series of targeting pathways and complex proteinaceous machinery at the plastid surface to direct these proteins back to their target organelle. Chloroplasts are the most well-characterized plastids, responsible for photosynthesis and other important metabolic functions. The biogenesis and function of chloroplasts rely heavily on the fidelity of intracellular protein trafficking pathways. Therefore, understanding these pathways and their regulation is essential. Furthermore, the chloroplast outer membrane proteome remains relatively uncharted territory in our understanding of protein targeting. Many key players in the cytosol, receptors at the organelle surface, and insertases that facilitate insertion into the chloroplast outer membrane remain elusive for this group of proteins. In this review, we summarize recent advances in the understanding of well-characterized chloroplast outer membrane protein targeting pathways as well as provide new insights into novel targeting signals and pathways more recently identified using a bioinformatic approach. As a result of our analyses, we expand the known number of chloroplast outer membrane proteins from 117 to 138.
Collapse
|
4
|
Lung SC, Yogadasan N, Yanagisawa M, Chuong SDX. Protoplast Isolation and Transfection in the Single-Cell C 4 Species Bienertia sinuspersici. Methods Mol Biol 2022; 2464:21-28. [PMID: 35258822 DOI: 10.1007/978-1-0716-2164-6_2] [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: 06/14/2023]
Abstract
We have developed an optimized protocol for isolating protoplasts from chlorenchyma cells of the single-cell C4 species Bienertia sinuspersici. The isolated protoplasts maintained the integrity of the unique single-cell C4 intracellular compartmentation of organelles as observed in chlorenchyma cells after cell wall digestion. Approximately over 80% of isolated protoplasts expressed the fusion reporter gene following the polyethylene glycol-mediated transfection procedures. Overall, fluorescent protein fusion tagged with various intraorganellular sorting signals validated the potential use of the transient gene expression system in subcellular localization and organelle dynamics studies.
Collapse
Affiliation(s)
- Shiu-Cheung Lung
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong, SAR, China
| | | | - Makoto Yanagisawa
- Botany and Plant Pathology, Purdue University, West Lafayette, IN, USA
| | - Simon D X Chuong
- Department of Biology, University of Waterloo, Waterloo, ON, Canada.
| |
Collapse
|
5
|
Ma SH, Kim HM, Park SH, Park SY, Mai TD, Do JH, Koo Y, Joung YH. The ten amino acids of the oxygen-evolving enhancer of tobacco is sufficient as the peptide residues for protein transport to the chloroplast thylakoid. PLANT MOLECULAR BIOLOGY 2021; 105:513-523. [PMID: 33393067 PMCID: PMC7892526 DOI: 10.1007/s11103-020-01106-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/16/2020] [Accepted: 12/10/2020] [Indexed: 06/12/2023]
Abstract
KEY MESSAGE The thylakoid transit peptide of tobacco oxygen-evolving enhancer protein contains a minimal ten amino acid sequences for thylakoid lumen transports. This ten amino acids do not contain twin-arginine, which is required for typical chloroplast lumen translocation. Chloroplasts are intracellular organelles responsible for photosynthesis to produce organic carbon for all organisms. Numerous proteins must be transported from the cytosol to chloroplasts to support photosynthesis. This transport is facilitated by chloroplast transit peptides (TPs). Four chloroplast thylakoid lumen TPs were isolated from Nicotiana tabacum and were functionally analyzed as thylakoid lumen TPs. Typical chloroplast stroma-transit peptides and thylakoid lumen transit peptides (tTPs) are found in N. tabacum transit peptides (NtTPs) and the functions of these peptides are confirmed with TP-GFP fusion proteins under fluorescence microscopy and chloroplast fractionation, followed by Western blot analysis. During the functional analysis of tTPs, we uncovered the minimum 10 amino acid sequence is sufficient for thylakoid lumen transport. These ten amino acids can efficiently translocate GFP protein, even if they do not contain the twin-arginine residues required for the twin-arginine translocation (Tat) pathway, which is a typical thylakoid lumen transport. Further, thylakoid lumen transporting processes through the Tat pathway was examined by analyzing tTP sequence functions and we demonstrate that the importance of hydrophobic core for the tTP cleavage and target protein translocation.
