1
|
Inès D, Courty PE, Wendehenne D, Rosnoblet C. CDC48 in plants and its emerging function in plant immunity. TRENDS IN PLANT SCIENCE 2024; 29:786-798. [PMID: 38218650 DOI: 10.1016/j.tplants.2023.12.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2023] [Revised: 12/14/2023] [Accepted: 12/14/2023] [Indexed: 01/15/2024]
Abstract
Protein homeostasis, namely the balance between protein synthesis and degradation, must be finely controlled to ensure cell survival, notably through the ubiquitin-proteasome system (UPS). In all species, including plants, homeostasis is disrupted by biotic and abiotic stresses. A key player in the maintenance of protein balance, the protein CDC48, shows emerging functions in plants, particularly in response to biotic stress. In this review on CDC48 in plants, we detail its highly conserved structure, describe a gene expansion that is only present in Viridiplantae, discuss its various functions and regulations, and finally highlight its recruitment, still not clear, during the plant immune response.
Collapse
Affiliation(s)
- Damien Inès
- Agroécologie, Institut National de Recherche pour l'Agriculture, l'Alimentation, et l'Environnement (INRAE), Institut Agro, Université de Bourgogne, Université Bourgogne-Franche-Comté, Dijon, France
| | - Pierre-Emmanuel Courty
- Agroécologie, Institut National de Recherche pour l'Agriculture, l'Alimentation, et l'Environnement (INRAE), Institut Agro, Université de Bourgogne, Université Bourgogne-Franche-Comté, Dijon, France
| | - David Wendehenne
- Agroécologie, Institut National de Recherche pour l'Agriculture, l'Alimentation, et l'Environnement (INRAE), Institut Agro, Université de Bourgogne, Université Bourgogne-Franche-Comté, Dijon, France
| | - Claire Rosnoblet
- Agroécologie, Institut National de Recherche pour l'Agriculture, l'Alimentation, et l'Environnement (INRAE), Institut Agro, Université de Bourgogne, Université Bourgogne-Franche-Comté, Dijon, France.
| |
Collapse
|
2
|
Luthuli SD, Shonhai A. The multi-faceted roles of R2TP complex span across regulation of gene expression, translation, and protein functional assembly. Biophys Rev 2023; 15:1951-1965. [PMID: 38192347 PMCID: PMC10771493 DOI: 10.1007/s12551-023-01127-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 08/27/2023] [Indexed: 01/10/2024] Open
Abstract
Macromolecular complexes play essential roles in various cellular processes. The assembly of macromolecular assemblies within the cell must overcome barriers imposed by a crowded cellular environment which is characterized by an estimated concentration of biological macromolecules amounting to 100-450 g/L that take up approximately 5-40% of the cytoplasmic volume. The formation of the macromolecular assemblies is facilitated by molecular chaperones in cooperation with their co-chaperones. The R2TP protein complex has emerged as a co-chaperone of Hsp90 that plays an important role in macromolecular assembly. The R2TP complex is composed of a heterodimer of RPAP3:P1H1DI that is in turn complexed to members of the ATPase associated with diverse cellular activities (AAA +), RUVBL1 and RUVBL2 (R1 and R2) families. What makes the R2TP co-chaperone complex particularly important is that it is involved in a wide variety of cellular processes including gene expression, translation, co-translational complex assembly, and posttranslational protein complex formation. The functional versatility of the R2TP co-chaperone complex makes it central to cellular development; hence, it is implicated in various human diseases. In addition, their roles in the development of infectious disease agents has become of interest. In the current review, we discuss the roles of these proteins as co-chaperones regulating Hsp90 and its partnership with Hsp70. Furthermore, we highlight the structure-function features of the individual proteins within the R2TP complex and describe their roles in various cellular processes.
Collapse
Affiliation(s)
- Sifiso Duncan Luthuli
- Department of Biochemistry and Microbiology, University of Venda, Thohoyandou, South Africa
| | - Addmore Shonhai
- Department of Biochemistry and Microbiology, University of Venda, Thohoyandou, South Africa
| |
Collapse
|
3
|
Rieger J, Fitz M, Fischer SM, Wallmeroth N, Flores-Romero H, Fischer NM, Brand LH, García-Sáez AJ, Berendzen KW, Mira-Rodado V. Exploring the Binding Affinity of the ARR2 GARP DNA Binding Domain via Comparative Methods. Genes (Basel) 2023; 14:1638. [PMID: 37628689 PMCID: PMC10454580 DOI: 10.3390/genes14081638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Revised: 08/01/2023] [Accepted: 08/07/2023] [Indexed: 08/27/2023] Open
Abstract
Plants have evolved signaling mechanisms such as the multi-step phosphorelay (MSP) to respond to different internal and external stimuli. MSP responses often result in gene transcription regulation that is modulated through transcription factors such as B-type Arabidopsis response regulator (ARR) proteins. Among these proteins, ARR2 is a key component that is expressed ubiquitously and is involved in many aspects of plant development. Although it has been noted that B-type ARRs bind to their cognate genes through a DNA-binding domain termed the GARP domain, little is known about the structure and function of this type of DNA-binding domain; thus, how ARRs bind to DNA at a structural level is still poorly understood. In order to understand how the MSP functions in planta, it is crucial to unravel both the kinetics as well as the structural identity of the components involved in such interactions. For this reason, this work focusses on resolving how the GARP domain of ARR2 (GARP2) binds to the promoter region of ARR5, one of its native target genes in cytokinin signaling. We have established that GARP2 specifically binds to the ARR5 promoter with three different bi-molecular interaction systems-qDPI-ELISA, FCS, and MST-and we also determined the KD of this interaction. In addition, structural modeling of the GARP2 domain confirms that GARP2 entails a HTH motif, and that protein-DNA interaction most likely occurs via the α3-helix and the N-terminal arm of this domain since mutations in this region hinder ARR2's ability to activate transcription.
Collapse
Affiliation(s)
- Janine Rieger
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Michael Fitz
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Stefan Markus Fischer
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Niklas Wallmeroth
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Hector Flores-Romero
- Interfaculty Institute of Biochemistry (IFIB), Tübingen University, 72076 Tübingen, Germany
- CECAD Research Center, Institute of Genetics, Cologne University, 51069 Cologne, Germany
| | - Nina Monika Fischer
- Institute for Bioinformatics and Medical Informatics, Tübingen University, 72076 Tübingen, Germany
| | - Luise Helene Brand
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| | - Ana J. García-Sáez
- Interfaculty Institute of Biochemistry (IFIB), Tübingen University, 72076 Tübingen, Germany
- CECAD Research Center, Institute of Genetics, Cologne University, 51069 Cologne, Germany
| | | | - Virtudes Mira-Rodado
- Center for Plant Molecular Biology (ZMBP), Tübingen University, 72076 Tübingen, Germany
| |
Collapse
|
4
|
Investigating Plant Protein-Protein Interactions Using FRET-FLIM with a Focus on the Actin Cytoskeleton. Methods Mol Biol 2023; 2604:353-366. [PMID: 36773249 DOI: 10.1007/978-1-0716-2867-6_29] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/12/2023]
Abstract
The study of protein-protein interactions is fundamental to understanding how actin-dependent processes are controlled through the regulation of actin-binding proteins by their interactors. FRET-FLIM (Förster resonance energy transfer-fluorescence lifetime imaging microscopy) is a sensitive bioimaging method to detect protein-protein interactions in living cells through measurement of FRET, facilitated by the interactions of fluorophore-tagged fusion protein. As a sensitive and noninvasive method for the spatiotemporal visualization of dynamic protein-protein interactions, FRET-FLIM holds several advantages over other methods of protein interaction assays. FRET-FLIM has been widely employed to characterize many plant protein interactions, including interactions between actin-regulatory proteins and their binding partners. As we increasingly understand the plant actin cytoskeleton to coordinate a diverse number of complex functions, the study of actin-regulatory proteins and their interactors becomes increasingly technically challenging. Sophisticated and sensitive in vivo methods such as FRET-FLIM are likely to be crucial to the study of protein-protein interactions as more complex and challenging hypotheses are addressed.
Collapse
|
5
|
Gao L, Lin F, Han D, Jiang J, Yang C, Zhuang Z, Chen T. Quantitative Fluorescence Resonance Energy Transfer Analysis on the Direct Interaction of Activation-2b with Histone H3/Switch-3B Protein in Arabidopsis Mesophyll Protoplasts. J Fluoresc 2021; 31:981-988. [PMID: 33880705 DOI: 10.1007/s10895-021-02728-x] [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: 01/24/2021] [Accepted: 03/23/2021] [Indexed: 11/30/2022]
Abstract
Interaction between the alteration/deficiency in activation-2b (ADA2b) and histone H3/switch-3B (SWI3B) proteins was evaluated in arabidopsis mesophyll protoplasts by quantitative fluorescence resonance energy transfer (FRET) analysis. Microscopic image showed that ADA2b, SWI3B and H3 proteins colocalized in nucleus, and quantitative FRET measurements showed 0.31 of FRET efficiency (E) for the protoplasts coexpressing ECFP-ADA2b and EYFP-SWI3B, and 0.285 of E for the protoplasts coexpressing ECFP-H3 and EYFP-ADA2b, demonstrating the direct interaction of ADA2b with SWI3B/H3 protein. Collectively, SWI3B and H3 proteins are the inherent components of the ADA2b complex in which ADA2b directly interacts with SWI3B/H3 protein.
Collapse
Affiliation(s)
- Lu Gao
- MOE Key Laboratory of Laser Life Science & College of Life Science, South China Normal University, Guangzhou, 510631, China
| | - Fangrui Lin
- Key Laboratory of Optoelectronic Devices and Systems of Guangdong Province & Ministry of Education, College of Physics and Optoelectronic Engineering, Shenzhen University, Shenzhen, 518060, Guangdong Province, China
| | - Danlu Han
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou, 510631, China
| | - Jieming Jiang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou, 510631, China
| | - Chengwei Yang
- Guangdong Provincial Key Laboratory of Biotechnology for Plant Development, School of Life Science, South China Normal University, Guangzhou, 510631, China
| | - Zhengfei Zhuang
- SCNU Qingyuan Institute of Science and Technology Innovation Co., Ltd., Qingyuan, 511517, China.
| | - Tongsheng Chen
- MOE Key Laboratory of Laser Life Science & College of Life Science, South China Normal University, Guangzhou, 510631, China.
| |
Collapse
|
6
|
Chen Q, Yu F, Xie Q. Insights into endoplasmic reticulum-associated degradation in plants. THE NEW PHYTOLOGIST 2020; 226:345-350. [PMID: 31838748 DOI: 10.1111/nph.16369] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2019] [Accepted: 11/22/2019] [Indexed: 06/10/2023]
Abstract
Secretory and transmembrane protein synthesis and initial modification are essential processes in protein maturation, and these processes are important for maintaining protein homeostasis in the endoplasmic reticulum (ER). ER homeostasis can be disrupted by the accumulation of misfolded proteins, resulting in ER stress, due to specific intra- or extracellular stresses. Processes including the unfolded protein response (UPR), ER-associated degradation (ERAD) and autophagy are thought to play important roles in restoring ER homeostasis. Here, we focus on summarizing and analysing recent advances in our understanding of the role of ERAD in plant physiological processes, especially in plant adaption to biotic and abiotic stresses, and also identify several issues that still need to be resolved in this field.
