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Ngo KX, Vu HT, Umeda K, Trinh MN, Kodera N, Uyeda T. Deciphering the actin structure-dependent preferential cooperative binding of cofilin. eLife 2024; 13:RP95257. [PMID: 39093938 PMCID: PMC11296705 DOI: 10.7554/elife.95257] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/04/2024] Open
Abstract
The mechanism underlying the preferential and cooperative binding of cofilin and the expansion of clusters toward the pointed-end side of actin filaments remains poorly understood. To address this, we conducted a principal component analysis based on available filamentous actin (F-actin) and C-actin (cofilins were excluded from cofilactin) structures and compared to monomeric G-actin. The results strongly suggest that C-actin, rather than F-ADP-actin, represented the favourable structure for binding preference of cofilin. High-speed atomic force microscopy explored that the shortened bare half helix adjacent to the cofilin clusters on the pointed end side included fewer actin protomers than normal helices. The mean axial distance (MAD) between two adjacent actin protomers along the same long-pitch strand within shortened bare half helices was longer (5.0-6.3 nm) than the MAD within typical helices (4.3-5.6 nm). The inhibition of torsional motion during helical twisting, achieved through stronger attachment to the lipid membrane, led to more pronounced inhibition of cofilin binding and cluster formation than the presence of inorganic phosphate (Pi) in solution. F-ADP-actin exhibited more naturally supertwisted half helices than F-ADP.Pi-actin, explaining how Pi inhibits cofilin binding to F-actin with variable helical twists. We propose that protomers within the shorter bare helical twists, either influenced by thermal fluctuation or induced allosterically by cofilin clusters, exhibit characteristics of C-actin-like structures with an elongated MAD, leading to preferential and cooperative binding of cofilin.
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Affiliation(s)
- Kien Xuan Ngo
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa UniversityKanazawaJapan
| | - Huong T Vu
- Centre for Mechanochemical Cell Biology, Warwick Medical SchoolCoventryUnited Kingdom
| | - Kenichi Umeda
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa UniversityKanazawaJapan
| | - Minh-Nhat Trinh
- School of Electrical and Electronic Engineering, Hanoi University of Science and TechnologyHanoiViet Nam
| | - Noriyuki Kodera
- Nano Life Science Institute (WPI-NanoLSI), Kanazawa UniversityKanazawaJapan
| | - Taro Uyeda
- Department of Physics, Faculty of Advanced Science and Engineering, Waseda University, ShinjukuTokyoJapan
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Yu CJ, Park YH, An MY, Ryu B, Jung HS. Insights into Actin Isoform-Specific Interactions with Myosin via Computational Analysis. Molecules 2024; 29:2992. [PMID: 38998944 PMCID: PMC11242942 DOI: 10.3390/molecules29132992] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2024] [Revised: 06/19/2024] [Accepted: 06/20/2024] [Indexed: 07/14/2024] Open
Abstract
Actin, which plays a crucial role in cellular structure and function, interacts with various binding proteins, notably myosin. In mammals, actin is composed of six isoforms that exhibit high levels of sequence conservation and structural similarity overall. As a result, the selection of actin isoforms was considered unimportant in structural studies of their binding with myosin. However, recent high-resolution structural research discovered subtle structural differences in the N-terminus of actin isoforms, suggesting the possibility that each actin isoform may engage in specific interactions with myosin isoforms. In this study, we aimed to explore this possibility, particularly by understanding the influence of different actin isoforms on the interaction with myosin 7A. First, we compared the reported actomyosin structures utilizing the same type of actin isoforms as the high-resolution filamentous skeletal α-actin (3.5 Å) structure elucidated using cryo-EM. Through this comparison, we confirmed that the diversity of myosin isoforms leads to differences in interaction with the actin N-terminus, and that loop 2 of the myosin actin-binding sites directly interacts with the actin N-terminus. Subsequently, with the aid of multiple sequence alignment, we observed significant variations in the length of loop 2 across different myosin isoforms. We predicted that these length differences in loop 2 would likely result in structural variations that would affect the interaction with the actin N-terminus. For myosin 7A, loop 2 was found to be very short, and protein complex predictions using skeletal α-actin confirmed an interaction between loop 2 and the actin N-terminus. The prediction indicated that the positively charged residues present in loop 2 electrostatically interact with the acidic patch residues D24 and D25 of actin subdomain 1, whereas interaction with the actin N-terminus beyond this was not observed. Additionally, analyses of the actomyosin-7A prediction models generated using various actin isoforms consistently yielded the same results regardless of the type of actin isoform employed. The results of this study suggest that the subtle structural differences in the N-terminus of actin isoforms are unlikely to influence the binding structure with short loop 2 myosin 7A. Our findings are expected to provide a deeper understanding for future high-resolution structural binding studies of actin and myosin.
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Affiliation(s)
- Chan Jong Yu
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 24341, Gangwon, Republic of Korea
| | - Yoon Ho Park
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 24341, Gangwon, Republic of Korea
| | - Mi Young An
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 24341, Gangwon, Republic of Korea
| | - Bumhan Ryu
- Research Solution Center, Institute for Basic Science, Daejeon 34126, Republic of Korea
| | - Hyun Suk Jung
- Department of Biochemistry, College of Natural Sciences, Kangwon National University, Chuncheon 24341, Gangwon, Republic of Korea
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3
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Niedzialkowska E, Runyan LA, Kudryashova E, Egelman EH, Kudryashov DS. Stabilization of F-actin by Salmonella effector SipA resembles the structural effects of inorganic phosphate and phalloidin. Structure 2024; 32:725-738.e8. [PMID: 38518780 PMCID: PMC11162321 DOI: 10.1016/j.str.2024.02.022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2024] [Revised: 02/08/2024] [Accepted: 02/26/2024] [Indexed: 03/24/2024]
Abstract
Entry of Salmonella into host enterocytes relies on its pathogenicity island 1 effector SipA. We found that SipA binds to F-actin in a 1:2 stoichiometry with sub-nanomolar affinity. A cryo-EM reconstruction revealed that SipA's globular core binds at the groove between actin strands, whereas the extended C-terminal arm penetrates deeply into the inter-strand space, stabilizing F-actin from within. The unusually strong binding of SipA is achieved by a combination of fast association via the core and very slow dissociation dictated by the arm. Similar to Pi, BeF3, and phalloidin, SipA potently inhibited actin depolymerization by actin depolymerizing factor (ADF)/cofilin, which correlated with increased filament stiffness, supporting the hypothesis that F-actin's mechanical properties contribute to the recognition of its nucleotide state by protein partners. The remarkably strong binding to F-actin maximizes the toxin's effects at the injection site while minimizing global influence on the cytoskeleton and preventing pathogen detection by the host cell.
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Affiliation(s)
- Ewa Niedzialkowska
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Lucas A Runyan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Elena Kudryashova
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Edward H Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA.
| | - Dmitri S Kudryashov
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA.
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4
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Heissler SM, Chinthalapudi K. Structural and functional mechanisms of actin isoforms. FEBS J 2024. [PMID: 38779987 DOI: 10.1111/febs.17153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2024] [Revised: 04/01/2024] [Accepted: 04/23/2024] [Indexed: 05/25/2024]
Abstract
Actin is a highly conserved and fundamental protein in eukaryotes and participates in a broad spectrum of cellular functions. Cells maintain a conserved ratio of actin isoforms, with muscle and non-muscle actins representing the main actin isoforms in muscle and non-muscle cells, respectively. Actin isoforms have specific and redundant functional roles and display different biochemistries, cellular localization, and interactions with myosins and actin-binding proteins. Understanding the specific roles of actin isoforms from the structural and functional perspective is crucial for elucidating the intricacies of cytoskeletal dynamics and regulation and their implications in health and disease. Here, we review how the structure contributes to the functional mechanisms of actin isoforms with a special emphasis on the questions of how post-translational modifications and disease-linked mutations affect actin isoforms biochemistry, function, and interaction with actin-binding proteins and myosin motors.
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Affiliation(s)
- Sarah M Heissler
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH, USA
| | - Krishna Chinthalapudi
- Department of Physiology and Cell Biology, Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University, Columbus, OH, USA
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5
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Le HT, Tran LH, Phung HTT. SARS-CoV-2 omicron RBD forms a weaker binding affinity to hACE2 compared to Delta RBD in in-silico studies. J Biomol Struct Dyn 2024; 42:4087-4096. [PMID: 37345564 DOI: 10.1080/07391102.2023.2222827] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2023] [Accepted: 05/21/2023] [Indexed: 06/23/2023]
Abstract
The COVID-19 pandemic sparked an unprecedented race in biotechnology in a search for effective therapies and a preventive vaccine. The continued appearance of SARS-CoV-2 variants of concern (VoCs) further swept the world. The entry of SARS-CoV-2 into cells is mediated by binding the receptor-binding domain (RBD) of the S protein to the cell-surface receptor, human angiotensin-converting enzyme 2 (hACE2). In this study, using a coarse-grained force field to parameterize the system, we employed steered-molecular dynamics (SMD) simulations to reveal the binding of SARS-CoV-2 Delta/Omicron RBD to hACE2. Our benchmarked results demonstrate a good correlation between computed rupture force and experimental binding free energy for known protein-protein systems. Moreover, our findings show that the Omicron RBD has a weaker binding affinity to hACE2, consistent with the respective experimental results. This indicates that our method can effectively be applied to other emerging SARS-CoV-2 strains.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Hoa Thanh Le
- Laboratory of Theoretical and Computational Biophysics, Advanced Institute of Materials Science, Ton Duc Thang University, Ho Chi Minh City, Vietnam
- Faculty of Applied Sciences, Ton Duc Thang University, Ho Chi Minh City, Vietnam
| | - Linh Hoang Tran
- Faculty of Civil Engineering, Ho Chi Minh City University of Technology (HCMUT), Ho Chi Minh City, Vietnam
- Vietnam National University Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Huong Thi Thu Phung
- NTT Hi-Tech Institute, Nguyen Tat Thanh University, Ho Chi Minh City, Vietnam
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Kwak SB, Kim SJ, Kang YJ, Lee WW, Huh J, Park JW. Development of a rectally administrable Dnase1 to treat septic shock by targeting NETs. Life Sci 2024; 342:122526. [PMID: 38417543 DOI: 10.1016/j.lfs.2024.122526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2023] [Revised: 02/11/2024] [Accepted: 02/21/2024] [Indexed: 03/01/2024]
Abstract
AIMS Neutrophil extracellular trap (NET), which is formed by DNA threads, induces septic shock by aggravating systemic inflammation. An intravenous administration of deoxyribonuclease is regarded as a compelling modality for treating septic shock. However, alternative routes should be chosen when cutaneous veins are all collapsed due to hypotension. In this study, we genetically engineered this enzyme to develop a rectal suppository formulation to treat septic shock. MAIN METHODS Dnase1 was mutated at two amino acid residues to increase its stability in the blood and fused with a cell-penetrating peptide CR8 to increase its absorption through the rectal mucosa, which is designated AR-CR8. The life-saving effect of AR-CR8 was evaluated in a LPS-induced shock mouse model. KEY FINDINGS AR-CR8 was shown to remove NETs effectively in human neutrophils. When AR-CR8 was administered to the mouse rectum, the deoxyribonuclease activity in the mouse serum was significantly increased. In the LPS-induced shock model, 90 % of the control mice died over 72 h after LPS injection. In contrast, the rectal administration of AR-CR8 showed a mortality rate of 30 % by 72 h after LPS injection. The Log-rank test revealed that the survival rate is significantly higher in the AR-CR8 group. The NET markers in the mouse serum were enhanced by LPS, and significantly downregulated in the AR-CR8 group. These results suggest that AR-CR8 ameliorates LPS-induced shock by degrading NETs. SIGNIFICANCE The engineered DNASE1 could be developed as a rectal suppository formulation to treat septic shock urgently at out-of-hospital places where no syringe is available.
