1
|
de Roij M, Borst JW, Weijers D. Protein degradation in the auxin response. Plant Cell 2024:koae125. [PMID: 38652687 DOI: 10.1093/plcell/koae125] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 02/14/2024] [Accepted: 03/01/2024] [Indexed: 04/25/2024]
Abstract
The signaling molecule auxin sits at the nexus of plant biology and coordinates essentially all growth and developmental processes in plants. Auxin molecules are transported throughout plant tissues and are capable of evoking highly specific physiological responses in plant cells by inducing various molecular pathways. In many of these pathways, proteolysis plays a crucial role for correct physiological responses. This review provides a chronology of the discovery and characterisation of the auxin receptor, which is a fascinating example of separate research trajectories ultimately converging on the discovery of a core auxin signaling hub which relies on degradation of a family of transcriptional inhibitor proteins - the Aux/IAAs. Beyond describing the "classical" proteolysis-driven auxin response system, we explore more recent examples of the interconnection of proteolytic systems, which target a range of other auxin signaling proteins, and auxin response. By highlighting these emerging concepts, we provide potential future directions to further investigate the role of protein degradation within the framework of auxin response.
Collapse
Affiliation(s)
- Martijn de Roij
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, the Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, the Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, the Netherlands
| |
Collapse
|
2
|
Borst JW, Fransen J, Weidtkamp‐Peters S, Stahl Y. Microspectroscopy: functional imaging of biological systems. FEBS Lett 2022; 596:2469-2471. [DOI: 10.1002/1873-3468.14498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Jan Willem Borst
- Laboratory of Biochemistry/Microspectroscopy Research Facility Wageningen University & Research The Netherlands
| | - Jack Fransen
- Department of Cell Biology and Radboud Technology Center Microscopy Radboud University Medical Center Nijmegen The Netherlands
| | | | - Yvonne Stahl
- Institute for Developmental Genetics Heinrich Heine University Düsseldorf Germany
| |
Collapse
|
3
|
Skakun VV, Digris A, Nolles A, Borst JW, Visser A. Revealing heterogeneity in correlation times of EGFP encapsulated in complex coacervate core micelles by analysis of fluorescence anisotropies. Methods Appl Fluoresc 2022; 10. [PMID: 35952674 DOI: 10.1088/2050-6120/ac8911] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 08/11/2022] [Indexed: 11/11/2022]
Abstract
Encapsulation of enhanced green fluorescent protein (EGFP) in complex coacervate core micelles (C3Ms) can be established by mixing EGFP with diblock polymers at equal charge ratio. It has previously been shown that this encapsulation system is highly dynamic, implying existence of different populations; GFP free in solution or complexed with polymers (small complexes) and EGFP encapsulated in C3Ms. We performed time resolved fluorescence anisotropy experiments to determine the relative populations of EGFP encapsulated in C3Ms using three different fluorescence anisotropy decay analysis methods. First, Maximum Entropy Method (MEM) data analysis was employed for five different EGFP concentrations in C3Ms that were mixed with dark fluorescent proteins (10, 20, 30, 40 and 50% EGFP, respectively). In all cases, correlation-time distributions between 0.1 and 100 ns (on a logarithmic timescale) are clearly visible showing bimodal distribution. The distribution between 0.1 and 2.0 ns is due to homo-FRET between EGFP molecules packed in micelles and the distribution between 8 and 30 ns coincides with the correlation-time distribution of free EGFP in solution. The fraction of homo-FRET distribution linearly increases with increase of relative micellar EGFP concentrations. These MEM results were corroborated by two different analysis methods: global population analysis of all five fluorescence anisotropy decays arising from EGFP in micelles together with the one of free EGFP (direct analysis of anisotropies) and global associative population analysis of anisotropies by fitting parallel and perpendicular fluorescence decay components. In contrast to global analyses approaches, the MEM method directly reveals distributions of correlation times without any prior information about the sample. However, global associative analysis of anisotropies by fitting parallel and perpendicular fluorescence decay components is the only method that allows to estimate accurately fractions of free fluorophores in solution and encapsulated fluorophores.
Collapse
Affiliation(s)
- Victor V Skakun
- Department of Systems Analysis and Computer Simulation, Belarusian State University, Nezavisimisty Ave., 4, Minsk, 220030, BELARUS
| | - Anatoli Digris
- Department of Systems Analysis and Computer Simulation, Belarusian State University, Nezavisimisty Ave., 4, Minsk, 220030, BELARUS
| | - Antsje Nolles
- Wageningen University & Research, Stippeneng 4, Wageningen, Gelderland, 6700 HB, NETHERLANDS
| | - Jan Willem Borst
- Laboratory of Biochemistry, Microspectroscopy Research Facility , Wageningen University & Research, Stippeneng 4, 6708WE, Wageningen, Gelderland, 6700 HB, NETHERLANDS
| | - Antonie Visser
- Wageningen University & Research, Stippeneng 4, Wageningen, Gelderland, 6700 HB, NETHERLANDS
| |
Collapse
|
4
|
Kembaren R, Kleijn JM, Borst JW, Kamperman M, Hofman AH. Enhanced stability of complex coacervate core micelles following different core-crosslinking strategies. Soft Matter 2022; 18:3052-3062. [PMID: 35363245 DOI: 10.1039/d2sm00088a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Complex coacervate core micelles (C3Ms) are formed by mixing aqueous solutions of a charged (bio)macromolecule with an oppositely charged-neutral hydrophilic diblock copolymer. The stability of these structures is dependent on the ionic strength of the solution; above a critical ionic strength, the micelles will completely disintegrate. This instability at high ionic strengths is the main drawback for their application in, e.g., drug delivery systems or protein protection. In addition, the stability of C3Ms composed of weak polyelectrolytes is pH-dependent as well. The aim of this study is to assess the effectiveness of covalent crosslinking of the complex coacervate core to improve the stability of C3Ms. We studied the formation of C3Ms using a quaternized and amine-functionalized cationic-neutral diblock copolymer, poly(2-vinylpyridine)-block-poly(ethylene oxide) (QP2VP-b-PEO), and an anionic homopolymer, poly(acrylic acid) (PAA). Two different core-crosslinking strategies were employed that resulted in crosslinks between both types of polyelectrolyte chains in the core (i.e., between QP2VP and PAA) or in crosslinks between polyelectrolyte chains of the same type only (i.e., QP2VP). For these two strategies we used the crosslinkers 1-ethyl-3-(3'-dimethylaminopropyl)carbodiimide hydrochloride (EDC) and dimethyl-3,3'-dithiopropionimidate dihydrochloride (DTBP), respectively. EDC provides permanent crosslinks, while DTBP crosslinks can be broken by a reducing agent. Dynamic light scattering showed that both approaches significantly improved the stability of C3Ms against salt and pH changes. Furthermore, reduction of the disulphide bridges in the DTBP core-crosslinked micelles largely restored the original salt-stability profile. Therefore, this feature provides an excellent starting point for the application of C3Ms in controlled release formulations.
Collapse
Affiliation(s)
- Riahna Kembaren
- Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
- Laboratory of Biochemistry, Microspectroscopy Research Facility, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - J Mieke Kleijn
- Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Microspectroscopy Research Facility, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Marleen Kamperman
- Polymer Science, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| | - Anton H Hofman
- Polymer Science, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands.
| |
Collapse
|
5
|
Kembaren R, Westphal AH, Kamperman M, Kleijn JM, Borst JW. Charged Polypeptide Tail Boosts the Salt Resistance of Enzyme-Containing Complex Coacervate Micelles. Biomacromolecules 2022; 23:1195-1204. [PMID: 35042326 PMCID: PMC8924873 DOI: 10.1021/acs.biomac.1c01466] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
![]()
Encapsulation of
proteins can have advantages for their protection,
stability, and delivery purposes. One of the options to encapsulate
proteins is to incorporate them in complex coacervate core micelles
(C3Ms). This can easily be achieved by mixing aqueous solutions of
the protein and an oppositely charged neutral-hydrophilic diblock
copolymer. However, protein-containing C3Ms often suffer from salt-inducible
disintegration due to the low charge density of proteins. The aim
of this study is to improve the salt stability of protein-containing
C3Ms by increasing the net charge of the protein by tagging it with
a charged polypeptide. As a model protein, we used CotA laccase and
generated variants with 10, 20, 30, and 40 glutamic acids attached
at the C-terminus of CotA using genetic engineering. Micelles were
obtained by mixing the five CotA variants with poly(N-methyl-2-vinyl-pyridinium)-block-poly(ethylene
oxide) (PM2VP128-b-PEO477)
at pH 10.8. Hydrodynamic radii of the micelles of approximately 31,
27, and 23 nm for native CotA, CotA-E20, and CotA-E40, respectively,
were determined using dynamic light scattering (DLS) and fluorescence
correlation spectroscopy (FCS). The encapsulation efficiency was not
affected using enzymes with a polyglutamic acid tail but resulted
in more micelles with a smaller number of enzyme molecules per micelle.
Furthermore, it was shown that the addition of a polyglutamic acid
tail to CotA indeed resulted in improved salt stability of enzyme-containing
C3Ms. Interestingly, the polyglutamic acid CotA variants showed an
enhanced enzyme activity. This study demonstrates that increasing
the net charge of enzymes through genetic engineering is a promising
strategy to improve the practical applicability of C3Ms as enzyme
delivery systems.
Collapse
Affiliation(s)
- Riahna Kembaren
- Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
- Laboratory of Biochemistry, Microspectroscopy Research Facility, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Adrie H. Westphal
- Laboratory of Biochemistry, Microspectroscopy Research Facility, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Marleen Kamperman
- Polymer Science, Zernike Institute for Advanced Materials, University of Groningen, Nijenborgh 4, 9747 AG Groningen, The Netherlands
| | - J. Mieke Kleijn
- Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Microspectroscopy Research Facility, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| |
Collapse
|
6
|
Nederveen-Schippers LM, Pathak P, Keizer-Gunnink I, Westphal AH, van Haastert PJM, Borst JW, Kortholt A, Skakun V. Combined FCS and PCH Analysis to Quantify Protein Dimerization in Living Cells. Int J Mol Sci 2021; 22:ijms22147300. [PMID: 34298920 PMCID: PMC8307594 DOI: 10.3390/ijms22147300] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2021] [Revised: 06/25/2021] [Accepted: 07/01/2021] [Indexed: 11/29/2022] Open
Abstract
Protein dimerization plays a crucial role in the regulation of numerous biological processes. However, detecting protein dimers in a cellular environment is still a challenge. Here we present a methodology to measure the extent of dimerization of GFP-tagged proteins in living cells, using a combination of fluorescence correlation spectroscopy (FCS) and photon counting histogram (PCH) analysis of single-color fluorescence fluctuation data. We named this analysis method brightness and diffusion global analysis (BDGA) and adapted it for biological purposes. Using cell lysates containing different ratios of GFP and tandem-dimer GFP (diGFP), we show that the average brightness per particle is proportional to the fraction of dimer present. We further adapted this methodology for its application in living cells, and we were able to distinguish GFP, diGFP, as well as ligand-induced dimerization of FKBP12 (FK506 binding protein 12)-GFP. While other analysis methods have only sporadically been used to study dimerization in living cells and may be prone to errors, this paper provides a robust approach for the investigation of any cytosolic protein using single-color fluorescence fluctuation spectroscopy.
Collapse
Affiliation(s)
- Laura M. Nederveen-Schippers
- Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, The Netherlands; (L.M.N.-S.); (P.P.); (I.K.-G.); (P.J.M.v.H.)
| | - Pragya Pathak
- Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, The Netherlands; (L.M.N.-S.); (P.P.); (I.K.-G.); (P.J.M.v.H.)
| | - Ineke Keizer-Gunnink
- Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, The Netherlands; (L.M.N.-S.); (P.P.); (I.K.-G.); (P.J.M.v.H.)
| | - Adrie H. Westphal
- Laboratory of Biochemistry, Wageningen University & Research, 6708 WE Wageningen, The Netherlands; (A.H.W.); (J.W.B.)
| | - Peter J. M. van Haastert
- Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, The Netherlands; (L.M.N.-S.); (P.P.); (I.K.-G.); (P.J.M.v.H.)
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University & Research, 6708 WE Wageningen, The Netherlands; (A.H.W.); (J.W.B.)
| | - Arjan Kortholt
- Department of Cell Biochemistry, University of Groningen, 9747 AG Groningen, The Netherlands; (L.M.N.-S.); (P.P.); (I.K.-G.); (P.J.M.v.H.)
