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Wang L, Lin Z, Carli J, Gladala‐Kostarz A, Davies JM, Franklin‐Tong VE, Bosch M. Depletion plays a pivotal role in self-incompatibility, revealing a link between cellular energy status, cytosolic acidification and actin remodelling in pollen tubes. THE NEW PHYTOLOGIST 2022; 236:1691-1707. [PMID: 35775998 PMCID: PMC9796540 DOI: 10.1111/nph.18350] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 06/15/2022] [Indexed: 06/08/2023]
Abstract
Self-incompatibility (SI) involves specific interactions during pollination to reject incompatible ('self') pollen, preventing inbreeding in angiosperms. A key event observed in pollen undergoing the Papaver rhoeas SI response is the formation of punctate F-actin foci. Pollen tube growth is heavily energy-dependent, yet ATP levels in pollen tubes have not been directly measured during SI. Here we used transgenic Arabidopsis lines expressing the Papaver pollen S-determinant to investigate a possible link between ATP levels, cytosolic pH ([pH]cyt ) and alterations to the actin cytoskeleton. We identify for the first time that SI triggers a rapid and significant ATP depletion in pollen tubes. Artificial depletion of ATP triggered cytosolic acidification and formation of actin aggregates. We also identify in vivo, evidence for a threshold [pH]cyt of 5.8 for actin foci formation. Imaging revealed that SI stimulates acidic cytosolic patches adjacent to the plasma membrane. In conclusion, this study provides evidence that ATP depletion plays a pivotal role in SI upstream of programmed cell death and reveals a link between the cellular energy status, cytosolic acidification and alterations to the actin cytoskeleton in regulating Papaver SI in pollen tubes.
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Affiliation(s)
- Ludi Wang
- Institute of Biological, Environmental and Rural Sciences (IBERS)Aberystwyth UniversityPlas GogerddanAberystwythSY23 3EEUK
| | - Zongcheng Lin
- Key Laboratory of Horticultural Plant BiologyHuazhong Agricultural UniversityWuhan430070China
| | - José Carli
- Institute of Biological, Environmental and Rural Sciences (IBERS)Aberystwyth UniversityPlas GogerddanAberystwythSY23 3EEUK
| | - Agnieszka Gladala‐Kostarz
- Institute of Biological, Environmental and Rural Sciences (IBERS)Aberystwyth UniversityPlas GogerddanAberystwythSY23 3EEUK
| | - Julia M. Davies
- Department of Plant SciencesUniversity of CambridgeCambridgeCB2 3EAUK
| | - Vernonica E. Franklin‐Tong
- School of Biosciences, College of Life and Environmental SciencesUniversity of BirminghamEdgbastonBirminghamB15 2TTUK
| | - Maurice Bosch
- Institute of Biological, Environmental and Rural Sciences (IBERS)Aberystwyth UniversityPlas GogerddanAberystwythSY23 3EEUK
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2
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Inaba H, Sueki Y, Ichikawa M, Kabir AMR, Iwasaki T, Shigematsu H, Kakugo A, Sada K, Tsukazaki T, Matsuura K. Generation of stable microtubule superstructures by binding of peptide-fused tetrameric proteins to inside and outside. SCIENCE ADVANCES 2022; 8:eabq3817. [PMID: 36070375 PMCID: PMC9451167 DOI: 10.1126/sciadv.abq3817] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/05/2022] [Accepted: 07/22/2022] [Indexed: 05/24/2023]
Abstract
Microtubules play important roles in biological functions by forming superstructures, such as doublets and branched structures, in vivo. Despite the importance, it is challenging to construct these superstructures in vitro. Here, we designed a tetrameric fluorescent protein Azami-Green (AG) fused with His-tag and Tau-derived peptide (TP), TP-AG, to generate the superstructures. Main binding sites of TP-AG can be controlled to the inside and outside of microtubules by changing the polymerization conditions. The binding of TP-AG to the inside promoted microtubule formation and generated rigid and stable microtubules. The binding of TP-AG to the outside induced various microtubule superstructures, including doublets, multiplets, branched structures, and extremely long microtubules by recruiting tubulins to microtubules. Motile microtubule aster structures were also constructed by TP-AG. The generation of various microtubule superstructures by a single type of exogenous protein is a new concept for understanding the functions of microtubules and constructing microtubule-based nanomaterials.