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Affiliation(s)
- Su-Bin Kwak
- Department of Pharmacology, Seoul National University College of Medicine, Daehak-ro 103, Jongno-gu, Seoul 03080, Republic of Korea
| | - Sang-Jin Kim
- Department of Pharmacology, Seoul National University College of Medicine, Daehak-ro 103, Jongno-gu, Seoul 03080, Republic of Korea
| | - Yeon Jun Kang
- Laboratory of Autoimmunity and Inflammation, Department of Biomedical Sciences, Seoul National University College of Medicine, Daehak-ro 103, Jongno-gu, Seoul 03080, Republic of Korea; Department of Microbiology and Immunology, Seoul National University College of Medicine, Daehak-ro 103, Jongno-gu, Seoul 03080, Republic of Korea
| | - Won-Woo Lee
- Laboratory of Autoimmunity and Inflammation, Department of Biomedical Sciences, Seoul National University College of Medicine, Daehak-ro 103, Jongno-gu, Seoul 03080, Republic of Korea; Department of Microbiology and Immunology, Seoul National University College of Medicine, Daehak-ro 103, Jongno-gu, Seoul 03080, Republic of Korea
| | - June Huh
- Department of Chemical and Biological Engineering, Korea University, Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea
| | - Jong-Wan Park
- Department of Pharmacology, Seoul National University College of Medicine, Daehak-ro 103, Jongno-gu, Seoul 03080, Republic of Korea; Department of Biomedical Science, BK21-plus education program, Seoul National University College of Medicine, Daehak-ro 103, Jongno-gu, Seoul 03080, Republic of Korea; Cancer Research Institute and Ischemic/Hypoxic Disease Institute, Seoul National University College of Medicine, Daehak-ro 103, Jongno-gu, Seoul 03080, Republic of Korea.
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7
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Charles-Orszag A, Petek-Seoane NA, Mullins RD. Archaeal actins and the origin of a multi-functional cytoskeleton. J Bacteriol 2024; 206:e0034823. [PMID: 38391233 PMCID: PMC10955848 DOI: 10.1128/jb.00348-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/24/2024] Open
Abstract
Actin and actin-like proteins form filamentous polymers that carry out important cellular functions in all domains of life. In this review, we sketch a map of the function and regulation of actin-like proteins across bacteria, archaea, and eukarya, marking some of the terra incognita that remain in this landscape. We focus particular attention on archaea because mapping the structure and function of cytoskeletal systems across this domain promises to help us understand the evolutionary relationship between the (mostly) mono-functional actin-like filaments found in bacteria and the multi-functional actin cytoskeletons that characterize eukaryotic cells.
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Affiliation(s)
- Arthur Charles-Orszag
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, USA
| | - Natalie A. Petek-Seoane
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, USA
| | - R. Dyche Mullins
- Department of Cellular and Molecular Pharmacology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, California, USA
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Ferrer P, Upadhyay S, Cai JJ, Clement TM. Novel Nuclear Roles for Testis-Specific ACTL7A and ACTL7B Supported by In Vivo Characterizations and AI Facilitated In Silico Mechanistic Modeling with Implications for Epigenetic Regulation in Spermiogenesis. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.29.582797. [PMID: 38464253 PMCID: PMC10925299 DOI: 10.1101/2024.02.29.582797] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
A mechanistic role for nuclear function of testis-specific actin related proteins (ARPs) is proposed here through contributions of ARP subunit swapping in canonical chromatin regulatory complexes. This is significant to our understanding of both mechanisms controlling regulation of spermiogenesis, and the expanding functional roles of the ARPs in cell biology. Among these roles, actins and ARPs are pivotal not only in cytoskeletal regulation, but also in intranuclear chromatin organization, influencing gene regulation and nucleosome remodeling. This study focuses on two testis-specific ARPs, ACTL7A and ACTL7B, exploring their intranuclear activities and broader implications utilizing combined in vivo, in vitro, and in silico approaches. ACTL7A and ACTL7B, previously associated with structural roles, are hypothesized here to serve in chromatin regulation during germline development. This study confirms the intranuclear presence of ACTL7B in spermatocytes and round spermatids, revealing a potential role in intranuclear processes, and identifies a putative nuclear localization sequence conserved across mammalian ACTL7B, indicating a potentially unique mode of nuclear transport which differs from conventional actin. Ablation of ACTL7B leads to varied transcriptional changes reported here. Additionally, in the absence of ACTL7A or ACTL7B there is a loss of intranuclear localization of HDAC1 and HDAC3, which are known regulators of epigenetic associated acetylation changes that in turn regulate gene expression. Thus, these HDACs are implicated as contributors to the aberrant gene expression observed in the KO mouse testis transcriptomic analysis. Furthermore, this study employed and confirmed the accuracy of in silico models to predict ARP interactions with Helicase-SANT-associated (HSA) domains, uncovering putative roles for testis-specific ARPs in nucleosome remodeling complexes. In these models, ACTL7A and ACTL7B were found capable of binding to INO80 and SWI/SNF nucleosome remodeler family members in a manner akin to nuclear actin and ACTL6A. These models thus implicate germline-specific ARP subunit swapping within chromatin regulatory complexes as a potential regulatory mechanism for chromatin and associated molecular machinery adaptations in nuclear reorganizations required during spermiogenesis. These results hold implications for male fertility and epigenetic programing in the male-germline that warrant significant future investigation. In summary, this study reveals that ACTL7A and ACTL7B play intranuclear gene regulation roles in male gametogenesis, adding to the multifaceted roles identified also spanning structural, acrosomal, and flagellar stability. ACTL7A and ACTL7B unique nuclear transport, impact on HDAC nuclear associations, impact on transcriptional processes, and proposed mechanism for involvement in nucleosome remodeling complexes supported by AI facilitated in silico modeling contribute to a more comprehensive understanding of the indispensable functions of ARPs broadly in cell biology, and specifically in male fertility.
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Affiliation(s)
- Pierre Ferrer
- Interdisciplinary Faculty of Toxicology Program, Texas A&M University, College Station, TX 77843
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
| | - Srijana Upadhyay
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
| | - James J Cai
- Department of Veterinary Integrative Biosciences, School of Veterinary Medicine and Biomedical Sciences, Texas A&M University, College Station, TX 77843
| | - Tracy M Clement
- Interdisciplinary Faculty of Toxicology Program, Texas A&M University, College Station, TX 77843
- Department of Veterinary Physiology and Pharmacology, Texas A&M University, College Station, TX 77843
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Ryzhykau YL, Povarova OI, Dronova EA, Kuklina DD, Antifeeva IA, Ilyinsky NS, Okhrimenko IS, Semenov YS, Kuklin AI, Ivanovich V, Fonin AV, Uversky VN, Turoverov KK, Kuznetsova IM. Small-angle X-ray scattering structural insights into alternative pathway of actin oligomerization associated with inactivated state. Biochem Biophys Res Commun 2024; 693:149340. [PMID: 38141525 DOI: 10.1016/j.bbrc.2023.149340] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2023] [Revised: 11/23/2023] [Accepted: 11/24/2023] [Indexed: 12/25/2023]
Abstract
In addition to the well-known monomeric globular (G-actin) and polymeric fibrillar (F-actin) forms, actin can exist in the so-called inactivated form (I-actin). Hsp70 chaperon, prefoldin, and CCT chaperonin are required to obtain native globular state. In contrast, I-actin is spontaneously formed in the absence of intracellular folding machinery. I-actin can be obtained from G-actin by elimination of divalent ion, incubation in presence of small concentrations of denaturants, and by heat exposure. Since G-actin is a quasi-stationary, thermodynamically unstable form, it can gradually transform into inactivated state in the absence of chelating/denaturating agents or heat exposure, but the transition is much slower. I-actin was shown to associate into oligomers up to the molecular weight of 14-16 G-actin monomers, though the structure of these oligomers remains uncharacterized. This study employs small-angle X-ray scattering to reveal novel insights into the oligomerization process of such spontaneously formed inactivated actin. These oligomers are differentiated from F-actin through comparative analysis, highlighting a unique oligomerization pathway.
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Affiliation(s)
- Yury L Ryzhykau
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russian Federation; Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, 141980, Russian Federation
| | - Olga I Povarova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation
| | - Elizaveta A Dronova
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russian Federation
| | - Daria D Kuklina
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russian Federation; Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation
| | - Iuliia A Antifeeva
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation
| | - Nikolay S Ilyinsky
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russian Federation
| | - Ivan S Okhrimenko
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russian Federation
| | - Yury S Semenov
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russian Federation
| | - Alexander I Kuklin
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russian Federation; Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research, Dubna, 141980, Russian Federation
| | - Valentin Ivanovich
- Research Center for Molecular Mechanisms of Aging and Age-Related Diseases, Moscow Institute of Physics and Technology, Dolgoprudny, 141700, Russian Federation
| | - Alexander V Fonin
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, 33612, USA
| | - Konstantin K Turoverov
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation
| | - Irina M Kuznetsova
- Laboratory of Structural Dynamics, Stability and Folding of Proteins, Institute of Cytology, Russian Academy of Sciences, St. Petersburg, 194064, Russian Federation.