- Correspondence: (A.K.); (V.S.)
| | - Victor Skakun
- Department of Systems Analysis and Computer Simulation, Belarusian State University, 220030 Minsk, Belarus
- Correspondence: (A.K.); (V.S.)
| |
Collapse
|
7
|
Abstract
Auxin is fundamental to the growth and development of land plants, and acts in large part through the control of gene activity. Genetic and biochemical analysis of the nuclear auxin signaling pathway (NAP) has led to the establishment of a generic model for auxin-dependent gene regulation. To understand how this dynamic system operates in living cells, quantitative data are needed. For this, the liverwort Marchantia polymorpha provides a useful model system. Its limited number of NAP components, combined with experimental approaches to determine concentrations, binding affinities, and turnover rates, will enable a new, quantitative view on the mechanisms that allow auxin to control plant growth and development.
Collapse
Affiliation(s)
- Shubhajit Das
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, The Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, The Netherlands.
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708WE Wageningen, The Netherlands.
| |
Collapse
|
8
|
van Dierendonck XAMH, de la Rosa Rodriguez MA, Georgiadi A, Mattijssen F, Dijk W, van Weeghel M, Singh R, Borst JW, Stienstra R, Kersten S. HILPDA Uncouples Lipid Droplet Accumulation in Adipose Tissue Macrophages from Inflammation and Metabolic Dysregulation. Cell Rep 2021; 30:1811-1822.e6. [PMID: 32049012 DOI: 10.1016/j.celrep.2020.01.046] [Citation(s) in RCA: 28] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2019] [Revised: 12/10/2019] [Accepted: 01/15/2020] [Indexed: 01/15/2023] Open
Abstract
Obesity leads to a state of chronic, low-grade inflammation that features the accumulation of lipid-laden macrophages in adipose tissue. Here, we determined the role of macrophage lipid-droplet accumulation in the development of obesity-induced adipose-tissue inflammation, using mice with myeloid-specific deficiency of the lipid-inducible HILPDA protein. HILPDA deficiency markedly reduced intracellular lipid levels and accumulation of fluorescently labeled fatty acids. Decreased lipid storage in HILPDA-deficient macrophages can be rescued by inhibition of adipose triglyceride lipase (ATGL) and is associated with increased oxidative metabolism. In diet-induced obese mice, HILPDA deficiency does not alter inflammatory and metabolic parameters, despite markedly reducing lipid accumulation in macrophages. Overall, we find that HILPDA is a lipid-inducible, physiological inhibitor of ATGL-mediated lipolysis in macrophages and uncouples lipid storage in adipose tissue macrophages from inflammation and metabolic dysregulation. Our data question the contribution of lipid droplet accumulation in adipose tissue macrophages in obesity-induced inflammation and metabolic dysregulation.
Collapse
Affiliation(s)
- Xanthe A M H van Dierendonck
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands; Department of Internal Medicine, Radboud University Medical Center, Geert Grooteplein 8, 6525 GA Nijmegen, the Netherlands
| | - Montserrat A de la Rosa Rodriguez
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Anastasia Georgiadi
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Frits Mattijssen
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Wieneke Dijk
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Michel van Weeghel
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands; Gastroenterology and Metabolism, Amsterdam Cardiovascular Sciences, Meibergdreef 9, 1105 AZ Amsterdam, the Netherlands
| | - Rajat Singh
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Forchheimer 505D, Bronx, NY 10461, USA
| | - Jan Willem Borst
- Laboratory of Biochemistry, Microspectroscopy Research Facility, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Rinke Stienstra
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands; Department of Internal Medicine, Radboud University Medical Center, Geert Grooteplein 8, 6525 GA Nijmegen, the Netherlands.
| | - Sander Kersten
- Nutrition, Metabolism and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, 6708 WE Wageningen, the Netherlands.
| |
Collapse
|
9
|
de la Rosa Rodriguez MA, Deng L, Gemmink A, van Weeghel M, Aoun ML, Warnecke C, Singh R, Borst JW, Kersten S. Hypoxia-inducible lipid droplet-associated induces DGAT1 and promotes lipid storage in hepatocytes. Mol Metab 2021; 47:101168. [PMID: 33465519 PMCID: PMC7881268 DOI: 10.1016/j.molmet.2021.101168] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Revised: 01/08/2021] [Accepted: 01/12/2021] [Indexed: 12/26/2022] Open
Abstract
Objective Storage of triglycerides in lipid droplets is governed by a set of lipid droplet-associated proteins. One of these lipid droplet-associated proteins, hypoxia-inducible lipid droplet-associated (HILPDA), was found to impair lipid droplet breakdown in macrophages and cancer cells by inhibiting adipose triglyceride lipase. Here, we aimed to better characterize the role and mechanism of action of HILPDA in hepatocytes. Methods We performed studies in HILPDA-deficient and HILPDA-overexpressing liver cells, liver slices, and mice. The functional role and physical interactions of HILPDA were investigated using a variety of biochemical and microscopic techniques, including real-time fluorescence live-cell imaging and Förster resonance energy transfer-fluorescence lifetime imaging microscopy (FRET-FLIM). Results Levels of HILPDA were markedly induced by fatty acids in several hepatoma cell lines. Hepatocyte-specific deficiency of HILPDA in mice modestly but significantly reduced hepatic triglycerides in mice with non-alcoholic steatohepatitis. Similarly, deficiency of HILPDA in mouse liver slices and primary hepatocytes reduced lipid storage and accumulation of fluorescently-labeled fatty acids in lipid droplets, respectively, which was independent of adipose triglyceride lipase. Fluorescence microscopy showed that HILPDA partly colocalizes with lipid droplets and with the endoplasmic reticulum, is especially abundant in perinuclear areas, and mainly associates with newly added fatty acids. Real-time fluorescence live-cell imaging further revealed that HILPDA preferentially localizes to lipid droplets that are being remodeled. Overexpression of HILPDA in liver cells increased the activity of diacylglycerol acyltransferases (DGAT) and DGAT1 protein levels, concurrent with increased lipid storage. Confocal microscopy coupled to FRET-FLIM analysis demonstrated that HILPDA physically interacts with DGAT1 in living liver cells. The stimulatory effect of HILPDA on lipid storage via DGAT1 was corroborated in adipocytes. Conclusions Our data indicate that HILPDA physically interacts with DGAT1 and increases DGAT activity. Our findings suggest a novel regulatory mechanism by which fatty acids promote triglyceride synthesis and storage. HILPDA expression is induced by fatty acids in hepatoma cells. HILPDA deficiency modestly decreases liver triglyceride storage in mice with NASH. HILPDA preferentially associates with newly synthesized lipid droplets and active lipid droplets. HILPDA promotes lipid storage at least in part independently of ATGL. HILPDA physically interacts and induces DGAT1.
Collapse
Affiliation(s)
- Montserrat A de la Rosa Rodriguez
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, Wageningen, 6708 WE, the Netherlands
| | - Lei Deng
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, Wageningen, 6708 WE, the Netherlands
| | - Anne Gemmink
- Department of Nutrition and Movement Sciences, Maastricht University Medical Center+, Maastricht, 6200 MD, the Netherlands
| | - Michel van Weeghel
- Laboratory Genetic Metabolic Diseases, Amsterdam UMC, University of Amsterdam, Meibergdreef 9, Amsterdam, 1105 AZ, the Netherlands
| | - Marie Louise Aoun
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Forchheimer 505D, Bronx, NY, 10461, USA
| | - Christina Warnecke
- Department of Nephrology and Hypertension, University Hospital Erlangen, Friedrich-Alexander-University Erlangen-Nürnberg, Erlangen, Germany
| | - Rajat Singh
- Department of Medicine, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Forchheimer 505D, Bronx, NY, 10461, USA
| | - Jan Willem Borst
- Laboratory of Biochemistry, Microspectroscopy Research Facility, Wageningen University, Stippeneng 4, Wageningen, 6708 WE, the Netherlands
| | - Sander Kersten
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition and Health, Wageningen University, Stippeneng 4, Wageningen, 6708 WE, the Netherlands.
| |
Collapse
|
10
|
Kembaren R, Fokkink R, Westphal AH, Kamperman M, Kleijn JM, Borst JW. Balancing Enzyme Encapsulation Efficiency and Stability in Complex Coacervate Core Micelles. Langmuir 2020; 36:8494-8502. [PMID: 32598154 PMCID: PMC7467766 DOI: 10.1021/acs.langmuir.0c01073] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 06/29/2020] [Indexed: 06/11/2023]
Abstract
Encapsulation of charged proteins into complex coacervate core micelles (C3Ms) can be accomplished by mixing them with oppositely charged diblock copolymers. However, these micelles tend to disintegrate at high ionic strength. Previous research showed that the addition of a homopolymer with the same charge sign as the protein improved the stability of protein-containing C3Ms. In this research, we used fluorescence correlation spectroscopy (FCS) and dynamic light scattering (DLS) to study how the addition of the homopolymer affects the encapsulation efficiency and salt stability of the micelles. We studied the encapsulation of laccase spore coat protein A (CotA), a multicopper oxidase, using a strong cationic-neutral diblock copolymer, poly(N-methyl-2-vinyl-pyridinium iodide)-block-poly(ethylene oxide) (PM2VP128-b-PEO477), and a negatively charged homopolymer, poly(4-styrenesulfonate) (PSS215). DLS indeed showed an improved stability of this three-component C3M system against the addition of salt compared to a two-component system. Remarkably, FCS showed that the release of CotA from a three-component C3M system occurred at a lower salt concentration and over a narrower concentration range than the dissociation of C3Ms. In conclusion, although the addition of the homopolymer to the system leads to micelles with a higher salt stability, CotA is excluded from the C3Ms already at lower ionic strengths because the homopolymer acts as a competitor of the enzyme for encapsulation.
Collapse
Affiliation(s)
- Riahna Kembaren
- Physical
Chemistry and Soft Matter, Wageningen University
and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
- Laboratory
of Biochemistry, Microspectroscopy Research Facility, Wageningen University and Research, Stippeneng 4, 6708
WE Wageningen, Netherlands
| | - Remco Fokkink
- Physical
Chemistry and Soft Matter, Wageningen University
and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Adrie H. Westphal
- Laboratory
of Biochemistry, Microspectroscopy Research Facility, Wageningen University and Research, Stippeneng 4, 6708
WE Wageningen, Netherlands
| | - Marleen Kamperman
- Zernike
Institute for Advanced Research, University
of Groningen, Nijenborgh 4, 9747 AG Groningen, the Netherlands
| | - J. Mieke Kleijn
- Physical
Chemistry and Soft Matter, Wageningen University
and Research, Stippeneng 4, 6708 WE Wageningen, the Netherlands
| | - Jan Willem Borst
- Laboratory
of Biochemistry, Microspectroscopy Research Facility, Wageningen University and Research, Stippeneng 4, 6708
WE Wageningen, Netherlands
| |
Collapse
|
11
|
Michels L, Gorelova V, Harnvanichvech Y, Borst JW, Albada B, Weijers D, Sprakel J. Complete microviscosity maps of living plant cells and tissues with a toolbox of targeting mechanoprobes. Proc Natl Acad Sci U S A 2020; 117:18110-18118. [PMID: 32669427 PMCID: PMC7395454 DOI: 10.1073/pnas.1921374117] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Mechanical patterns control a variety of biological processes in plants. The microviscosity of cellular structures effects the diffusion rate of molecules and organelles, thereby affecting processes such as metabolism and signaling. Spatial variations in local viscosity are also generated during fundamental events in the cell life cycle. While crucial to a complete understanding of plant mechanobiology, resolving subcellular microviscosity patterns in plants has remained an unsolved challenge. We present an imaging microviscosimetry toolbox of molecular rotors that yield complete microviscosity maps of cells and tissues, specifically targeting the cytosol, vacuole, plasma membrane, and wall of plant cells. These boron-dipyrromethene (BODIPY)-based molecular rotors are rigidochromic by means of coupling the rate of an intramolecular rotation, which depends on the mechanics of their direct surroundings, with their fluorescence lifetime. This enables the optical mapping of fluidity and porosity patterns in targeted cellular compartments. We show how apparent viscosity relates to cell function in the root, how the growth of cellular protrusions induces local tension, and how the cell wall is adapted to perform actuation surrounding leaf pores. These results pave the way to the noninvasive micromechanical mapping of complex tissues.
