1
|
Zhang Y, Tian L, Lu C. Chloroplast gene expression: Recent advances and perspectives. PLANT COMMUNICATIONS 2023; 4:100611. [PMID: 37147800 PMCID: PMC10504595 DOI: 10.1016/j.xplc.2023.100611] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 04/11/2023] [Accepted: 05/01/2023] [Indexed: 05/07/2023]
Abstract
Chloroplasts evolved from an ancient cyanobacterial endosymbiont more than 1.5 billion years ago. During subsequent coevolution with the nuclear genome, the chloroplast genome has remained independent, albeit strongly reduced, with its own transcriptional machinery and distinct features, such as chloroplast-specific innovations in gene expression and complicated post-transcriptional processing. Light activates the expression of chloroplast genes via mechanisms that optimize photosynthesis, minimize photodamage, and prioritize energy investments. Over the past few years, studies have moved from describing phases of chloroplast gene expression to exploring the underlying mechanisms. In this review, we focus on recent advances and emerging principles that govern chloroplast gene expression in land plants. We discuss engineering of pentatricopeptide repeat proteins and its biotechnological effects on chloroplast RNA research; new techniques for characterizing the molecular mechanisms of chloroplast gene expression; and important aspects of chloroplast gene expression for improving crop yield and stress tolerance. We also discuss biological and mechanistic questions that remain to be answered in the future.
Collapse
Affiliation(s)
- Yi Zhang
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Lin Tian
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China
| | - Congming Lu
- National Key Laboratory of Wheat Improvement, College of Life Sciences, Shandong Agricultural University, Taian, Shandong 271018, China.
| |
Collapse
|
2
|
Frangedakis E, Guzman-Chavez F, Rebmann M, Markel K, Yu Y, Perraki A, Tse SW, Liu Y, Rever J, Sauret-Gueto S, Goffinet B, Schneider H, Haseloff J. Construction of DNA Tools for Hyperexpression in Marchantia Chloroplasts. ACS Synth Biol 2021; 10:1651-1666. [PMID: 34097383 PMCID: PMC8296666 DOI: 10.1021/acssynbio.0c00637] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Chloroplasts are attractive platforms for synthetic biology applications since they are capable of driving very high levels of transgene expression, if mRNA production and stability are properly regulated. However, plastid transformation is a slow process and currently limited to a few plant species. The liverwort Marchantia polymorpha is a simple model plant that allows rapid transformation studies; however, its potential for protein hyperexpression has not been fully exploited. This is partially due to the fact that chloroplast post-transcriptional regulation is poorly characterized in this plant. We have mapped patterns of transcription in Marchantia chloroplasts. Furthermore, we have obtained and compared sequences from 51 bryophyte species and identified putative sites for pentatricopeptide repeat protein binding that are thought to play important roles in mRNA stabilization. Candidate binding sites were tested for their ability to confer high levels of reporter gene expression in Marchantia chloroplasts, and levels of protein production and effects on growth were measured in homoplastic transformed plants. We have produced novel DNA tools for protein hyperexpression in this facile plant system that is a test-bed for chloroplast engineering.