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10
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Morrison JJ, Camberg JL. Building the Bacterial Divisome at the Septum. Subcell Biochem 2024; 104:49-71. [PMID: 38963483 DOI: 10.1007/978-3-031-58843-3_4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/05/2024]
Abstract
Across living organisms, division is necessary for cell survival and passing heritable information to the next generation. For this reason, cell division is highly conserved among eukaryotes and prokaryotes. Among the most highly conserved cell division proteins in eukaryotes are tubulin and actin. Tubulin polymerizes to form microtubules, which assemble into cytoskeletal structures in eukaryotes, such as the mitotic spindle that pulls chromatids apart during mitosis. Actin polymerizes to form a morphological framework for the eukaryotic cell, or cytoskeleton, that undergoes reorganization during mitosis. In prokaryotes, two of the most highly conserved cell division proteins are the tubulin homolog FtsZ and the actin homolog FtsA. In this chapter, the functions of the essential bacterial cell division proteins FtsZ and FtsA and their roles in assembly of the divisome at the septum, the site of cell division, will be discussed. In most bacteria, including Escherichia coli, the tubulin homolog FtsZ polymerizes at midcell, and this step is crucial for recruitment of many other proteins to the division site. For this reason, both FtsZ abundance and polymerization are tightly regulated by a variety of proteins. The actin-like FtsA protein polymerizes and tethers FtsZ polymers to the cytoplasmic membrane. Additionally, FtsA interacts with later stage cell division proteins, which are essential for division and for building the new cell wall at the septum. Recent studies have investigated how actin-like polymerization of FtsA on the lipid membrane may impact division, and we will discuss this and other ways that division in bacteria is regulated through FtsZ and FtsA.
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Affiliation(s)
- Josiah J Morrison
- Department of Cell and Molecular Biology, The University of Rhode Island, Kingston, RI, USA
| | - Jodi L Camberg
- Department of Cell and Molecular Biology, The University of Rhode Island, Kingston, RI, USA.
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11
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Niedzialkowska E, Runyan LA, Kudryashova E, Egelman EH, Kudryashov DS. Stabilization of F-actin by Salmonella effector SipA resembles the structural effects of inorganic phosphate and phalloidin. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.26.573373. [PMID: 38234808 PMCID: PMC10793455 DOI: 10.1101/2023.12.26.573373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2024]
Abstract
Entry of Salmonella into host enterocytes strictly relies on its pathogenicity island 1 effector SipA. We found that SipA binds to F-actin in a unique mode in a 1:2 stoichiometry with picomolar affinity. A cryo-EM reconstruction revealed that SipA's globular core binds at the grove between actin strands, whereas the extended C-terminal arm penetrates deeply into the inter-strand space, stabilizing F-actin from within. The unusually strong binding of SipA is achieved via a combination of fast association via the core and very slow dissociation dictated by the arm. Similarly to Pi, BeF3, and phalloidin, SipA potently inhibited actin depolymerization by ADF/cofilin, which correlated with the increased filament stiffness, supporting the hypothesis that F-actin's mechanical properties contribute to the recognition of its nucleotide state by protein partners. The remarkably strong binding to F-actin maximizes the toxin's effects at the injection site while minimizing global influence on the cytoskeleton and preventing pathogen detection by the host cell.
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Affiliation(s)
- Ewa Niedzialkowska
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Lucas A. Runyan
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Elena Kudryashova
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Edward H. Egelman
- Department of Biochemistry and Molecular Genetics, University of Virginia, Charlottesville, VA 22903, USA
| | - Dmitri S. Kudryashov
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
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12
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Wu J, Xue W, Voth GA. K-Means Clustering Coarse-Graining (KMC-CG): A Next Generation Methodology for Determining Optimal Coarse-Grained Mappings of Large Biomolecules. J Chem Theory Comput 2023; 19:8987-8997. [PMID: 37957028 PMCID: PMC10720621 DOI: 10.1021/acs.jctc.3c01053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2023] [Revised: 10/25/2023] [Accepted: 10/27/2023] [Indexed: 11/21/2023]
Abstract
Coarse-grained (CG) molecular dynamics (MD) has become a method of choice for simulating various large scale biomolecular processes; therefore, the systematic definition of the CG mappings for biomolecules remains an important topic. Appropriate CG mappings can significantly enhance the representability of a CG model and improve its ability to capture critical features of large biomolecules. In this work, we present a systematic and more generalized method called K-means clustering coarse-graining (KMC-CG), which builds on the earlier approach of essential dynamics coarse-graining (ED-CG). KMC-CG removes the sequence-dependent constraints of ED-CG, allowing it to explore a more extensive space and thus enabling the discovery of more physically optimal CG mappings. Furthermore, the implementation of the K-means clustering algorithm can variationally optimize the CG mapping with efficiency and stability. This new method is tested in three cases: ATP-bound G-actin, the HIV-1 CA pentamer, and the Arp2/3 complex. In these examples, the CG models generated by KMC-CG are seen to better capture the structural, dynamic, and functional domains. KMC-CG therefore provides a robust and consistent approach to generating CG models of large biomolecules that can then be more accurately parametrized by either bottom-up or top-down CG force fields.
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Affiliation(s)
| | | | - Gregory A. Voth
- Department of Chemistry,
Chicago Center for Theoretical Chemistry, The James Franck Institute,
and Institute for Biophysical Dynamics, The University of Chicago, Chicago, Illinois 60637, United States
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13
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Hadjivasiliou Z, Kruse K. Selection for Size in Molecular Self-Assembly Drives the De Novo Evolution of a Molecular Machine. PHYSICAL REVIEW LETTERS 2023; 131:208402. [PMID: 38039477 DOI: 10.1103/physrevlett.131.208402] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 09/27/2023] [Indexed: 12/03/2023]
Abstract
The functioning of machines typically requires a concerted action of their parts. This requirement also holds for molecular motors that drive vital cellular processes and imposes constraints on their conformational changes as well as the rates at which they occur. It remains unclear whether, during evolution, features required for functional molecular machines can emerge simultaneously or require sequential adaptation to different selection pressures. We address this question by theoretically analyzing the evolution of filament treadmilling. This process refers to the self-assembly of linear polymers that grow and shrink at equal rates at their opposite ends. It constitutes a simple biological molecular machine that is involved in bacterial cell division and requires that several conditions are met. In our simulation framework, treadmilling emerges as a consequence of selecting for a target average polymer length. We discuss why other forms of assembly dynamics, which also reach the imposed target length, do not emerge in our simulations. Our work shows that complex molecular functions can evolve de novo under selection for a single physical feature.
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Affiliation(s)
- Zena Hadjivasiliou
- London Centre for Nanotechnology, University College London, London, United Kingdom
- Department of Physics and Astronomy, University College London, London, United Kingdom
- Institute for the Physics of Living Systems, University College London, London, United Kingdom
- Mathematical and Physical Biology Laboratory, The Francis Crick Institute, London, United Kingdom
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Karsten Kruse
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
- NCCR for Chemical Biology, University of Geneva, Geneva, Switzerland
- Department of Theoretical Physics, University of Geneva, Geneva, Switzerland
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14
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Oosterheert W, Blanc FEC, Roy A, Belyy A, Sanders MB, Hofnagel O, Hummer G, Bieling P, Raunser S. Molecular mechanisms of inorganic-phosphate release from the core and barbed end of actin filaments. Nat Struct Mol Biol 2023; 30:1774-1785. [PMID: 37749275 PMCID: PMC10643162 DOI: 10.1038/s41594-023-01101-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2023] [Accepted: 08/18/2023] [Indexed: 09/27/2023]
Abstract
The release of inorganic phosphate (Pi) from actin filaments constitutes a key step in their regulated turnover, which is fundamental to many cellular functions. The mechanisms underlying Pi release from the core and barbed end of actin filaments remain unclear. Here, using human and bovine actin isoforms, we combine cryo-EM with molecular-dynamics simulations and in vitro reconstitution to demonstrate how actin releases Pi through a 'molecular backdoor'. While constantly open at the barbed end, the backdoor is predominantly closed in filament-core subunits and opens only transiently through concerted amino acid rearrangements. This explains why Pi escapes rapidly from the filament end but slowly from internal subunits. In a nemaline-myopathy-associated actin variant, the backdoor is predominantly open in filament-core subunits, resulting in accelerated Pi release and filaments with drastically shortened ADP-Pi caps. Our results provide the molecular basis for Pi release from actin and exemplify how a disease-linked mutation distorts the nucleotide-state distribution and atomic structure of the filament.
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Affiliation(s)
- Wout Oosterheert
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Florian E C Blanc
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany
| | - Ankit Roy
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Alexander Belyy
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Micaela Boiero Sanders
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Oliver Hofnagel
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Gerhard Hummer
- Department of Theoretical Biophysics, Max Planck Institute of Biophysics, Frankfurt am Main, Germany.
- Institute for Biophysics, Goethe University, Frankfurt am Main, Germany.
| | - Peter Bieling
- Department of Systemic Cell Biology, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
| | - Stefan Raunser
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany.
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15
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Chen X, Kriebisch BAK, Bergmann AM, Boekhoven J. Design rules for reciprocal coupling in chemically fueled assembly. Chem Sci 2023; 14:10176-10183. [PMID: 37772095 PMCID: PMC10530897 DOI: 10.1039/d3sc02062b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2023] [Accepted: 08/21/2023] [Indexed: 09/30/2023] Open
Abstract
Biology regulates the function and assembly of proteins through non-equilibrium reaction cycles. Reciprocally, the assembly of proteins can influence the reaction rates of these cycles. Such reciprocal coupling between assembly and reaction cycle is a prerequisite for behavior like dynamic instabilities, treadmilling, pattern formation, and oscillations between morphologies. While assemblies regulated by chemical reaction cycles gained traction, the concept of reciprocal coupling is under-explored. In this work, we provide two molecular design strategies to tweak the degree of reciprocal coupling between the assembly and reaction cycle. The strategies involve spacing the chemically active site away from the assembly or burying it into the assembly. We envision that design strategies facilitate the creation of reciprocally coupled and, by extension, dynamic supramolecular materials in the future.