Collapse
Affiliation(s)
- Sang Hoon Ma
- School of Biological Science and Technology, Chonnam National University, Gwangju, 61186, South Korea
| | - Hyun Min Kim
- School of Biological Science and Technology, Chonnam National University, Gwangju, 61186, South Korea
| | - Se Hee Park
- School of Biological Science and Technology, Chonnam National University, Gwangju, 61186, South Korea
| | - Seo Young Park
- School of Biological Science and Technology, Chonnam National University, Gwangju, 61186, South Korea
| | - Thanh Dat Mai
- School of Biological Science and Technology, Chonnam National University, Gwangju, 61186, South Korea
| | - Ju Hui Do
- School of Biological Science and Technology, Chonnam National University, Gwangju, 61186, South Korea
| | - Yeonjong Koo
- Department of Agricultural Chemistry, Chonnam National University, Gwangju, 61186, South Korea.
| | - Young Hee Joung
- School of Biological Science and Technology, Chonnam National University, Gwangju, 61186, South Korea.
| |
Collapse
|
6
|
Qiu Z, Chen D, He L, Zhang S, Yang Z, Zhang Y, Wang Z, Ren D, Qian Q, Guo L, Zhu L. The rice white green leaf 2 gene causes defects in chloroplast development and affects the plastid ribosomal protein S9. RICE (NEW YORK, N.Y.) 2018; 11:39. [PMID: 29995230 PMCID: PMC6041223 DOI: 10.1186/s12284-018-0233-2] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Accepted: 07/04/2018] [Indexed: 05/22/2023]
Abstract
BACKGROUND Plastid ribosomal proteins (PRPs) play important roles in the translation of key proteins involved in chloroplast development and photosynthesis. PRPs have been widely studied in many plant species; however, few studies have investigated their roles in rice. RESULT In the present study, we used ethyl methane sulfonate mutagenesis and obtained a novel rice mutant called white green leaf 2 (wgl2). The wgl2 mutants exhibited an albino phenotype from germination through the three-leaf stage, and then gradually transitioned to green through the later developmental stages. Consistent with this albino phenotype, wgl2 mutants had abnormal chloroplasts and lower levels of photosynthetic pigments. Map-based cloning and DNA sequencing analyses of wgl2 revealed a single-nucleotide substitution (G to T) in the first exon of LOC_Os03g55930, which resulted in a substitution of glycine 92 to valine (G92 V). WGL2 encodes a conserved ribosomal protein, which localizes to the chloroplast. Complementation and targeted deletion experiments confirmed that the point mutation in WGL2 is responsible for the wgl2 mutant phenotype. WGL2 is preferentially expressed in the leaf, and mutating WGL2 led to obvious changes in the expression of genes related to chlorophyll biosynthesis, photosynthesis, chloroplast development, and ribosome development compared with wild-type. CONCLUSIONS WGL2 encodes a conserved ribosomal protein, which localizes to the chloroplast. WGL2 is essential for early chloroplast development in rice. These results facilitate research that will further uncover the molecular mechanism of chloroplast development.
Collapse
Affiliation(s)
- Zhennan Qiu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| | - Dongdong Chen
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| | - Lei He
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| | - Sen Zhang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| | - Zenan Yang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| | - Yu Zhang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| | - Zhongwei Wang
- Biotechnology Research Center, Chongqing Academy of Agricultural Sciences, Chongqing, 401329 China
| | - Deyong Ren
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| | - Qian Qian
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| | - Longbiao Guo
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| | - Li Zhu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou, 310006 China
| |
Collapse
|
7
|
Keller RCA. Identification of Possible Lipid Binding Regions in Food Proteins and Peptides and Additional In Silico Analysis. FOOD BIOPHYS 2018. [DOI: 10.1007/s11483-018-9519-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
|
8
|
Qiu Z, Kang S, He L, Zhao J, Zhang S, Hu J, Zeng D, Zhang G, Dong G, Gao Z, Ren D, Chen G, Guo L, Qian Q, Zhu L. The newly identified heat-stress sensitive albino 1 gene affects chloroplast development in rice. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 267:168-179. [PMID: 29362095 DOI: 10.1016/j.plantsci.2017.11.015] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2017] [Revised: 11/28/2017] [Accepted: 11/28/2017] [Indexed: 05/18/2023]
Abstract
High temperature, a major abiotic stress, significantly affects the yield and quality of crops in many parts of the world. Components of the photosynthetic apparatus are highly susceptible to thermal damage. Although the responses to acute heat stress have been studied intensively, the mechanisms that regulate chloroplast development under heat stress remain obscure, especially in crop plants. Here, we cloned and characterized the gene responsible for the heat-sensitive albino1 (hsa1) mutation in rice (Oryza sativa). The hsa1 mutant harbors a recessive mutation in a gene encoding fructokinase-like protein2 (FLN2); the mutation causes a premature stop codon and results in a severe albino phenotype, with defects in early chloroplast development. The color of hsa1 mutant plants gradually changed from albino to green at later stages of development at various temperatures and chloroplast biogenesis was strongly delayed at high temperature (32 °C). HSA1 expression was strongly reduced in hsa1 plants compared to wild type (WT). HSA1 localizes to the chloroplast and regulates chloroplast development. An HSA1 deletion mutant induced by CRISPR/Cas9 was heat sensitive but had a faster greening phenotype than the original hsa1 allele at all temperatures. RNA and protein levels of plastid-encoded RNA polymerase-dependent plastid genes were markedly reduced in hsa1 plants compared to WT. These results demonstrated that HSA1 plays important roles in chloroplast development at early stages, and functions in protecting chloroplasts under heat stress at later stages in rice.