Collapse
Affiliation(s)
- Lucile Michels
- Physical Chemistry and Soft Matter, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
| | - Vera Gorelova
- Laboratory of Biochemistry, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
| | - Yosapol Harnvanichvech
- Physical Chemistry and Soft Matter, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
- Laboratory of Biochemistry, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
| | - Bauke Albada
- Laboratory of Organic Chemistry, Wageningen University & Research, 6708 WE Wageningen, The Netherlands
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University & Research, 6708 WE Wageningen, The Netherlands;
| | - Joris Sprakel
- Physical Chemistry and Soft Matter, Wageningen University & Research, 6708 WE Wageningen, The Netherlands;
| |
Collapse
|
12
|
Kato H, Mutte SK, Suzuki H, Crespo I, Das S, Radoeva T, Fontana M, Yoshitake Y, Hainiwa E, van den Berg W, Lindhoud S, Ishizaki K, Hohlbein J, Borst JW, Boer DR, Nishihama R, Kohchi T, Weijers D. Design principles of a minimal auxin response system. Nat Plants 2020; 6:473-482. [PMID: 32415296 DOI: 10.1038/s41477-020-0662-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/06/2019] [Accepted: 04/09/2020] [Indexed: 06/11/2023]
Abstract
Auxin controls numerous growth processes in land plants through a gene expression system that modulates ARF transcription factor activity1-3. Gene duplications in families encoding auxin response components have generated tremendous complexity in most land plants, and neofunctionalization enabled various unique response outputs during development1,3,4. However, it is unclear what fundamental biochemical principles underlie this complex response system. By studying the minimal system in Marchantia polymorpha, we derive an intuitive and simple model where a single auxin-dependent A-ARF activates gene expression. It is antagonized by an auxin-independent B-ARF that represses common target genes. The expression patterns of both ARF proteins define developmental zones where auxin response is permitted, quantitatively tuned or prevented. This fundamental design probably represents the ancestral system and formed the basis for inflated, complex systems.
Collapse
Affiliation(s)
- Hirotaka Kato
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
- Graduate School of Science, Kobe University, Kobe, Japan
| | - Sumanth K Mutte
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | - Hidemasa Suzuki
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Isidro Crespo
- Alba Synchrotron, Cerdanyola del Vallès, Barcelona, Spain
| | - Shubhajit Das
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | - Tatyana Radoeva
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | - Mattia Fontana
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
- Laboratory of Biophysics, Wageningen University, Wageningen, The Netherlands
| | | | - Emi Hainiwa
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Willy van den Berg
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | - Simon Lindhoud
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | | | - Johannes Hohlbein
- Laboratory of Biophysics, Wageningen University, Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | - D Roeland Boer
- Alba Synchrotron, Cerdanyola del Vallès, Barcelona, Spain
| | | | - Takayuki Kohchi
- Graduate School of Biostudies, Kyoto University, Kyoto, Japan
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands.
| |
Collapse
|
13
|
Overdijk EJR, Tang H, Borst JW, Govers F, Ketelaar T. Time-gated confocal microscopy reveals accumulation of exocyst subunits at the plant-pathogen interface. J Exp Bot 2020; 71:837-849. [PMID: 31665494 DOI: 10.1093/jxb/erz478] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 10/16/2019] [Indexed: 06/10/2023]
Abstract
Polarized exocytosis is essential for plant development and defence. The exocyst, an octameric protein complex that tethers exocytotic vesicles to the plasma membrane, targets exocytosis. Upon pathogen attack, secreted materials form papillae to halt pathogen penetration. To determine if the exocyst is directly involved in targeting exocytosis to infection sites, information about its localization is instrumental. Here, we investigated exocyst subunit localization in the moss Physcomitrella patens upon pathogen attack and infection by Phytophthora capsici. Time-gated confocal microscopy was used to eliminate autofluorescence of deposited material around infection sites, allowing the visualization of the subcellular localization of exocyst subunits and of v-SNARE Vamp72A1-labelled exocytotic vesicles during infection. This showed that exocyst subunits Sec3a, Sec5b, Sec5d, and Sec6 accumulated at sites of attempted pathogen penetration. Upon pathogen invasion, the exocyst subunits accumulated on the membrane surrounding papilla-like structures and hyphal encasements. Vamp72A1-labelled vesicles were found to localize in the cytoplasm around infection sites. The re-localization of exocyst subunits to infection sites suggests that the exocyst is directly involved in facilitating polarized exocytosis during pathogenesis.
Collapse
Affiliation(s)
- Elysa J R Overdijk
- Laboratory of Cell Biology, Wageningen University & Research, Wageningen, The Netherlands
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, The Netherlands
| | - Han Tang
- Laboratory of Cell Biology, Wageningen University & Research, Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, The Netherlands
| | - Francine Govers
- Laboratory of Phytopathology, Wageningen University & Research, Wageningen, The Netherlands
| | - Tijs Ketelaar
- Laboratory of Cell Biology, Wageningen University & Research, Wageningen, The Netherlands
| |
Collapse
|
14
|
Luo Q, Sewalt E, Borst JW, Westphal AH, Boom RM, Janssen AE. Analysis and modeling of enhanced green fluorescent protein diffusivity in whey protein gels. Food Res Int 2019; 120:449-455. [DOI: 10.1016/j.foodres.2018.10.087] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Revised: 10/28/2018] [Accepted: 10/30/2018] [Indexed: 10/28/2022]
|
15
|
Borst JW, van den Berg P, Hink M. Appreciation of Professor Dr Visser. Methods Appl Fluoresc 2019; 7:020401. [PMID: 30654344 DOI: 10.1088/2050-6120/aaffab] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
16
|
Houwman JA, Westphal AH, Visser AJWG, Borst JW, van Mierlo CPM. Concurrent presence of on- and off-pathway folding intermediates of apoflavodoxin at physiological ionic strength. Phys Chem Chem Phys 2018; 20:7059-7072. [PMID: 29473921 DOI: 10.1039/c7cp07922b] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Flavodoxins have a protein topology that can be traced back to the universal ancestor of the three kingdoms of life. Proteins with this type of architecture tend to temporarily misfold during unassisted folding to their native state and form intermediates. Several of these intermediate species are molten globules (MGs), which are characterized by a substantial amount of secondary structure, yet without the tertiary side-chain packing of natively folded proteins. An off-pathway MG is formed at physiological ionic strength in the case of the F44Y variant of Azotobacter vinelandii apoflavodoxin (i.e., flavodoxin without flavin mononucleotide (FMN)). Here, we show that at this condition actually two folding species of this apoprotein co-exist at equilibrium. These species were detected by using a combination of FMN fluorescence quenching upon cofactor binding to the apoprotein and of polarized time-resolved tryptophan fluorescence spectroscopy. Besides the off-pathway MG, we observe the simultaneous presence of an on-pathway folding intermediate, which is native-like. Presence of concurrent intermediates at physiological ionic strength enables future exploration of how aspects of the cellular environment, like for example involvement of chaperones, affect these species.
Collapse
Affiliation(s)
- Joseline A Houwman
- Laboratory of Biochemistry, Wageningen University, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | | | | | | | | |
Collapse
|
17
|
Slootweg EJ, Spiridon LN, Martin EC, Tameling WIL, Townsend PD, Pomp R, Roosien J, Drawska O, Sukarta OCA, Schots A, Borst JW, Joosten MHAJ, Bakker J, Smant G, Cann MJ, Petrescu AJ, Goverse A. Distinct Roles of Non-Overlapping Surface Regions of the Coiled-Coil Domain in the Potato Immune Receptor Rx1. Plant Physiol 2018; 178:1310-1331. [PMID: 30194238 PMCID: PMC6236623 DOI: 10.1104/pp.18.00603] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/22/2018] [Accepted: 08/28/2018] [Indexed: 05/20/2023]
Abstract
The intracellular immune receptor Rx1 of potato (Solanum tuberosum), which confers effector-triggered immunity to Potato virus X, consists of a central nucleotide-binding domain (NB-ARC) flanked by a carboxyl-terminal leucine-rich repeat (LRR) domain and an amino-terminal coiled-coil (CC) domain. Rx1 activity is strictly regulated by interdomain interactions between the NB-ARC and LRR, but the contribution of the CC domain in regulating Rx1 activity or immune signaling is not fully understood. Therefore, we used a structure-informed approach to investigate the role of the CC domain in Rx1 functionality. Targeted mutagenesis of CC surface residues revealed separate regions required for the intramolecular and intermolecular interaction of the CC with the NB-ARC-LRR and the cofactor Ran GTPase-activating protein2 (RanGAP2), respectively. None of the mutant Rx1 proteins was constitutively active, indicating that the CC does not contribute to the autoinhibition of Rx1 activity. Instead, the CC domain acted as a modulator of downstream responses involved in effector-triggered immunity. Systematic disruption of the hydrophobic interface between the four helices of the CC enabled the uncoupling of cell death and disease resistance responses. Moreover, a strong dominant negative effect on Rx1-mediated resistance and cell death was observed upon coexpression of the CC alone with full-length Rx1 protein, which depended on the RanGAP2-binding surface of the CC. Surprisingly, coexpression of the N-terminal half of the CC enhanced Rx1-mediated resistance, which further indicated that the CC functions as a scaffold for downstream components involved in the modulation of disease resistance or cell death signaling.
Collapse
Affiliation(s)
- Erik J Slootweg
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | | | - Eliza C Martin
- Institute of Biochemistry of the Romanian Academy, 060031 Bucharest, Romania
| | - Wladimir I L Tameling
- Laboratory of Phytopathology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Philip D Townsend
- Department of Biosciences and Biophysical Sciences Institute, Durham University, Durham DH1 3LE, United Kingdom
| | - Rikus Pomp
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Jan Roosien
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Olga Drawska
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Octavina C A Sukarta
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Arjen Schots
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry/Microspectroscopy Centre, Department of Agrotechnology and Food Sciences, Wageningen University, 6708 WE Wageningen, The Netherlands
| | - Matthieu H A J Joosten
- Laboratory of Phytopathology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Jaap Bakker
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Geert Smant
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| | - Martin J Cann
- Department of Biosciences and Biophysical Sciences Institute, Durham University, Durham DH1 3LE, United Kingdom
| | | | - Aska Goverse
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands
| |
Collapse
|
18
|
Nolles A, Hooiveld E, Westphal AH, van Berkel WJH, Kleijn JM, Borst JW. FRET Reveals the Formation and Exchange Dynamics of Protein-Containing Complex Coacervate Core Micelles. Langmuir 2018; 34:12083-12092. [PMID: 30212214 PMCID: PMC6209312 DOI: 10.1021/acs.langmuir.8b01272] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 09/10/2018] [Indexed: 06/08/2023]
Abstract
The encapsulation of proteins into complex coacervate core micelles (C3Ms) is of potential interest for a wide range of applications. To address the stability and dynamic properties of these polyelectrolyte complexes, combinations of cyan, yellow, and blue fluorescent proteins were encapsulated with cationic-neutral diblock copolymer poly(2-methyl-vinyl-pyridinium)128- b-poly(ethylene-oxide)477. Förster resonance energy transfer (FRET) allowed us to determine the kinetics of C3M formation and of protein exchange between C3Ms. Both processes follow first-order kinetics with relaxation times of ±100 s at low ionic strength ( I = 2.5 mM). Stability studies revealed that 50% of FRET was lost at I = 20 mM, pointing to the disintegration of the C3Ms. On the basis of experimental and theoretical considerations, we propose that C3Ms relax to their final state by association and dissociation of near-neutral soluble protein-polymer complexes. To obtain protein-containing C3Ms suitable for applications, it is necessary to improve the rigidity and salt stability of these complexes.
Collapse
Affiliation(s)
- Antsje Nolles
- Laboratory
of Biochemistry, Physical Chemistry and Soft Matter,
and MicroSpectroscopy Centre
Wageningen, Wageningen University &
Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Ellard Hooiveld
- Laboratory
of Biochemistry, Physical Chemistry and Soft Matter,
and MicroSpectroscopy Centre
Wageningen, Wageningen University &
Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Adrie H. Westphal
- Laboratory
of Biochemistry, Physical Chemistry and Soft Matter,
and MicroSpectroscopy Centre
Wageningen, Wageningen University &
Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Willem J. H. van Berkel
- Laboratory
of Biochemistry, Physical Chemistry and Soft Matter,
and MicroSpectroscopy Centre
Wageningen, Wageningen University &
Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - J. Mieke Kleijn
- Laboratory
of Biochemistry, Physical Chemistry and Soft Matter,
and MicroSpectroscopy Centre
Wageningen, Wageningen University &
Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory
of Biochemistry, Physical Chemistry and Soft Matter,
and MicroSpectroscopy Centre
Wageningen, Wageningen University &
Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands
| |
Collapse
|
19
|
Nolles A, van Dongen NJE, Westphal AH, Visser AJWG, Kleijn JM, van Berkel WJH, Borst JW. Encapsulation into complex coacervate core micelles promotes EGFP dimerization. Phys Chem Chem Phys 2018; 19:11380-11389. [PMID: 28422208 DOI: 10.1039/c7cp00755h] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Complex coacervate core micelles (C3Ms) are colloidal structures useful for encapsulation of biomacromolecules. We previously demonstrated that enhanced green fluorescent protein (EGFP) can be encapsulated into C3Ms using the diblock copolymer poly(2-methyl-vinyl-pyridinium)41-b-poly(ethylene-oxide)205. This packaging resulted in deviating spectroscopic features of the encapsulated EGFP molecules. Here we show that for monomeric EGFP variant (mEGFP) micellar encapsulation affects the absorption and fluorescence properties to a much lesser extent, and that changes in circular dichroism characteristics are specific for encapsulated EGFP. Time-resolved fluorescence anisotropy of encapsulated (m)EGFP established the occurrence of homo-FRET (Förster resonance energy transfer) with larger transfer correlation times in the case of EGFP. Together, these findings support that EGFP dimerizes whereas the mEGFP mainly remains as a monomer in the densely packed C3Ms. We propose that dimerization of encapsulated EGFP causes a reorientation of Glu222, resulting in a pKa shift of the chromophore, which is fully reversible after release of EGFP from the C3Ms at a high ionic strength.