Collapse
Affiliation(s)
- Qian Chen
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- State Key Laboratory of Agrobiotechnology and Ministry of Agriculture Key Laboratory of Plant Pathology, China Agricultural University, Beijing, 100193, China
| | - Feifei Yu
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
| | - Qi Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| |
Collapse
|
7
|
McBride Z, Chen D, Lee Y, Aryal UK, Xie J, Szymanski DB. A Label-free Mass Spectrometry Method to Predict Endogenous Protein Complex Composition. Mol Cell Proteomics 2019; 18:1588-1606. [PMID: 31186290 PMCID: PMC6683005 DOI: 10.1074/mcp.ra119.001400] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 06/05/2019] [Indexed: 12/15/2022] Open
Abstract
Information on the composition of protein complexes can accelerate mechanistic analyses of cellular systems. Protein complex composition identifies genes that function together and provides clues about regulation within and between cellular pathways. Cytosolic protein complexes control metabolic flux, signal transduction, protein abundance, and the activities of cytoskeletal and endomembrane systems. It has been estimated that one third of all cytosolic proteins in leaves exist in an oligomeric state, yet the composition of nearly all remain unknown. Subunits of stable protein complexes copurify, and combinations of mass-spectrometry-based protein correlation profiling and bioinformatic analyses have been used to predict protein complex subunits. Because of uncertainty regarding the power or availability of bioinformatic data to inform protein complex predictions across diverse species, it would be highly advantageous to predict composition based on elution profile data alone. Here we describe a mass spectrometry-based protein correlation profiling approach to predict the composition of hundreds of protein complexes based on biochemical data. Extracts were obtained from an intact organ and separated in parallel by size and charge under nondenaturing conditions. More than 1000 proteins with reproducible elution profiles across all replicates were subjected to clustering analyses. The resulting dendrograms were used to predict the composition of known and novel protein complexes, including many that are likely to assemble through self-interaction. An array of validation experiments demonstrated that this new method can drive protein complex discovery, guide hypothesis testing, and enable systems-level analyses of protein complex dynamics in any organism with a sequenced genome.
Collapse
Affiliation(s)
- Zachary McBride
- ‡Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana
| | - Donglai Chen
- §Department of Statistics, Purdue University, West Lafayette, Indiana
| | - Youngwoo Lee
- ‡Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana
| | - Uma K Aryal
- ¶Purdue Proteomics Facility, Bindley Biosciences Center, Discovery Park, Purdue University, West Lafayette, Indiana
| | - Jun Xie
- §Department of Statistics, Purdue University, West Lafayette, Indiana
| | - Daniel B Szymanski
- ‡Department of Botany and Plant Pathology, Purdue University, West Lafayette, Indiana; ‖Department of Biological Sciences,Purdue University, West Lafayette, Indiana.
| |
Collapse
|
8
|
Guo P, Driver D, Zhao Z, Zheng Z, Chan C, Cheng X. Controlling the Revolving and Rotating Motion Direction of Asymmetric Hexameric Nanomotor by Arginine Finger and Channel Chirality. ACS NANO 2019; 13:6207-6223. [PMID: 31067030 PMCID: PMC6595433 DOI: 10.1021/acsnano.8b08849] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
Nanomotors in nanotechnology are as important as engines in daily life. Many ATPases are nanoscale biomotors classified into three categories based on the motion mechanisms in transporting substrates: linear, rotating, and the recently discovered revolving motion. Most biomotors adopt a multisubunit ring-shaped structure that hydrolyzes ATP to generate force. How these biomotors control the motion direction and regulate the sequential action of their multiple subunits is intriguing. Many ATPases are hexameric with each monomer containing a conserved arginine finger. This review focuses on recent findings on how the arginine finger controls motion direction and coordinates adjacent subunit interactions in both revolving and rotating biomotors. Mechanisms of intersubunit interactions and sequential movements of individual subunits are evidenced by the asymmetrical appearance of one dimer and four monomers in high-resolution structural complexes. The arginine finger is situated at the interface of two subunits and extends into the ATP binding pocket of the downstream subunit. An arginine finger mutation results in deficiency in ATP binding/hydrolysis, substrate binding, and transport, highlighting the importance of the arginine finger in regulating energy transduction and motor function. Additionally, the roles of channel chirality and channel size are discussed as related to controlling one-way trafficking and differentiating the revolving and rotating mechanisms. Finally, the review concludes by discussing the conformational changes and entropy conversion triggered by ATP binding/hydrolysis, offering a view different from the traditional concept of ATP-mediated mechanochemical energy coupling. The elucidation of the motion mechanism and direction control in ATPases could facilitate nanomotor fabrication in nanotechnology.
Collapse
Affiliation(s)
- Peixuan Guo
- Center
for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy
and College of Medicine, Dorothy M. Davis Heart and Lung Research
Institute, Comprehensive Cancer Center and College of Pharmacy, Biophysics
Graduate Program, Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio 43210, United
States
- E-mail:
| | - Dana Driver
- Center
for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy
and College of Medicine, Dorothy M. Davis Heart and Lung Research
Institute, Comprehensive Cancer Center and College of Pharmacy, Biophysics
Graduate Program, Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio 43210, United
States
| | - Zhengyi Zhao
- Center
for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy
and College of Medicine, Dorothy M. Davis Heart and Lung Research
Institute, Comprehensive Cancer Center and College of Pharmacy, Biophysics
Graduate Program, Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio 43210, United
States
| | - Zhen Zheng
- Center
for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy
and College of Medicine, Dorothy M. Davis Heart and Lung Research
Institute, Comprehensive Cancer Center and College of Pharmacy, Biophysics
Graduate Program, Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio 43210, United
States
| | - Chun Chan
- Center
for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy
and College of Medicine, Dorothy M. Davis Heart and Lung Research
Institute, Comprehensive Cancer Center and College of Pharmacy, Biophysics
Graduate Program, Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio 43210, United
States
| | - Xiaolin Cheng
- Center
for RNA Nanobiotechnology and Nanomedicine, College of Pharmacy
and College of Medicine, Dorothy M. Davis Heart and Lung Research
Institute, Comprehensive Cancer Center and College of Pharmacy, Biophysics
Graduate Program, Translational Data Analytics Institute, The Ohio State University, Columbus, Ohio 43210, United
States
| |
Collapse
|
9
|
Bègue H, Mounier A, Rosnoblet C, Wendehenne D. Toward the understanding of the role of CDC48, a major component of the protein quality control, in plant immunity. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2019; 279:34-44. [PMID: 30709491 DOI: 10.1016/j.plantsci.2018.10.029] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/27/2018] [Revised: 10/29/2018] [Accepted: 10/31/2018] [Indexed: 06/09/2023]
Abstract
The evolutionally conserved chaperone-like protein CDC48 (cell division cycle 48) is a major component of ubiquitin-dependent protein degradation pathways in animal and yeast and, more generally, of the protein quality control machinery. In plants, CDC48 plays essential regulatory functions in development and the possibly that it contributes to protein degradation through the ubiquitin-proteasome system (UPS) and the endoplasmic reticulum-associated protein degradation (ERAD) system has been reported. In this review we described recent findings highlighting a role for CDC48 in plant immunity. First data indicated that CDC48 is S-nitrosylated in plant cells undergoing an immune response, regulates the turnover of immune receptors and mediates the degradation of viral proteins. Furthermore its overexpression was associated to an exacerbated hypersensitive-like cell death. We also designed and reported here the first CDC48 interactome. The corresponding data confirm the closed interaction of CDC48 with components of the UPS and shed light on its putative regulatory function of S-adenosyl-methionine synthesis and metabolism. More generally, these investigations further support the concept that plant cells facing pathogen attack finely regulate the protein quality control machinery.
Collapse
Affiliation(s)
- Hervé Bègue
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne, Univ. Bourgogne Franche-Comté, F-21000, Dijon, France.
| | - Arnaud Mounier
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne, Univ. Bourgogne Franche-Comté, F-21000, Dijon, France
| | - Claire Rosnoblet
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne, Univ. Bourgogne Franche-Comté, F-21000, Dijon, France
| | - David Wendehenne
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne, Univ. Bourgogne Franche-Comté, F-21000, Dijon, France.
| |
Collapse
|
10
|
Wang L, Xue Y, Xing J, Song K, Lin J. Exploring the Spatiotemporal Organization of Membrane Proteins in Living Plant Cells. ANNUAL REVIEW OF PLANT BIOLOGY 2018; 69:525-551. [PMID: 29489393 DOI: 10.1146/annurev-arplant-042817-040233] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
Plasma membrane proteins have important roles in transport and signal transduction. Deciphering the spatiotemporal organization of these proteins provides crucial information for elucidating the links between the behaviors of different molecules. However, monitoring membrane proteins without disrupting their membrane environment remains difficult. Over the past decade, many studies have developed single-molecule techniques, opening avenues for probing the stoichiometry and interactions of membrane proteins in their native environment by providing nanometer-scale spatial information and nanosecond-scale temporal information. In this review, we assess recent progress in the development of labeling and imaging technology for membrane protein analysis. We focus in particular on several single-molecule techniques for quantifying the dynamics and assembly of membrane proteins. Finally, we provide examples of how these new techniques are advancing our understanding of the complex biological functions of membrane proteins.
Collapse
Affiliation(s)
- Li Wang
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China;
- Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- College of Horticulture and Plant Protection, Yangzhou University, Yangzhou 225009, China
| | - Yiqun Xue
- Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Jingjing Xing
- Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Kai Song
- Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
| | - Jinxing Lin
- Beijing Advanced Innovation Center for Tree Breeding by Molecular Design, Beijing Forestry University, Beijing 100083, China;
- Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| |
Collapse
|
11
|
Bassard JE, Halkier BA. How to prove the existence of metabolons? PHYTOCHEMISTRY REVIEWS : PROCEEDINGS OF THE PHYTOCHEMICAL SOCIETY OF EUROPE 2018; 17:211-227. [PMID: 29755303 PMCID: PMC5932110 DOI: 10.1007/s11101-017-9509-1] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/09/2016] [Accepted: 04/19/2017] [Indexed: 05/21/2023]
Abstract
Sequential enzymes in biosynthetic pathways are organized in metabolons. It is challenging to provide experimental evidence for the existence of metabolons as biosynthetic pathways are composed of highly dynamic protein-protein interactions. Many different methods are being applied, each with strengths and weaknesses. We will present and evaluate several techniques that have been applied in providing evidence for the orchestration of the biosynthetic pathways of cyanogenic glucosides and glucosinolates in metabolons. These evolutionarily related pathways have ER-localized cytochromes P450 that are proposed to function as anchoring site for assembly of the enzymes into metabolons. Additionally, we have included commonly used techniques, even though they have not been used (yet) on these two pathways. In the review, special attention will be given to less-exploited fluorescence-based methods such as FCS and FLIM. Ultimately, understanding the orchestration of biosynthetic pathways may contribute to successful engineering in heterologous hosts.