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Affiliation(s)
- Xiaoyao Chen
- Department of Chemistry, School of Natural Sciences, Technical University of Munich Lichtenbergstrasse 4 85748 Garching bei München Germany
| | - Brigitte A K Kriebisch
- Department of Chemistry, School of Natural Sciences, Technical University of Munich Lichtenbergstrasse 4 85748 Garching bei München Germany
| | - Alexander M Bergmann
- Department of Chemistry, School of Natural Sciences, Technical University of Munich Lichtenbergstrasse 4 85748 Garching bei München Germany
| | - Job Boekhoven
- Department of Chemistry, School of Natural Sciences, Technical University of Munich Lichtenbergstrasse 4 85748 Garching bei München Germany
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16
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Bai Y, Zhao F, Wu T, Chen F, Pang X. Actin polymerization and depolymerization in developing vertebrates. Front Physiol 2023; 14:1213668. [PMID: 37745245 PMCID: PMC10515290 DOI: 10.3389/fphys.2023.1213668] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/22/2023] [Indexed: 09/26/2023] Open
Abstract
Development is a complex process that occurs throughout the life cycle. F-actin, a major component of the cytoskeleton, is essential for the morphogenesis of tissues and organs during development. F-actin is formed by the polymerization of G-actin, and the dynamic balance of polymerization and depolymerization ensures proper cellular function. Disruption of this balance results in various abnormalities and defects or even embryonic lethality. Here, we reviewed recent findings on the structure of G-actin and F-actin and the polymerization of G-actin to F-actin. We also focused on the functions of actin isoforms and the underlying mechanisms of actin polymerization/depolymerization in cellular and organic morphogenesis during development. This information will extend our understanding of the role of actin polymerization in the physiologic or pathologic processes during development and may open new avenues for developing therapeutics for embryonic developmental abnormalities or tissue regeneration.
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Affiliation(s)
- Yang Bai
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Feng Zhao
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Tingting Wu
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Fangchun Chen
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
| | - Xiaoxiao Pang
- Stomatological Hospital of Chongqing Medical University, Chongqing, China
- Chongqing Key Laboratory of Oral Diseases and Biomedical Sciences, Chongqing, China
- Chongqing Municipal Key Laboratory of Oral Biomedical Engineering of Higher Education, Chongqing, China
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17
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Chen X, Roeters SJ, Cavanna F, Alvarado J, Baiz CR. Crowding alters F-actin secondary structure and hydration. Commun Biol 2023; 6:900. [PMID: 37660224 PMCID: PMC10475093 DOI: 10.1038/s42003-023-05274-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2023] [Accepted: 08/22/2023] [Indexed: 09/04/2023] Open
Abstract
Actin, an important component of eukaryotic cell cytoskeleton, regulates cell shape and transport. The morphology and biochemical properties of actin filaments are determined by their structure and protein-protein contacts. Crowded environments can organize filaments into bundles, but less is known about how they affect F-actin structure. This study used 2D IR spectroscopy and spectral calculations to examine how crowding and bundling impact the secondary structure and local environments in filaments and weakly or strongly bundled networks. The results reveal that bundling induces changes in actin's secondary structure, leading to a decrease in β-sheet and an increase in loop conformations. Strongly bundled networks exhibit a decrease in backbone solvent exposure, with less perturbed α-helices and nearly "locked" β-sheets. Similarly, the loops become less hydrated but maintain a dynamic environment. These findings highlight the role of loop structure in actin network morphology and stability under morphology control by PEG.
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Affiliation(s)
- Xiaobing Chen
- Department of Chemistry, University of Texas at Austin, Austin, TX, USA
| | - Steven J Roeters
- Department of Chemistry, Aarhus University, Aarhus, Denmark
- Department of Anatomy and Neurosciences, Vrije Universiteit, Amsterdam UMC, Amsterdam, Netherlands
| | - Francis Cavanna
- Department of Physics, University of Texas at Austin, Center for Nonlinear Dynamics, Austin, TX, USA
| | - José Alvarado
- Department of Physics, University of Texas at Austin, Center for Nonlinear Dynamics, Austin, TX, USA
| | - Carlos R Baiz
- Department of Chemistry, University of Texas at Austin, Austin, TX, USA.
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18
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Barrie KR, Carman PJ, Dominguez R. Conformation of actin subunits at the barbed and pointed ends of F-actin with and without capping proteins. Cytoskeleton (Hoboken) 2023; 80:309-312. [PMID: 37632366 PMCID: PMC10592188 DOI: 10.1002/cm.21770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2023] [Accepted: 07/18/2023] [Indexed: 08/28/2023]
Abstract
Advances in cryo-electron microscopy have made possible the determination of structures of the barbed and pointed ends of F-actin, both in the absence and the presence of capping proteins that block subunit exchange. The conformation of the two exposed protomers at the barbed end resembles the "flat" conformation of protomers in the middle of F-actin. The barbed end changes little upon binding of CapZ, which in turn undergoes a major conformational change. At the pointed end, however, protomers have the "twisted" conformation characteristic of G-actin, whereas tropomodulin binding forces a flat conformation upon the second subunit. The structures provide a mechanistic understanding for the asymmetric addition/dissociation of actin subunits at the ends of F-actin and open the way to future studies of other regulators of filament end dynamics.
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Affiliation(s)
- Kyle R. Barrie
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania; Philadelphia, Pennsylvania, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania; Philadelphia, Pennsylvania, USA
| | - Peter J. Carman
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania; Philadelphia, Pennsylvania, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania; Philadelphia, Pennsylvania, USA
| | - Roberto Dominguez
- Department of Physiology, Perelman School of Medicine, University of Pennsylvania; Philadelphia, Pennsylvania, USA
- Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania; Philadelphia, Pennsylvania, USA
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19
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Steffensen KE, Dawson JF. Actin's C-terminus coordinates actin structural changes and functions. Cytoskeleton (Hoboken) 2023; 80:313-329. [PMID: 37036084 DOI: 10.1002/cm.21757] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 03/17/2023] [Accepted: 03/30/2023] [Indexed: 04/11/2023]
Abstract
Actin is essential to eukaryotic cellular processes. Actin's C-terminus appears to play a direct role in modulating actin's structure and properties, facilitating the binding and function of actin-binding proteins (ABPs). The structural and functional characterization of filamentous actin's C-terminus has been impeded by its inherent flexibility, as well as actin's resistance to crystallization for x-ray diffraction and the historical resolution constraints associated with electron microscopy. Many biochemical studies have established that actin's C-terminus must retain its flexibility and structural integrity to modulate actin's structure and functions. For example, C-terminal structural changes are known to affect nucleotide binding and exchange, as well as propagate actin structural changes throughout extensive allosteric networks, facilitating the binding and function of ABPs. Advances in electron microscopy have resulted in high-resolution structures of filamentous actin, providing insights into subtle structural changes that are mediated by actin's C-terminus. Here, we review existing knowledge establishing the importance of actin's C-terminus within actin structural changes and functions and discuss how modern structural characterization techniques provide the tools to understand the role of actin's C-terminus in cellular processes.
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Affiliation(s)
- Karl E Steffensen
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - John F Dawson
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
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20
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Xia S, Zhang H, He S. Genome-Wide Identification and Expression Analysis of ACTIN Family Genes in the Sweet Potato and Its Two Diploid Relatives. Int J Mol Sci 2023; 24:10930. [PMID: 37446107 DOI: 10.3390/ijms241310930] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Revised: 06/23/2023] [Accepted: 06/26/2023] [Indexed: 07/15/2023] Open
Abstract
ACTINs are structural proteins widely distributed in plants. They are the main components of microfilaments and participate in many crucial physiological activities, including the maintenance of cell shape and cytoplasmic streaming. Meanwhile, ACTIN, as a housekeeping gene, is widely used in qRT-PCR analyses of plants. However, ACTIN family genes have not been explored in the sweet potato. In this study, we identified 30, 39, and 44 ACTINs in the cultivated hexaploid sweet potato (Ipomoea batatas, 2n = 6x = 90) and its two diploid relatives, Ipomoea trifida (2n = 2x = 30) and Ipomoea triloba (2n = 2x = 30), respectively, via analysis of their genome structure and by phylogenetic characterization. These ACTINs were divided into six subgroups according to their phylogenetic relationships with Arabidopsis thaliana. The physiological properties of the protein, chromosome localization, phylogenetic relationship, gene structure, promoter cis-elements, protein interaction networks, and expression patterns of these 113 ACTINs were systematically investigated. The results suggested that homologous ACTINs are differentiated in the sweet potato and its two diploid relatives, and play various vital roles in plant growth, tuberous root development, hormone crosstalk, and abiotic stress responses. Some stable ACTINs that could be used as internal reference genes were found in the sweet potato and its two diploid relatives, e.g., IbACTIN18, -20, and -16.2; ItfACTIN2.2, -16, and -10; ItbACTIN18 and -19.1. This work provides a comprehensive comparison and furthers our understanding of the ACTIN genes in the sweet potato and its two diploid relatives, thereby supplying a theoretical foundation for their functional study and further facilitating the molecular breeding of sweet potatoes.
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Affiliation(s)
- Shuanghong Xia
- Key Laboratory of Sweet Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis & Utilization and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Agronomy & Biotechnology, China Agricultural University, Beijing 100193, China
| | - Huan Zhang
- Key Laboratory of Sweet Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis & Utilization and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Agronomy & Biotechnology, China Agricultural University, Beijing 100193, China
- Sanya Institute of China Agricultural University, Sanya 572025, China
| | - Shaozhen He
- Key Laboratory of Sweet Potato Biology and Biotechnology, Ministry of Agriculture and Rural Affairs/Beijing Key Laboratory of Crop Genetic Improvement/Laboratory of Crop Heterosis & Utilization and Joint Laboratory for International Cooperation in Crop Molecular Breeding, Ministry of Education, College of Agronomy & Biotechnology, China Agricultural University, Beijing 100193, China
- Sanya Institute of China Agricultural University, Sanya 572025, China
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21
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Nogales E. The tubulin structure, a quarter of a century later. Mol Biol Cell 2023; 34:rt2. [PMID: 36913319 PMCID: PMC10092645 DOI: 10.1091/mbc.e23-01-0005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/13/2023] [Accepted: 02/23/2023] [Indexed: 03/14/2023] Open
Abstract
This retrospective on the 25th anniversary of the publication of the first structure of tubulin is shaped by my own personal experiences rather than being a strict and complete historical account of the event. It is a reflection on how working in science felt many years ago, on the struggles and the joys of reaching for the high-hanging fruit, and, ultimately, on how relevant or not our personal scientific contributions are to the broader scientific community. Writing it brought back memories of my unique and sadly lost postdoctoral advisor Ken Downing, who dreamt of this structure and brought it to fruition against all odds.