Collapse
Affiliation(s)
- A Nolles
- Laboratory of Biochemistry, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
20
|
Padmanabha Das KM, Wechselberger L, Liziczai M, De la Rosa Rodriguez M, Grabner GF, Heier C, Viertlmayr R, Radler C, Lichtenegger J, Zimmermann R, Borst JW, Zechner R, Kersten S, Oberer M. Hypoxia-inducible lipid droplet-associated protein inhibits adipose triglyceride lipase. J Lipid Res 2018; 59:531-541. [PMID: 29326160 PMCID: PMC5832925 DOI: 10.1194/jlr.m082388] [Citation(s) in RCA: 50] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 01/10/2018] [Indexed: 11/29/2022] Open
Abstract
Elaborate control mechanisms of intracellular triacylglycerol (TAG) breakdown are critically involved in the maintenance of energy homeostasis. Hypoxia-inducible lipid droplet-associated protein (HILPDA)/hypoxia-inducible gene-2 (Hig-2) has been shown to affect intracellular TAG levels, yet, the underlying molecular mechanisms are unclear. Here, we show that HILPDA inhibits adipose triglyceride lipase (ATGL), the enzyme catalyzing the first step of intracellular TAG hydrolysis. HILPDA shares structural similarity with G0/G1 switch gene 2 (G0S2), an established inhibitor of ATGL. HILPDA inhibits ATGL activity in a dose-dependent manner with an IC50 value of ∼2 μM. ATGL inhibition depends on the direct physical interaction of both proteins and involves the N-terminal hydrophobic region of HILPDA and the N-terminal patatin domain-containing segment of ATGL. Finally, confocal microscopy combined with Förster resonance energy transfer-fluorescence lifetime imaging microscopy analysis indicated that HILPDA and ATGL colocalize and physically interact intracellularly. These findings provide a rational biochemical explanation for the tissue-specific increased TAG accumulation in HILPDA-overexpressing transgenic mouse models.
Collapse
Affiliation(s)
| | - Lisa Wechselberger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Márton Liziczai
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | | | - Gernot F Grabner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Christoph Heier
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Roland Viertlmayr
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Claudia Radler
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Jörg Lichtenegger
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria
| | - Robert Zimmermann
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria.,BioTechMed-Graz, 8010 Graz, Austria
| | - Jan Willem Borst
- Laboratory of Biochemistry and Microspectroscopy Research Facility, Wageningen University, Wageningen, The Netherlands
| | - Rudolf Zechner
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria.,BioTechMed-Graz, 8010 Graz, Austria
| | - Sander Kersten
- Division of Human Nutrition University of Graz, 8010 Graz, Austria
| | - Monika Oberer
- Institute of Molecular Biosciences, University of Graz, 8010 Graz, Austria .,BioTechMed-Graz, 8010 Graz, Austria
| |
Collapse
|
21
|
Novikov EG, Skakun VV, Borst JW, Visser AJWG. Maximum entropy analysis of polarized fluorescence decay of (E)GFP in aqueous solution. Methods Appl Fluoresc 2017; 6:014001. [PMID: 28858857 DOI: 10.1088/2050-6120/aa898b] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The maximum entropy method (MEM) was used for the analysis of polarized fluorescence decays of enhanced green fluorescent protein (EGFP) in buffered water/glycerol mixtures, obtained with time-correlated single-photon counting (Visser et al 2016 Methods Appl. Fluoresc. 4 035002). To this end, we used a general-purpose software module of MEM that was earlier developed to analyze (complex) laser photolysis kinetics of ligand rebinding reactions in oxygen binding proteins. We demonstrate that the MEM software provides reliable results and is easy to use for the analysis of both total fluorescence decay and fluorescence anisotropy decay of aqueous solutions of EGFP. The rotational correlation times of EGFP in water/glycerol mixtures, obtained by MEM as maxima of the correlation-time distributions, are identical to the single correlation times determined by global analysis of parallel and perpendicular polarized decay components. The MEM software is also able to determine homo-FRET in another dimeric GFP, for which the transfer correlation time is an order of magnitude shorter than the rotational correlation time. One important advantage utilizing MEM analysis is that no initial guesses of parameters are required, since MEM is able to select the least correlated solution from the feasible set of solutions.
Collapse
Affiliation(s)
- Eugene G Novikov
- Institut Curie-Recherche (INSERM U350), Centre Universitaire, F-91405 Orsay, France. Carl Zeiss Microscopy GmbH, D-07745 Jena, Germany
| | | | | | | |
Collapse
|
22
|
Smith RW, Helwig B, Westphal AH, Pel E, Borst JW, Fleck C. Interactions Between phyB and PIF Proteins Alter Thermal Reversion Reactions in vitro. Photochem Photobiol 2017; 93:1525-1531. [PMID: 28503745 DOI: 10.1111/php.12793] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2017] [Accepted: 05/02/2017] [Indexed: 10/19/2022]
Abstract
The dynamic behavior of the plant red/far-red light photoreceptor phytochrome B (phyB) has been elucidated in natural and synthetic systems. Red light switches phyB from the inactive Pr state to the active Pfr state, a process that is reversed by far-red light. Alongside light signals, phyB activity is constrained by thermal reversion (that is prominent in the dark) and protein-protein interactions between phyB, other phytochrome molecules, and, among others, PHYTOCHROME INTERACTING FACTORs (PIFs). Requirements for phyB-PIF association have been well studied and are central to light-regulated synthetic tools. However, it is unknown whether PIF interactions influence transitions of phyB between different conformers. Here, we show that the in vitro thermal reversion of phyB involves multiple reactions. Thermal reversion of phyB in vitro is inhibited by PIF6, and this effect is observed at all temperatures tested. We analyzed our experimental data using a mathematical model containing multiple Pfr conformers, in accordance with previous findings. Remarkably, each Pfr conformer is differentially regulated by PIF6 and temperature. As a result, we speculate that in vivo phytochrome signaling networks may require similar levels of complexity to fine-tune responses to the external environment.
Collapse
Affiliation(s)
- Robert W Smith
- Laboratory of Systems & Synthetic Biology, Wageningen University & Research, Wageningen, The Netherlands.,LifeGlimmer GmbH, Berlin, Germany
| | - Britta Helwig
- Laboratory of Systems & Synthetic Biology, Wageningen University & Research, Wageningen, The Netherlands
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, The Netherlands
| | - Eran Pel
- Laboratory of Systems & Synthetic Biology, Wageningen University & Research, Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University & Research, Wageningen, The Netherlands
| | - Christian Fleck
- Laboratory of Systems & Synthetic Biology, Wageningen University & Research, Wageningen, The Netherlands
| |
Collapse
|
23
|
Nolles A, Westphal AH, Kleijn JM, van Berkel WJH, Borst JW. Colorful Packages: Encapsulation of Fluorescent Proteins in Complex Coacervate Core Micelles. Int J Mol Sci 2017; 18:ijms18071557. [PMID: 28753915 PMCID: PMC5536045 DOI: 10.3390/ijms18071557] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2017] [Revised: 06/30/2017] [Accepted: 07/13/2017] [Indexed: 12/02/2022] Open
Abstract
Encapsulation of proteins can be beneficial for food and biomedical applications. To study their biophysical properties in complex coacervate core micelles (C3Ms), we previously encapsulated enhanced green fluorescent protein (EGFP) and its monomeric variant, mEGFP, with the cationic-neutral diblock copolymer poly(2-methyl-vinyl-pyridinium)n-b-poly(ethylene-oxide)m (P2MVPn-b-PEOm) as enveloping material. C3Ms with high packaging densities of fluorescent proteins (FPs) were obtained, resulting in a restricted orientational freedom of the protein molecules, influencing their structural and spectral properties. To address the generality of this behavior, we encapsulated seven FPs with P2MVP41-b-PEO205 and P2MVP128-b-PEO477. Dynamic light scattering and fluorescence correlation spectroscopy showed lower encapsulation efficiencies for members of the Anthozoa class (anFPs) than for Hydrozoa FPs derived from Aequorea victoria (avFPs). Far-UV CD spectra of the free FPs showed remarkable differences between avFPs and anFPs, caused by rounder barrel structures for avFPs and more elliptic ones for anFPs. These structural differences, along with the differences in charge distribution, might explain the variations in encapsulation efficiency between avFPs and anFPs. Furthermore, the avFPs remain monomeric in C3Ms with minor spectral and structural changes. In contrast, the encapsulation of anFPs gives rise to decreased quantum yields (monomeric Kusabira Orange 2 (mKO2) and Tag red fluorescent protein (TagRFP)) or to a pKa shift of the chromophore (FP variant mCherry).
Collapse
Affiliation(s)
- Antsje Nolles
- Laboratory of Biochemistry, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
- Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
- MicroSpectroscopy Centre Wageningen, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - J Mieke Kleijn
- Physical Chemistry and Soft Matter, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Willem J H van Berkel
- Laboratory of Biochemistry, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
- MicroSpectroscopy Centre Wageningen, Wageningen University & Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
| |
Collapse
|
24
|
Dijk W, Mattijssen F, de la Rosa Rodriguez M, Loza Valdes A, Loft A, Mandrup S, Kalkhoven E, Qi L, Borst JW, Kersten S. Hypoxia-Inducible Lipid Droplet-Associated Is Not a Direct Physiological Regulator of Lipolysis in Adipose Tissue. Endocrinology 2017; 158:1231-1251. [PMID: 28323980 PMCID: PMC5460841 DOI: 10.1210/en.2016-1809] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2016] [Accepted: 03/13/2017] [Indexed: 12/20/2022]
Abstract
Triglycerides are stored in specialized organelles called lipid droplets. Numerous proteins have been shown to be physically associated with lipid droplets and govern their function. Previously, the protein hypoxia-inducible lipid droplet-associated (HILPDA) was localized to lipid droplets and was suggested to inhibit triglyceride lipolysis in hepatocytes. We confirm the partial localization of HILPDA to lipid droplets and show that HILPDA is highly abundant in adipose tissue, where its expression is controlled by the peroxisome proliferator-activated receptor γ and by β-adrenergic stimulation. Levels of HILPDA markedly increased during 3T3-L1 adipocyte differentiation. Nevertheless, silencing of Hilpda using small interfering RNA or overexpression of Hilpda using adenovirus did not show a clear impact on 3T3-L1 adipogenesis. Following β-adrenergic stimulation, the silencing of Hilpda in adipocytes did not significantly alter the release of nonesterified fatty acids (NEFA) and glycerol. By contrast, adenoviral-mediated overexpression of Hilpda modestly attenuated the release of NEFA from adipocytes following β-adrenergic stimulation. In mice, adipocyte-specific inactivation of Hilpda had no effect on plasma levels of NEFA and glycerol after fasting, cold exposure, or pharmacological β-adrenergic stimulation. In addition, other relevant metabolic parameters were unchanged by adipocyte-specific inactivation of Hilpda. Taken together, we find that HILPDA is highly abundant in adipose tissue, where its levels are induced by peroxisome proliferator-activated receptor γ and β-adrenergic stimulation. In contrast to the reported inhibition of lipolysis by HILPDA in hepatocytes, our data do not support an important direct role of HILPDA in the regulation of lipolysis in adipocytes in vivo and in vitro.