Collapse
Affiliation(s)
- Zhennan Qiu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Shujing Kang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Lei He
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Juan Zhao
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Sen Zhang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Jiang Hu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Dali Zeng
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Guangheng Zhang
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Guojun Dong
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Zhenyu Gao
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Deyong Ren
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Guang Chen
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Longbiao Guo
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China
| | - Qian Qian
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China.
| | - Li Zhu
- State Key Laboratory of Rice Biology, China National Rice Research Institute, Hangzhou 310006, China.
| |
Collapse
|
9
|
Ferreira MJ, Vale D, Cunha L, Melo P. Role of the C-terminal extension peptide of plastid located glutamine synthetase from Medicago truncatula: Crucial for enzyme activity and needless for protein import into the plastids. PLANT PHYSIOLOGY AND BIOCHEMISTRY : PPB 2017; 111:226-233. [PMID: 27951492 DOI: 10.1016/j.plaphy.2016.11.015] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2016] [Revised: 11/22/2016] [Accepted: 11/22/2016] [Indexed: 06/06/2023]
Abstract
Glutamine synthetase (GS), a key enzyme in plant nitrogen metabolism, is encoded by a small family of highly homologous nuclear genes that produce cytosolic (GS1) and plastidic (GS2) isoforms. Compared to GS1, GS2 proteins have two extension peptides, one at the N- and the other at the C-terminus, which show a high degree of conservation among plant species. It has long been known that the N-terminal peptide acts as a transit peptide, targeting the protein to the plastids however, the function of the C-terminal extension is still unknown. To investigate whether the C-terminal extension influences the activity of the enzyme, we produced a C-terminal truncated version of Medicago truncatula GS2a in Escherechia coli and studied its catalytic properties. The activity of the truncated protein was found to be lower than that of MtGS2a and with less affinity for glutamate. The importance of the C-terminal extension for the protein import into the chloroplast was also assessed by transient expression of fluorescently-tagged MtGS2a truncated at the C-terminus, which was correctly detected in the chloroplast. The results obtained in this work demonstrate that the C-terminal extension of M. truncatula GS2a is important for the activity of the enzyme and does not contain crucial information for the import process.
Collapse
Affiliation(s)
- Maria João Ferreira
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Diogo Vale
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Luis Cunha
- Departamento de Biologia, Faculdade de Ciências da Universidade do Porto, Rua do Campo Alegre, s/n, 4169-007 Porto, Portugal
| | - Paula Melo
- BioISI-Biosystems & Integrative Sciences Institute, Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua Campo Alegre s/n, 4169-007 Porto, Portugal.
| |
Collapse
|
10
|
Wimmer D, Bohnhorst P, Shekhar V, Hwang I, Offermann S. Transit peptide elements mediate selective protein targeting to two different types of chloroplasts in the single-cell C4 species Bienertia sinuspersici. Sci Rep 2017; 7:41187. [PMID: 28112241 PMCID: PMC5253730 DOI: 10.1038/srep41187] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2016] [Accepted: 12/16/2016] [Indexed: 01/23/2023] Open
Abstract
Bienertia sinuspersici is a terrestrial plant that performs C4 photosynthesis within individual cells through operating a carbon concentrating mechanism between different subcellular domains including two types of chloroplasts. It is currently unknown how differentiation of two highly specialized chloroplasts within the same cell occurs as no similar cases have been reported. Here we show that this differentiation in photosynthetic cells of B. sinuspersici is enabled by a transit peptide (TP) mediated selective protein targeting mechanism. Mutations in the TPs cause loss of selectivity but not general loss of chloroplast import, indicating the mechanism operates by specifically blocking protein accumulation in one chloroplast type. Hybrid studies indicate that this selectivity is transferable to transit peptides of plants which perform C4 by cooperative function of chloroplasts between two photosynthetic cells. Codon swap experiments as well as introducing an artificial bait mRNA show that RNA affects are not crucial for the sorting process. In summary, our analysis shows how the mechanism of subcellular targeting to form two types of chloroplast within the same cell can be achieved. This information is not only crucial for understanding single-cell C4 photosynthesis; it provides new insights in control of subcellular protein targeting in cell biology.