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Affiliation(s)
- Hiroshi Inaba
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan
- Centre for Research on Green Sustainable Chemistry, Tottori University, Tottori 680-8552, Japan
| | - Yurina Sueki
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan
| | - Muneyoshi Ichikawa
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
- PRESTO, Japan Science and Technology Agency, Kawaguchi, Japan
| | | | - Takashi Iwasaki
- Department of Bioresources Science, Graduate School of Agricultural Sciences, Tottori University, Tottori 680-8553, Japan
| | | | - Akira Kakugo
- Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
| | - Kazuki Sada
- Faculty of Science, Hokkaido University, Sapporo 060-0810, Japan
- Graduate School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
| | - Tomoya Tsukazaki
- Division of Biological Science, Graduate School of Science and Technology, Nara Institute of Science and Technology, Ikoma, Nara 630-0192, Japan
| | - Kazunori Matsuura
- Department of Chemistry and Biotechnology, Graduate School of Engineering, Tottori University, Tottori 680-8552, Japan
- Centre for Research on Green Sustainable Chemistry, Tottori University, Tottori 680-8552, Japan
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3
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Alva E, George A, Brancaleon L, Marucho M. Hydrodynamic and Polyelectrolyte Properties of Actin Filaments: Theory and Experiments. Polymers (Basel) 2022; 14:polym14122438. [PMID: 35746014 PMCID: PMC9230757 DOI: 10.3390/polym14122438] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2022] [Revised: 06/07/2022] [Accepted: 06/14/2022] [Indexed: 11/17/2022] Open
Abstract
Actin filament’s polyelectrolyte and hydrodynamic properties, their interactions with the biological environment, and external force fields play an essential role in their biological activities in eukaryotic cellular processes. In this article, we introduce a unique approach that combines dynamics and electrophoresis light-scattering experiments, an extended semiflexible worm-like chain model, and an asymmetric polymer length distribution theory to characterize the polyelectrolyte and hydrodynamic properties of actin filaments in aqueous electrolyte solutions. A fitting approach was used to optimize the theories and filament models for hydrodynamic conditions. We used the same sample and experimental conditions and considered several g-actin and polymerization buffers to elucidate the impact of their chemical composition, reducing agents, pH values, and ionic strengths on the filament translational diffusion coefficient, electrophoretic mobility, structure factor, asymmetric length distribution, effective filament diameter, electric charge, zeta potential, and semiflexibility. Compared to those values obtained from molecular structure models, our results revealed a lower value of the effective G-actin charge and a more significant value of the effective filament diameter due to the formation of the double layer of the electrolyte surrounding the filaments. Contrary to the data usually reported from electron micrographs, the lower values of our results for the persistence length and average contour filament length agree with the significant difference in the association rates at the filament ends that shift to sub-micro lengths, which is the maximum of the length distribution.
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4
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Kabir AMR, Munmun T, Hayashi T, Yasuda S, Kimura AP, Kinoshita M, Murata T, Sada K, Kakugo A. Controlling the Rigidity of Kinesin-Propelled Microtubules in an In Vitro Gliding Assay Using the Deep-Sea Osmolyte Trimethylamine N-Oxide. ACS OMEGA 2022; 7:3796-3803. [PMID: 35128287 PMCID: PMC8811939 DOI: 10.1021/acsomega.1c06699] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Accepted: 01/05/2022] [Indexed: 06/14/2023]
Abstract
The biomolecular motor protein kinesin and its associated filamentous protein microtubule have been finding important nanotechnological applications in the recent years. Rigidity of the microtubules, which are propelled by kinesin motors in an in vitro gliding assay, is an important metric that determines the success of utilization of microtubules and kinesins in various applications, such as transportation, sensing, sorting, molecular robotics, etc. Therefore, regulating the rigidity of kinesin-propelled microtubules has been critical. In this work, we report a simple strategy to regulate the rigidity of kinesin-propelled microtubules in an in vitro gliding assay. We demonstrate that rigidity of the microtubules, propelled by kinesins in an in vitro gliding assay, can be modulated simply by using the natural osmolyte trimethylamine N-oxide (TMAO). By varying the concentration of TMAO in the gliding assay, the rigidity of microtubules can be modulated over a wide range. Based on this strategy, we are able to reduce the persistence length of microtubules, a measure of microtubule rigidity, ∼8 fold by using TMAO at the concentration of 1.5 M. Furthermore, we found that the decreased rigidity of the kinesin-propelled microtubules can be restored upon elimination of TMAO from the in vitro gliding assay. Alteration in the rigidity of microtubules is accounted for by the non-uniformity of the force applied by kinesins along the microtubules in the presence of TMAO. This work offers a facile strategy to reversibly regulate the rigidity of kinesin-propelled microtubules in situ, which would widen the applications of the biomolecular motor kinesin and its associated protein microtubule in various fields.