Collapse
Affiliation(s)
- Wieneke Dijk
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition, Wageningen University, 6708 WE Wageningen, The Netherlands
| | - Frits Mattijssen
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition, Wageningen University, 6708 WE Wageningen, The Netherlands
| | - Montserrat de la Rosa Rodriguez
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition, Wageningen University, 6708 WE Wageningen, The Netherlands
| | - Angel Loza Valdes
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition, Wageningen University, 6708 WE Wageningen, The Netherlands
| | - Anne Loft
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense, Denmark
| | - Susanne Mandrup
- Department of Biochemistry and Molecular Biology, University of Southern Denmark, DK-5230 Odense, Denmark
| | - Eric Kalkhoven
- Molecular Cancer Research and Center for Molecular Medicine, University Medical Centre Utrecht, 3584 CG Utrecht, The Netherlands
| | - Ling Qi
- University of Michigan Medical School, Ann Arbor, Michigan 48105
| | - Jan Willem Borst
- Laboratory of Biochemistry, Microspectroscopy Centre, Wageningen University, 6708 WE Wageningen, The Netherlands
| | - Sander Kersten
- Nutrition, Metabolism, and Genomics Group, Division of Human Nutrition, Wageningen University, 6708 WE Wageningen, The Netherlands
- University of Michigan Medical School, Ann Arbor, Michigan 48105
| |
Collapse
|
25
|
Wientjes E, Philippi J, Borst JW, van Amerongen H. Imaging the Photosystem I/Photosystem II chlorophyll ratio inside the leaf. Biochimica et Biophysica Acta (BBA) - Bioenergetics 2017; 1858:259-265. [DOI: 10.1016/j.bbabio.2017.01.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 01/10/2017] [Accepted: 01/13/2017] [Indexed: 02/03/2023]
|
26
|
Abstract
Proteins are the workhorses that control most biological processes in living cells. Although proteins can accomplish their functions independently, the vast majority of functions require proteins to interact with other proteins or biomacromolecules. Protein interactions can be investigated through biochemical assays such as co-immunoprecipitation (co-IP) or Western blot analysis, but such assays lack spatial information. Here we describe a well-developed imaging method, Förster resonance energy transfer (FRET) analyzed by fluorescence lifetime imaging microscopy (FLIM), that can be used to visualize protein interactions with both spatial and temporal resolution in live cells. We demonstrate its use in plant developmental research by visualizing in vivo dimerization of AUXIN RESPONSE FACTOR (ARF) proteins, mediating auxin responses.
Collapse
Affiliation(s)
- Alejandra Freire Rios
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703HA, Wageningen, The Netherlands
| | - Tatyana Radoeva
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703HA, Wageningen, The Netherlands
| | - Bert De Rybel
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703HA, Wageningen, The Netherlands
- Department of Plant Systems Biology, Flemish Institute of Biotechnology, VIB, Ghent University, Technologiepark 927, 9052, Ghent, Belgium
- Department of Plant Biotechnology and Bioinformatics, Ghent University, Technologiepark 927, 9052, Ghent, Belgium
| | - Dolf Weijers
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703HA, Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703HA, Wageningen, The Netherlands.
- Microspectroscopy Center, Wageningen University, Dreijenlaan 3, 6703HA, Wageningen, The Netherlands.
| |
Collapse
|
27
|
Smith RW, Helwig B, Westphal AH, Pel E, Hörner M, Beyer HM, Samodelov SL, Weber W, Zurbriggen MD, Borst JW, Fleck C. Unearthing the transition rates between photoreceptor conformers. BMC Syst Biol 2016; 10:110. [PMID: 27884151 PMCID: PMC5123409 DOI: 10.1186/s12918-016-0368-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 11/07/2016] [Indexed: 12/04/2022]
Abstract
Background Obtaining accurate estimates of biological or enzymatic reaction rates is critical in understanding the design principles of a network and how biological processes can be experimentally manipulated on demand. In many cases experimental limitations mean that some enzymatic rates cannot be measured directly, requiring mathematical algorithms to estimate them. Here, we describe a methodology that calculates rates at which light-regulated proteins switch between conformational states. We focus our analysis on the phytochrome family of photoreceptors found in cyanobacteria, plants and many optogenetic tools. Phytochrome proteins change between active (PA) and inactive (PI) states at rates that are proportional to photoconversion cross-sections and influenced by light quality, light intensity, thermal reactions and dimerisation. This work presents a method that can accurately calculate these photoconversion cross-sections in the presence of multiple non-light regulated reactions. Results Our approach to calculating the photoconversion cross-sections comprises three steps: i) calculate the thermal reversion reaction rate(s); ii) develop search spaces from which all possible sets of photoconversion cross-sections exist, and; iii) estimate extinction coefficients that describe our absorption spectra. We confirm that the presented approach yields accurate results through the use of simulated test cases. Our test cases were further expanded to more realistic scenarios where noise, multiple thermal reactions and dimerisation are considered. Finally, we present the photoconversion cross-sections of an Arabidopsis phyB N-terminal fragment commonly used in optogenetic tools. Conclusions The calculation of photoconversion cross-sections has implications for both photoreceptor and synthetic biologists. Our method allows, for the first time, direct comparisons of photoconversion cross-sections and response speeds of photoreceptors in different cellular environments and synthetic tools. Due to the generality of our procedure, as shown by the application to multiple test cases, the photoconversion cross-sections and quantum yields of any photoreceptor might now, in principle, be obtained. Electronic supplementary material The online version of this article (doi:10.1186/s12918-016-0368-y) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Robert W Smith
- Laboratory of Systems & Synthetic Biology, Wageningen UR, PO Box 8033, Wageningen, 6700EJ, The Netherlands.,LifeGlimmer GmbH, Markelstrasse 38, Berlin, 12163, Germany
| | - Britta Helwig
- Laboratory of Systems & Synthetic Biology, Wageningen UR, PO Box 8033, Wageningen, 6700EJ, The Netherlands.,Laboratory of Biochemistry, PO Box 8128, Wageningen, 6700ET, The Netherlands
| | - Adrie H Westphal
- Laboratory of Biochemistry, PO Box 8128, Wageningen, 6700ET, The Netherlands
| | - Eran Pel
- Laboratory of Systems & Synthetic Biology, Wageningen UR, PO Box 8033, Wageningen, 6700EJ, The Netherlands.,Laboratory of Biochemistry, PO Box 8128, Wageningen, 6700ET, The Netherlands
| | - Maximilian Hörner
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstrasse 19A, Freiburg, 79104, Germany.,Faculty of Biology & BioSS, University of Freiburg, Schänzlestrasse 18, Freiburg, 79104, Germany
| | - Hannes M Beyer
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstrasse 19A, Freiburg, 79104, Germany.,Faculty of Biology & BioSS, University of Freiburg, Schänzlestrasse 18, Freiburg, 79104, Germany
| | - Sophia L Samodelov
- Spemann Graduate School of Biology and Medicine, University of Freiburg, Albertstrasse 19A, Freiburg, 79104, Germany.,Institute of Synthetic Biology, Heinrich Heine University, Universitätsstrasse 1, Düsseldorf, 40225, Germany
| | - Wilfried Weber
- Faculty of Biology & BioSS, University of Freiburg, Schänzlestrasse 18, Freiburg, 79104, Germany
| | - Matias D Zurbriggen
- Institute of Synthetic Biology, Heinrich Heine University, Universitätsstrasse 1, Düsseldorf, 40225, Germany
| | - Jan Willem Borst
- Laboratory of Biochemistry, PO Box 8128, Wageningen, 6700ET, The Netherlands
| | - Christian Fleck
- Laboratory of Systems & Synthetic Biology, Wageningen UR, PO Box 8033, Wageningen, 6700EJ, The Netherlands.
| |
Collapse
|
28
|
den Hollander PW, Kieper SN, Borst JW, van Lent JWM. The role of plasmodesma-located proteins in tubule-guided virus transport is limited to the plasmodesmata. Arch Virol 2016; 161:2431-40. [PMID: 27339685 PMCID: PMC4987395 DOI: 10.1007/s00705-016-2936-2] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 06/15/2016] [Indexed: 12/13/2022]
Abstract
Intercellular spread of plant viruses involves passage of the viral genome or virion through a plasmodesma (PD). Some viruses severely modify the PD structure, as they assemble a virion carrying tubule composed of the viral movement protein (MP) inside the PD channel. Successful modulation of the host plant to allow infection requires an intimate interaction between viral proteins and both structural and regulatory host proteins. To date, however, very few host proteins are known to promote virus spread. Plasmodesmata-located proteins (PDLPs) localised in the PD have been shown to contribute to tubule formation in cauliflower mosaic virus and grapevine fanleaf virus infections. In this study, we have investigated the role of PDLPs in intercellular transport of another tubule-forming virus, cowpea mosaic virus. The MP of this virus was found to interact with PDLPs in the PD, as was shown for other tubule-forming viruses. Expression of PDLPs and MPs in protoplasts in the absence of a PD revealed that these proteins do not co-localise at the site of tubule initiation. Furthermore, we show that tubule assembly in protoplasts does not require an interaction with PDLPs at the base of the tubule, as has been observed in planta. These results suggest that a physical interaction between MPs and PDLPs is not required for assembly of the movement tubule and that the beneficial role of PDLPs in virus movement is confined to the structural context of the PD.
Collapse
Affiliation(s)
- P W den Hollander
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - S N Kieper
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands
| | - J W Borst
- Laboratory of Biochemistry, Microspectroscopy Centre, Dreijenlaan 3, 6703 HA, Wageningen, The Netherlands
| | - J W M van Lent
- Laboratory of Virology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, The Netherlands.
| |
Collapse
|
29
|
Abstract
The molecular dimensions of proteins such as green fluorescent protein (GFP) are large as compared to the ones of solvents like water or glycerol. The microscopic viscosity, which determines the resistance to diffusion of, e.g. GFP, is then the same as that determined from the resistance of the solvent to flow, which is known as macroscopic viscosity. GFP in water/glycerol mixtures senses this macroscopic viscosity, because the translational and rotational diffusion coefficients are proportional to the reciprocal value of the viscosity as predicted by the Stokes-Einstein equations. To test this hypothesis, we have performed time-resolved fluorescence anisotropy (reporting on rotational diffusion) and fluorescence correlation spectroscopy (reporting on translational diffusion) experiments of GFP in water/glycerol mixtures. When the solvent also contains macromolecules of similar or larger dimensions as GFP, the microscopic and macroscopic viscosities can be markedly different and the Stokes-Einstein relations must be adapted. It was established from previous dynamic fluorescence spectroscopy observations of diffusing proteins with dextran polysaccharides as co-solvents (Lavalette et al 2006 Eur. Biophys. J. 35 517-22), that rotation and translation sense a different microscopic viscosity, in which the one arising from rotation is always less than that from translation. A microscopic viscosity parameter is defined that depends on scaling factors between GFP and its immediate environment. The direct consequence is discussed for two reported diffusion coefficients of GFP in living cells.
Collapse
Affiliation(s)
- Antonie J W G Visser
- Laboratory of Biochemistry, Microspectroscopy Centre, Wageningen University, PO Box 8128, 6700 ET Wageningen, The Netherlands
| | | | | | | |
Collapse
|
30
|
Bourdais G, Burdiak P, Gauthier A, Nitsch L, Salojärvi J, Rayapuram C, Idänheimo N, Hunter K, Kimura S, Merilo E, Vaattovaara A, Oracz K, Kaufholdt D, Pallon A, Anggoro DT, Glów D, Lowe J, Zhou J, Mohammadi O, Puukko T, Albert A, Lang H, Ernst D, Kollist H, Brosché M, Durner J, Borst JW, Collinge DB, Karpiński S, Lyngkjær MF, Robatzek S, Wrzaczek M, Kangasjärvi J. Large-Scale Phenomics Identifies Primary and Fine-Tuning Roles for CRKs in Responses Related to Oxidative Stress. PLoS Genet 2015; 11:e1005373. [PMID: 26197346 PMCID: PMC4511522 DOI: 10.1371/journal.pgen.1005373] [Citation(s) in RCA: 129] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2014] [Accepted: 06/19/2015] [Indexed: 12/20/2022] Open
Abstract
Cysteine-rich receptor-like kinases (CRKs) are transmembrane proteins characterized by the presence of two domains of unknown function 26 (DUF26) in their ectodomain. The CRKs form one of the largest groups of receptor-like protein kinases in plants, but their biological functions have so far remained largely uncharacterized. We conducted a large-scale phenotyping approach of a nearly complete crk T-DNA insertion line collection showing that CRKs control important aspects of plant development and stress adaptation in response to biotic and abiotic stimuli in a non-redundant fashion. In particular, the analysis of reactive oxygen species (ROS)-related stress responses, such as regulation of the stomatal aperture, suggests that CRKs participate in ROS/redox signalling and sensing. CRKs play general and fine-tuning roles in the regulation of stomatal closure induced by microbial and abiotic cues. Despite their great number and high similarity, large-scale phenotyping identified specific functions in diverse processes for many CRKs and indicated that CRK2 and CRK5 play predominant roles in growth regulation and stress adaptation, respectively. As a whole, the CRKs contribute to specificity in ROS signalling. Individual CRKs control distinct responses in an antagonistic fashion suggesting future potential for using CRKs in genetic approaches to improve plant performance and stress tolerance.