Collapse
Affiliation(s)
- Eftychios Frangedakis
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Fernando Guzman-Chavez
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Marius Rebmann
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Kasey Markel
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Ying Yu
- College of Life and Environmental Sciences, Hangzhou Normal University, Hangzhou 311121, China
| | - Artemis Perraki
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Sze Wai Tse
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Yang Liu
- Fairy Lake Botanical Garden & Chinese Academy of Sciences, Shenzhen, Guangdong 518004, China
| | - Jenna Rever
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Susanna Sauret-Gueto
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| | - Bernard Goffinet
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, Connecticut 06269-3043, United States
| | - Harald Schneider
- Center for Integrative Conservation, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Menglun, Yunnan 666303, China
| | - Jim Haseloff
- Department of Plant Sciences, University of Cambridge, Downing Street, Cambridge CB2 3EA, U.K
| |
Collapse
|
3
|
de Santana Lopes A, Gomes Pacheco T, Nascimento da Silva O, do Nascimento Vieira L, Guerra MP, Pacca Luna Mattar E, de Baura VA, Balsanelli E, Maltempi de Souza E, de Oliveira Pedrosa F, Rogalski M. Plastid genome evolution in Amazonian açaí palm (Euterpe oleracea Mart.) and Atlantic forest açaí palm (Euterpe edulis Mart.). PLANT MOLECULAR BIOLOGY 2021; 105:559-574. [PMID: 33386578 DOI: 10.1007/s11103-020-01109-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2020] [Accepted: 12/15/2020] [Indexed: 06/12/2023]
Abstract
The plastomes of E. edulis and E. oleracea revealed several molecular markers useful for genetic studies in natural populations and indicate specific evolutionary features determined by vicariant speciation. Arecaceae is a large and diverse family occurring in tropical and subtropical ecosystems worldwide. E. oleracea is a hyperdominant species of the Amazon forest, while E. edulis is a keystone species of the Atlantic forest. It has reported that E. edulis arose from vicariant speciation after the emergence of the belt barrier of dry environment (Cerrado and Caatinga biomes) between Amazon and Atlantic forests, isolating the E. edulis in the Atlantic forest. We sequenced the complete plastomes of E. edulis and E. oleracea and compared them concerning plastome structure, SSRs, tandem repeats, SNPs, indels, hotspots of nucleotide polymorphism, codon Ka/Ks ratios and RNA editing sites aiming to investigate evolutionary traits possibly affected by distinct environments. Our analyses revealed 303 SNPs, 91 indels, and 82 polymorphic SSRs among both species. Curiously, the narrow correlation among localization of repetitive sequences and indels strongly suggests that replication slippage is involved in plastid DNA mutations in Euterpe. Moreover, most non-synonymous substitutions represent amino acid variants in E. edulis that evolved specifically or in a convergent manner across the palm phylogeny. Amino acid variants observed in several plastid proteins in E. edulis were also identified as positive signatures across palm phylogeny. The higher incidence of specific amino acid changes in plastid genes of E. edulis in comparison with E. oleracea probably configures adaptive genetic variations determined by vicariant speciation. Our data indicate that the environment generates a selective pressure on the plastome making it more adapted to specific conditions.
Collapse
Affiliation(s)
- Amanda de Santana Lopes
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Túlio Gomes Pacheco
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Odyone Nascimento da Silva
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Leila do Nascimento Vieira
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | - Miguel Pedro Guerra
- Laboratório de Fisiologia do Desenvolvimento e Genética Vegetal, Programa de Pós-graduação em Recursos Genéticos Vegetais, Universidade Federal de Santa Catarina, Florianópolis, SC, Brazil
| | | | - Valter Antonio de Baura
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Eduardo Balsanelli
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Emanuel Maltempi de Souza
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Fábio de Oliveira Pedrosa
- Departamento de Bioquímica e Biologia Molecular, Núcleo de Fixação Biológica de Nitrogênio, Universidade Federal do Paraná, Curitiba, PR, Brazil
| | - Marcelo Rogalski
- Laboratório de Fisiologia Molecular de Plantas, Departamento de Biologia Vegetal, Universidade Federal de Viçosa, Viçosa, MG, Brazil.
| |
Collapse
|
4
|
Puthiyaveetil S, McKenzie SD, Kayanja GE, Ibrahim IM. Transcription initiation as a control point in plastid gene expression. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2021; 1864:194689. [PMID: 33561560 DOI: 10.1016/j.bbagrm.2021.194689] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Revised: 01/29/2021] [Accepted: 02/01/2021] [Indexed: 12/18/2022]
Abstract
The extensive processing and protein-assisted stabilization of transcripts have been taken as evidence for a viewpoint that the control of gene expression had shifted entirely in evolution from transcriptional in the bacterial endosymbiont to posttranscriptional in the plastid. This suggestion is however at odds with many observations on plastid gene transcription. Chloroplasts of flowering plants and mosses contain two or more RNA polymerases with distinct promoter preference and division of labor for the coordinated synthesis of plastid RNAs. Plant and algal plastids further possess multiple nonredundant sigma factors that function as transcription initiation factors. The controlled accumulation of plastid sigma factors and modification of their activity by sigma-binding proteins and phosphorylation constitute additional transcriptional regulatory strategies. Plant and algal plastids also contain dedicated one- or two-component transcriptional regulators. Transcription initiation thus continues to form a critical control point at which varied developmental and environmental signals intersect with plastid gene expression.