Collapse
Affiliation(s)
- Diana Wimmer
- Institute for Botany, Leibniz University Hannover, Herrenhaeuser Strasse 2, Hannover 30419, Germany
| | - Philipp Bohnhorst
- Institute for Botany, Leibniz University Hannover, Herrenhaeuser Strasse 2, Hannover 30419, Germany
| | - Vinay Shekhar
- Faculty of Biology, Department Biology I – Botany, Ludwig-Maximilians-University Muenchen, Grosshaderner Strasse 2-4, 82152 Planegg-Martinsried, Germany
| | - Inhwan Hwang
- Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang 790–784, Korea
| | - Sascha Offermann
- Institute for Botany, Leibniz University Hannover, Herrenhaeuser Strasse 2, Hannover 30419, Germany
| |
Collapse
|
11
|
|
12
|
Erlinghaeuser M, Hagenau L, Wimmer D, Offermann S. Development, subcellular positioning and selective protein accumulation in the dimorphic chloroplasts of single-cell C4 species. CURRENT OPINION IN PLANT BIOLOGY 2016; 31:76-82. [PMID: 27061048 DOI: 10.1016/j.pbi.2016.03.017] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Revised: 03/17/2016] [Accepted: 03/28/2016] [Indexed: 05/17/2023]
Abstract
C4 photosynthesis is typically associated with a carbon concentrating mechanism based on close collaboration between two photosynthetic cell types (Kranz C4). Surprisingly, four species in the family Chenopodiaceae have been described, which perform all required steps for a functional and effective C4 cycle within individual photosynthetic cells. These single-cell C4 species utilize a unique subcellular compartmentation and two functionally different chloroplast types that mimic the functions of the two cell types of the Kranz C4 system. In this review, we will summarize and discuss studies on chloroplast development, positioning and selective accumulation of nuclear encoded proteins, which ultimately allow the operation of a C4 carbon concentrating mechanism within individual cells.
Collapse
Affiliation(s)
| | - Lisa Hagenau
- Institute for Botany, Leibniz University Hannover, Germany
| | - Diana Wimmer
- Institute for Botany, Leibniz University Hannover, Germany
| | | |
Collapse
|
13
|
Lung SC, Smith MD, Chuong SDX. Isolation of Chloroplasts from Plant Protoplasts. Cold Spring Harb Protoc 2015; 2015:895-899. [PMID: 26430249 DOI: 10.1101/pdb.prot074559] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
Chloroplasts can be isolated from higher plants directly following homogenization; however, the resulting yield, purity, and intactness are often low, necessitating a large amount of starting material. This protocol is optimized to produce a high yield of pure chloroplasts from isolated Arabidopsis protoplasts. The two-part method is a simple, scaled-down, and low-cost procedure that readily provides healthy mesophyll protoplasts, which are then ruptured to release intact chloroplasts. Chloroplasts isolated using this method are competent for use in biochemical, cellular, and molecular analyses.
Collapse
Affiliation(s)
- Shiu-Cheung Lung
- School of Biological Sciences, University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Matthew D Smith
- Department of Biology, Wilfrid Laurier University, Waterloo, Ontario N2L 3C5, Canada
| | - Simon D X Chuong
- Department of Biology, University of Waterloo, Waterloo, Ontario N2L 3G1, Canada
| |
Collapse
|
14
|
Offermann S, Friso G, Doroshenk KA, Sun Q, Sharpe RM, Okita TW, Wimmer D, Edwards GE, van Wijk KJ. Developmental and Subcellular Organization of Single-Cell C₄ Photosynthesis in Bienertia sinuspersici Determined by Large-Scale Proteomics and cDNA Assembly from 454 DNA Sequencing. J Proteome Res 2015; 14:2090-108. [PMID: 25772754 DOI: 10.1021/pr5011907] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Kranz C4 species strictly depend on separation of primary and secondary carbon fixation reactions in different cell types. In contrast, the single-cell C4 (SCC4) species Bienertia sinuspersici utilizes intracellular compartmentation including two physiologically and biochemically different chloroplast types; however, information on identity, localization, and induction of proteins required for this SCC4 system is currently very limited. In this study, we determined the distribution of photosynthesis-related proteins and the induction of the C4 system during development by label-free proteomics of subcellular fractions and leaves of different developmental stages. This was enabled by inferring a protein sequence database from 454 sequencing of Bienertia cDNAs. Large-scale proteome rearrangements were observed as C4 photosynthesis developed during leaf maturation. The proteomes of the two chloroplasts are different with differential accumulation of linear and cyclic electron transport components, primary and secondary carbon fixation reactions, and a triose-phosphate shuttle that is shared between the two chloroplast types. This differential protein distribution pattern suggests the presence of a mRNA or protein-sorting mechanism for nuclear-encoded, chloroplast-targeted proteins in SCC4 species. The combined information was used to provide a comprehensive model for NAD-ME type carbon fixation in SCC4 species.