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Affiliation(s)
| | - Tasrina Munmun
- Graduate
School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
| | - Tomohiko Hayashi
- Institute
of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Satoshi Yasuda
- Graduate
School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
- Membrane
Protein Research and Molecular Chirality Research Centers, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Atsushi P. Kimura
- Faculty
of Science, Hokkaido University, Sapporo 060-0810, Japan
- Graduate
School of Life Science, Hokkaido University, Sapporo 060-0810, Japan
| | - Masahiro Kinoshita
- Institute
of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
- Graduate
School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
- Membrane
Protein Research and Molecular Chirality Research Centers, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Takeshi Murata
- Graduate
School of Science, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
- Membrane
Protein Research and Molecular Chirality Research Centers, Chiba University, 1-33 Yayoi-cho, Inage, Chiba 263-8522, Japan
| | - Kazuki Sada
- Faculty
of Science, Hokkaido University, Sapporo 060-0810, Japan
- Graduate
School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
| | - Akira Kakugo
- Faculty
of Science, Hokkaido University, Sapporo 060-0810, Japan
- Graduate
School of Chemical Sciences and Engineering, Hokkaido University, Sapporo 060-0810, Japan
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5
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Bortolini C, Jones NC, Hoffmann SV, Besenbacher F, Dong M. The influence of the localised charge of C- and N-termini on peptide self-assembly. SOFT MATTER 2016; 12:373-377. [PMID: 26472087 DOI: 10.1039/c5sm01669j] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
The charge of a peptide influences final assembled structures. It is important to consider not only global charge, but also local, such as that found on the terminal residues. This work investigates the change of peptide self-assembly through the selection of different amino acid sequences and by varying the local charge of the residues on the C- and N-termini.
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Affiliation(s)
- C Bortolini
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds 14, Building 1590, Aarhus C, Denmark.
| | - N C Jones
- ISA, Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - S V Hoffmann
- ISA, Department of Physics and Astronomy, Aarhus University, 8000 Aarhus C, Denmark
| | - F Besenbacher
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds 14, Building 1590, Aarhus C, Denmark.
| | - M Dong
- Interdisciplinary Nanoscience Center (iNANO), Aarhus University, Gustav Wieds 14, Building 1590, Aarhus C, Denmark.
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6
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Bortolini C, Jones NC, Hoffmann SV, Wang C, Besenbacher F, Dong M. Mechanical properties of amyloid-like fibrils defined by secondary structures. NANOSCALE 2015; 7:7745-7752. [PMID: 25839069 DOI: 10.1039/c4nr05109b] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Amyloid and amyloid-like fibrils represent a generic class of highly ordered nanostructures that are implicated in some of the most fatal neurodegenerative diseases. On the other hand, amyloids, by possessing outstanding mechanical robustness, have also been successfully employed as functional biomaterials. For these reasons, physical and chemical factors driving fibril self-assembly and morphology are extensively studied - among these parameters, the secondary structures and the pH have been revealed to be crucial, since a variation in pH changes the fibril morphology and net chirality during protein aggregation. It is important to quantify the mechanical properties of these fibrils in order to help the design of effective strategies for treating diseases related to the presence of amyloid fibrils. In this work, we show that by changing pH the mechanical properties of amyloid-like fibrils vary as well. In particular, we reveal that these mechanical properties are strongly related to the content of secondary structures. We analysed and estimated the Young's modulus (E) by comparing the persistence length (Lp) - measured from the observation of TEM images by using statistical mechanics arguments - with the mechanical information provided by peak force quantitative nanomechanical property mapping (PF-QNM). The secondary structure content and the chirality are investigated by means of synchrotron radiation circular dichroism (SR-CD). Results arising from this study could be fruitfully used as a protocol to investigate other medical or engineering relevant peptide fibrils.
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Affiliation(s)
- C Bortolini
- Interdisciplinary Nanoscience Center (iNANO), Gustav Wieds 14, Building 1590, Aarhus C., Denmark.