Collapse
Affiliation(s)
- Jean-Etienne Bassard
- Plant Biochemistry Laboratory, Center for Synthetic Biology, VILLUM Research Center “Plant Plasticity”, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Barbara Ann Halkier
- DynaMo Center, Department of Plant and Environmental Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
12
|
Rosnoblet C, Bègue H, Blanchard C, Pichereaux C, Besson-Bard A, Aimé S, Wendehenne D. Functional characterization of the chaperon-like protein Cdc48 in cryptogein-induced immune response in tobacco. PLANT, CELL & ENVIRONMENT 2017; 40:491-508. [PMID: 26662183 DOI: 10.1111/pce.12686] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/02/2015] [Revised: 11/20/2015] [Accepted: 11/27/2015] [Indexed: 05/06/2023]
Abstract
Cdc48, a molecular chaperone conserved in different kingdoms, is a member of the AAA+ family contributing to numerous processes in mammals including proteins quality control and degradation, vesicular trafficking, autophagy and immunity. The functions of Cdc48 plant orthologues are less understood. We previously reported that Cdc48 is regulated by S-nitrosylation in tobacco cells undergoing an immune response triggered by cryptogein, an elicitin produced by the oomycete Phytophthora cryptogea. Here, we inv estigated the function of NtCdc48 in cryptogein signalling and induced hypersensitive-like cell death. NtCdc48 was found to accumulate in elicited cells at both the protein and transcript levels. Interestingly, only a small proportion of the overall NtCdc48 population appeared to be S-nitrosylated. Using gel filtration in native conditions, we confirmed that NtCdc48 was present in its hexameric active form. An immunoprecipitation-based strategy following my mass spectrometry analysis led to the identification of about a hundred NtCdc48 partners and underlined its contribution in cellular processes including targeting of ubiquitylated proteins for proteasome-dependent degradation, subcellular trafficking and redox regulation. Finally, the analysis of cryptogein-induced events in NtCdc48-overexpressing cells highlighted a correlation between NtCdc48 expression and hypersensitive cell death. Altogether, this study identified NtCdc48 as a component of cryptogein signalling and plant immunity.
Collapse
Affiliation(s)
- Claire Rosnoblet
- Pôle Mécanisme et Gestion des Interactions Plantes-Microorganismes - ERL CNRS 6300, Université de Bourgogne Franche-Comté, UMR 1347 Agroécologie, 17 rue Sully, BP 86510, 21065, Dijon cédex, France
| | - Hervé Bègue
- Pôle Mécanisme et Gestion des Interactions Plantes-Microorganismes - ERL CNRS 6300, Université de Bourgogne Franche-Comté, UMR 1347 Agroécologie, 17 rue Sully, BP 86510, 21065, Dijon cédex, France
| | - Cécile Blanchard
- Pôle Mécanisme et Gestion des Interactions Plantes-Microorganismes - ERL CNRS 6300, Université de Bourgogne Franche-Comté, UMR 1347 Agroécologie, 17 rue Sully, BP 86510, 21065, Dijon cédex, France
| | - Carole Pichereaux
- Fédération de Recherche 3450, Agrobiosciences, Interactions et Biodiversité, CNRS, 31326, Castanet-Tolosan, France
- Institut de Pharmacologie et de Biologie Structurale - CNRS, Université de Toulouse, 205 route de Narbonne,, 31077, Toulouse, France
| | - Angélique Besson-Bard
- Pôle Mécanisme et Gestion des Interactions Plantes-Microorganismes - ERL CNRS 6300, Université de Bourgogne Franche-Comté, UMR 1347 Agroécologie, 17 rue Sully, BP 86510, 21065, Dijon cédex, France
| | - Sébastien Aimé
- INRA, UMR 1347 Agroécologie, Pôle Mécanisme et Gestion des Interactions Plantes-Microorganismes - ERL CNRS 6300, 17 rue Sully, BP 86510, 21065, Dijon cédex, France
| | - David Wendehenne
- Pôle Mécanisme et Gestion des Interactions Plantes-Microorganismes - ERL CNRS 6300, Université de Bourgogne Franche-Comté, UMR 1347 Agroécologie, 17 rue Sully, BP 86510, 21065, Dijon cédex, France
| |
Collapse
|
13
|
Sysoeva TA. Assessing heterogeneity in oligomeric AAA+ machines. Cell Mol Life Sci 2017; 74:1001-1018. [PMID: 27669691 PMCID: PMC11107579 DOI: 10.1007/s00018-016-2374-z] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2016] [Revised: 09/13/2016] [Accepted: 09/19/2016] [Indexed: 10/20/2022]
Abstract
ATPases Associated with various cellular Activities (AAA+ ATPases) are molecular motors that use the energy of ATP binding and hydrolysis to remodel their target macromolecules. The majority of these ATPases form ring-shaped hexamers in which the active sites are located at the interfaces between neighboring subunits. Structural changes initiate in an active site and propagate to distant motor parts that interface and reshape the target macromolecules, thereby performing mechanical work. During the functioning cycle, the AAA+ motor transits through multiple distinct states. Ring architecture and placement of the catalytic sites at the intersubunit interfaces allow for a unique level of coordination among subunits of the motor. This in turn results in conformational differences among subunits and overall asymmetry of the motor ring as it functions. To date, a large amount of structural information has been gathered for different AAA+ motors, but even for the most characterized of them only a few structural states are known and the full mechanistic cycle cannot be yet reconstructed. Therefore, the first part of this work will provide a broad overview of what arrangements of AAA+ subunits have been structurally observed focusing on diversity of ATPase oligomeric ensembles and heterogeneity within the ensembles. The second part of this review will concentrate on methods that assess structural and functional heterogeneity among subunits of AAA+ motors, thus bringing us closer to understanding the mechanism of these fascinating molecular motors.
Collapse
Affiliation(s)
- Tatyana A Sysoeva
- Department of Biomedical Engineering, Duke University, Durham, NC, 27708, USA.
| |
Collapse
|
14
|
Bègue H, Jeandroz S, Blanchard C, Wendehenne D, Rosnoblet C. Structure and functions of the chaperone-like p97/CDC48 in plants. Biochim Biophys Acta Gen Subj 2016; 1861:3053-3060. [PMID: 27717811 DOI: 10.1016/j.bbagen.2016.10.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2016] [Revised: 09/29/2016] [Accepted: 10/01/2016] [Indexed: 12/15/2022]
Abstract
BACKGROUND The chaperone-like p97 is a member of the AAA+ ATPase enzyme family that contributes to numerous cellular activities. P97 has been broadly studied in mammals (VCP/p97) and yeasts (CDC48: Cell Division Cycle 48/p97) and numerous investigations highlighted that this protein is post-translationally regulated, is structured in homohexamer and interacts with partners and cofactors that direct it to distinct cellular signalization pathway including protein quality control and degradation, cell cycle regulation, genome stability, vesicular trafficking, autophagy and immunity. SCOPE OF REVIEW p97 is also conserved in plants (CDC48) but its functions are less understood. In the present review we intended to present the state of the art of the structure, regulation and functions of CDC48 in plants. MAJOR CONCLUSIONS Evidence accumulated underline that CDC48 plays a crucial role in development, cell cycle regulation and protein turnover in plants. Furthermore, its involvement in plant immunity has recently emerged and first interacting partners have been identified, shedding light on its putative cellular activities. GENERAL SIGNIFICANCE Identification of emerging functions of CDC48 in plants opens new roads of research in immunity and provides new insights into the mechanisms of protein quality control.
Collapse
Affiliation(s)
- Hervé Bègue
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Sylvain Jeandroz
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Cécile Blanchard
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne Franche-Comté, F-21000 Dijon, France
| | - David Wendehenne
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne Franche-Comté, F-21000 Dijon, France
| | - Claire Rosnoblet
- Agroécologie, AgroSup Dijon, CNRS, INRA, Univ. Bourgogne Franche-Comté, F-21000 Dijon, France.
| |
Collapse
|
15
|
Copeland C, Woloshen V, Huang Y, Li X. AtCDC48A is involved in the turnover of an NLR immune receptor. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2016; 88:294-305. [PMID: 27340941 DOI: 10.1111/tpj.13251] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 05/27/2016] [Accepted: 06/21/2016] [Indexed: 05/20/2023]
Abstract
Plants rely on different immune receptors to recognize pathogens and defend against pathogen attacks. Nucleotide-binding domain and leucine-rich repeat (NLR) proteins play a major role as intracellular immune receptors. Their homeostasis must be maintained at optimal levels in order to effectively recognize pathogens without causing autoimmunity. Previous studies have shown that the activity of the ubiquitin-proteasome system is essential to prevent excessive accumulation of NLR proteins such as Suppressor of NPR1, Constitutive 1 (SNC1). Attenuation of the ubiquitin E3 ligase SCFCPR1 (Constitutive expressor of Pathogenesis Related genes 1) or the E4 protein MUSE3 (Mutant, SNC1-Enhancing 3) leads to NLR accumulation and autoimmunity. In the current study, we report the identification of AtCDC48A as a negative regulator of NLR-mediated immunity. Plants carrying Atcdc48A-4, a partial loss-of-function allele of AtCDC48A, exhibit dwarf morphology and enhanced disease resistance to the oomycete pathogen Hyaloperonospora arabidopsidis (H.a.) Noco2. The SNC1 level is increased in Atcdc48A-4 plants and AtCDC48A interacts with MUSE3 in co-immunoprecipitation experiments, supporting a role for AtCDC48A in NLR turnover. While Arabidopsis contains four other paralogs of AtCDC48A, knockout mutants of these genes do not show obvious immunity-related phenotypes, suggesting functional divergence within this family. As an AAA-ATPase, AtCDC48A likely serves to process the poly-ubiquitinated NLR substrate for final protein degradation by the 26S proteasome.
Collapse
Affiliation(s)
- Charles Copeland
- Michael Smith Laboratories and Botany Department, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Virginia Woloshen
- Michael Smith Laboratories and Botany Department, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Yan Huang
- Michael Smith Laboratories and Botany Department, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| | - Xin Li
- Michael Smith Laboratories and Botany Department, University of British Columbia, Vancouver, BC, V6T 1Z4, Canada
| |
Collapse
|
16
|
Li X, Xing J, Qiu Z, He Q, Lin J. Quantification of Membrane Protein Dynamics and Interactions in Plant Cells by Fluorescence Correlation Spectroscopy. MOLECULAR PLANT 2016; 9:1229-1239. [PMID: 27381442 DOI: 10.1016/j.molp.2016.06.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2016] [Revised: 06/25/2016] [Accepted: 06/27/2016] [Indexed: 05/25/2023]
Abstract
Deciphering the dynamics of protein and lipid molecules on appropriate spatial and temporal scales may shed light on protein function and membrane organization. However, traditional bulk approaches cannot unambiguously quantify the extremely diverse mobility and interactions of proteins in living cells. Fluorescence correlation spectroscopy (FCS) is a powerful technique to describe events that occur at the single-molecule level and on the nanosecond to second timescales; therefore, FCS can provide data on the heterogeneous organization of membrane systems. FCS can also be combined with other microscopy techniques, such as super-resolution techniques. More importantly, FCS is minimally invasive, which makes it an ideal approach to detect the heterogeneous distribution and dynamics of key proteins during development. In this review, we give a brief introduction about the development of FCS and summarize the significant contributions of FCS in understanding the organization of plant cell membranes and the dynamics and interactions of membrane proteins. We also discuss the potential applications of this technique in plant biology.