Collapse
Affiliation(s)
- Sujith Puthiyaveetil
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA.
| | - Steven D McKenzie
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Gilbert E Kayanja
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| | - Iskander M Ibrahim
- Department of Biochemistry and Center for Plant Biology, Purdue University, West Lafayette, IN 47907, USA
| |
Collapse
|
5
|
Nozoe M, Tsunoyama Y, Ishizaki Y, Nakahira Y, Shiina T. Selective Activation of Chloroplast psbD Light-Responsive Promoter and psaA/B Promoter in Transplastomic Tobacco Plants Overexpressing Arabidopsis Sigma Factor AtSIG5. Protein Pept Lett 2020; 27:168-175. [PMID: 31612816 DOI: 10.2174/0929866526666191014130605] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2018] [Revised: 04/30/2019] [Accepted: 08/09/2019] [Indexed: 11/22/2022]
Abstract
BACKGROUND Plastid-encoded eubacterial-type RNA polymerase (PEP) plays a critical role in the transcription of photosynthesis genes in chloroplasts. Notably, some of the reaction center genes, including psaA, psaB, psbA, and psbD genes, are differentially transcribed by PEP in mature chloroplasts. However, the molecular mechanism of promoter selection in the reaction center gene transcription by PEP is not well understood. OBJECTIVE Sigma factor proteins direct promoter selection by a core PEP in chloroplasts as well as bacteria. AtSIG5 is a unique chloroplast sigma factor essential for psbD light-responsive promoter (psbD LRP) activity. To analyze the role of AtSIG5 in chloroplast transcription in more detail, we assessed the effect of AtSIG5 hyper-expression on the transcription of plastid-encoded genes in chloroplast transgenic plants. RESULTS The chloroplast transgenic tobacco (CpOX-AtSIG5) accumulates AtSIG5 protein at extremely high levels in chloroplasts. Due to the extremely high-level expression of recombinant AtSIG5, most PEP holoenzymes are most likely to include the recombinant AtSIG5 in the CpOXAtSIG5 chloroplasts. Thus, we can assess the promoter preference of AtSIG5 in vivo. The overexpression of AtSIG5 significantly increased the expression of psbD LRP transcripts encoding PSII reaction center D2 protein and psaA/B operon transcripts encoding PSI core proteins. Furthermore, run-on transcription analyses revealed that AtSIG5 preferentially recognizes the psaA/B promoter, as well as the psbD LRP. Moreover, we found that psbD LRP is constitutively active in CpOX-AtSIG5 plants irrespective of light and dark. CONCLUSION AtSIG5 probably plays a significant role in differential transcription of reaction center genes in mature chloroplasts.