Collapse
Affiliation(s)
- Sascha Offermann
- †Institute of Botany, Leibniz University, Herrenhaeuser Strasse 2, Hannover 30419, Germany
| | - Giulia Friso
- ‡Department of Plant Biology, Cornell University, 332 Emerson Hall, Ithaca, New York 14853, United States
| | - Kelly A Doroshenk
- §Institute of Biological Chemistry, Washington State University, 299 Clark Hall, Pullman, Washington 99164, United States
| | - Qi Sun
- ∥Computational Biology Service Unit, Cornell University, 618 Rhodes Hall, Ithaca, New York 14853, United States
| | - Richard M Sharpe
- ⊥School of Biological Science, Washington State University, 303 Heald Hall, Pullman, Washington 99164, United States
| | - Thomas W Okita
- §Institute of Biological Chemistry, Washington State University, 299 Clark Hall, Pullman, Washington 99164, United States
| | - Diana Wimmer
- †Institute of Botany, Leibniz University, Herrenhaeuser Strasse 2, Hannover 30419, Germany
| | - Gerald E Edwards
- ⊥School of Biological Science, Washington State University, 303 Heald Hall, Pullman, Washington 99164, United States
| | - Klaas J van Wijk
- ‡Department of Plant Biology, Cornell University, 332 Emerson Hall, Ithaca, New York 14853, United States
| |
Collapse
|
15
|
Lung SC, Smith MD, Weston JK, Gwynne W, Secord N, Chuong SDX. The C-terminus of Bienertia sinuspersici Toc159 contains essential elements for its targeting and anchorage to the chloroplast outer membrane. FRONTIERS IN PLANT SCIENCE 2014; 5:722. [PMID: 25566294 PMCID: PMC4274882 DOI: 10.3389/fpls.2014.00722] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2014] [Accepted: 11/30/2014] [Indexed: 05/11/2023]
Abstract
Most nucleus-encoded chloroplast proteins rely on an N-terminal transit peptide (TP) as a post-translational sorting signal for directing them to the organelle. Although Toc159 is known to be a receptor for specific preprotein TPs at the chloroplast surface, the mechanism for its own targeting and integration into the chloroplast outer membrane is not completely understood. In a previous study, we identified a novel TP-like sorting signal at the C-terminus (CT) of a Toc159 homolog from the single-cell C4 species, Bienertia sinuspersici. In the current study, we have extended our understanding of the sorting signal using transient expression of fluorescently-tagged fusion proteins of variable-length, and with truncated and swapped versions of the CT. As was shown in the earlier study, the 56 residues of the CT contain crucial sorting information for reversible interaction of the receptor with the chloroplast envelope. Extension of this region to 100 residues in the current study stabilized the interaction via membrane integration, as demonstrated by more prominent plastid-associated signals and resistance of the fusion protein to alkaline extraction. Despite a high degree of sequence similarity, the plastid localization signals of the equivalent CT regions of Arabidopsis thaliana Toc159 homologs were not as strong as that of the B. sinuspersici counterparts. Together with computational and circular dichroism analyses of the CT domain structures, our data provide insights into the critical elements of the CT for the efficient targeting and anchorage of Toc159 receptors to the dimorphic chloroplasts in the single-cell C4 species.