Collapse
Affiliation(s)
- Xiaojuan Li
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China
| | - Jingjing Xing
- Key Laboratory of Plant Resources, Institute of Botany, Chinese Academy of Sciences, Beijing 100093, China; University of Chinese Academy of Sciences, Beijing 10049, China
| | - Zongbo Qiu
- College of Life Sciences, Henan Normal University, Xinxiang 453007, China
| | - Qihua He
- The Health Science Center, Peking University, Beijing 100191, China
| | - Jinxing Lin
- College of Biological Sciences and Biotechnology, Beijing Forestry University, Beijing 100083, China.
| |
Collapse
|
17
|
Zhou M, Li Q, Wang R. Current Experimental Methods for Characterizing Protein-Protein Interactions. ChemMedChem 2016; 11:738-56. [PMID: 26864455 PMCID: PMC7162211 DOI: 10.1002/cmdc.201500495] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 01/08/2016] [Indexed: 12/14/2022]
Abstract
Protein molecules often interact with other partner protein molecules in order to execute their vital functions in living organisms. Characterization of protein-protein interactions thus plays a central role in understanding the molecular mechanism of relevant protein molecules, elucidating the cellular processes and pathways relevant to health or disease for drug discovery, and charting large-scale interaction networks in systems biology research. A whole spectrum of methods, based on biophysical, biochemical, or genetic principles, have been developed to detect the time, space, and functional relevance of protein-protein interactions at various degrees of affinity and specificity. This article presents an overview of these experimental methods, outlining the principles, strengths and limitations, and recent developments of each type of method.
Collapse
Affiliation(s)
- Mi Zhou
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Qing Li
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Renxiao Wang
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China.
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Avenida Wai Long, Macau, 999078, People's Republic of China.
| |
Collapse
|
18
|
Zhou M, Li Q, Wang R. Current Experimental Methods for Characterizing Protein-Protein Interactions. ChemMedChem 2016. [PMID: 26864455 DOI: 10.1002/cmdc.201500495.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Protein molecules often interact with other partner protein molecules in order to execute their vital functions in living organisms. Characterization of protein-protein interactions thus plays a central role in understanding the molecular mechanism of relevant protein molecules, elucidating the cellular processes and pathways relevant to health or disease for drug discovery, and charting large-scale interaction networks in systems biology research. A whole spectrum of methods, based on biophysical, biochemical, or genetic principles, have been developed to detect the time, space, and functional relevance of protein-protein interactions at various degrees of affinity and specificity. This article presents an overview of these experimental methods, outlining the principles, strengths and limitations, and recent developments of each type of method.
Collapse
Affiliation(s)
- Mi Zhou
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Qing Li
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Renxiao Wang
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China. .,State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Avenida Wai Long, Macau, 999078, People's Republic of China.
| |
Collapse
|
19
|
Shu D, Pi F, Wang C, Zhang P, Guo P. New approach to develop ultra-high inhibitory drug using the power function of the stoichiometry of the targeted nanomachine or biocomplex. Nanomedicine (Lond) 2016; 10:1881-97. [PMID: 26139124 DOI: 10.2217/nnm.15.37] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
AIMS To find methods for potent drug development by targeting to biocomplex with high copy number. METHODS Phi29 DNA packaging motor components with different stoichiometries were used as model to assay virion assembly with Yang Hui's Triangle [Formula: see text], where Z = stoichiometry, M = drugged subunits per biocomplex, p and q are the fraction of drugged and undrugged subunits in the population. RESULTS Inhibition efficiency follows a power function. When number of drugged subunits to block the function of the complex K = 1, the uninhibited biocomplex equals q(z), demonstrating the multiplicative effect of stoichiometry on inhibition with stoichiometry 1000 > 6 > 1. Complete inhibition of virus replication was found when Z = 6. CONCLUSION Drug inhibition potency depends on the stoichiometry of the targeted components of the biocomplex or nanomachine. The inhibition effect follows a power function of the stoichiometry of the target biocomplex.
Collapse
Affiliation(s)
- Dan Shu
- Department of Pharmaceutical Sciences, Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - Fengmei Pi
- Department of Pharmaceutical Sciences, Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| | - Chi Wang
- Department of Biostatistics & Nanobiotechnology Center, University of Kentucky, Lexington, KY 40536, USA
| | - Peng Zhang
- Department of Surgery, University of Michigan Health System, Ann Arbor, MI 48109, USA
| | - Peixuan Guo
- Department of Pharmaceutical Sciences, Markey Cancer Center, University of Kentucky, Lexington, KY 40536, USA
| |
Collapse
|
20
|
Pi F, Vieweger M, Zhao Z, Wang S, Guo P. Discovery of a new method for potent drug development using power function of stoichiometry of homomeric biocomplexes or biological nanomotors. Expert Opin Drug Deliv 2015; 13:23-36. [PMID: 26307193 DOI: 10.1517/17425247.2015.1082544] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Multidrug resistance and the appearance of incurable diseases inspire the quest for potent therapeutics. AREAS COVERED We review a new methodology in designing potent drugs by targeting multi-subunit homomeric biological motors, machines or complexes with Z > 1 and K = 1, where Z is the stoichiometry of the target, and K is the number of drugged subunits required to block the function of the complex. The condition is similar to a series electrical circuit of Christmas decorations: failure of one light bulb causes the entire lighting system to lose power. In most multi-subunit, homomeric biological systems, a sequential coordination or cooperative action mechanism is utilized, thus K equals 1. Drug inhibition depends on the ratio of drugged to non-drugged complexes. When K = 1, and Z > 1, the inhibition effect follows a power law with respect to Z, leading to enhanced drug potency. The hypothesis that the potency of drug inhibition depends on the stoichiometry of the targeted biological complexes was recently quantified by Yang-Hui's Triangle (or binomial distribution), and proved using a highly sensitive in vitro phi29 viral DNA packaging system. Examples of targeting homomeric bio-complexes with high stoichiometry for potent drug discovery are discussed. EXPERT OPINION Biomotors with multiple subunits are widespread in viruses, bacteria and cells, making this approach generally applicable in the development of inhibition drugs with high efficiency.
Collapse
Affiliation(s)
- Fengmei Pi
- a 1 University of Kentucky, Nanobiotechnology Center , Lexington, KY 40536, USA.,b 2 University of Kentucky, Markey Cancer Center , Lexington, KY 40536, USA.,c 3 University of Kentucky, Department of Pharmaceutical Sciences , 789 S. Limestone Street, Room # 576, Lexington, KY 40536, USA +1 859 218 0128 ; +1 859 257 1307 ;
| | - Mario Vieweger
- a 1 University of Kentucky, Nanobiotechnology Center , Lexington, KY 40536, USA.,b 2 University of Kentucky, Markey Cancer Center , Lexington, KY 40536, USA.,c 3 University of Kentucky, Department of Pharmaceutical Sciences , 789 S. Limestone Street, Room # 576, Lexington, KY 40536, USA +1 859 218 0128 ; +1 859 257 1307 ;
| | - Zhengyi Zhao
- a 1 University of Kentucky, Nanobiotechnology Center , Lexington, KY 40536, USA.,b 2 University of Kentucky, Markey Cancer Center , Lexington, KY 40536, USA.,c 3 University of Kentucky, Department of Pharmaceutical Sciences , 789 S. Limestone Street, Room # 576, Lexington, KY 40536, USA +1 859 218 0128 ; +1 859 257 1307 ;
| | - Shaoying Wang
- a 1 University of Kentucky, Nanobiotechnology Center , Lexington, KY 40536, USA.,b 2 University of Kentucky, Markey Cancer Center , Lexington, KY 40536, USA.,c 3 University of Kentucky, Department of Pharmaceutical Sciences , 789 S. Limestone Street, Room # 576, Lexington, KY 40536, USA +1 859 218 0128 ; +1 859 257 1307 ;
| | - Peixuan Guo
- a 1 University of Kentucky, Nanobiotechnology Center , Lexington, KY 40536, USA.,b 2 University of Kentucky, Markey Cancer Center , Lexington, KY 40536, USA.,c 3 University of Kentucky, Department of Pharmaceutical Sciences , 789 S. Limestone Street, Room # 576, Lexington, KY 40536, USA +1 859 218 0128 ; +1 859 257 1307 ;
| |
Collapse
|
21
|
Investigating protein-protein interactions in the plant endomembrane system using multiphoton-induced FRET-FLIM. Methods Mol Biol 2015; 1209:81-95. [PMID: 25117276 DOI: 10.1007/978-1-4939-1420-3_6] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
Real-time noninvasive fluorescence-based protein assays enable a direct access to study interactions in their natural environment and hence overcome the limitations of other methods that rely on invasive cell disruption techniques. The determination of Förster resonance energy transfer (FRET) by means of fluorescence lifetime imaging microscopy (FLIM) is currently the most advanced method to observe protein-protein interactions at nanometer resolution inside single living cells and in real-time. In the FRET-FLIM approach, the information gained using steady-state FRET between interacting proteins is considerably improved by monitoring changes in the excited-state lifetime of the donor fluorophore where its quenching in the presence of the acceptor is evidence for a direct physical interaction. The combination of confocal laser scanning microscopy with the sensitive advanced technique of time-correlated single photon counting allows the mapping of the spatial distribution of fluorescence lifetimes inside living cells on a pixel-by-pixel basis that is the same as the fluorescence image. Moreover, the use of multiphoton excitation particularly for plant cells provides further advantages such as reduced phototoxicity and photobleaching. In this protocol, we briefly describe the instrumentation and experimental design to study protein interactions within the plant endomembrane system, with a focus on the imaging of plant cells expressing fluorescent proteins and acquisition and analysis of fluorescence lifetime resolved data.
Collapse
|
22
|
Common mechanisms of DNA translocation motors in bacteria and viruses using one-way revolution mechanism without rotation. Biotechnol Adv 2015; 32:853-72. [PMID: 24913057 DOI: 10.1016/j.biotechadv.2014.01.006] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2013] [Revised: 01/24/2014] [Accepted: 01/25/2014] [Indexed: 12/15/2022]
Abstract
Biomotors were once described into two categories: linear motor and rotation motor. Recently, a third type of biomotor with revolution mechanism without rotation has been discovered. By analogy, rotation resembles the Earth rotating on its axis in a complete cycle every 24h, while revolution resembles the Earth revolving around the Sun one circle per 365 days (see animations http://nanobio.uky.edu/movie.html). The action of revolution that enables a motor free of coiling and torque has solved many puzzles and debates that have occurred throughout the history of viral DNA packaging motor studies. It also settles the discrepancies concerning the structure, stoichiometry, and functioning of DNA translocation motors. This review uses bacteriophages Phi29, HK97, SPP1, P22, T4, and T7 as well as bacterial DNA translocase FtsK and SpoIIIE or the large eukaryotic dsDNA viruses such as mimivirus and vaccinia virus as examples to elucidate the puzzles. These motors use ATPase, some of which have been confirmed to be a hexamer, to revolve around the dsDNA sequentially. ATP binding induces conformational change and possibly an entropy alteration in ATPase to a high affinity toward dsDNA; but ATP hydrolysis triggers another entropic and conformational change in ATPase to a low affinity for DNA, by which dsDNA is pushed toward an adjacent ATPase subunit. The rotation and revolution mechanisms can be distinguished by the size of channel: the channels of rotation motors are equal to or smaller than 2 nm, that is the size of dsDNA, whereas channels of revolution motors are larger than 3 nm. Rotation motors use parallel threads to operate with a right-handed channel, while revolution motors use a left-handed channel to drive the right-handed DNA in an anti-chiral arrangement. Coordination of several vector factors in the same direction makes viral DNA-packaging motors unusually powerful and effective. Revolution mechanism that avoids DNA coiling in translocating the lengthy genomic dsDNA helix could be advantageous for cell replication such as bacterial binary fission and cell mitosis without the need for topoisomerase or helicase to consume additional energy.