Collapse
Affiliation(s)
- Mikio Nozoe
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606- 8522,Japan
| | - Yuichi Tsunoyama
- Radioisotope Research Center, Kyoto University, Kitashirakawa-oiwake-cho, Sakyo-ku, Kyoto 606-8502,Japan
| | - Yoko Ishizaki
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606- 8522,Japan
| | - Yoichi Nakahira
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606- 8522,Japan
- College of Agriculture, Ibaraki University, Ami, Inashiki 300-0393, Japan
| | - Takashi Shiina
- Graduate School of Life and Environmental Sciences, Kyoto Prefectural University, Shimogamo, Sakyo-ku, Kyoto 606- 8522,Japan
| |
Collapse
|
6
|
Thairu MW, Hansen AK. It's a small, small world: unravelling the role and evolution of small RNAs in organelle and endosymbiont genomes. FEMS Microbiol Lett 2019; 366:5371121. [PMID: 30844054 DOI: 10.1093/femsle/fnz049] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2018] [Accepted: 03/05/2019] [Indexed: 12/19/2022] Open
Abstract
Organelles and host-restricted bacterial symbionts are characterized by having highly reduced genomes that lack many key regulatory genes and elements. Thus, it has been hypothesized that the eukaryotic nuclear genome is primarily responsible for regulating these symbioses. However, with the discovery of organelle- and symbiont-expressed small RNAs (sRNAs) there is emerging evidence that these sRNAs may play a role in gene regulation as well. Here, we compare the diversity of organelle and bacterial symbiont sRNAs recently identified using genome-enabled '-omic' technologies and discuss their potential role in gene regulation. We also discuss how the genome architecture of small genomes may influence the evolution of these sRNAs and their potential function. Additionally, these new studies suggest that some sRNAs are conserved within organelle and symbiont taxa and respond to changes in the environment and/or their hosts. In summary, these results suggest that organelle and symbiont sRNAs may play a role in gene regulation in addition to nuclear-encoded host mechanisms.
Collapse
Affiliation(s)
- Margaret W Thairu
- Department of Entomology, University of California, Riverside, Riverside, CA, USA
| | - Allison K Hansen
- Department of Entomology, University of California, Riverside, Riverside, CA, USA
| |
Collapse
|
7
|
Pérez Di Giorgio JA, Lepage É, Tremblay-Belzile S, Truche S, Loubert-Hudon A, Brisson N. Transcription is a major driving force for plastid genome instability in Arabidopsis. PLoS One 2019; 14:e0214552. [PMID: 30943245 PMCID: PMC6447228 DOI: 10.1371/journal.pone.0214552] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Accepted: 03/15/2019] [Indexed: 12/14/2022] Open
Abstract
Though it is an essential process, transcription can be a source of genomic instability. For instance, it may generate RNA:DNA hybrids as the nascent transcript hybridizes with the complementary DNA template. These hybrids, called R-loops, act as a major cause of replication fork stalling and DNA breaks. In this study, we show that lowering transcription and R-loop levels in plastids of Arabidopsis thaliana reduces DNA rearrangements and mitigates plastid genome instability phenotypes. This effect can be observed on a genome-wide scale, as the loss of the plastid sigma transcription factor SIG6 prevents DNA rearrangements by favoring conservative repair in the presence of ciprofloxacin-induced DNA damage or in the absence of plastid genome maintenance actors such as WHY1/WHY3, RECA1 and POLIB. Additionally, resolving R-loops by the expression of a plastid-targeted exogenous RNAse H1 produces similar results. We also show that highly-transcribed genes are more susceptible to DNA rearrangements, as increased transcription of the psbD operon by SIG5 correlates with more locus-specific rearrangements. The effect of transcription is not specific to Sigma factors, as decreased global transcription levels by mutation of heat-stress-induced factor HSP21, mutation of nuclear-encoded polymerase RPOTp, or treatment with transcription-inhibitor rifampicin all prevent the formation of plastid genome rearrangements, especially under induced DNA damage conditions.
Collapse
Affiliation(s)
| | - Étienne Lepage
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Samuel Tremblay-Belzile
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Sébastien Truche
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Audrey Loubert-Hudon
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| | - Normand Brisson
- Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec, Canada
| |
Collapse
|
8
|
Yurina NP, Sharapova LS, Odintsova MS. Structure of Plastid Genomes of Photosynthetic Eukaryotes. BIOCHEMISTRY (MOSCOW) 2017; 82:678-691. [PMID: 28601077 DOI: 10.1134/s0006297917060049] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
This review presents current views on the plastid genomes of higher plants and summarizes data on the size, structural organization, gene content, and other features of plastid DNAs. Special emphasis is placed on the properties of organization of land plant plastid genomes (nucleoids) that distinguish them from bacterial genomes. The prospects of genetic engineering of chloroplast genomes are discussed.