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Affiliation(s)
- Eva Nogales
- Molecular and Cell Biology Department, University of California, Berkeley
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory
- Howard Hughes Medical Institute, University of California Berkeley, Berkeley, CA 94720-3220
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22
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Rangarajan ES, Smith EW, Izard T. Distinct inter-domain interactions of dimeric versus monomeric α-catenin link cell junctions to filaments. Commun Biol 2023; 6:276. [PMID: 36928388 PMCID: PMC10020564 DOI: 10.1038/s42003-023-04610-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 02/17/2023] [Indexed: 03/18/2023] Open
Abstract
Attachment between cells is crucial for almost all aspects of the life of cells. These inter-cell adhesions are mediated by the binding of transmembrane cadherin receptors of one cell to cadherins of a neighboring cell. Inside the cell, cadherin binds β-catenin, which interacts with α-catenin. The transitioning of cells between migration and adhesion is modulated by α-catenin, which links cell junctions and the plasma membrane to the actin cytoskeleton. At cell junctions, a single β-catenin/α-catenin heterodimer slips along filamentous actin in the direction of cytoskeletal tension which unfolds clustered heterodimers to form catch bonds with F-actin. Outside cell junctions, α-catenin dimerizes and links the plasma membrane to F-actin. Under cytoskeletal tension, α-catenin unfolds and forms an asymmetric catch bond with F-actin. To understand the mechanism of this important α-catenin function, we determined the 2.7 Å cryogenic electron microscopy (cryoEM) structures of filamentous actin alone and bound to human dimeric α-catenin. Our structures provide mechanistic insights into the role of the α-catenin interdomain interactions in directing α-catenin function and suggest a bivalent mechanism. Further, our cryoEM structure of human monomeric α-catenin provides mechanistic insights into α-catenin autoinhibition. Collectively, our structures capture the initial α-catenin interaction with F-actin before the sensing of force, which is a crucial event in cell adhesion and human disease.
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Affiliation(s)
| | - Emmanuel W Smith
- The Cell Adhesion Laboratory, UF Scripps, Jupiter, FL, 33458, USA
| | - Tina Izard
- The Cell Adhesion Laboratory, UF Scripps, Jupiter, FL, 33458, USA.
- The Skaggs Graduate School, The Scripps Research Institute, Jupiter, FL, 33458, USA.
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23
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Iwasa M, Takeda S, Narita A, Maéda Y, Oda T. Mutagenic analysis of actin reveals the mechanism of His161 flipping that triggers ATP hydrolysis. Front Cell Dev Biol 2023; 11:1105460. [PMID: 37009486 PMCID: PMC10062479 DOI: 10.3389/fcell.2023.1105460] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2022] [Accepted: 02/21/2023] [Indexed: 03/18/2023] Open
Abstract
The dynamic assembly of actin is controlled by the hydrolysis of ATP, bound to the center of the molecule. Upon polymerization, actin undergoes a conformational change from the monomeric G-form to the fibrous F-form, which is associated with the flipping of the side chain of His161 toward ATP. His161 flipping from the gauche-minus to gauche-plus conformation leads to a rearrangement of the active site water molecules, including ATP attacking water (W1), into an orientation capable of hydrolysis. We previously showed that by using a human cardiac muscle α-actin expression system, mutations in the Pro-rich loop residues (A108G and P109A) and in a residue that was hydrogen-bonded to W1 (Q137A) affect the rate of polymerization and ATP hydrolysis. Here, we report the crystal structures of the three mutant actins bound to AMPPNP or ADP-Pi determined at a resolution of 1.35–1.55 Å, which are stabilized in the F-form conformation with the aid of the fragmin F1 domain. In A108G, His161 remained non-flipped despite the global actin conformation adopting the F-form, demonstrating that the side chain of His161 is flipped to avoid a steric clash with the methyl group of A108. Because of the non-flipped His161, W1 was located away from ATP, similar to G-actin, which was accompanied by incomplete hydrolysis. In P109A, the absence of the bulky proline ring allowed His161 to be positioned near the Pro-rich loop, with a minor influence on ATPase activity. In Q137A, two water molecules replaced the side-chain oxygen and nitrogen of Gln137 almost exactly at their positions; consequently, the active site structure, including the W1 position, is essentially conserved. This seemingly contradictory observation to the reported low ATPase activity of the Q137A filament could be attributed to a high fluctuation of the active site water. Together, our results suggest that the elaborate structural design of the active site residues ensures the precise control of the ATPase activity of actin.
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Affiliation(s)
- Mitsusada Iwasa
- Graduate School of Informatics, Nagoya University, Nagoya, Japan
- Structural Biology Research Center, Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Shuichi Takeda
- Structural Biology Research Center, Graduate School of Science, Nagoya University, Nagoya, Japan
- Research Institute for Interdisciplinary Science (RIIS), Okayama University, Okayama, Japan
- *Correspondence: Toshiro Oda, ; Shuichi Takeda,
| | - Akihiro Narita
- Structural Biology Research Center, Graduate School of Science, Nagoya University, Nagoya, Japan
- Graduate School of Science, Nagoya University, Nagoya, Japan
| | - Yuichiro Maéda
- Graduate School of Informatics, Nagoya University, Nagoya, Japan
- Structural Biology Research Center, Graduate School of Science, Nagoya University, Nagoya, Japan
- Research Institute for Interdisciplinary Science (RIIS), Okayama University, Okayama, Japan
| | - Toshiro Oda
- Faculty of Health and Welfare, Tokai Gakuin University, Kakamigahara, Japan
- *Correspondence: Toshiro Oda, ; Shuichi Takeda,
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24
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Lopez AJ, Andreadaki M, Vahokoski J, Deligianni E, Calder LJ, Camerini S, Freitag A, Bergmann U, Rosenthal PB, Sidén-Kiamos I, Kursula I. Structure and function of Plasmodium actin II in the parasite mosquito stages. PLoS Pathog 2023; 19:e1011174. [PMID: 36877739 PMCID: PMC10019781 DOI: 10.1371/journal.ppat.1011174] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 03/16/2023] [Accepted: 02/03/2023] [Indexed: 03/07/2023] Open
Abstract
Actins are filament-forming, highly-conserved proteins in eukaryotes. They are involved in essential processes in the cytoplasm and also have nuclear functions. Malaria parasites (Plasmodium spp.) have two actin isoforms that differ from each other and from canonical actins in structure and filament-forming properties. Actin I has an essential role in motility and is fairly well characterized. The structure and function of actin II are not as well understood, but mutational analyses have revealed two essential functions in male gametogenesis and in the oocyst. Here, we present expression analysis, high-resolution filament structures, and biochemical characterization of Plasmodium actin II. We confirm expression in male gametocytes and zygotes and show that actin II is associated with the nucleus in both stages in filament-like structures. Unlike actin I, actin II readily forms long filaments in vitro, and near-atomic structures in the presence or absence of jasplakinolide reveal very similar structures. Small but significant differences compared to other actins in the openness and twist, the active site, the D-loop, and the plug region contribute to filament stability. The function of actin II was investigated through mutational analysis, suggesting that long and stable filaments are necessary for male gametogenesis, while a second function in the oocyst stage also requires fine-tuned regulation by methylation of histidine 73. Actin II polymerizes via the classical nucleation-elongation mechanism and has a critical concentration of ~0.1 μM at the steady-state, like actin I and canonical actins. Similarly to actin I, dimers are a stable form of actin II at equilibrium.
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Affiliation(s)
- Andrea J. Lopez
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Maria Andreadaki
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Juha Vahokoski
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Elena Deligianni
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Lesley J. Calder
- Structural Biology of Cells and Viruses Laboratory, Francis Crick Institute, London, United Kingdom
| | | | - Anika Freitag
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
| | - Ulrich Bergmann
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
| | - Peter B. Rosenthal
- Structural Biology of Cells and Viruses Laboratory, Francis Crick Institute, London, United Kingdom
| | - Inga Sidén-Kiamos
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece
- * E-mail: (ISK); (IK)
| | - Inari Kursula
- Department of Biomedicine, University of Bergen, Bergen, Norway
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, Oulu, Finland
- * E-mail: (ISK); (IK)
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25
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Liu Y, Wang X, Wan Z, Ngai T, Tse YLS. Capturing coacervate formation and protein partition by molecular dynamics simulation. Chem Sci 2023; 14:1168-1175. [PMID: 36756326 PMCID: PMC9891350 DOI: 10.1039/d2sc01164f] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2022] [Accepted: 12/22/2022] [Indexed: 12/25/2022] Open
Abstract
Biomolecules localize and function in microenvironments where their local concentration, spatial organization, and biochemical reactivity are regulated. To compartmentalize and control the local properties of the native microenvironment, cellular mimics and artificial bioreactors have been developed to study the properties of membraneless organelles or mimic the bio-environment for life origin. Here, we carried out molecular dynamics simulation with the Martini 3.0 model to reproduce the experimental salt concentration and pH dependency of different complex coacervates. We showed that coacervates inside vesicles are able to change their shape. In addition, we used these coacervate systems to explore the partitioning of the ubiquitous cytoskeletal protein actin and found that actin spontaneously partitions to all the coacervate peripheries. Therefore, we believe that our study can provide a better understanding of the versatile coacervate platform, where biomolecules partition and gather to fulfill their biological duties.
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Affiliation(s)
- Yang Liu
- College of Polymer Science and Engineering, State Key Laboratory of Polymer Materials Engineering, Sichuan University Chengdu 610065 China.,Department of Chemistry, The Chinese University of Hong Kong Sha Tin Hong Kong China
| | - Xinyan Wang
- Department of Chemistry, The Chinese University of Hong Kong Sha Tin Hong Kong China
| | - Zhili Wan
- School of Food Science and Engineering, South China University of TechnologyGuangzhouChina
| | - To Ngai
- Department of Chemistry, The Chinese University of Hong Kong Sha Tin Hong Kong China
| | - Ying-Lung Steve Tse
- Department of Chemistry, The Chinese University of Hong Kong Sha Tin Hong Kong China
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26
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Burley SK, Berman HM, Chiu W, Dai W, Flatt JW, Hudson BP, Kaelber JT, Khare SD, Kulczyk AW, Lawson CL, Pintilie GD, Sali A, Vallat B, Westbrook JD, Young JY, Zardecki C. Electron microscopy holdings of the Protein Data Bank: the impact of the resolution revolution, new validation tools, and implications for the future. Biophys Rev 2022; 14:1281-1301. [PMID: 36474933 PMCID: PMC9715422 DOI: 10.1007/s12551-022-01013-w] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 11/06/2022] [Indexed: 12/04/2022] Open
Abstract
As a discipline, structural biology has been transformed by the three-dimensional electron microscopy (3DEM) "Resolution Revolution" made possible by convergence of robust cryo-preservation of vitrified biological materials, sample handling systems, and measurement stages operating a liquid nitrogen temperature, improvements in electron optics that preserve phase information at the atomic level, direct electron detectors (DEDs), high-speed computing with graphics processing units, and rapid advances in data acquisition and processing software. 3DEM structure information (atomic coordinates and related metadata) are archived in the open-access Protein Data Bank (PDB), which currently holds more than 11,000 3DEM structures of proteins and nucleic acids, and their complexes with one another and small-molecule ligands (~ 6% of the archive). Underlying experimental data (3DEM density maps and related metadata) are stored in the Electron Microscopy Data Bank (EMDB), which currently holds more than 21,000 3DEM density maps. After describing the history of the PDB and the Worldwide Protein Data Bank (wwPDB) partnership, which jointly manages both the PDB and EMDB archives, this review examines the origins of the resolution revolution and analyzes its impact on structural biology viewed through the lens of PDB holdings. Six areas of focus exemplifying the impact of 3DEM across the biosciences are discussed in detail (icosahedral viruses, ribosomes, integral membrane proteins, SARS-CoV-2 spike proteins, cryogenic electron tomography, and integrative structure determination combining 3DEM with complementary biophysical measurement techniques), followed by a review of 3DEM structure validation by the wwPDB that underscores the importance of community engagement.