Collapse
|
23
|
Jarsch IK, Konrad SSA, Stratil TF, Urbanus SL, Szymanski W, Braun P, Braun KH, Ott T. Plasma Membranes Are Subcompartmentalized into a Plethora of Coexisting and Diverse Microdomains in Arabidopsis and Nicotiana benthamiana. THE PLANT CELL 2014; 26:1698-1711. [PMID: 24714763 PMCID: PMC4036580 DOI: 10.1105/tpc.114.124446] [Citation(s) in RCA: 118] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Revised: 03/17/2014] [Accepted: 03/24/2014] [Indexed: 05/19/2023]
Abstract
Eukaryotic plasma membranes are highly compartmentalized structures. So far, only a few individual proteins that function in a wide range of cellular processes have been shown to segregate into microdomains. However, the biological roles of most microdomain-associated proteins are unknown. Here, we investigated the heterogeneity of distinct microdomains and the complexity of their coexistence. This diversity was determined in living cells of intact multicellular tissues using 20 different marker proteins from Arabidopsis thaliana, mostly belonging to the Remorin protein family. These proteins associate with microdomains at the cytosolic leaflet of the plasma membrane. We characterized these membrane domains and determined their lateral dynamics by extensive quantitative image analysis. Systematic colocalization experiments with an extended subset of marker proteins tested in 45 different combinations revealed the coexistence of highly distinct membrane domains on individual cell surfaces. These data provide valuable tools to study the lateral segregation of membrane proteins and their biological functions in living plant cells. They also demonstrate that widely used biochemical approaches such as detergent-resistant membranes cannot resolve this biological complexity of membrane compartmentalization in vivo.
Collapse
Affiliation(s)
- Iris K Jarsch
- Ludwig-Maximilians-University of Munich, Faculty of Biology, Institute of Genetics, 82152 Martinsried, Germany
| | - Sebastian S A Konrad
- Ludwig-Maximilians-University of Munich, Faculty of Biology, Institute of Genetics, 82152 Martinsried, Germany
| | - Thomas F Stratil
- Ludwig-Maximilians-University of Munich, Faculty of Biology, Institute of Genetics, 82152 Martinsried, Germany
| | - Susan L Urbanus
- Ludwig-Maximilians-University of Munich, Faculty of Biology, Institute of Genetics, 82152 Martinsried, Germany
| | - Witold Szymanski
- Max-Planck-Institute of Molecular Plant Physiology, 14476 Potsdam-Golm, Germany
| | - Pascal Braun
- Department of Plant Systems Biology, Center for Life and Food Sciences Weihenstephan, Technische Universität München, 85354 Freising-Weihenstephan, Germany
| | - Karl-Heinz Braun
- Ludwig-Maximilians-University of Munich, Faculty of Biology, Institute of Genetics, 82152 Martinsried, Germany
| | - Thomas Ott
- Ludwig-Maximilians-University of Munich, Faculty of Biology, Institute of Genetics, 82152 Martinsried, Germany
| |
Collapse
|
24
|
Kørner CJ, Klauser D, Niehl A, Domínguez-Ferreras A, Chinchilla D, Boller T, Heinlein M, Hann DR. The immunity regulator BAK1 contributes to resistance against diverse RNA viruses. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2013; 26:1271-80. [PMID: 23902263 DOI: 10.1094/mpmi-06-13-0179-r] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
The plant's innate immune system detects potential biotic threats through recognition of microbe-associated molecular patterns (MAMPs) or danger-associated molecular patterns (DAMPs) by pattern recognition receptors (PRR). A central regulator of pattern-triggered immunity (PTI) is the BRI1-associated kinase 1 (BAK1), which undergoes complex formation with PRR upon ligand binding. Although viral patterns inducing PTI are well known from animal systems, nothing similar has been reported for plants. Rather, antiviral defense in plants is thought to be mediated by post-transcriptional gene silencing of viral RNA or through effector-triggered immunity, i.e., recognition of virus-specific effectors by resistance proteins. Nevertheless, infection by compatible viruses can also lead to the induction of defense gene expression, indicating that plants may also recognize viruses through PTI. Here, we show that PTI, or at least the presence of the regulator BAK1, is important for antiviral defense of Arabidopsis plants. Arabidopsis bak1 mutants show increased susceptibility to three different RNA viruses during compatible interactions. Furthermore, crude viral extracts but not purified virions induce several PTI marker responses in a BAK1-dependent manner. Overall, we conclude that BAK1-dependent PTI contributes to antiviral resistance in plants.
Collapse
|
25
|
Guo P, Schwartz C, Haak J, Zhao Z. Discovery of a new motion mechanism of biomotors similar to the earth revolving around the sun without rotation. Virology 2013; 446:133-43. [PMID: 24074575 PMCID: PMC3941703 DOI: 10.1016/j.virol.2013.07.025] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 05/27/2013] [Accepted: 07/21/2013] [Indexed: 12/14/2022]
Abstract
Biomotors have been classified into linear and rotational motors. For 35 years, it has been popularly believed that viral dsDNA-packaging apparatuses are pentameric rotation motors. Recently, a third class of hexameric motor has been found in bacteriophage phi29 that utilizes a mechanism of revolution without rotation, friction, coiling, or torque. This review addresses how packaging motors control dsDNA one-way traffic; how four electropositive layers in the channel interact with the electronegative phosphate backbone to generate four steps in translocating one dsDNA helix; how motors resolve the mismatch between 10.5 bases and 12 connector subunits per cycle of revolution; and how ATP regulates sequential action of motor ATPase. Since motors with all number of subunits can utilize the revolution mechanism, this finding helps resolve puzzles and debates concerning the oligomeric nature of packaging motors in many phage systems. This revolution mechanism helps to solve the undesirable dsDNA supercoiling issue involved in rotation.
Collapse
Affiliation(s)
- Peixuan Guo
- Nanobiotechnology Center, and Markey Cancer Center, Department of Pharmaceutical Sciences, College of Pharmacy, University of Kentucky, Lexington, KY 40536, USA.
| | | | | | | |
Collapse
|
26
|
Schoberer J, Liebminger E, Botchway SW, Strasser R, Hawes C. Time-resolved fluorescence imaging reveals differential interactions of N-glycan processing enzymes across the Golgi stack in planta. PLANT PHYSIOLOGY 2013; 161:1737-54. [PMID: 23400704 PMCID: PMC3613452 DOI: 10.1104/pp.112.210757] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Accepted: 02/10/2013] [Indexed: 05/18/2023]
Abstract
N-Glycan processing is one of the most important cellular protein modifications in plants and as such is essential for plant development and defense mechanisms. The accuracy of Golgi-located processing steps is governed by the strict intra-Golgi localization of sequentially acting glycosidases and glycosyltransferases. Their differential distribution goes hand in hand with the compartmentalization of the Golgi stack into cis-, medial-, and trans-cisternae, which separate early from late processing steps. The mechanisms that direct differential enzyme concentration are still unknown, but the formation of multienzyme complexes is considered a feasible Golgi protein localization strategy. In this study, we used two-photon excitation-Förster resonance energy transfer-fluorescence lifetime imaging microscopy to determine the interaction of N-glycan processing enzymes with differential intra-Golgi locations. Following the coexpression of fluorescent protein-tagged amino-terminal Golgi-targeting sequences (cytoplasmic-transmembrane-stem [CTS] region) of enzyme pairs in leaves of tobacco (Nicotiana spp.), we observed that all tested cis- and medial-Golgi enzymes, namely Arabidopsis (Arabidopsis thaliana) Golgi α-mannosidase I, Nicotiana tabacum β1,2-N-acetylglucosaminyltransferase I, Arabidopsis Golgi α-mannosidase II (GMII), and Arabidopsis β1,2-xylosyltransferase, form homodimers and heterodimers, whereas among the late-acting enzymes Arabidopsis β1,3-galactosyltransferase1 (GALT1), Arabidopsis α1,4-fucosyltransferase, and Rattus norvegicus α2,6-sialyltransferase (a nonplant Golgi marker), only GALT1 and medial-Golgi GMII were found to form a heterodimer. Furthermore, the efficiency of energy transfer indicating the formation of interactions decreased considerably in a cis-to-trans fashion. The comparative fluorescence lifetime imaging of several full-length cis- and medial-Golgi enzymes and their respective catalytic domain-deleted CTS clones further suggested that the formation of protein-protein interactions can occur through their amino-terminal CTS region.
Collapse
Affiliation(s)
| | - Eva Liebminger
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria (J.S., E.L., R.S.)
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, United Kingdom (J.S., C.H.); and
- Research Complex at Harwell, Central Laser Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell-Oxford, Didcot OX11 0QX, United Kingdom (S.W.B.)
| | - Stanley W. Botchway
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria (J.S., E.L., R.S.)
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, United Kingdom (J.S., C.H.); and
- Research Complex at Harwell, Central Laser Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell-Oxford, Didcot OX11 0QX, United Kingdom (S.W.B.)
| | - Richard Strasser
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria (J.S., E.L., R.S.)
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, United Kingdom (J.S., C.H.); and
- Research Complex at Harwell, Central Laser Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell-Oxford, Didcot OX11 0QX, United Kingdom (S.W.B.)
| | - Chris Hawes
- Department of Applied Genetics and Cell Biology, University of Natural Resources and Life Sciences, Muthgasse 18, 1190 Vienna, Austria (J.S., E.L., R.S.)
- Department of Biological and Medical Sciences, Faculty of Health and Life Sciences, Oxford Brookes University, Headington, Oxford OX3 0BP, United Kingdom (J.S., C.H.); and
- Research Complex at Harwell, Central Laser Facility, Science and Technology Facilities Council, Rutherford Appleton Laboratory, Harwell-Oxford, Didcot OX11 0QX, United Kingdom (S.W.B.)
| |
Collapse
|
27
|
McMichael CM, Bednarek SY. Cytoskeletal and membrane dynamics during higher plant cytokinesis. THE NEW PHYTOLOGIST 2013; 197:1039-1057. [PMID: 23343343 DOI: 10.1111/nph.12122] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2012] [Accepted: 12/02/2012] [Indexed: 05/08/2023]
Abstract
Following mitosis, cytoplasm, organelles and genetic material are partitioned into daughter cells through the process of cytokinesis. In somatic cells of higher plants, two cytoskeletal arrays, the preprophase band and the phragmoplast, facilitate the positioning and de novo assembly of the plant-specific cytokinetic organelle, the cell plate, which develops across the division plane and fuses with the parental plasma membrane to yield distinct new cells. The coordination of cytoskeletal and membrane dynamics required to initiate, assemble and shape the cell plate as it grows toward the mother cell cortex is dependent upon a large array of proteins, including molecular motors, membrane tethering, fusion and restructuring factors and biosynthetic, structural and regulatory elements. This review focuses on the temporal and molecular requirements of cytokinesis in somatic cells of higher plants gleaned from recent studies using cell biology, genetics, pharmacology and biochemistry.