Collapse
Affiliation(s)
- Gildas Bourdais
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Paweł Burdiak
- Department of Plant Genetics, Breeding and Plant Biotechnology, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
| | - Adrien Gauthier
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Lisette Nitsch
- Laboratory of Biochemistry and Microspectroscopy Center, Wageningen University, Wageningen, The Netherlands
| | - Jarkko Salojärvi
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Channabasavangowda Rayapuram
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Center, University of Copenhagen, Frederiksberg, Denmark
| | - Niina Idänheimo
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Kerri Hunter
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Sachie Kimura
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Ebe Merilo
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Aleksia Vaattovaara
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Krystyna Oracz
- Department of Plant Genetics, Breeding and Plant Biotechnology, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
- Department of Plant Physiology, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
| | - David Kaufholdt
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Andres Pallon
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Damar Tri Anggoro
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Dawid Glów
- Department of Plant Genetics, Breeding and Plant Biotechnology, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
| | - Jennifer Lowe
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Ji Zhou
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Omid Mohammadi
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Tuomas Puukko
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Andreas Albert
- Research Unit Environmental Simulation, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Hans Lang
- Research Unit Environmental Simulation, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Dieter Ernst
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Hannes Kollist
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Mikael Brosché
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
- Institute of Technology, University of Tartu, Tartu, Estonia
| | - Jörg Durner
- Institute of Biochemical Plant Pathology, Helmholtz Zentrum München, German Research Center for Environmental Health, Neuherberg, Germany
| | - Jan Willem Borst
- Laboratory of Biochemistry and Microspectroscopy Center, Wageningen University, Wageningen, The Netherlands
| | - David B. Collinge
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Center, University of Copenhagen, Frederiksberg, Denmark
| | - Stanisław Karpiński
- Department of Plant Genetics, Breeding and Plant Biotechnology, Warsaw University of Life Sciences-SGGW, Warsaw, Poland
| | - Michael F. Lyngkjær
- Department of Plant and Environmental Sciences and Copenhagen Plant Science Center, University of Copenhagen, Frederiksberg, Denmark
| | - Silke Robatzek
- The Sainsbury Laboratory, Norwich Research Park, Norwich, United Kingdom
| | - Michael Wrzaczek
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
| | - Jaakko Kangasjärvi
- Department of Biosciences, Plant Biology, University of Helsinki, Helsinki, Finland
- Distinguished Scientist Fellowship Program, College of Science, King Saud University, Riyadh, Saudi Arabia
| | | |
Collapse
|
31
|
Nolles A, Westphal AH, de Hoop JA, Fokkink RG, Kleijn JM, van Berkel WJH, Borst JW. Encapsulation of GFP in Complex Coacervate Core Micelles. Biomacromolecules 2015; 16:1542-9. [DOI: 10.1021/acs.biomac.5b00092] [Citation(s) in RCA: 48] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Antsje Nolles
- Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter,
and §MicroSpectroscopy Centre
Wageningen, Wageningen University, Wageningen, The Netherlands
| | - Adrie H. Westphal
- Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter,
and §MicroSpectroscopy Centre
Wageningen, Wageningen University, Wageningen, The Netherlands
| | - Jacob A. de Hoop
- Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter,
and §MicroSpectroscopy Centre
Wageningen, Wageningen University, Wageningen, The Netherlands
| | - Remco G. Fokkink
- Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter,
and §MicroSpectroscopy Centre
Wageningen, Wageningen University, Wageningen, The Netherlands
| | - J. Mieke Kleijn
- Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter,
and §MicroSpectroscopy Centre
Wageningen, Wageningen University, Wageningen, The Netherlands
| | - Willem J. H. van Berkel
- Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter,
and §MicroSpectroscopy Centre
Wageningen, Wageningen University, Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, ‡Physical Chemistry and Soft Matter,
and §MicroSpectroscopy Centre
Wageningen, Wageningen University, Wageningen, The Netherlands
| |
Collapse
|
32
|
Lindhoud S, Westphal AH, van Mierlo CPM, Visser AJWG, Borst JW. Rise-time of FRET-acceptor fluorescence tracks protein folding. Int J Mol Sci 2014; 15:23836-50. [PMID: 25535076 PMCID: PMC4284793 DOI: 10.3390/ijms151223836] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2014] [Revised: 11/26/2014] [Accepted: 11/28/2014] [Indexed: 01/15/2023] Open
Abstract
Uniform labeling of proteins with fluorescent donor and acceptor dyes with an equimolar ratio is paramount for accurate determination of Förster resonance energy transfer (FRET) efficiencies. In practice, however, the labeled protein population contains donor-labeled molecules that have no corresponding acceptor. These FRET-inactive donors contaminate the donor fluorescence signal, which leads to underestimation of FRET efficiencies in conventional fluorescence intensity and lifetime-based FRET experiments. Such contamination is avoided if FRET efficiencies are extracted from the rise time of acceptor fluorescence upon donor excitation. The reciprocal value of the rise time of acceptor fluorescence is equal to the decay rate of the FRET-active donor fluorescence. Here, we have determined rise times of sensitized acceptor fluorescence to study the folding of double-labeled apoflavodoxin molecules and show that this approach tracks the characteristics of apoflavodoxinʼs complex folding pathway.
Collapse
Affiliation(s)
- Simon Lindhoud
- Laboratory of Biochemistry, Wageningen University, Wageningen 6703HA, The Netherlands.
| | - Adrie H Westphal
- Laboratory of Biochemistry, Wageningen University, Wageningen 6703HA, The Netherlands.
| | - Carlo P M van Mierlo
- Laboratory of Biochemistry, Wageningen University, Wageningen 6703HA, The Netherlands.
| | - Antonie J W G Visser
- Laboratory of Biochemistry, Wageningen University, Wageningen 6703HA, The Netherlands.
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University, Wageningen 6703HA, The Netherlands.
| |
Collapse
|
33
|
Borst JW, Robinson D. Editorial for Protoplasma--special issue on microscopy. Protoplasma 2014; 251:273-275. [PMID: 24534924 DOI: 10.1007/s00709-013-0603-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/14/2013] [Accepted: 12/14/2013] [Indexed: 06/03/2023]
Affiliation(s)
- J W Borst
- Wageningen University, Wageningen, The Netherlands,
| | | |
Collapse
|
34
|
Bücherl CA, Bader A, Westphal AH, Laptenok SP, Borst JW. FRET-FLIM applications in plant systems. Protoplasma 2014; 251:383-394. [PMID: 24390247 DOI: 10.1007/s00709-013-0595-7] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/04/2013] [Accepted: 12/05/2013] [Indexed: 05/28/2023]
Abstract
A hallmark of cellular processes is the spatio-temporally regulated interplay of biochemical components. Assessing spatial information of molecular interactions within living cells is difficult using traditional biochemical methods. Developments in green fluorescent protein technology in combination with advances in fluorescence microscopy have revolutionised this field of research by providing the genetic tools to investigate the spatio-temporal dynamics of biomolecules in live cells. In particular, fluorescence lifetime imaging microscopy (FLIM) has become an inevitable technique for spatially resolving cellular processes and physical interactions of cellular components in real time based on the detection of Förster resonance energy transfer (FRET). In this review, we provide a theoretical background of FLIM as well as FRET-FLIM analysis. Furthermore, we show two cases in which advanced microscopy applications revealed many new insights of cellular processes in living plant cells as well as in whole plants.
Collapse
|
35
|
Hamers D, van Voorst Vader L, Borst JW, Goedhart J. Development of FRET biosensors for mammalian and plant systems. Protoplasma 2014; 251:333-347. [PMID: 24337770 DOI: 10.1007/s00709-013-0590-z] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/14/2013] [Accepted: 11/19/2013] [Indexed: 06/03/2023]
Abstract
Genetically encoded biosensors are increasingly used in visualising signalling processes in different organisms. Sensors based on green fluorescent protein technology are providing a great opportunity for using Förster resonance energy transfer (FRET) as a tool that allows for monitoring dynamic processes in living cells. The development of these FRET biosensors requires careful selection of fluorophores, substrates and recognition domains. In this review, we will discuss recent developments, strategies to create and optimise FRET biosensors and applications of FRET-based biosensors for use in the two major eukaryotic kingdoms and elaborate on different methods for FRET detection.
Collapse
Affiliation(s)
- Danny Hamers
- Laboratory of Biochemistry and Microspectroscopy Centre, Wageningen University, Wageningen, The Netherlands
| | | | | | | |
Collapse
|
36
|
Ribeiro D, Jung M, Moling S, Borst JW, Goldbach R, Kormelink R. The cytosolic nucleoprotein of the plant-infecting bunyavirus tomato spotted wilt recruits endoplasmic reticulum-resident proteins to endoplasmic reticulum export sites. Plant Cell 2013; 25:3602-14. [PMID: 24045023 PMCID: PMC3809552 DOI: 10.1105/tpc.113.114298] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2013] [Revised: 07/25/2013] [Accepted: 08/27/2013] [Indexed: 05/04/2023]
Abstract
In contrast with animal-infecting viruses, few known plant viruses contain a lipid envelope, and the processes leading to their membrane envelopment remain largely unknown. Plant viruses with lipid envelopes include viruses of the Bunyaviridae, which obtain their envelope from the Golgi complex. The envelopment process is predominantly dictated by two viral glycoproteins (Gn and Gc) and the viral nucleoprotein (N). During maturation of the plant-infecting bunyavirus Tomato spotted wilt, Gc localizes at endoplasmic reticulum (ER) membranes and becomes ER export competent only upon coexpression with Gn. In the presence of cytosolic N, Gc remains arrested in the ER but changes its distribution from reticular into punctate spots. Here, we show that these areas correspond to ER export sites (ERESs), distinct ER domains where glycoprotein cargo concentrates prior to coat protein II vesicle-mediated transport to the Golgi. Gc concentration at ERES is mediated by an interaction between its cytoplasmic tail (CT) and N. Interestingly, an ER-resident calnexin provided with Gc-CT was similarly recruited to ERES when coexpressed with N. Furthermore, disruption of actin filaments caused the appearance of a larger amount of smaller ERES loaded with N-Gc complexes, suggesting that glycoprotein cargo concentration acts as a trigger for de novo synthesis of ERES.
Collapse
Affiliation(s)
- Daniela Ribeiro
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, 6708PB Wageningen, The Netherlands
| | - Maartje Jung
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, 6708PB Wageningen, The Netherlands
| | - Sjef Moling
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, 6708PB Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Microspectroscopy Centre, Wageningen University, 6703HA Wageningen, The Netherlands
| | - Rob Goldbach
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, 6708PB Wageningen, The Netherlands
| | - Richard Kormelink
- Laboratory of Virology, Department of Plant Sciences, Wageningen University, 6708PB Wageningen, The Netherlands
| |
Collapse
|
37
|
Bücherl CA, van Esse GW, Kruis A, Luchtenberg J, Westphal AH, Aker J, van Hoek A, Albrecht C, Borst JW, de Vries SC. Visualization of BRI1 and BAK1(SERK3) membrane receptor heterooligomers during brassinosteroid signaling. Plant Physiol 2013; 162:1911-25. [PMID: 23796795 PMCID: PMC3729770 DOI: 10.1104/pp.113.220152] [Citation(s) in RCA: 80] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Accepted: 06/21/2013] [Indexed: 05/18/2023]
Abstract
The leucine-rich repeat receptor-like kinase BRASSINOSTEROID-INSENSITIVE1 (BRI1) is the main ligand-perceiving receptor for brassinosteroids (BRs) in Arabidopsis (Arabidopsis thaliana). Binding of BRs to the ectodomain of plasma membrane (PM)-located BRI1 receptors initiates an intracellular signal transduction cascade that influences various aspects of plant growth and development. Even though the major components of BR signaling have been revealed and the PM was identified as the main site of BRI1 signaling activity, the very first steps of signal transmission are still elusive. Recently, it was shown that the initiation of BR signal transduction requires the interaction of BRI1 with its SOMATIC EMBRYOGENESIS RECEPTOR-LIKE KINASE (SERK) coreceptors. In addition, the resolved structure of the BRI1 ectodomain suggested that BRI1-ASSOCIATED KINASE1 [BAK1](SERK3) may constitute a component of the ligand-perceiving receptor complex. Therefore, we investigated the spatial correlation between BRI1 and BAK1(SERK3) in the natural habitat of both leucine-rich repeat receptor-like kinases using comparative colocalization analysis and fluorescence lifetime imaging microscopy. We show that activation of BR signaling by exogenous ligand application resulted in both elevated colocalization between BRI1 and BAK1(SERK3) and an about 50% increase of receptor heterooligomerization in the PM of live Arabidopsis root epidermal cells. However, large populations of BRI1 and BAK1(SERK3) colocalized independently of BRs. Moreover, we could visualize that approximately 7% of the BRI1 PM pool constitutively heterooligomerizes with BAK1(SERK3) in live root cells. We propose that only small populations of PM-located BRI1 and BAK1(SERK3) receptors participate in active BR signaling and that the initiation of downstream signal transduction involves preassembled BRI1-BAK1(SERK3) heterooligomers.