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Affiliation(s)
- Stephen K. Burley
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 USA
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, San Diego Supercomputer Center, University of California San Diego, La Jolla, CA 92093 USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854 USA
| | - Helen M. Berman
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854 USA
| | - Wah Chiu
- Department of Bioengineering, Stanford University, Stanford, CA USA
- Division of CryoEM and Bioimaging, SSRL, SLAC National Accelerator Laboratory, Stanford University, Menlo Park, CA USA
| | - Wei Dai
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Department of Cell Biology and Neuroscience, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
| | - Justin W. Flatt
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
| | - Brian P. Hudson
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
| | - Jason T. Kaelber
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
| | - Sagar D. Khare
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 USA
- Department of Chemistry and Chemical Biology, Rutgers, The State University of New Jersey, 174 Frelinghuysen Road, Piscataway, NJ 08854 USA
| | - Arkadiusz W. Kulczyk
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Department of Biochemistry and Microbiology, Rutgers, The State University of New Jersey, Piscataway, NJ 08901 USA
| | - Catherine L. Lawson
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
| | | | - Andrej Sali
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, Quantitative Biosciences Institute, University of California San Francisco, San Francisco, CA 94158 USA
| | - Brinda Vallat
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 USA
| | - John D. Westbrook
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Cancer Institute of New Jersey, Rutgers, The State University of New Jersey, New Brunswick, NJ 08901 USA
| | - Jasmine Y. Young
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
| | - Christine Zardecki
- Research Collaboratory for Structural Bioinformatics Protein Data Bank, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
- Institute for Quantitative Biomedicine, Rutgers, The State University of New Jersey, Piscataway, NJ 08854 USA
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27
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Schwan C, Lang AE, Schlosser A, Fujita-Becker S, AlHaj A, Schröder RR, Faix J, Aktories K, Mannherz HG. Inhibition of Arp2/3 Complex after ADP-Ribosylation of Arp2 by Binary Clostridioides Toxins. Cells 2022; 11:cells11223661. [PMID: 36429089 PMCID: PMC9688287 DOI: 10.3390/cells11223661] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2022] [Revised: 11/10/2022] [Accepted: 11/14/2022] [Indexed: 11/19/2022] Open
Abstract
Clostridioides bacteria are responsible for life threatening infections. Here, we show that in addition to actin, the binary toxins CDT, C2I, and Iota from Clostridioides difficile, botulinum, and perfrigens, respectively, ADP-ribosylate the actin-related protein Arp2 of Arp2/3 complex and its additional components ArpC1, ArpC2, and ArpC4/5. The Arp2/3 complex is composed of seven subunits and stimulates the formation of branched actin filament networks. This activity is inhibited after ADP-ribosylation of Arp2. Translocation of the ADP-ribosyltransferase component of CDT toxin into human colon carcinoma Caco2 cells led to ADP-ribosylation of cellular Arp2 and actin followed by a collapse of the lamellipodial extensions and F-actin network. Exposure of isolated mouse colon pieces to CDT toxin induced the dissolution of the enterocytes leading to luminal aggregation of cellular debris and the collapse of the mucosal organization. Thus, we identify the Arp2/3 complex as hitherto unknown target of clostridial ADP-ribosyltransferases.
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Affiliation(s)
- Carsten Schwan
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwig-University, 79104 Freiburg, Germany
| | - Alexander E. Lang
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwig-University, 79104 Freiburg, Germany
| | - Andreas Schlosser
- Rudolf Virchow Center of Experimental Biomedicine, University of Würzburg, 97080 Würzburg, Germany
| | | | - Abdulatif AlHaj
- Department of Anatomy and Molecular Embryology, Ruhr-University, 44780 Bochum, Germany
- Department of Cellular Physiology, Ruhr-University, 44780 Bochum, Germany
| | - Rasmus R. Schröder
- Cryo-Electron Microscopy, BioQuant, University Hospital, 69120 Heidelberg, Germany
| | - Jan Faix
- Institute of Biophysical Chemistry, Hannover Medical School, 30625 Hannover, Germany
| | - Klaus Aktories
- Institute of Experimental and Clinical Pharmacology and Toxicology, Faculty of Medicine, Albert-Ludwig-University, 79104 Freiburg, Germany
| | - Hans Georg Mannherz
- Department of Anatomy and Molecular Embryology, Ruhr-University, 44780 Bochum, Germany
- Department of Cellular Physiology, Ruhr-University, 44780 Bochum, Germany
- Department of Anatomy and Molecular Embryology and of Cellular Physiology, Ruhr-University, Universitätsstr. 150, 44780 Bochum, Germany
- Correspondence: ; Tel.: +49-234-3223164; Fax: +49-234-321447
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28
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Abstract
A variety of cellular functions are driven by actin, which undergoes cyclic transitions between the monomeric G-form and the filamentous F-form. To gain insights into actin dynamics, the mechanism by which the energy is supplied by the ATP hydrolysis reaction in the F-form actin must be elucidated. This has been hampered by the lack of actin filament structures at atomic resolutions. Here, we have crystallized actin molecules trapped in the F-form without forming filaments, and based upon these structures we determined the reaction path by quantum mechanics calculations. The results are consistent with previous biochemical data. Remarkably, the hydrolysis reaction mechanism is essentially identical to those of motor proteins, while the process of Pi release is distinct. The major cytoskeleton protein actin undergoes cyclic transitions between the monomeric G-form and the filamentous F-form, which drive organelle transport and cell motility. This mechanical work is driven by the ATPase activity at the catalytic site in the F-form. For deeper understanding of the actin cellular functions, the reaction mechanism must be elucidated. Here, we show that a single actin molecule is trapped in the F-form by fragmin domain-1 binding and present their crystal structures in the ATP analog-, ADP-Pi-, and ADP-bound forms, at 1.15-Å resolutions. The G-to-F conformational transition shifts the side chains of Gln137 and His161, which relocate four water molecules including W1 (attacking water) and W2 (helping water) to facilitate the hydrolysis. By applying quantum mechanics/molecular mechanics calculations to the structures, we have revealed a consistent and comprehensive reaction path of ATP hydrolysis by the F-form actin. The reaction path consists of four steps: 1) W1 and W2 rotations; 2) PG–O3B bond cleavage; 3) four concomitant events: W1–PO3− formation, OH− and proton cleavage, nucleophilic attack by the OH− against PG, and the abstracted proton transfer; and 4) proton relocation that stabilizes the ADP-Pi–bound F-form actin. The mechanism explains the slow rate of ATP hydrolysis by actin and the irreversibility of the hydrolysis reaction. While the catalytic strategy of actin ATP hydrolysis is essentially the same as those of motor proteins like myosin, the process after the hydrolysis is distinct and discussed in terms of Pi release, F-form destabilization, and global conformational changes.
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29
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Li T, Du J, Ren M. Structural Significance of His73 in F-Actin Dynamics: Insights from Ab Initio Study. Int J Mol Sci 2022; 23:ijms231810447. [PMID: 36142357 PMCID: PMC9499316 DOI: 10.3390/ijms231810447] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Revised: 09/01/2022] [Accepted: 09/08/2022] [Indexed: 11/28/2022] Open
Abstract
F-actin dynamics (polymerization and depolymerization) are associated with nucleotide exchange, providing the driving forces for dynamic cellular activities. As an important residue in the nucleotide state-sensing region in actin, His73 is often found to be methylated in natural actin and directly participates in F-actin dynamics by regulating nucleotide exchange. The interaction between His73 and its neighboring residue, Gly158, has significance for F-actin dynamics. However, this weak chemical interaction is difficult to characterize using classic molecular modeling methods. In this study, ab initio modeling was employed to explore the binding energy between His73 and Gly158. The results confirm that the methyl group on the His73 side chain contributes to the structural stability of atomistic networks in the nucleotide state-sensing region of actin monomers and confines the material exchange (Pi release) pathway within F-actin dynamics. Further binding energy analyses of actin structures under different nucleotide states showed that the potential model of His73/Gly158 hydrogen bond breaking in the material exchange mechanism is not obligatory within F-actin dynamics.
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Affiliation(s)
- Tong Li
- Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China
| | - Juan Du
- Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China
| | - Mingfa Ren
- Department of Engineering Mechanics, Dalian University of Technology, Dalian 116024, China
- State Key Laboratory of Structural Analysis for Industrial Equipment, Dalian University of Technology, Dalian 116024, China
- Correspondence: ; Tel.: +86-411-8479161
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30
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Zhang S, Wang Y, Jiang X, Wang Z. GFP fusion promotes the soluble and active expression of a pea actin isoform ( PEAc1) in Escherichia coli. Prep Biochem Biotechnol 2022; 53:557-564. [PMID: 36036389 DOI: 10.1080/10826068.2022.2114011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
In the present study, we report that a GFP fusion tag facilitated the soluble expression of a pea actin isoform (PEAc1) in E. coli. To investigate the influence of a GFP fusion tag on PEAc1 structure and activity, PEAc1, His-tagged PEAc1 (His-PEAc1), His-tagged GFP (His-GFP), and His-tagged PEAc1 fusion with GFP (His-PEAc1-GFP) were expressed in E. coli. SDS-PAGE and western blot analyses reveal that the solubility of His-PEAc1-GFP was higher than that of PEAc1 and His-PEAc1. The His-PEAc1-GFP and His-GFP fusion proteins were purified from the supernatant of cell homogenate on a Ni-affinity column, and PEAc1 and His-PEAc1 were purified from inclusion bodies. CD spectrum analysis of the four purified proteins indicated that the proportion of α-helix and β-sheet in PEAc1 was closest to the predicted data in His-PEAc1-GFP (compared with His-PEAc1 or PEAc1). In addition, the actin-associated activities of His-PEAc1-GFP, including polymerization to microfilaments under specific ionic conditions and DNase I inhibition by monomers, were more similar to those of muscle actin (compared with PEAc1 and His-PEAc1). These improvements in PEAc1 solubility and activity are likely the result of correct PEAc1 folding mediated by GFP fusion.