Collapse
Affiliation(s)
- Shiu-Cheung Lung
- School of Biological Sciences, The University of Hong KongHong Kong SAR, China
| | - Matthew D. Smith
- Department of Biology, Wilfrid Laurier UniversityWaterloo, ON, Canada
| | - J. Kyle Weston
- Department of Biology, Wilfrid Laurier UniversityWaterloo, ON, Canada
| | - William Gwynne
- Department of Biology, University of WaterlooWaterloo, ON, Canada
| | - Nathan Secord
- Department of Biology, University of WaterlooWaterloo, ON, Canada
| | | |
Collapse
|
16
|
Identification and in silico analysis of helical lipid binding regions in proteins belonging to the amphitropic protein family. J Biosci 2014; 39:771-83. [DOI: 10.1007/s12038-014-9479-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
|
17
|
Roston RL, Wang K, Kuhn LA, Benning C. Structural determinants allowing transferase activity in SENSITIVE TO FREEZING 2, classified as a family I glycosyl hydrolase. J Biol Chem 2014; 289:26089-26106. [PMID: 25100720 DOI: 10.1074/jbc.m114.576694] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
SENSITIVE TO FREEZING 2 (SFR2) is classified as a family I glycosyl hydrolase but has recently been shown to have galactosyltransferase activity in Arabidopsis thaliana. Natural occurrences of apparent glycosyl hydrolases acting as transferases are interesting from a biocatalysis standpoint, and knowledge about the interconversion can assist in engineering SFR2 in crop plants to resist freezing. To understand how SFR2 evolved into a transferase, the relationship between its structure and function are investigated by activity assay, molecular modeling, and site-directed mutagenesis. SFR2 has no detectable hydrolase activity, although its catalytic site is highly conserved with that of family 1 glycosyl hydrolases. Three regions disparate from glycosyl hydrolases are identified as required for transferase activity as follows: a loop insertion, the C-terminal peptide, and a hydrophobic patch adjacent to the catalytic site. Rationales for the effects of these regions on the SFR2 mechanism are discussed.
Collapse
Affiliation(s)
- Rebecca L Roston
- Departments of Biochemistry and Molecular Biology and Michigan State University, East Lansing, Michigan 48824.
| | - Kun Wang
- Departments of Biochemistry and Molecular Biology and Michigan State University, East Lansing, Michigan 48824
| | - Leslie A Kuhn
- Departments of Biochemistry and Molecular Biology and Michigan State University, East Lansing, Michigan 48824; Departments of Computer Science and Engineering, Michigan State University, East Lansing, Michigan 48824
| | - Christoph Benning
- Departments of Biochemistry and Molecular Biology and Michigan State University, East Lansing, Michigan 48824
| |
Collapse
|
18
|
Sharpe RM, Offermann S. One decade after the discovery of single-cell C4 species in terrestrial plants: what did we learn about the minimal requirements of C4 photosynthesis? PHOTOSYNTHESIS RESEARCH 2014; 119:169-80. [PMID: 23494362 DOI: 10.1007/s11120-013-9810-9] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2012] [Accepted: 03/04/2013] [Indexed: 05/17/2023]
Abstract
Until about 10 years ago the general accepted textbook knowledge was that terrestrial C4 photosynthesis requires separation of photosynthetic functions into two specialized cell types, the mesophyll and bundle sheath cells forming the distinctive Kranz anatomy typical for C4 plants. This paradigm has been broken with the discovery of Suaeda aralocaspica, a chenopod from central Asia, performing C4 photosynthesis within individual chlorenchyma cells. Since then, three more single-cell C4 (SCC4) species have been discovered in the genus Bienertia. They are interesting not only because of their unusual mode of photosynthesis but also present a puzzle for cell biologists. In these species, two morphological and biochemical specialized types of chloroplasts develop within individual chlorenchyma cells, a situation that has never been observed in plants before. Here we review recent literature concerning the biochemistry, physiology, and molecular biology of SCC4 photosynthesis. Particularly, we focus on what has been learned in relation to the following questions: How does the specialized morphology required for the operation of SCC4 develop and is there a C3 intermediate type of photosynthesis during development? What is the degree of specialization between the two chloroplast types and how does this compare to the chloroplasts of Kranz C4 species? How do nucleus-encoded proteins that are targeted to chloroplasts accumulate differentially in the two chloroplast types and how efficient is the CO2 concentrating mechanism in SCC4 species compared to the Kranz C4 forms?