Collapse
Affiliation(s)
- Colleen M McMichael
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Dr, Madison, WI, 53713, USA
| | - Sebastian Y Bednarek
- Department of Biochemistry, University of Wisconsin-Madison, 433 Babcock Dr, Madison, WI, 53713, USA
| |
Collapse
|
28
|
Niehl A, Amari K, Gereige D, Brandner K, Mély Y, Heinlein M. Control of Tobacco mosaic virus movement protein fate by CELL-DIVISION-CYCLE protein48. PLANT PHYSIOLOGY 2012; 160:2093-108. [PMID: 23027663 PMCID: PMC3510134 DOI: 10.1104/pp.112.207399] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/15/2012] [Accepted: 09/27/2012] [Indexed: 05/08/2023]
Abstract
Like many other viruses, Tobacco mosaic virus replicates in association with the endoplasmic reticulum (ER) and exploits this membrane network for intercellular spread through plasmodesmata (PD), a process depending on virus-encoded movement protein (MP). The movement process involves interactions of MP with the ER and the cytoskeleton as well as its targeting to PD. Later in the infection cycle, the MP further accumulates and localizes to ER-associated inclusions, the viral factories, and along microtubules before it is finally degraded. Although these patterns of MP accumulation have been described in great detail, the underlying mechanisms that control MP fate and function during infection are not known. Here, we identify CELL-DIVISION-CYCLE protein48 (CDC48), a conserved chaperone controlling protein fate in yeast (Saccharomyces cerevisiae) and animal cells by extracting protein substrates from membranes or complexes, as a cellular factor regulating MP accumulation patterns in plant cells. We demonstrate that Arabidopsis (Arabidopsis thaliana) CDC48 is induced upon infection, interacts with MP in ER inclusions dependent on the MP N terminus, and promotes degradation of the protein. We further provide evidence that CDC48 extracts MP from ER inclusions to the cytosol, where it subsequently accumulates on and stabilizes microtubules. We show that virus movement is impaired upon overexpression of CDC48, suggesting that CDC48 further functions in controlling virus movement by removal of MP from the ER transport pathway and by promoting interference of MP with microtubule dynamics. CDC48 acts also in response to other proteins expressed in the ER, thus suggesting a general role of CDC48 in ER membrane maintenance upon ER stress.
Collapse
Affiliation(s)
- Annette Niehl
- Institut de Biologie Moléculaire des Plantes, Unité Propre de Recherche 2357 Centre National de la Recherche Scientifique, Université de Strasbourg, 67000 Strasbourg, France (A.N., K.A., D.G., K.B., M.H.); Botanisches Institut der Universität Basel, 4056 Basel, Switzerland (A.N., K.A., M.H.); and Laboratoire de Biophotonique et Pharmacologie, Unité Mixte de Recherche 7213 Centre National de la Recherche Scientifique, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France (Y.M.)
| | - Khalid Amari
- Institut de Biologie Moléculaire des Plantes, Unité Propre de Recherche 2357 Centre National de la Recherche Scientifique, Université de Strasbourg, 67000 Strasbourg, France (A.N., K.A., D.G., K.B., M.H.); Botanisches Institut der Universität Basel, 4056 Basel, Switzerland (A.N., K.A., M.H.); and Laboratoire de Biophotonique et Pharmacologie, Unité Mixte de Recherche 7213 Centre National de la Recherche Scientifique, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France (Y.M.)
| | | | - Katrin Brandner
- Institut de Biologie Moléculaire des Plantes, Unité Propre de Recherche 2357 Centre National de la Recherche Scientifique, Université de Strasbourg, 67000 Strasbourg, France (A.N., K.A., D.G., K.B., M.H.); Botanisches Institut der Universität Basel, 4056 Basel, Switzerland (A.N., K.A., M.H.); and Laboratoire de Biophotonique et Pharmacologie, Unité Mixte de Recherche 7213 Centre National de la Recherche Scientifique, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France (Y.M.)
| | - Yves Mély
- Institut de Biologie Moléculaire des Plantes, Unité Propre de Recherche 2357 Centre National de la Recherche Scientifique, Université de Strasbourg, 67000 Strasbourg, France (A.N., K.A., D.G., K.B., M.H.); Botanisches Institut der Universität Basel, 4056 Basel, Switzerland (A.N., K.A., M.H.); and Laboratoire de Biophotonique et Pharmacologie, Unité Mixte de Recherche 7213 Centre National de la Recherche Scientifique, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France (Y.M.)
| | - Manfred Heinlein
- Institut de Biologie Moléculaire des Plantes, Unité Propre de Recherche 2357 Centre National de la Recherche Scientifique, Université de Strasbourg, 67000 Strasbourg, France (A.N., K.A., D.G., K.B., M.H.); Botanisches Institut der Universität Basel, 4056 Basel, Switzerland (A.N., K.A., M.H.); and Laboratoire de Biophotonique et Pharmacologie, Unité Mixte de Recherche 7213 Centre National de la Recherche Scientifique, Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France (Y.M.)
| |
Collapse
|
29
|
[Biological function of the Somatic embryogenesis receptor-like kinases in plant]. YI CHUAN = HEREDITAS 2012; 34:551-9. [PMID: 22659427 DOI: 10.3724/sp.j.1005.2012.00551] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Somatic Embryogenesis Receptor-Like Kinases (SERKs) belong to the LRR-RLK II subfamily, which contain three conserved domains: an extracellular domain, a transmembrane domain, and an intracellular catalytic kinase domain. Previous studies had found that SERKs play many roles during plant development. This review made a brief introduction about the character of the SERKs and described the biological function of these proteins in somatic embryogenesis, sporogenesis, hormone response and host defense response. The research value and the application prospects of the SERKs were discussed.
Collapse
|
30
|
Heskes AM, Lincoln CN, Goodger JQD, Woodrow IE, Smith TA. Multiphoton fluorescence lifetime imaging shows spatial segregation of secondary metabolites in Eucalyptus secretory cavities. J Microsc 2012; 247:33-42. [PMID: 22394321 DOI: 10.1111/j.1365-2818.2011.03593.x] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Multiphoton fluorescence lifetime imaging provides an excellent tool for imaging deep within plant tissues while providing a means to distinguish between fluorophores with high spatial and temporal resolution. Ideal candidates for the application of multiphoton fluorescence lifetime imaging to plants are the embedded secretory cavities found in numerous species because they house complex mixtures of secondary metabolites within extracellular lumina. Previous investigations of this type of structure have been restricted by the use of sectioned material resulting in the loss of lumen contents and often disorganization of the delicate secretory cells; thus it is not known if there is spatial segregation of secondary metabolites within these structures. In this paper, we apply multiphoton fluorescence lifetime imaging to investigate the spatial arrangement of metabolites within intact secretory cavities isolated from Eucalyptus polybractea R.T. Baker leaves. The secretory cavities of this species are abundant (up to 10 000 per leaf), large (up to 6 nL) and importantly house volatile essential oil rich in the monoterpene 1,8-cineole, together with an immiscible, non-volatile component comprised largely of autofluorescent oleuropeic acid glucose esters. We have been able to optically section into the lumina of secretory cavities to a depth of ∼80 μm, revealing a unique spatial organization of cavity metabolites whereby the non-volatile component forms a layer between the secretory cells lining the lumen and the essential oil. This finding could be indicative of a functional role of the non-volatile component in providing a protective region of low diffusivity between the secretory cells and potentially autotoxic essential oil.
Collapse
Affiliation(s)
- A M Heskes
- School of Botany, University of Melbourne, Australia.
| | | | | | | | | |
Collapse
|
31
|
Orme CM, Bogan JS. The ubiquitin regulatory X (UBX) domain-containing protein TUG regulates the p97 ATPase and resides at the endoplasmic reticulum-golgi intermediate compartment. J Biol Chem 2011; 287:6679-92. [PMID: 22207755 DOI: 10.1074/jbc.m111.284232] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
p97/VCP is a hexameric ATPase that is coupled to diverse cellular processes, such as membrane fusion and proteolysis. How p97 activity is regulated is not fully understood. Here we studied the potential role of TUG, a widely expressed protein containing a UBX domain, to control mammalian p97. In HEK293 cells, the vast majority of TUG was bound to p97. Surprisingly, the TUG UBX domain was neither necessary nor sufficient for this interaction. Rather, an extended sequence, comprising three regions of TUG, bound to the p97 N-terminal domain. The TUG C terminus resembled the Arabidopsis protein PUX1. Similar to the previously described action of PUX1 on AtCDC48, TUG caused the conversion of p97 hexamers into monomers. Hexamer disassembly was stoichiometric rather than catalytic and was not greatly affected by the p97 ATP-binding state or by TUG N-terminal regions in vitro. In HeLa cells, TUG localized to the endoplasmic reticulum-to-Golgi intermediate compartment and endoplasmic reticulum exit sites. Although siRNA-mediated TUG depletion had no marked effect on total ubiquitylated proteins or p97 localization, TUG overexpression caused an accumulation of ubiquitylated substrates and targeted both TUG and p97 to the nucleus. A physiologic role of TUG was revealed by siRNA-mediated depletion, which showed that TUG is required for efficient reassembly of the Golgi complex after brefeldin A removal. Together, these data support a model in which TUG controls p97 oligomeric status at a particular location in the early secretory pathway and in which this process regulates membrane trafficking in various cell types.
Collapse
Affiliation(s)
- Charisse M Orme
- Section of Endocrinology and Metabolism, Department of Internal Medicine, University School of Medicine, New Haven, Connecticut 06520-8020, USA
| | | |
Collapse
|
32
|
Fluorescence Correlation Spectroscopy and Fluorescence Recovery After Photobleaching to study receptor kinase mobility in planta. Methods Mol Biol 2011; 779:225-42. [PMID: 21837570 DOI: 10.1007/978-1-61779-264-9_13] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Plasma-membrane-localized receptor kinases are essential for cell-cell communication and as sensors for the extracellular environment. Receptor function is dependent on their distribution in the membrane and interaction with other proteins that are either membrane-localized, present in the cytoplasm, or in the extracellular space. The organized distribution and mobility of receptor kinases is, therefore, thought to regulate the efficiency of downstream signaling. This chapter describes two methods to study receptor mobility in the plasma membrane. Fluorescence Correlation Spectroscopy (FCS) and Fluorescence Recovery After Photobleaching (FRAP). Especially, the combination of FRAP and FCS provides a better insight into plasma membrane receptor mobility.