Collapse
Affiliation(s)
- Christoph A. Bücherl
- Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; and
- Centre for BioSystems Genomics, 6708 PB Wageningen, The Netherlands (J.W.B.)
| | - G. Wilma van Esse
- Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; and
- Centre for BioSystems Genomics, 6708 PB Wageningen, The Netherlands (J.W.B.)
| | - Alex Kruis
- Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; and
- Centre for BioSystems Genomics, 6708 PB Wageningen, The Netherlands (J.W.B.)
| | - Jeroen Luchtenberg
- Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; and
- Centre for BioSystems Genomics, 6708 PB Wageningen, The Netherlands (J.W.B.)
| | - Adrie H. Westphal
- Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; and
- Centre for BioSystems Genomics, 6708 PB Wageningen, The Netherlands (J.W.B.)
| | - José Aker
- Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; and
- Centre for BioSystems Genomics, 6708 PB Wageningen, The Netherlands (J.W.B.)
| | - Arie van Hoek
- Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; and
- Centre for BioSystems Genomics, 6708 PB Wageningen, The Netherlands (J.W.B.)
| | - Catherine Albrecht
- Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; and
- Centre for BioSystems Genomics, 6708 PB Wageningen, The Netherlands (J.W.B.)
| | - Jan Willem Borst
- Laboratory of Biochemistry (C.A.B., G.W.v.E., A.K., J.L., A.H.W., J.A., C.A., J.W.B., S.C.d.V.), Laboratory of Biophysics (A.v.H.), and Microspectroscopy Centre (A.v.H., J.W.B.), Department of Agrotechnology and Food Sciences, 6703 HA Wageningen, The Netherlands; and
- Centre for BioSystems Genomics, 6708 PB Wageningen, The Netherlands (J.W.B.)
| | | |
Collapse
|
38
|
Niranjan Y, Ungureanu D, Hammarén H, Sanz-Sanz A, Westphal AH, Borst JW, Silvennoinen O, Hilhorst R. Analysis of steady-state Förster resonance energy transfer data by avoiding pitfalls: interaction of JAK2 tyrosine kinase with N-methylanthraniloyl nucleotides. Anal Biochem 2013; 442:213-22. [PMID: 23891636 DOI: 10.1016/j.ab.2013.07.020] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2013] [Revised: 07/10/2013] [Accepted: 07/14/2013] [Indexed: 10/26/2022]
Abstract
Förster resonance energy transfer (FRET) between the fluorescent ATP analogue 2'/3'-(N-methyl-anthraniloyl)-adenosine-5'-triphosphate (MANT-ATP) and enzymes is widely used to determine affinities for ATP-protein binding. However, in analysis of FRET fluorescence data, several important parameters are often ignored, resulting in poor accuracy of the calculated dissociation constant (Kd). In this study, we systematically analyze factors that interfere with Kd determination and describe methods for correction of primary and secondary inner filter effects that extend the use of the FRET method to higher MANT nucleotide concentrations. The interactions of the fluorescent nucleotide analogues MANT-ATP, MANT-ADP [2'/3'-O-(N-methylanthraniloyl) adenosine diphosphate], and MANT-AMP [2'/3'-O-(N-methylanthraniloyl) adenosine monophosphate] with the JAK2 tyrosine kinase domain are characterized. Taking all interfering factors into consideration, we found that JAK2 binds MANT-ATP tightly with a Kd of 15 to 25nM and excluded the presence of a second binding site. The affinity for MANT-ADP is also tight with a Kd of 50 to 80nM, whereas MANT-AMP does not bind. Titrations of JAK2 JH1 with nonhydrolyzable ATP analogue MANT-ATP-γ-S [2'/3'-O-(N-methylanthraniloyl) adenosine-5'-(thio)- triphosphate] yielded a Kd of 30 to 50nM. The methods demonstrated here are applicable to other enzyme-fluorophore combinations and are expected to help improve the analysis of steady-state FRET data in MANT nucleotide binding studies and to obtain more accurate results for the affinities of nucleotide binding proteins.
Collapse
Affiliation(s)
- Yashavanthi Niranjan
- Institute of Biomedical Technology, University of Tampere, FI-33014 Tampere, Finland
| | | | | | | | | | | | | | | |
Collapse
|
39
|
Skakun VV, Engel R, Borst JW, Apanasovich VV, Visser AJWG. Simultaneous diffusion and brightness measurements and brightness profile visualization from single fluorescence fluctuation traces of GFP in living cells. Eur Biophys J 2012; 41:1055-64. [PMID: 23064964 DOI: 10.1007/s00249-012-0864-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2012] [Revised: 09/12/2012] [Accepted: 09/21/2012] [Indexed: 10/27/2022]
Abstract
Fluorescence correlation spectroscopy (FCS) and photon-counting histogram (PCH) analysis use the same experimental fluorescence intensity fluctuations, but each analytical method focuses on a different property of the signal. The time-dependent decay of the correlation of fluorescence fluctuations is measured in FCS yielding, for instance, molecular diffusion coefficients. The amplitude distribution of these fluctuations is calculated by PCH analysis yielding information about the molecular brightness of fluorescent species. Analysis of both FCS and PCH results in the molecular concentration of the sample. Using a previously described global analysis procedure we report here precise, simultaneous measurements of diffusion constants and brightness values from single fluorescence fluctuation traces of green-fluorescent protein (GFP, S65T) in the cytoplasm of Dictyostelium cells. The use of a polynomial profile in PCH analysis, describing the detected three-dimensional shape of the confocal volume, enabled us to obtain well fitting results for GFP in cells. We could visualize the polynomial profile and show its deviation from a Gaussian profile.
Collapse
Affiliation(s)
- Victor V Skakun
- Department of Systems Analysis and Computer Simulation, Belarusian State University, 220030 Minsk, Belarus.
| | | | | | | | | |
Collapse
|
40
|
Abstract
Fluorescence spectroscopy is an important tool for the characterization of protein folding. Often, a protein is labeled with appropriate fluorescent donor and acceptor probes and folding-induced changes in Förster Resonance Energy Transfer (FRET) are monitored. However, conformational changes of the protein potentially affect fluorescence properties of both probes, thereby profoundly complicating interpretation of FRET data. In this study, we assess the effects protein folding has on fluorescence properties of Alexa Fluor 488 (A488), which is commonly used as FRET donor. Here, A488 is covalently attached to Cys69 of apoflavodoxin from Azotobacter vinelandii. Although coupling of A488 slightly destabilizes apoflavodoxin, the three-state folding of this protein, which involves a molten globule intermediate, is unaffected. Upon folding of apoflavodoxin, fluorescence emission intensity of A488 changes significantly. To illuminate the molecular sources of this alteration, we applied steady state and time-resolved fluorescence techniques. The results obtained show that tryptophans cause folding-induced changes in quenching of Alexa dye. Compared to unfolded protein, static quenching of A488 is increased in the molten globule. Upon populating the native state both static and dynamic quenching of A488 decrease considerably. We show that fluorescence quenching of Alexa Fluor dyes is a sensitive reporter of conformational changes during protein folding.
Collapse
Affiliation(s)
- Simon Lindhoud
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | - Adrie H. Westphal
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | - Antonie J. W. G. Visser
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
- Microspectroscopy Centre, Wageningen University, Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
- Microspectroscopy Centre, Wageningen University, Wageningen, The Netherlands
| | | |
Collapse
|
41
|
Lindhoud S, Westphal AH, Borst JW, van Mierlo CPM. Illuminating the off-pathway nature of the molten globule folding intermediate of an α-β parallel protein. PLoS One 2012; 7:e45746. [PMID: 23029219 PMCID: PMC3448718 DOI: 10.1371/journal.pone.0045746] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2012] [Accepted: 08/22/2012] [Indexed: 11/19/2022] Open
Abstract
Partially folded protein species transiently form during folding of most proteins. Often, these species are molten globules, which may be on- or off-pathway to the native state. Molten globules are ensembles of interconverting protein conformers that have a substantial amount of secondary structure, but lack virtually all tertiary side-chain packing characteristics of natively folded proteins. Due to solvent-exposed hydrophobic groups, molten globules are prone to aggregation, which can have detrimental effects on organisms. The molten globule observed during folding of the 179-residue apoflavodoxin from Azotobacter vinelandii is off-pathway, as it has to unfold before native protein can form. Here, we study folding of apoflavodoxin and characterize its molten globule using fluorescence spectroscopy and Förster Resonance Energy Transfer (FRET). Apoflavodoxin is site-specifically labeled with fluorescent donor and acceptor dyes, utilizing dye-inaccessibility of Cys69 in cofactor-bound protein. Donor (i.e., Alexa Fluor 488) is covalently attached to Cys69 in all apoflavodoxin variants used. Acceptor (i.e., Alexa Fluor 568) is coupled to Cys1, Cys131 and Cys178, respectively. Our FRET data show that apoflavodoxin's molten globule forms in a non-cooperative manner and that its N-terminal 69 residues fold last. In addition, striking conformational differences between molten globule and native protein are revealed, because the inter-label distances sampled in the 111-residue C-terminal segment of the molten globule are shorter than observed for native apoflavodoxin. Thus, FRET sheds light on the off-pathway nature of the molten globule during folding of an α-β parallel protein.
Collapse
Affiliation(s)
- Simon Lindhoud
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
| | - Adrie H. Westphal
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
- Microspectroscopy Centre, Wageningen University, Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University, Wageningen, The Netherlands
- Microspectroscopy Centre, Wageningen University, Wageningen, The Netherlands
| | | |
Collapse
|
42
|
Frei dit Frey N, Mbengue M, Kwaaitaal M, Nitsch L, Altenbach D, Häweker H, Lozano-Duran R, Njo MF, Beeckman T, Huettel B, Borst JW, Panstruga R, Robatzek S. Plasma membrane calcium ATPases are important components of receptor-mediated signaling in plant immune responses and development. Plant Physiol 2012; 159:798-809. [PMID: 22535420 PMCID: PMC3375942 DOI: 10.1104/pp.111.192575] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2012] [Accepted: 04/24/2012] [Indexed: 05/18/2023]
Abstract
Plasma membrane-resident receptor kinases (RKs) initiate signaling pathways important for plant immunity and development. In Arabidopsis (Arabidopsis thaliana), the receptor for the elicitor-active peptide epitope of bacterial flagellin, flg22, is encoded by FLAGELLIN SENSING2 (FLS2), which promotes plant immunity. Despite its relevance, the molecular components regulating FLS2-mediated signaling remain largely unknown. We show that plasma membrane ARABIDOPSIS-AUTOINHIBITED Ca(2+)-ATPase (ACA8) forms a complex with FLS2 in planta. ACA8 and its closest homolog ACA10 are required for limiting the growth of virulent bacteria. One of the earliest flg22 responses is the transient increase of cytosolic Ca(2+) ions, which is crucial for many of the well-described downstream responses (e.g. generation of reactive oxygen species and the transcriptional activation of defense-associated genes). Mutant aca8 aca10 plants show decreased flg22-induced Ca(2+) and reactive oxygen species bursts and exhibit altered transcriptional reprogramming. In particular, mitogen-activated protein kinase-dependent flg22-induced gene expression is elevated, whereas calcium-dependent protein kinase-dependent flg22-induced gene expression is reduced. These results demonstrate that the fine regulation of Ca(2+) fluxes across the plasma membrane is critical for the coordination of the downstream microbe-associated molecular pattern responses and suggest a mechanistic link between the FLS2 receptor complex and signaling kinases via the secondary messenger Ca(2+). ACA8 also interacts with other RKs such as BRI1 and CLV1 known to regulate plant development, and both aca8 and aca10 mutants show morphological phenotypes, suggesting additional roles for ACA8 and ACA10 in developmental processes. Thus, Ca(2+) ATPases appear to represent general regulatory components of RK-mediated signaling pathways.