Collapse
Affiliation(s)
- Richard M Sharpe
- School of Biological Science, Washington State University, Pullman, WA, USA
| | | |
Collapse
|
19
|
Rosnow J, Yerramsetty P, Berry JO, Okita TW, Edwards GE. Exploring mechanisms linked to differentiation and function of dimorphic chloroplasts in the single cell C4 species Bienertia sinuspersici. BMC PLANT BIOLOGY 2014; 14:34. [PMID: 24443986 PMCID: PMC3904190 DOI: 10.1186/1471-2229-14-34] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2013] [Accepted: 01/15/2014] [Indexed: 05/11/2023]
Abstract
BACKGROUND In the model single-cell C4 plant Bienertia sinuspersici, chloroplast- and nuclear-encoded photosynthetic enzymes, characteristically confined to either bundle sheath or mesophyll cells in Kranz-type C4 leaves, all occur together within individual leaf chlorenchyma cells. Intracellular separation of dimorphic chloroplasts and key enzymes within central and peripheral compartments allow for C4 carbon fixation analogous to NAD-malic enzyme (NAD-ME) Kranz type species. Several methods were used to investigate dimorphic chloroplast differentiation in B. sinuspersici. RESULTS Confocal analysis revealed that Rubisco-containing chloroplasts in the central compartment chloroplasts (CCC) contained more photosystem II proteins than the peripheral compartment chloroplasts (PCC) which contain pyruvate,Pi dikinase (PPDK), a pattern analogous to the cell type-specific chloroplasts of many Kranz type NAD-ME species. Transient expression analysis using GFP fusion constructs containing various lengths of a B. sinuspersici Rubisco small subunit (RbcS) gene and the transit peptide of PPDK revealed that their import was not specific to either chloroplast type. Immunolocalization showed the rbcL-specific mRNA binding protein RLSB to be selectively localized to the CCC in B. sinuspersici, and to Rubisco-containing BS chloroplasts in the closely related Kranz species Suaeda taxifolia. Comparative fluorescence analyses were made using redox-sensitive and insensitive GFP forms, as well comparative staining using the peroxidase indicator 3,3-diaminobenzidine (DAB), which demonstrated differences in stromal redox potential, with the CCC having a more negative potential than the PCC. CONCLUSIONS Both CCC RLSB localization and the differential chloroplast redox state are suggested to have a role in post-transcriptional rbcL expression.
Collapse
Affiliation(s)
- Josh Rosnow
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| | - Pradeep Yerramsetty
- Department of Biological Sciences, State University of New York, Buffalo, NY 14260, USA
| | - James O Berry
- Department of Biological Sciences, State University of New York, Buffalo, NY 14260, USA
| | - Thomas W Okita
- Institute of Biological Chemistry, Washington State University, Pullman, WA 99164-6340, USA
| | - Gerald E Edwards
- School of Biological Sciences, Washington State University, Pullman, WA 99164-4236, USA
| |
Collapse
|
20
|
Richardson LGL, Paila YD, Siman SR, Chen Y, Smith MD, Schnell DJ. Targeting and assembly of components of the TOC protein import complex at the chloroplast outer envelope membrane. FRONTIERS IN PLANT SCIENCE 2014; 5:269. [PMID: 24966864 PMCID: PMC4052903 DOI: 10.3389/fpls.2014.00269] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Accepted: 05/24/2014] [Indexed: 05/20/2023]
Abstract
The translocon at the outer envelope membrane of chloroplasts (TOC) initiates the import of thousands of nuclear encoded preproteins required for chloroplast biogenesis and function. The multimeric TOC complex contains two GTP-regulated receptors, Toc34 and Toc159, which recognize the transit peptides of preproteins and initiate protein import through a β-barrel membrane channel, Toc75. Different isoforms of Toc34 and Toc159 assemble with Toc75 to form structurally and functionally diverse translocons, and the composition and levels of TOC translocons is required for the import of specific subsets of coordinately expressed proteins during plant growth and development. Consequently, the proper assembly of the TOC complexes is key to ensuring organelle homeostasis. This review will focus on our current knowledge of the targeting and assembly of TOC components to form functional translocons at the outer membrane. Our analyses reveal that the targeting of TOC components involves elements common to the targeting of other outer membrane proteins, but also include unique features that appear to have evolved to specifically facilitate assembly of the import apparatus.
Collapse
Affiliation(s)
- Lynn G. L. Richardson
- Department of Biochemistry and Molecular Biology, University of Massachusetts, AmherstMA, USA
| | - Yamuna D. Paila
- Department of Biochemistry and Molecular Biology, University of Massachusetts, AmherstMA, USA
| | - Steven R. Siman
- Department of Biology, Wilfrid Laurier University, WaterlooON, Canada
| | - Yi Chen
- Department of Biology, Wilfrid Laurier University, WaterlooON, Canada
| | - Matthew D. Smith
- Department of Biology, Wilfrid Laurier University, WaterlooON, Canada
| | - Danny J. Schnell
- Department of Biochemistry and Molecular Biology, University of Massachusetts, AmherstMA, USA
- *Correspondence: Danny J. Schnell, Department of Biochemistry and Molecular Biology, University of Massachusetts, Amherst, Life Sciences Laboratories, Room N431, 240 Thatcher Way, Amherst, MA 01003-9364, USA e-mail:
| |
Collapse
|
21
|
Li HM, Teng YS. Transit peptide design and plastid import regulation. TRENDS IN PLANT SCIENCE 2013; 18:360-6. [PMID: 23688728 DOI: 10.1016/j.tplants.2013.04.003] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2013] [Revised: 03/25/2013] [Accepted: 04/05/2013] [Indexed: 05/04/2023]
Abstract
Import of most nuclear encoded proteins into plastids is directed by an N-terminal transit peptide. Early studies suggested that transit peptides are interchangeable between precursor proteins. However, emerging evidence shows that different transit peptides contain different motifs specifying their preference for certain plastid types or ages. In this opinion article, we propose a 'multi-selection and multi-order' (M&M) model for transit peptide design, describing each transit peptide as an assembly of motifs for interacting with selected translocon components. These interactions determine the preference of the precursor for a particular plastid type or age. Furthermore, the order of the motifs varies among transit peptides, explaining why no consensus sequences have been identified through linear sequence comparison of all transit peptides as one group.