Collapse
|
33
|
McKeown PC, Laouielle-Duprat S, Prins P, Wolff P, Schmid MW, Donoghue MTA, Fort A, Duszynska D, Comte A, Lao NT, Wennblom TJ, Smant G, Köhler C, Grossniklaus U, Spillane C. Identification of imprinted genes subject to parent-of-origin specific expression in Arabidopsis thaliana seeds. BMC PLANT BIOLOGY 2011; 11:113. [PMID: 21838868 PMCID: PMC3174879 DOI: 10.1186/1471-2229-11-113] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/07/2011] [Accepted: 08/12/2011] [Indexed: 05/02/2023]
Abstract
BACKGROUND Epigenetic regulation of gene dosage by genomic imprinting of some autosomal genes facilitates normal reproductive development in both mammals and flowering plants. While many imprinted genes have been identified and intensively studied in mammals, smaller numbers have been characterized in flowering plants, mostly in Arabidopsis thaliana. Identification of additional imprinted loci in flowering plants by genome-wide screening for parent-of-origin specific uniparental expression in seed tissues will facilitate our understanding of the origins and functions of imprinted genes in flowering plants. RESULTS cDNA-AFLP can detect allele-specific expression that is parent-of-origin dependent for expressed genes in which restriction site polymorphisms exist in the transcripts derived from each allele. Using a genome-wide cDNA-AFLP screen surveying allele-specific expression of 4500 transcript-derived fragments, we report the identification of 52 maternally expressed genes (MEGs) displaying parent-of-origin dependent expression patterns in Arabidopsis siliques containing F1 hybrid seeds (3, 4 and 5 days after pollination). We identified these MEGs by developing a bioinformatics tool (GenFrag) which can directly determine the identities of transcript-derived fragments from (i) their size and (ii) which selective nucleotides were added to the primers used to generate them. Hence, GenFrag facilitates increased throughput for genome-wide cDNA-AFLP fragment analyses. The 52 MEGs we identified were further filtered for high expression levels in the endosperm relative to the seed coat to identify the candidate genes most likely representing novel imprinted genes expressed in the endosperm of Arabidopsis thaliana. Expression in seed tissues of the three top-ranked candidate genes, ATCDC48, PDE120 and MS5-like, was confirmed by Laser-Capture Microdissection and qRT-PCR analysis. Maternal-specific expression of these genes in Arabidopsis thaliana F1 seeds was confirmed via allele-specific transcript analysis across a range of different accessions. Differentially methylated regions were identified adjacent to ATCDC48 and PDE120, which may represent candidate imprinting control regions. Finally, we demonstrate that expression levels of these three genes in vegetative tissues are MET1-dependent, while their uniparental maternal expression in the seed is not dependent on MET1. CONCLUSIONS Using a cDNA-AFLP transcriptome profiling approach, we have identified three genes, ATCDC48, PDE120 and MS5-like which represent novel maternally expressed imprinted genes in the Arabidopsis thaliana seed. The extent of overlap between our cDNA-AFLP screen for maternally expressed imprinted genes, and other screens for imprinted and endosperm-expressed genes is discussed.
Collapse
Affiliation(s)
- Peter C McKeown
- Genetics and Biotechnology Lab, Botany and Plant Science, National University of Ireland Galway (NUIG), C306 Aras de Brun, University Road, Galway, Ireland
| | - Sylvia Laouielle-Duprat
- Genetics and Biotechnology Lab, Botany and Plant Science, National University of Ireland Galway (NUIG), C306 Aras de Brun, University Road, Galway, Ireland
| | - Pjotr Prins
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, Wageningen, The Netherlands
| | - Philip Wolff
- Department of Biology and Zürich-Basel Plant Science Center, Swiss Federal Institute of Technology, ETH Centre, CH-8092 Zürich, Switzerland
- Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Marc W Schmid
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Mark TA Donoghue
- Genetics and Biotechnology Lab, Botany and Plant Science, National University of Ireland Galway (NUIG), C306 Aras de Brun, University Road, Galway, Ireland
| | - Antoine Fort
- Genetics and Biotechnology Lab, Botany and Plant Science, National University of Ireland Galway (NUIG), C306 Aras de Brun, University Road, Galway, Ireland
| | - Dorota Duszynska
- Genetics and Biotechnology Lab, Botany and Plant Science, National University of Ireland Galway (NUIG), C306 Aras de Brun, University Road, Galway, Ireland
| | - Aurélie Comte
- Genetics and Biotechnology Lab, Botany and Plant Science, National University of Ireland Galway (NUIG), C306 Aras de Brun, University Road, Galway, Ireland
| | - Nga Thi Lao
- Genetics and Biotechnology Lab, Botany and Plant Science, National University of Ireland Galway (NUIG), C306 Aras de Brun, University Road, Galway, Ireland
| | | | - Geert Smant
- Laboratory of Nematology, Wageningen University, Droevendaalsesteeg 1, Wageningen, The Netherlands
| | - Claudia Köhler
- Department of Biology and Zürich-Basel Plant Science Center, Swiss Federal Institute of Technology, ETH Centre, CH-8092 Zürich, Switzerland
- Department of Plant Biology and Forest Genetics, Uppsala BioCenter, Swedish University of Agricultural Sciences, SE-75007 Uppsala, Sweden
| | - Ueli Grossniklaus
- Institute of Plant Biology and Zürich-Basel Plant Science Center, University of Zürich, Zollikerstrasse 107, CH-8008 Zürich, Switzerland
| | - Charles Spillane
- Genetics and Biotechnology Lab, Botany and Plant Science, National University of Ireland Galway (NUIG), C306 Aras de Brun, University Road, Galway, Ireland
| |
Collapse
|
34
|
Requirements for the catalytic cycle of the N-ethylmaleimide-Sensitive Factor (NSF). BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2011; 1823:159-71. [PMID: 21689688 DOI: 10.1016/j.bbamcr.2011.06.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/23/2011] [Revised: 05/23/2011] [Accepted: 06/06/2011] [Indexed: 12/23/2022]
Abstract
The N-ethylmaleimide-Sensitive Factor (NSF) was one of the initial members of the ATPases Associated with various cellular Activities Plus (AAA(+)) family. In this review, we discuss what is known about the mechanism of NSF action and how that relates to the mechanisms of other AAA(+) proteins. Like other family members, NSF binds to a protein complex (i.e., SNAP-SNARE complex) and utilizes ATP hydrolysis to affect the conformations of that complex. SNAP-SNARE complex disassembly is essential for SNARE recycling and sustained membrane trafficking. NSF is a homo-hexamer; each protomer is composed of an N-terminal domain, NSF-N, and two adjacent AAA-domains, NSF-D1 and NSF-D2. Mutagenesis analysis has established specific roles for many of the structural elements of NSF-D1, the catalytic ATPase domain, and NSF-N, the SNAP-SNARE binding domain. Hydrodynamic analysis of NSF, labeled with (Ni(2+)-NTA)(2)-Cy3, detected conformational differences in NSF, in which the ATP-bound conformation appears more compact than the ADP-bound form. This indicates that NSF undergoes significant conformational changes as it progresses through its ATP-hydrolysis cycle. Incorporating these data, we propose a sequential mechanism by which NSF uses NSF-N and NSF-D1 to disassemble SNAP-SNARE complexes. We also illustrate how analytical centrifugation might be used to study other AAA(+) proteins.
Collapse
|
35
|
Moog D, Stork S, Zauner S, Maier UG. In silico and in vivo investigations of proteins of a minimized eukaryotic cytoplasm. Genome Biol Evol 2011; 3:375-82. [PMID: 21498883 PMCID: PMC3101018 DOI: 10.1093/gbe/evr031] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Algae with secondary plastids such as diatoms maintain two different eukaryotic cytoplasms. One of them, the so-called periplastidal compartment (PPC), is the naturally minimized cytoplasm of a eukaryotic endosymbiont. In order to investigate the protein composition of the PPC of diatoms, we applied knowledge of the targeting signals of PPC-directed proteins in searches of the genome data for proteins acting in the PPC and proved their in vivo localization via expressing green fluorescent protein (GFP) fusions. Our investigation increased the knowledge of the protein content of the PPC approximately 3-fold and thereby indicated that this narrow compartment was functionally reduced to some important cellular functions with nearly no housekeeping biochemical pathways.
Collapse
Affiliation(s)
- Daniel Moog
- LOEWE-Zentrum für Synthetische Mikrobiologie (SynMikro), Hans-Meerwein-Strasse, Marburg, Germany
| | | | | | | |
Collapse
|
36
|
van den Wildenberg SMJL, Bollen YJM, Peterman EJG. How to quantify protein diffusion in the bacterial membrane. Biopolymers 2011; 95:312-21. [PMID: 21240922 DOI: 10.1002/bip.21585] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2010] [Revised: 12/10/2010] [Accepted: 12/10/2010] [Indexed: 01/18/2023]
Abstract
Lateral diffusion of proteins in the plane of a biological membrane is important for many vital processes, including energy conversion, signaling, chemotaxis, cell division, protein insertion, and secretion. In bacteria, all these functions are located in a single membrane. Therefore, quantitative measurements of protein diffusion in bacterial membranes can provide insight into many important processes. Diffusion of membrane proteins in eukaryotes has been studied in detail using various experimental techniques, including fluorescence correlation spectroscopy (FCS), fluorescence recovery after photobleaching (FRAP), and particle tracking using single-molecule fluorescence (SMF) microscopy. In case of bacteria, such experiments are intrinsically difficult due to the small size of the cells. Here, we review these experimental approaches to quantify diffusion in general and their strengths and weaknesses when applied to bacteria. In addition, we propose a method to extract multiple diffusion coefficients from trajectories obtained from SMF data, using cumulative probability distributions (CPDs). We demonstrate the power of this approach by quantifying the heterogeneous diffusion of the bacterial membrane protein TatA, which forms a pore for the translocation of folded proteins. Using computer simulations, we study the effect of cell dimensions and membrane curvature on measured CPDs. We find that at least two mobile populations with distinct diffusion coefficients (of 7 and 169 nm(2) ms(-1) , respectively) are necessary to explain the experimental data. The approach described here should be widely applicable for the quantification of membrane-protein diffusion in living bacteria.
Collapse
|
37
|
Abstract
The quantification of molecular interactions or conformational changes can conveniently be studied by using Förster Resonance Energy Transfer (FRET) as a spectroscopic ruler. The FRET phenomenon describes the transfer of energy from a donor to an acceptor molecule, if they are in close proximity (<10 nm). The most straightforward method to measure FRET is Fluorescence Lifetime Imaging Microscopy (FLIM). In this chapter, we will describe an application of FRET using FLIM to monitor the hexamer formation of CrFP/eYFP-labeled Arabidopsis thaliana cell division cycle protein (AtCDC48) expressed in plant protoplasts.
Collapse
|
38
|
Laptenok SP, Borst JW, Mullen KM, van Stokkum IHM, Visser AJWG, van Amerongen H. Global analysis of Förster resonance energy transfer in live cells measured by fluorescence lifetime imaging microscopy exploiting the rise time of acceptor fluorescence. Phys Chem Chem Phys 2010; 12:7593-602. [DOI: 10.1039/b919700a] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
39
|
Zhao C, Matveeva EA, Ren Q, Whiteheart SW. Dissecting the N-ethylmaleimide-sensitive factor: required elements of the N and D1 domains. J Biol Chem 2009; 285:761-72. [PMID: 19887446 DOI: 10.1074/jbc.m109.056739] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
N-Ethylmaleimide-sensitive factor (NSF) is a homo-hexameric member of the AAA(+) (ATPases associated with various cellular activities plus) family. It plays an essential role in most intracellular membrane trafficking through its binding to and disassembly of soluble NSF attachment protein (SNAP) receptor (SNARE) complexes. Each NSF protomer contains an N-terminal domain (NSF-N) and two AAA domains, a catalytic NSF-D1 and a structural NSF-D2. This study presents detailed mutagenesis analyses of NSF-N and NSF-D1, dissecting their roles in ATP hydrolysis, SNAP.SNARE binding, and complex disassembly. Our results show that a positively charged surface on NSF-N, bounded by Arg(67) and Lys(105), and the conserved residues in the central pore of NSF-D1 (Tyr(296) and Gly(298)) are involved in SNAP.SNARE binding but not basal ATP hydrolysis. Mutagenesis of Sensor 1 (Thr(373)-Arg(375)), Sensor 2 (Glu(440)-Glu(442)), and Arginine Fingers (Arg(385) and Arg(388)) in NSF-D1 shows that each region plays a discrete role. Sensor 1 is important for basal ATPase activity and nucleotide binding. Sensor 2 plays a role in ATP- and SNAP-dependent SNARE complex binding and disassembly but does so in cis and not through inter-protomer interactions. Arginine Fingers are important for SNAP.SNARE complex-stimulated ATPase activity and complex disassembly. Mutants at these residues have a dominant-negative phenotype in cells, suggesting that Arginine Fingers function in trans via inter-protomer interactions. Taken together, these data establish functional roles for many of the structural elements of the N domain and of the D1 ATP-binding site of NSF.