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Affiliation(s)
- Shaobin Zhang
- College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Yiqing Wang
- College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Xin Jiang
- College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China
| | - Zhanyong Wang
- College of Biosciences and Biotechnology, Shenyang Agricultural University, Shenyang, China
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31
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Yee M, Walther T, Frischknecht F, Douglas RG. Divergent Plasmodium actin residues are essential for filament localization, mosquito salivary gland invasion and malaria transmission. PLoS Pathog 2022; 18:e1010779. [PMID: 35998188 PMCID: PMC9439217 DOI: 10.1371/journal.ppat.1010779] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2022] [Revised: 09/02/2022] [Accepted: 07/29/2022] [Indexed: 11/18/2022] Open
Abstract
Actin is one of the most conserved and ubiquitous proteins in eukaryotes. Its sequence has been highly conserved for its monomers to self-assemble into filaments that mediate essential cell functions such as trafficking, cell shape and motility. The malaria-causing parasite, Plasmodium, expresses a highly sequence divergent actin that is critical for its rapid motility at different stages within its mammalian and mosquito hosts. Each of Plasmodium actin’s four subdomains have divergent regions compared to canonical vertebrate actins. We previously identified subdomains 2 and 3 as providing critical contributions for parasite actin function as these regions could not be replaced by subdomains of vertebrate actins. Here we probed the contributions of individual divergent amino acid residues in these subdomains on parasite motility and progression. Non-lethal changes in these subdomains did not affect parasite development in the mammalian host but strongly affected progression through the mosquito with striking differences in transmission to and through the insect. Live visualization of actin filaments showed that divergent amino acid residues in subdomains 2 and 4 enhanced localization associated with filaments, while those in subdomain 3 negatively affected actin filaments. This suggests that finely tuned actin dynamics are essential for efficient organ entry in the mosquito vector affecting malaria transmission. This work provides residue level insight on the fundamental requirements of actin in highly motile cells. Actin is one of the most abundant and conserved proteins known. Actin monomers can join together to form long filaments. The malaria-causing parasite is transmitted by mosquitoes and needs actin to move very rapidly. An actin from the parasite is different to other actins: its amino acid sequence has relatively high amounts of changes compared to animal species and the actin tends to form only short filaments. We previously identified two large parts of the protein that were critical for the parasite since these large parts could not be exchanged with the equivalent regions of other species. In this study, we focused in on these regions by making more discrete mutations. Most mutations of the actin sequence were tolerated by the parasite in the blood stages. However, these mutants has striking defects in progressing through mosquitoes, especially in invading its salivary glands. We used a new filament labeler to visualize how these mutations affect the actin filaments and found surprisingly different effects. Taken together, small changes to the sequence can have large consequences for the parasite, which ultimately affects its ability to transmit to a new host.
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Affiliation(s)
- Michelle Yee
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
| | - Tobias Walther
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
| | - Friedrich Frischknecht
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
- German Centre for Infection Research, DZIF, partner site Heidelberg, Heidelberg, Germany
- * E-mail: (FF); (RGD)
| | - Ross G. Douglas
- Integrative Parasitology, Center for Infectious Diseases, Heidelberg University Medical School, Heidelberg, Germany
- Biochemistry and Molecular Biology, Interdisciplinary Research Centre and Molecular Infection Biology, Biomedical Research Centre Seltersberg, Justus Liebig University Giessen, Giessen, Germany
- * E-mail: (FF); (RGD)
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32
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McCord JJ, Engavale M, Masoumzadeh E, Villarreal J, Mapp B, Latham MP, Keyel PA, Sutton RB. Structural features of Dnase1L3 responsible for serum antigen clearance. Commun Biol 2022; 5:825. [PMID: 35974043 PMCID: PMC9381713 DOI: 10.1038/s42003-022-03755-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 07/22/2022] [Indexed: 11/09/2022] Open
Abstract
Autoimmunity develops when extracellular DNA released from dying cells is not cleared from serum. While serum DNA is primarily digested by Dnase1 and Dnase1L3, Dnase1 cannot rescue autoimmunity arising from Dnase1L3 deficiencies. Dnase1L3 uniquely degrades antigenic forms of cell-free DNA, including DNA complexed with lipids and proteins. The distinct activity of Dnase1L3 relies on its unique C-terminal Domain (CTD), but the mechanism is unknown. We used multiple biophysical techniques and functional assays to study the interplay between the core catalytic domain and the CTD. While the core domain resembles Dnase1, there are key structural differences between the two enzymes. First, Dnase1L3 is not inhibited by actin due to multiple differences in the actin recognition site. Second, the CTD augments the ability of the core to bind DNA, thereby facilitating the degradation of complexed DNA. Together, these structural insights will inform the development of Dnase1L3-based therapies for autoimmunity.
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Affiliation(s)
- Jon J McCord
- Texas Tech University Health Sciences Center, Dept of Cell Physiology and Molecular Biophysics, Lubbock, TX, USA
| | - Minal Engavale
- Texas Tech University, Dept. of Biological Sciences, Lubbock, TX, USA
| | - Elahe Masoumzadeh
- Texas Tech University, Dept. of Chemistry & Biochemistry, Lubbock, TX, USA
| | - Johanna Villarreal
- Texas Tech University Health Sciences Center, Dept of Cell Physiology and Molecular Biophysics, Lubbock, TX, USA
| | - Britney Mapp
- Texas Tech University, Dept. of Biological Sciences, Lubbock, TX, USA
| | - Michael P Latham
- Texas Tech University, Dept. of Chemistry & Biochemistry, Lubbock, TX, USA
| | - Peter A Keyel
- Texas Tech University, Dept. of Biological Sciences, Lubbock, TX, USA
| | - R Bryan Sutton
- Texas Tech University Health Sciences Center, Dept of Cell Physiology and Molecular Biophysics, Lubbock, TX, USA.
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33
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Vitkov L, Knopf J, Krunić J, Schauer C, Schoen J, Minnich B, Hannig M, Herrmann M. Periodontitis-Derived Dark-NETs in Severe Covid-19. Front Immunol 2022; 13:872695. [PMID: 35493525 PMCID: PMC9039207 DOI: 10.3389/fimmu.2022.872695] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Accepted: 03/23/2022] [Indexed: 11/15/2022] Open
Abstract
The frequent severe COVID-19 course in patients with periodontitis suggests a link of the aetiopathogenesis of both diseases. The formation of intravascular neutrophil extracellular traps (NETs) is crucial to the pathogenesis of severe COVID-19. Periodontitis is characterised by an increased level of circulating NETs, a propensity for increased NET formation, delayed NET clearance and low-grade endotoxemia (LGE). The latter has an enormous impact on innate immunity and susceptibility to infection with SARS-CoV-2. LPS binds the SARS-CoV-2 spike protein and this complex, which is more active than unbound LPS, precipitates massive NET formation. Thus, circulating NET formation is the common denominator in both COVID-19 and periodontitis and other diseases with low-grade endotoxemia like diabetes, obesity and cardiovascular diseases (CVD) also increase the risk to develop severe COVID-19. Here we discuss the role of propensity for increased NET formation, DNase I deficiency and low-grade endotoxaemia in periodontitis as aggravating factors for the severe course of COVID-19 and possible strategies for the diminution of increased levels of circulating periodontitis-derived NETs in COVID-19 with periodontitis comorbidity.
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Affiliation(s)
- Ljubomir Vitkov
- Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, Saarland University, Homburg, Germany.,Department of Environment & Biodiversity, University of Salzburg, Salzburg, Austria.,Department of Dental Pathology, University of East Sarajevo, East Sarajevo, Bosnia and Herzegovina
| | - Jasmin Knopf
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany.,Deutsches Zentrum für Immuntherapie (DZI), Friedrich-Alexander-University Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Jelena Krunić
- Department of Dental Pathology, University of East Sarajevo, East Sarajevo, Bosnia and Herzegovina
| | - Christine Schauer
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany.,Deutsches Zentrum für Immuntherapie (DZI), Friedrich-Alexander-University Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Janina Schoen
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany.,Deutsches Zentrum für Immuntherapie (DZI), Friedrich-Alexander-University Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany
| | - Bernd Minnich
- Department of Environment & Biodiversity, University of Salzburg, Salzburg, Austria
| | - Matthias Hannig
- Clinic of Operative Dentistry, Periodontology and Preventive Dentistry, Saarland University, Homburg, Germany
| | - Martin Herrmann
- Department of Internal Medicine 3 - Rheumatology and Immunology, Friedrich-Alexander-University Erlangen-Nürnberg (FAU) and Universitätsklinikum Erlangen, Erlangen, Germany.,Deutsches Zentrum für Immuntherapie (DZI), Friedrich-Alexander-University Erlangen-Nürnberg and Universitätsklinikum Erlangen, Erlangen, Germany
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Hintzen JCJ, Ma H, Deng H, Witecka A, Andersen SB, Drozak J, Guo H, Qian P, Li H, Mecinović J. Histidine methyltransferase SETD3 methylates structurally diverse histidine mimics in actin. Protein Sci 2022; 31:e4305. [PMID: 35481649 PMCID: PMC9004244 DOI: 10.1002/pro.4305] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2022] [Revised: 03/15/2022] [Accepted: 03/18/2022] [Indexed: 01/05/2023]
Abstract
Actin histidine Nτ -methylation by histidine methyltransferase SETD3 plays an important role in human biology and diseases. Here, we report integrated synthetic, biocatalytic, biostructural, and computational analyses on human SETD3-catalyzed methylation of actin peptides possessing histidine and its structurally and chemically diverse mimics. Our enzyme assays supported by biostructural analyses demonstrate that SETD3 has a broader substrate scope beyond histidine, including N-nucleophiles on the aromatic and aliphatic side chains. Quantum mechanical/molecular mechanical molecular dynamics and free-energy simulations provide insight into binding geometries and the free energy barrier for the enzymatic methyl transfer to histidine mimics, further supporting experimental data that histidine is the superior SETD3 substrate over its analogs. This work demonstrates that human SETD3 has a potential to catalyze efficient methylation of several histidine mimics, overall providing mechanistic, biocatalytic, and functional insight into actin histidine methylation by SETD3.