Collapse
Affiliation(s)
- Hsou-min Li
- Institute of Molecular Biology, Academia Sinica, Taipei 11529, Taiwan.
| | | |
Collapse
|
22
|
Lung SC, Yanagisawa M, Chuong SDX. Recent progress in the single-cell C4 photosynthesis in terrestrial plants. ACTA ACUST UNITED AC 2012. [DOI: 10.1007/s11515-012-9248-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|
23
|
Teng YS, Chan PT, Li HM. Differential age-dependent import regulation by signal peptides. PLoS Biol 2012; 10:e1001416. [PMID: 23118617 PMCID: PMC3484058 DOI: 10.1371/journal.pbio.1001416] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2012] [Accepted: 09/20/2012] [Indexed: 12/25/2022] Open
Abstract
Gene-specific, age-dependent regulations are common at the transcriptional and translational levels, while protein transport into organelles is generally thought to be constitutive. Here we report a new level of differential age-dependent regulation and show that chloroplast proteins are divided into three age-selective groups: group I proteins have a higher import efficiency into younger chloroplasts, import of group II proteins is nearly independent of chloroplast age, and group III proteins are preferentially imported into older chloroplasts. The age-selective signal is located within the transit peptide of each protein. A group III protein with its transit peptide replaced by a group I transit peptide failed to complement its own mutation. Two consecutive positive charges define the necessary motif in group III signals for older chloroplast preference. We further show that different members of a gene family often belong to different age-selective groups because of sequence differences in their transit peptides. These results indicate that organelle-targeting signal peptides are part of cells' differential age-dependent regulation networks. The sequence diversity of some organelle-targeting peptides is not a result of the lack of selection pressure but has evolved to mediate regulation.
Collapse
Affiliation(s)
- Yi-Shan Teng
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan
| | - Po-Ting Chan
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
- Institute of Molecular and Cellular Biology, College of Life Science, National Taiwan University, Taipei, Taiwan
| | - Hsou-min Li
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan
| |
Collapse
|
24
|
Shi LX, Theg SM. The chloroplast protein import system: from algae to trees. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2012; 1833:314-31. [PMID: 23063942 DOI: 10.1016/j.bbamcr.2012.10.002] [Citation(s) in RCA: 138] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2012] [Revised: 09/07/2012] [Accepted: 10/01/2012] [Indexed: 01/15/2023]
Abstract
Chloroplasts are essential organelles in the cells of plants and algae. The functions of these specialized plastids are largely dependent on the ~3000 proteins residing in the organelle. Although chloroplasts are capable of a limited amount of semiautonomous protein synthesis - their genomes encode ~100 proteins - they must import more than 95% of their proteins after synthesis in the cytosol. Imported proteins generally possess an N-terminal extension termed a transit peptide. The importing translocons are made up of two complexes in the outer and inner envelope membranes, the so-called Toc and Tic machineries, respectively. The Toc complex contains two precursor receptors, Toc159 and Toc34, a protein channel, Toc75, and a peripheral component, Toc64/OEP64. The Tic complex consists of as many as eight components, namely Tic22, Tic110, Tic40, Tic20, Tic21 Tic62, Tic55 and Tic32. This general Toc/Tic import pathway, worked out largely in pea chloroplasts, appears to operate in chloroplasts in all green plants, albeit with significant modifications. Sub-complexes of the Toc and Tic machineries are proposed to exist to satisfy different substrate-, tissue-, cell- and developmental requirements. In this review, we summarize our understanding of the functions of Toc and Tic components, comparing these components of the import machinery in green algae through trees. We emphasize recent findings that point to growing complexities of chloroplast protein import process, and use the evolutionary relationships between proteins of different species in an attempt to define the essential core translocon components and those more likely to be responsible for regulation. This article is part of a Special Issue entitled: Protein Import and Quality Control in Mitochondria and Plastids.
Collapse
Affiliation(s)
- Lan-Xin Shi
- Department of Plant Biology, University of California-Davis, One Shields Avenue, Davis, CA 95616, USA.
| | | |
Collapse
|