Collapse
Affiliation(s)
- Chunxia Zhao
- Department of Molecular and Cellular Biochemistry, University of Kentucky Medical Center, Lexington, Kentucky 40536-0509, USA
| | | | | | | |
Collapse
|
40
|
Osterrieder A, Carvalho CM, Latijnhouwers M, Johansen JN, Stubbs C, Botchway S, Hawes C. Fluorescence lifetime imaging of interactions between Golgi tethering factors and small GTPases in plants. Traffic 2009; 10:1034-46. [PMID: 19490533 DOI: 10.1111/j.1600-0854.2009.00930.x] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Peripheral tethering factors bind to small GTPases in order to obtain their correct location within the Golgi apparatus. Using fluorescence resonance energy transfer (FRET) and fluorescence lifetime imaging microscopy (FLIM) we visualized interactions between Arabidopsis homologues of tethering factors and small GTPases at the Golgi stacks in planta. Co-expression of the coiled-coil proteins AtGRIP and golgin candidate 5 (GC5) [TATA element modulatory factor (TMF)] and the putative post-Golgi tethering factor AtVPS52 fused to green fluorescent protein (GFP) with mRFP (monomeric red fluorescent protein) fusions to the small GTPases AtRab-H1(b), AtRab-H1(c) and AtARL1 resulted in reduced GFP lifetimes compared to the control proteins. Interestingly, we observed differences in GFP quenching between the different protein combinations as well as selective quenching of GFP-AtVPS52-labelled structures. The data presented here indicate that the FRET-FLIM technique should prove invaluable in assessing protein interactions in living plant cells at the organelle level.
Collapse
|
41
|
Bae H, Choi SM, Yang SW, Pai HS, Kim WT. Suppression of the ER-localized AAA ATPase NgCDC48 inhibits tobacco growth and development. Mol Cells 2009; 28:57-65. [PMID: 19711043 DOI: 10.1007/s10059-009-0101-4] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2009] [Revised: 05/29/2009] [Accepted: 06/03/2009] [Indexed: 10/20/2022] Open
Abstract
CDC48 is a member of the AAA ATPase superfamily. Yeast CDC48 and its mammalian homolog p97 are implicated in diverse cellular processes, including mitosis, membrane fusion, and ubiquitin-dependent protein degradation. However, the cellular functions of plant CDC48 proteins are largely unknown. In the present study, we performed virus-induced gene silencing (VIGS) screening and found that silencing of a gene encoding a tobacco CDC48 homolog, NgCDC48, resulted in severe abnormalities in leaf and shoot development in tobacco. Furthermore, transgenic tobacco plants (35S:anti-NgCDC48), in which the NgCDC48 gene was suppressed using the antisense RNA method, exhibited severely aberrant development of both vegetative and reproductive organs, resulting in arrested shoot and leaf growth and sterile flowers. Approximately 57-83% of 35S:anti-NgCDC48 plants failed to develop mature organs and died at early stage of development. Scanning electron microscopy showed that both adaxial and abaxial epidermal pavement cells in antisense transgenic leaves were significantly smaller and more numerous than those in wild type leaves. These results indicate that NgCDC48 is critically involved in cell growth and development of tobacco plants. An in vivo targeting experiment revealed that NgCDC48 resides in the endoplasmic reticulum (ER) in tobacco protoplasts. We consider the tantalizing possibility that CDC48-mediated degradation of an as-yet unidentified protein(s) in the ER might be a critical step for cell growth and expansion in tobacco leaves.
Collapse
Affiliation(s)
- Hansol Bae
- Department of Biology, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | | | | | | | | |
Collapse
|
42
|
Xiao F, Zhang H, Guo P. Novel mechanism of hexamer ring assembly in protein/RNA interactions revealed by single molecule imaging. Nucleic Acids Res 2008; 36:6620-32. [PMID: 18940870 PMCID: PMC2582624 DOI: 10.1093/nar/gkn669] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Many nucleic acid-binding proteins and the AAA+ family form hexameric rings, but the mechanism of hexamer assembly is unclear. It is generally believed that the specificity in protein/RNA interaction relies on molecular contact through a surface charge or 3D structure matching via conformational capture or induced fit. The pRNA of bacteriophage phi29 DNA-packaging motor also forms a ring, but whether the pRNA ring is a hexamer or a pentamer is under debate. Here, single molecule studies elucidated a mechanism suggesting the specificity and affinity in protein/RNA interaction relies on pRNA static ring formation. A combined pRNA ring-forming group was very specific for motor binding, but the isolated individual members of the ring-forming group bind to the motor nonspecifically. pRNA did not form a ring prior to motor binding. Only those RNAs that formed a static ring, via the interlocking loops, stayed on the motor. Single interlocking loop interruption resulted in pRNA detachment. Extension or reduction of the ring circumference failed in motor binding. This new mechanism was tested by redesigning two artificial RNAs that formed hexamer and packaged DNA. The results confirmed the stoichiometry of pRNA on the motor was the common multiple of two and three, thus, a hexamer.
Collapse
Affiliation(s)
- Feng Xiao
- Department of Biomedical Engineering, College of Engineering/College of Medicine, University of Cincinnati, Cincinnati, OH 45221, USA
| | | | | |
Collapse
|
43
|
Park S, Rancour DM, Bednarek SY. In planta analysis of the cell cycle-dependent localization of AtCDC48A and its critical roles in cell division, expansion, and differentiation. PLANT PHYSIOLOGY 2008; 148:246-58. [PMID: 18660433 PMCID: PMC2528134 DOI: 10.1104/pp.108.121897] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2008] [Accepted: 07/14/2008] [Indexed: 05/18/2023]
Abstract
CDC48/p97 is a conserved homohexameric AAA-ATPase chaperone required for a variety of cellular processes but whose role in the development of a multicellular model system has not been examined. Here, we have used reverse genetics, visualization of a functional Arabidopsis (Arabidopsis thaliana) CDC48 fluorescent fusion protein, and morphological analysis to examine the subcellular distribution and requirements for AtCDC48A in planta. Homozygous Atcdc48A T-DNA insertion mutants arrest during seedling development, exhibiting decreased cell expansion and displaying pleiotropic defects in pollen and embryo development. Atcdc48A insertion alleles show significantly reduced male transmission efficiency due to defects in pollen tube growth. Yellow fluorescent protein-AtCDC48A, a fusion protein that functionally complements the insertion mutant defects, localizes in the nucleus and cytoplasm and is recruited to the division mid-zone during cytokinesis. The pattern of nuclear localization differs according to the stage of the cell cycle and differentiation state. Inducible expression of an Atcdc48A Walker A ATPase mutant in planta results in cytokinesis abnormalities, aberrant cell divisions, and root trichoblast differentiation defects apparent in excessive root hair emergence. At the biochemical level, our data suggest that the endogenous steady-state protein level of AtCDC48A is dependent upon the presence of ATPase-active AtCDC48A. These results demonstrate that CDC48A/p97 is critical for cytokinesis, cell expansion, and differentiation in plants.
Collapse
Affiliation(s)
- Sookhee Park
- Department of Biochemistry , University of Wisconsin, Madison, Wisconsin 53706, USA
| | | | | |
Collapse
|
44
|
Held MA, Boulaflous A, Brandizzi F. Advances in fluorescent protein-based imaging for the analysis of plant endomembranes. PLANT PHYSIOLOGY 2008; 147:1469-81. [PMID: 18678739 PMCID: PMC2492624 DOI: 10.1104/pp.108.120147] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/17/2023]
Affiliation(s)
- Michael A Held
- Department of Energy Plant Research Laboratory, Michigan State University, East Lansing, Michigan 48824-1312, USA
| | | | | |
Collapse
|
45
|
Ali GS, Reddy A. PAMP-triggered immunity: Early events in the activation of FLAGELLIN SENSITIVE2. PLANT SIGNALING & BEHAVIOR 2008; 3:423-6. [PMID: 19704848 PMCID: PMC2634595 DOI: 10.4161/psb.3.6.5472] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/20/2007] [Accepted: 12/27/2007] [Indexed: 05/05/2023]
Abstract
The Arabidopsis FLAGELLIN SENSITIVE2 (FLS2) protein is a leucine-rich repeat receptor-like kinase (LRR-RLK) that plays important roles in pathogen-associated molecular pattern (PAMP)-triggered immunity (PTI). The binding of bacterial flagellin, one of the PAMPs, to the extracellular domain of FLS2 leads to activation of signaling cascades resulting in activation or repression of a specific set of genes involved in plant defense. The mechanisms at the cell membrane that lead to the activation of this signalling pathway are, however, not fully understood. Recently, we have shown that after ligand-treatment the mobility of FLS2 in the cell membrane is reduced and that the activation of FLS2 does not involve its constitutive or ligand-dependent homodimerization. Our data together with recently published reports suggest that FLS2 activation involves its association with other proteins, including BRI1-associated kinase 1 (BAK1), another LRR-RLK, and localization to less mobile areas, probably lipid rafts, in a ligand-dependent manner to initiate PTI.
Collapse
Affiliation(s)
- Gul Shad Ali
- Department of Biology and Program in Molecular Plant Biology; Colorado State University; Fort Collins, Colorado USA
| | | |
Collapse
|
46
|
Lalonde S, Ehrhardt DW, Loqué D, Chen J, Rhee SY, Frommer WB. Molecular and cellular approaches for the detection of protein-protein interactions: latest techniques and current limitations. THE PLANT JOURNAL : FOR CELL AND MOLECULAR BIOLOGY 2008; 53:610-635. [PMID: 18269572 DOI: 10.1111/j.1365-313x.2007.03332.x] [Citation(s) in RCA: 127] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
Homotypic and heterotypic protein interactions are crucial for all levels of cellular function, including architecture, regulation, metabolism, and signaling. Therefore, protein interaction maps represent essential components of post-genomic toolkits needed for understanding biological processes at a systems level. Over the past decade, a wide variety of methods have been developed to detect, analyze, and quantify protein interactions, including surface plasmon resonance spectroscopy, NMR, yeast two-hybrid screens, peptide tagging combined with mass spectrometry and fluorescence-based technologies. Fluorescence techniques range from co-localization of tags, which may be limited by the optical resolution of the microscope, to fluorescence resonance energy transfer-based methods that have molecular resolution and can also report on the dynamics and localization of the interactions within a cell. Proteins interact via highly evolved complementary surfaces with affinities that can vary over many orders of magnitude. Some of the techniques described in this review, such as surface plasmon resonance, provide detailed information on physical properties of these interactions, while others, such as two-hybrid techniques and mass spectrometry, are amenable to high-throughput analysis using robotics. In addition to providing an overview of these methods, this review emphasizes techniques that can be applied to determine interactions involving membrane proteins, including the split ubiquitin system and fluorescence-based technologies for characterizing hits obtained with high-throughput approaches. Mass spectrometry-based methods are covered by a review by Miernyk and Thelen (2008; this issue, pp. 597-609). In addition, we discuss the use of interaction data to construct interaction networks and as the basis for the exciting possibility of using to predict interaction surfaces.
Collapse
Affiliation(s)
- Sylvie Lalonde
- Carnegie Institution, 260 Panama Street, Stanford, CA 94305, USA.
| | | | | | | | | | | |
Collapse
|