Collapse
Affiliation(s)
- N P Yurina
- Bach Institute of Biochemistry, Research Center of Biotechnology, Russian Academy of Sciences, Moscow, 119071, Russia.
| | | | | |
Collapse
|
9
|
Chloroplast RNA polymerases: Role in chloroplast biogenesis. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:761-9. [PMID: 25680513 DOI: 10.1016/j.bbabio.2015.02.004] [Citation(s) in RCA: 146] [Impact Index Per Article: 16.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 01/26/2015] [Accepted: 02/02/2015] [Indexed: 12/18/2022]
Abstract
Plastid genes are transcribed by two types of RNA polymerase in angiosperms: the bacterial type plastid-encoded RNA polymerase (PEP) and one (RPOTp in monocots) or two (RPOTp and RPOTmp in dicots) nuclear-encoded RNA polymerase(s) (NEP). PEP is a bacterial-type multisubunit enzyme composed of core subunits (coded for by the plastid rpoA, rpoB, rpoC1 and rpoC2 genes) and additional protein factors (sigma factors and polymerase associated protein, PAPs) encoded in the nuclear genome. Sigma factors are required by PEP for promoter recognition. Six different sigma factors are used by PEP in Arabidopsis plastids. NEP activity is represented by phage-type RNA polymerases. Only one NEP subunit has been identified, which bears the catalytic activity. NEP and PEP use different promoters. Many plastid genes have both PEP and NEP promoters. PEP dominates in the transcription of photosynthesis genes. Intriguingly, rpoB belongs to the few genes transcribed exclusively by NEP. Both NEP and PEP are active in non-green plastids and in chloroplasts at all stages of development. The transcriptional activity of NEP and PEP is affected by endogenous and exogenous factors. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
Collapse
|
10
|
Chi W, He B, Mao J, Jiang J, Zhang L. Plastid sigma factors: Their individual functions and regulation in transcription. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2015; 1847:770-8. [PMID: 25596450 DOI: 10.1016/j.bbabio.2015.01.001] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Revised: 01/02/2015] [Accepted: 01/06/2015] [Indexed: 11/18/2022]
Abstract
Sigma factors are the predominant factors involved in transcription regulation in bacteria. These factors can recruit the core RNA polymerase to promoters with specific DNA sequences and initiate gene transcription. The plastids of higher plants originating from an ancestral cyanobacterial endosymbiont also contain sigma factors that are encoded by a small family of nuclear genes. Although all plastid sigma factors contain sequences conserved in bacterial sigma factors, a considerable number of distinct traits have been acquired during evolution. The present review summarises recent advances concerning the regulation of the structure, function and activity of plastid sigma factors since their discovery nearly 40 years ago. We highlight the specialised roles and overlapping redundant functions of plastid sigma factors according to their promoter selectivity. We also focus on the mechanisms that modulate the activity of sigma factors to optimise plastid function in response to developmental cues and environmental signals. This article is part of a Special Issue entitled: Chloroplast Biogenesis.
Collapse
Affiliation(s)
- Wei Chi
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China.
| | - Baoye He
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Juan Mao
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Jingjing Jiang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Lixin Zhang
- Photosynthesis Research Center, Key Laboratory of Photobiology, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| |
Collapse
|
11
|
Schönberg A, Bergner E, Helm S, Agne B, Dünschede B, Schünemann D, Schutkowski M, Baginsky S. The peptide microarray "ChloroPhos1.0" identifies new phosphorylation targets of plastid casein kinase II (pCKII) in Arabidopsis thaliana. PLoS One 2014; 9:e108344. [PMID: 25295873 PMCID: PMC4189921 DOI: 10.1371/journal.pone.0108344] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2014] [Accepted: 08/19/2014] [Indexed: 11/18/2022] Open
Abstract
We report the development of a peptide microarray based on previously determined phosphorylation sites in chloroplast proteins. Altogether, 905 peptides were spotted as 15mers in nine replicates onto glass slides. We used the microarray for in vitro phosphorylation experiments and specifically assessed the peptide substrate spectrum of chloroplast casein kinase II (pCKII). To this end, native pCKII from Arabidopsis thaliana and Sinapis alba chloroplasts was enriched by Heparin-Sepharose chromatography and its activity on the microarray was compared to the activity of a recombinant Arabidopsis pCKII. All three kinase preparations phosphorylated a similar set of peptides that were clearly distinct from those phosphorylated by bovine heart protein kinase A (PKA) in control experiments. The majority of the pCKII phosphorylation targets are involved in plastid gene expression, supporting the earlier denomination of pCKII as plastid transcription kinase (PTK). In addition we identified Alb3 as pCKII substrate that is essential for the integration of light-harvesting complex subunits (LHC) into the thylakoid membrane. Plastid CKII phosphorylation activity was characterized in greater detail in vitro with recombinant wildtype Alb3 and phosphorylation site mutants as substrates, establishing S424 as the pCKII phosphorylation site. Our data show that the peptide microarray ChloroPhos1.0 is a suitable tool for the identification of new kinase downstream targets in vitro that can be validated subsequently by in vivo experiments.