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7
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Bortolini C, Liu L, Gronewold TMA, Wang C, Besenbacher F, Dong M. The position of hydrophobic residues tunes peptide self-assembly. SOFT MATTER 2014; 10:5656-5661. [PMID: 24995505 DOI: 10.1039/c4sm01065e] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The final structure and properties of synthetic peptides mainly depend on their sequence composition and experimental conditions. This work demonstrates that a variation in the positions of hydrophobic residues within a peptide sequence can tune the self-assembly. Techniques employed are atomic force microscopy, transmission electron microscopy and an innovative method based on surface acoustic waves. In addition, a systematic investigation on pH dependence was carried out by utilizing constant experimental parameters.
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Affiliation(s)
- Christian Bortolini
- Interdisciplinary Nanoscience Center (iNANO), Gustav Wieds 14, Building 1590, Aarhus C., Denmark.
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8
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Bengtsson E, Persson M, Månsson A. Analysis of flexural rigidity of actin filaments propelled by surface adsorbed myosin motors. Cytoskeleton (Hoboken) 2013; 70:718-28. [PMID: 24039103 PMCID: PMC4230416 DOI: 10.1002/cm.21138] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2013] [Revised: 08/08/2013] [Accepted: 08/22/2013] [Indexed: 11/09/2022]
Abstract
Actin filaments are central components of the cytoskeleton and the contractile machinery of muscle. The filaments are known to exist in a range of conformational states presumably with different flexural rigidity and thereby different persistence lengths. Our results analyze the approaches proposed previously to measure the persistence length from the statistics of the winding paths of actin filaments that are propelled by surface-adsorbed myosin motor fragments in the in vitro motility assay. Our results suggest that the persistence length of heavy meromyosin propelled actin filaments can be estimated with high accuracy and reproducibility using this approach provided that: (1) the in vitro motility assay experiments are designed to prevent bias in filament sliding directions, (2) at least 200 independent filament paths are studied, (3) the ratio between the sliding distance between measurements and the camera pixel-size is between 4 and 12, (4) the sliding distances between measurements is less than 50% of the expected persistence length, and (5) an appropriate cut-off value is chosen to exclude abrupt large angular changes in sliding direction that are complications, e.g., due to the presence of rigor heads. If the above precautions are taken the described method should be a useful routine part of in vitro motility assays thus expanding the amount of information to be gained from these.
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Affiliation(s)
- Elina Bengtsson
- Faculty of Health and Life Sciences, Linnaeus University, Kalmar, Sweden
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9
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Hild G, Bugyi B, Nyitrai M. Conformational dynamics of actin: effectors and implications for biological function. Cytoskeleton (Hoboken) 2010; 67:609-29. [PMID: 20672362 PMCID: PMC3038201 DOI: 10.1002/cm.20473] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2010] [Accepted: 07/15/2010] [Indexed: 12/30/2022]
Abstract
Actin is a protein abundant in many cell types. Decades of investigations have provided evidence that it has many functions in living cells. The diverse morphology and dynamics of actin structures adapted to versatile cellular functions is established by a large repertoire of actin-binding proteins. The proper interactions with these proteins assume effective molecular adaptations from actin, in which its conformational transitions play essential role. This review attempts to summarise our current knowledge regarding the coupling between the conformational states of actin and its biological function.
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Affiliation(s)
- Gábor Hild
- Department of Biophysics, University of Pécs, Faculty of Medicine, Pécs, Szigeti str. 12, H-7624, Hungary
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10
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Abstract
Muscle contraction and other forms of cell motility occur as a result of cyclic interactions between myosin molecules and actin filaments. Force generation is generally attributed to ATP-driven structural changes in myosin, whereas a passive role is ascribed to actin. However, some results challenge this view, predicting structural changes in actin during motor activity, e.g., when the actin filaments slide on a myosin-coated surface in vitro. Here, we analyzed statistical properties of the sliding filament paths, allowing us to detect changes of this type. It is interesting to note that evidence for substantial structural changes that led to increased bending flexibility of the filaments was found in phalloidin-stabilized, but not in phalloidin-free, actin filaments. The results are in accordance with the idea that a high-flexibility structural state of actin is a prerequisite for force production, but not the idea that a low-to-high flexibility transition of the actin filament should be an important component of the force-generating step per se. Finally, our data challenge the general view that phalloidin-stabilized filaments behave as native actin filaments in their interaction with myosin. This has important implications, since phalloidin stabilization is a routine procedure in most studies of actomyosin function.
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