Collapse
|
43
|
Wilma van Esse G, Westphal AH, Surendran RP, Albrecht C, van Veen B, Borst JW, de Vries SC. Quantification of the brassinosteroid insensitive1 receptor in planta. Plant Physiol 2011; 156:1691-700. [PMID: 21617031 PMCID: PMC3149942 DOI: 10.1104/pp.111.179309] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 05/25/2011] [Indexed: 05/05/2023]
Abstract
In plants, green fluorescent protein (GFP) is routinely used to determine the subcellular location of fusion proteins. Here, we show that confocal imaging can be employed to approximate the number of GFP-labeled protein molecules present in living Arabidopsis (Arabidopsis thaliana) root cells. The technique involves calibration with soluble GFP to provide a usable protein concentration range within the confocal volume of the microscope. As a proof of principle, we quantified the Brassinosteroid Insensitive1 (BRI1) receptor fused to GFP, under control of its own promoter. The number of BRI1-GFP molecules per root epidermal cell ranges from 22,000 in the meristem and 130,000 in the elongation zone to 80,000 in the maturation zone, indicating that up to 6-fold differences in BRI1 receptor content exist. In contrast, when taking into account differences in cell size, BRI1-GFP receptor density in the plasma membrane is kept constant at 12 receptors μm⁻² in all cells throughout the meristem and elongation zone. Only the quiescent center and columella cells deviate from this pattern and have 5 to 6 receptors μm⁻². Remarkably, root cell sensitivity toward brassinosteroids appears to coincide with uniform meristem receptor density.
Collapse
Affiliation(s)
- G Wilma van Esse
- Department of Agrotechnology and Food Sciences, Laboratory of Biochemistry, Wageningen University, 6703 HA Wageningen, The Netherlands.
| | | | | | | | | | | | | |
Collapse
|
44
|
Willemse J, Borst JW, de Waal E, Bisseling T, van Wezel GP. Positive control of cell division: FtsZ is recruited by SsgB during sporulation of Streptomyces. Genes Dev 2011; 25:89-99. [PMID: 21205868 DOI: 10.1101/gad.600211] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
In bacteria that divide by binary fission, cell division starts with the polymerization of the tubulin homolog FtsZ at mid-cell to form a cell division scaffold (the Z ring), followed by recruitment of the other divisome components. The current view of bacterial cell division control starts from the principle of negative checkpoints that prevent incorrect Z-ring positioning. Here we provide evidence of positive control of cell division during sporulation of Streptomyces, via the direct recruitment of FtsZ by the membrane-associated divisome component SsgB. In vitro studies demonstrated that SsgB promotes the polymerization of FtsZ. The interactions are shown in vivo by time-lapse imaging and Förster resonance energy transfer and fluorescence lifetime imaging microscopy (FRET-FLIM), and are corroborated independently via two-hybrid studies. As determined by fluorescence recovery after photobleaching (FRAP), the turnover of FtsZ protofilaments increased strongly at the time of Z-ring formation. The surprising positive control of Z-ring formation by SsgB implies the evolution of an entirely new way of Z-ring control, which may be explained by the absence of a mid-cell reference point in the long multinucleoid hyphae. In turn, the localization of SsgB is mediated through the orthologous SsgA, and premature expression of the latter is sufficient to directly activate multiple Z-ring formation and hyperdivision at early stages of the Streptomyces cell cycle.
Collapse
Affiliation(s)
- Joost Willemse
- Molecular Biotechnology, Gorlaeus Laboratories, Leiden University, Leiden 2300RA, The Netherlands
| | | | | | | | | |
Collapse
|
45
|
Krumova SB, Laptenok SP, Borst JW, Ughy B, Gombos Z, Ajlani G, van Amerongen H. Monitoring photosynthesis in individual cells of Synechocystis sp. PCC 6803 on a picosecond timescale. Biophys J 2011; 99:2006-15. [PMID: 20858447 DOI: 10.1016/j.bpj.2010.07.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2010] [Revised: 07/09/2010] [Accepted: 07/13/2010] [Indexed: 01/20/2023] Open
Abstract
Picosecond fluorescence kinetics of wild-type (WT) and mutant cells of Synechocystis sp. PCC 6803, were studied at the ensemble level with a streak-camera and at the cell level using fluorescence-lifetime-imaging microscopy (FLIM). The FLIM measurements are in good agreement with the ensemble measurements, but they (can) unveil variations between and within cells. The BE mutant cells, devoid of photosystem II (PSII) and of the light-harvesting phycobilisomes, allowed the study of photosystem I (PSI) in vivo for the first time, and the observed 6-ps equilibration process and 25-ps trapping process are the same as found previously for isolated PSI. No major differences are detected between different cells. The PAL mutant cells, devoid of phycobilisomes, show four lifetimes: ∼20 ps (PSI and PSII), ∼80 ps, ∼440 ps, and 2.8 ns (all due to PSII), but not all cells are identical and variations in the kinetics are traced back to differences in the PSI/PSII ratio. Finally, FLIM measurements on WT cells reveal that in some cells or parts of cells, phycobilisomes are disconnected from PSI/PSII. It is argued that the FLIM setup used can become instrumental in unraveling photosynthetic regulation mechanisms in the future.
Collapse
Affiliation(s)
- S B Krumova
- Laboratory of Biophysics, Wageningen University, Wageningen, The Netherlands
| | | | | | | | | | | | | |
Collapse
|
46
|
Skakun VV, Engel R, Digris AV, Borst JW, Visser AJWG. Global analysis of autocorrelation functions and photon counting distributions. Front Biosci (Elite Ed) 2011; 3:489-505. [PMID: 21196329 DOI: 10.2741/e264] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
In fluorescence correlation spectroscopy (FCS) and photon counting histogram (PCH) analysis the same experimental fluorescence intensity fluctuations are used, but each analytical method focuses on a different property of the signal. The time-dependent decay of the correlation of fluorescence fluctuations is measured in FCS yielding, for instance, molecular diffusion coefficients. The amplitude distribution of these fluctuations is calculated by PCH yielding the molecular brightness. Both FCS and PCH give information about the molecular concentration. Here we describe a global analysis protocol that simultaneously recovers relevant and common parameters in model functions of FCS and PCH from a single fluorescence fluctuation trace. The global analysis approach is described and tested with experimental fluorescence fluctuation data of enhanced green-fluorescent protein (eGFP) and dimeric eGFP (two eGFP molecules connected by a six amino acid long linker) in aqueous buffer. Brightness values and diffusion constants are recovered with good precision elucidating novel excited-state and motional properties of both proteins.
Collapse
Affiliation(s)
- Victor V Skakun
- Department of Systems Analysis, Belarusian State University, Minsk, Belarus.
| | | | | | | | | |
Collapse
|
47
|
Slootweg E, Roosien J, Spiridon LN, Petrescu AJ, Tameling W, Joosten M, Pomp R, van Schaik C, Dees R, Borst JW, Smant G, Schots A, Bakker J, Goverse A. Nucleocytoplasmic distribution is required for activation of resistance by the potato NB-LRR receptor Rx1 and is balanced by its functional domains. Plant Cell 2010; 22:4195-215. [PMID: 21177483 PMCID: PMC3027179 DOI: 10.1105/tpc.110.077537] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2010] [Revised: 10/18/2010] [Accepted: 11/19/2010] [Indexed: 05/18/2023]
Abstract
The Rx1 protein, as many resistance proteins of the nucleotide binding-leucine-rich repeat (NB-LRR) class, is predicted to be cytoplasmic because it lacks discernable nuclear targeting signals. Here, we demonstrate that Rx1, which confers extreme resistance to Potato virus X, is located both in the nucleus and cytoplasm. Manipulating the nucleocytoplasmic distribution of Rx1 or its elicitor revealed that Rx1 is activated in the cytoplasm and cannot be activated in the nucleus. The coiled coil (CC) domain was found to be required for accumulation of Rx1 in the nucleus, whereas the LRR domain promoted the localization in the cytoplasm. Analyses of structural subdomains of the CC domain revealed no autonomous signals responsible for active nuclear import. Fluorescence recovery after photobleaching and nuclear fractionation indicated that the CC domain binds transiently to large complexes in the nucleus. Disruption of the Rx1 resistance function and protein conformation by mutating the ATP binding phosphate binding loop in the NB domain, or by silencing the cochaperone SGT1, impaired the accumulation of Rx1 protein in the nucleus, while Rx1 versions lacking the LRR domain were not affected in this respect. Our results support a model in which interdomain interactions and folding states determine the nucleocytoplasmic distribution of Rx1.
Collapse
Affiliation(s)
- Erik Slootweg
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Slootweg E, Roosien J, Spiridon LN, Petrescu AJ, Tameling W, Joosten M, Pomp R, van Schaik C, Dees R, Borst JW, Smant G, Schots A, Bakker J, Goverse A. Nucleocytoplasmic distribution is required for activation of resistance by the potato NB-LRR receptor Rx1 and is balanced by its functional domains. Plant Cell 2010; 22:4195-4215. [PMID: 21177483 DOI: 10.2307/41059420] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
The Rx1 protein, as many resistance proteins of the nucleotide binding-leucine-rich repeat (NB-LRR) class, is predicted to be cytoplasmic because it lacks discernable nuclear targeting signals. Here, we demonstrate that Rx1, which confers extreme resistance to Potato virus X, is located both in the nucleus and cytoplasm. Manipulating the nucleocytoplasmic distribution of Rx1 or its elicitor revealed that Rx1 is activated in the cytoplasm and cannot be activated in the nucleus. The coiled coil (CC) domain was found to be required for accumulation of Rx1 in the nucleus, whereas the LRR domain promoted the localization in the cytoplasm. Analyses of structural subdomains of the CC domain revealed no autonomous signals responsible for active nuclear import. Fluorescence recovery after photobleaching and nuclear fractionation indicated that the CC domain binds transiently to large complexes in the nucleus. Disruption of the Rx1 resistance function and protein conformation by mutating the ATP binding phosphate binding loop in the NB domain, or by silencing the cochaperone SGT1, impaired the accumulation of Rx1 protein in the nucleus, while Rx1 versions lacking the LRR domain were not affected in this respect. Our results support a model in which interdomain interactions and folding states determine the nucleocytoplasmic distribution of Rx1.
Collapse
Affiliation(s)
- Erik Slootweg
- Laboratory of Nematology, Department of Plant Sciences, Wageningen University, 6708 PB Wageningen, The Netherlands.
| | | | | | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
49
|
Borst JW, Willemse M, Slijkhuis R, van der Krogt G, Laptenok SP, Jalink K, Wieringa B, Fransen JAM. ATP changes the fluorescence lifetime of cyan fluorescent protein via an interaction with His148. PLoS One 2010; 5:e13862. [PMID: 21079777 PMCID: PMC2974648 DOI: 10.1371/journal.pone.0013862] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2010] [Accepted: 10/19/2010] [Indexed: 11/18/2022] Open
Abstract
Recently, we described that ATP induces changes in YFP/CFP fluorescence intensities of Fluorescence Resonance Energy Transfer (FRET) sensors based on CFP-YFP. To get insight into this phenomenon, we employed fluorescence lifetime spectroscopy to analyze the influence of ATP on these fluorescent proteins in more detail. Using different donor and acceptor pairs we found that ATP only affected the CFP-YFP based versions. Subsequent analysis of purified monomers of the used proteins showed that ATP has a direct effect on the fluorescence lifetime properties of CFP. Since the fluorescence lifetime analysis of CFP is rather complicated by the existence of different lifetimes, we tested a variant of CFP, i.e. Cerulean, as a monomer and in our FRET constructs. Surprisingly, this CFP variant shows no ATP concentration dependent changes in the fluorescence lifetime. The most important difference between CFP and Cerulean is a histidine residue at position 148. Indeed, changing this histidine in CFP into an aspartic acid results in identical fluorescence properties as observed for the Cerulean fluorescent based FRET sensor. We therefore conclude that the changes in fluorescence lifetime of CFP are affected specifically by possible electrostatic interactions of the negative charge of ATP with the positively charged histidine at position 148. Clearly, further physicochemical characterization is needed to explain the sensitivity of CFP fluorescence properties to changes in environmental (i.e. ATP concentrations) conditions.
Collapse
Affiliation(s)
- Jan Willem Borst
- Laboratory of Biochemistry, Microspectroscopy Centre, Wageningen University, Wageningen, The Netherlands
| | | | | | | | | | | | | | | |
Collapse
|
50
|
Affiliation(s)
- Evan Spruijt
- Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
| | - Adrie H. Westphal
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
- MicroSpectroscopy Centre, P.O. Box 8128, 6700 ET Wageningen, The Netherlands
| | - Jan Willem Borst
- Laboratory of Biochemistry, Wageningen University, Dreijenlaan 3, 6703 HA Wageningen, The Netherlands
- MicroSpectroscopy Centre, P.O. Box 8128, 6700 ET Wageningen, The Netherlands
| | - Martien A. Cohen Stuart
- Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
| | - Jasper van der Gucht
- Laboratory of Physical Chemistry and Colloid Science, Wageningen University, Dreijenplein 6, 6703 HB Wageningen, The Netherlands
| |
Collapse
|