Collapse
Affiliation(s)
- Anna Schönberg
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Elena Bergner
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Stefan Helm
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Birgit Agne
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
| | - Beatrix Dünschede
- Molecular Biology of Plant Organelles, Ruhr-University Bochum, Bochum, Germany
| | - Danja Schünemann
- Molecular Biology of Plant Organelles, Ruhr-University Bochum, Bochum, Germany
| | - Mike Schutkowski
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
- Steinbeis-Forschungszentrum, Peptide Microarrays, Halle (Saale), Germany
| | - Sacha Baginsky
- Institute of Biochemistry and Biotechnology, Martin-Luther-University Halle-Wittenberg, Halle (Saale), Germany
- * E-mail:
| |
Collapse
|
12
|
Bock S, Ortelt J, Link G. AtSIG6 and other members of the sigma gene family jointly but differentially determine plastid target gene expression in Arabidopsis thaliana. FRONTIERS IN PLANT SCIENCE 2014; 5:667. [PMID: 25505479 PMCID: PMC4243499 DOI: 10.3389/fpls.2014.00667] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/24/2014] [Accepted: 11/09/2014] [Indexed: 05/18/2023]
Abstract
Plants contain a nuclear gene family for plastid sigma factors, i.e., proteins that associate with the "bacterial-type" organellar RNA polymerase and confer the ability for correct promoter binding and transcription initiation. Questions that are still unresolved relate to the "division of labor" among members of the sigma family, both in terms of their range of target genes and their temporal and spatial activity during development. Clues to the in vivo role of individual sigma genes have mainly come from studies of sigma knockout lines. Despite its obvious strengths, however, this strategy does not necessarily trace-down causal relationships between mutant phenotype and a single sigma gene, if other family members act in a redundant and/or compensatory manner. We made efforts to reduce the complexity by genetic crosses of Arabidopsis single mutants (with focus on a chlorophyll-deficient sig6 line) to generate double knockout lines. The latter typically had a similar visible phenotype as the parental lines, but tended to be more strongly affected in the transcript patterns of both plastid and sigma genes. Because triple mutants were lethal under our growth conditions, we exploited a strategy of transformation of single and double mutants with RNAi constructs that contained sequences from the unconserved sigma region (UCR). These RNAi/knockout lines phenotypically resembled their parental lines, but were even more strongly affected in their plastid transcript patterns. Expression patterns of sigma genes revealed both similarities and differences compared to the parental lines, with transcripts at reduced or unchanged amounts and others that were found to be present in higher (perhaps compensatory) amounts. Together, our results reveal considerable flexibility of gene activity at the levels of both sigma and plastid gene expression. A (still viable) "basal state" seems to be reached, if 2-3 of the 6 Arabidopsis sigma genes are functionally compromised.
Collapse
Affiliation(s)
| | | | - Gerhard Link
- *Correspondence: Gerhard Link, Department of Biology and Biotechnology, University of Bochum, Universitaetsstr. 150, D-44780 Bochum, Germany e-mail:
| |
Collapse
|