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Affiliation(s)
- Jordi C. J. Hintzen
- Department of Physics, Chemistry and PharmacyUniversity of Southern DenmarkOdenseDenmark
| | - Huida Ma
- MOE Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Medicine, Tsinghua‐Peking Center for Life SciencesTsinghua UniversityBeijingChina
| | - Hao Deng
- Chemistry and Materials Science FacultyShandong Agricultural UniversityTai'anShandongChina
| | - Apolonia Witecka
- Department of Metabolic Regulation, Faculty of BiologyUniversity of WarsawWarsawPoland
| | - Steffen B. Andersen
- Department of Physics, Chemistry and PharmacyUniversity of Southern DenmarkOdenseDenmark
| | - Jakub Drozak
- Department of Metabolic Regulation, Faculty of BiologyUniversity of WarsawWarsawPoland
| | - Hong Guo
- Department of Biochemistry and Cellular and Molecular BiologyUniversity of TennesseeKnoxvilleTennesseeUSA
- UT/ORNL Center for Molecular BiophysicsOak Ridge National LaboratoryOak RidgeTennesseeUSA
| | - Ping Qian
- Chemistry and Materials Science FacultyShandong Agricultural UniversityTai'anShandongChina
| | - Haitao Li
- MOE Key Laboratory of Protein Sciences, Beijing Frontier Research Center for Biological Structure, School of Medicine, Tsinghua‐Peking Center for Life SciencesTsinghua UniversityBeijingChina
| | - Jasmin Mecinović
- Department of Physics, Chemistry and PharmacyUniversity of Southern DenmarkOdenseDenmark
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35
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Vaynberg J, Qin J. Characterization of pseudokinase ILK-mediated actin assembly. Methods Enzymol 2022; 667:123-146. [PMID: 35525540 DOI: 10.1016/bs.mie.2022.03.027] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Pseudokinase ILK is a key protein involved in regulating focal adhesion assembly and cell-extracellular matrix adhesion. By forming a tight trimeric complex (IPP) with adaptor proteins PINCH and Parvin that both contain an actin binding WH2 motif, IPP can promote the formation of unique actin bundles thereby linking the focal adhesions and actin cytoskeleton and triggering cytoskeleton reassembly and dynamic cell adhesion processes such as cell spreading and migration. This chapter describes detailed characterization of the IPP-mediated actin binding and bundle formation.
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Affiliation(s)
- Julia Vaynberg
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States
| | - Jun Qin
- Department of Cardiovascular & Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, United States.
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Hassoun R, Erdmann C, Schmitt S, Fujita-Becker S, Mügge A, Schröder RR, Geyer M, Borbor M, Jaquet K, Hamdani N, Mannherz HG. Functional Characterization of Cardiac Actin Mutants Causing Hypertrophic (p.A295S) and Dilated Cardiomyopathy (p.R312H and p.E361G). Int J Mol Sci 2022; 23:ijms23084465. [PMID: 35457283 PMCID: PMC9024677 DOI: 10.3390/ijms23084465] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2022] [Revised: 04/15/2022] [Accepted: 04/15/2022] [Indexed: 11/16/2022] Open
Abstract
Human wild type (wt) cardiac α-actin and its mutants p.A295S or p.R312H and p.E361G correlated with hypertrophic or dilated cardiomyopathy, respectively, were expressed by using the baculovirus/Sf21 insect cell system. The c-actin variants inhibited DNase I, indicating maintenance of their native state. Electron microscopy showed the formation of normal appearing actin filaments though they showed mutant specific differences in length and straightness correlating with their polymerization rates. TRITC-phalloidin staining showed that p.A295S and p.R312H exhibited reduced and the p.E361G mutant increased lengths of their formed filaments. Decoration of c-actins with cardiac tropomyosin (cTm) and troponin (cTn) conveyed Ca2+-sensitivity of the myosin-S1 ATPase stimulation, which was higher for the HCM p.A295S mutant and lower for the DCM p.R312H and p.E361G mutants than for wt c-actin. The lower Ca2+-sensitivity of myosin-S1 stimulation by both DCM actin mutants was corrected by the addition of levosimendan. Ca2+-dependency of the movement of pyrene-labeled cTm along polymerized c-actin variants decorated with cTn corresponded to the relations observed for the myosin-S1 ATPase stimulation though shifted to lower Ca2+-concentrations. The N-terminal C0C2 domain of cardiac myosin-binding protein-C increased the Ca2+-sensitivity of the pyrene-cTM movement of bovine, recombinant wt, p.A295S, and p.E361G c-actins, but not of the p.R312H mutant, suggesting decreased affinity to cTm.
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Affiliation(s)
- Roua Hassoun
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Cardiology, St. Josef-Hospital, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany
| | - Constanze Erdmann
- Department of Anatomy and Molecular Embryology, Medical Faculty, Ruhr-University Bochum, D-44780 Bochum, Germany;
| | - Sebastian Schmitt
- Institute of Structural Biology, University of Bonn, D-53127 Bonn, Germany; (S.S.); (M.G.)
| | - Setsuko Fujita-Becker
- Cryoelectron Microscopy, BioQuant, Medical Faculty, University of Heidelberg, D-69120 Heidelberg, Germany; (S.F.-B.); (R.R.S.)
| | - Andreas Mügge
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Cardiology, St. Josef-Hospital, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany
| | - Rasmus R. Schröder
- Cryoelectron Microscopy, BioQuant, Medical Faculty, University of Heidelberg, D-69120 Heidelberg, Germany; (S.F.-B.); (R.R.S.)
| | - Matthias Geyer
- Institute of Structural Biology, University of Bonn, D-53127 Bonn, Germany; (S.S.); (M.G.)
| | - Mina Borbor
- Department of Neurology, University Hospital Essen, D-45147 Essen, Germany;
| | - Kornelia Jaquet
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Cardiology, St. Josef-Hospital, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany
| | - Nazha Hamdani
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Cardiology, St. Josef-Hospital, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany
- Correspondence: (N.H.); (H.G.M.); Tel.: +49-234-32-29412 (N.H.); Fax: +49-234-32-14040 (N.H.); +49-234-32-14474 (H.G.M.)
| | - Hans Georg Mannherz
- Institut für Forschung und Lehre (IFL), Molecular and Experimental Cardiology, Medical Faculty, Ruhr University Bochum, D-44791 Bochum, Germany; (R.H.); (A.M.); (K.J.)
- Department of Anatomy and Molecular Embryology, Medical Faculty, Ruhr-University Bochum, D-44780 Bochum, Germany;
- Correspondence: (N.H.); (H.G.M.); Tel.: +49-234-32-29412 (N.H.); Fax: +49-234-32-14040 (N.H.); +49-234-32-14474 (H.G.M.)
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Ali R, Zahm JA, Rosen MK. Bound nucleotide can control the dynamic architecture of monomeric actin. Nat Struct Mol Biol 2022; 29:320-328. [PMID: 35332323 PMCID: PMC9010300 DOI: 10.1038/s41594-022-00743-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 02/11/2022] [Indexed: 11/12/2022]
Abstract
Polymerization of actin into cytoskeletal filaments is coupled to its bound adenine nucleotides. The mechanism by which nucleotide modulates actin functions has not been evident from analyses of ATP- and ADP-bound crystal structures of the actin monomer. We report that NMR chemical shift differences between the two forms are globally distributed. Furthermore, microsecond–millisecond motions are spread throughout the molecule in the ATP form, but largely confined to subdomains 1 and 2, and the nucleotide binding site in the ADP form. Through these motions, the ATP- and ADP-bound forms sample different high-energy conformations. A deafness-causing, fast-nucleating actin mutant populates the high-energy conformer of ATP-actin more than the wild-type protein, suggesting that this conformer may be on the pathway to nucleation. Together, the data suggest a model in which differential sampling of a nucleation-compatible form of the actin monomer may contribute to control of actin filament dynamics by nucleotide. NMR shows that ATP- and ADP-actin differ globally, including ground and excited state structures and dynamic architecture. Analyses of an actin mutant suggest the high-energy conformer of ATP-actin may be on the pathway to filament nucleation.
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Affiliation(s)
- Rustam Ali
- Department of Biophysics, Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX, USA.
| | - Jacob A Zahm
- Department of Biophysics, Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX, USA.,Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Boston, MA, USA
| | - Michael K Rosen
- Department of Biophysics, Howard Hughes Medical Institute, UT Southwestern Medical Center, Dallas, TX, USA.
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Miyoshi T, Belyantseva IA, Kitajiri SI, Miyajima H, Nishio SY, Usami SI, Kim BJ, Choi BY, Omori K, Shroff H, Friedman TB. Human deafness-associated variants alter the dynamics of key molecules in hair cell stereocilia F-actin cores. Hum Genet 2022; 141:363-382. [PMID: 34232383 PMCID: PMC11351816 DOI: 10.1007/s00439-021-02304-0] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Accepted: 06/15/2021] [Indexed: 12/16/2022]
Abstract
Stereocilia protrude up to 100 µm from the apical surface of vertebrate inner ear hair cells and are packed with cross-linked filamentous actin (F-actin). They function as mechanical switches to convert sound vibration into electrochemical neuronal signals transmitted to the brain. Several genes encode molecular components of stereocilia including actin monomers, actin regulatory and bundling proteins, motor proteins and the proteins of the mechanotransduction complex. A stereocilium F-actin core is a dynamic system, which is continuously being remodeled while maintaining an outwardly stable architecture under the regulation of F-actin barbed-end cappers, severing proteins and crosslinkers. The F-actin cores of stereocilia also provide a pathway for motor proteins to transport cargos including components of tip-link densities, scaffolding proteins and actin regulatory proteins. Deficiencies and mutations of stereocilia components that disturb this "dynamic equilibrium" in stereocilia can induce morphological changes and disrupt mechanotransduction causing sensorineural hearing loss, best studied in mouse and zebrafish models. Currently, at least 23 genes, associated with human syndromic and nonsyndromic hearing loss, encode proteins involved in the development and maintenance of stereocilia F-actin cores. However, it is challenging to predict how variants associated with sensorineural hearing loss segregating in families affect protein function. Here, we review the functions of several molecular components of stereocilia F-actin cores and provide new data from our experimental approach to directly evaluate the pathogenicity and functional impact of reported and novel variants of DIAPH1 in autosomal-dominant DFNA1 hearing loss using single-molecule fluorescence microscopy.
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Affiliation(s)
- Takushi Miyoshi
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, Room 1F-143A, Bethesda, MD, 20892, USA.
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan.
| | - Inna A Belyantseva
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, Room 1F-143A, Bethesda, MD, 20892, USA
| | - Shin-Ichiro Kitajiri
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 390-8621, Matsumoto, Japan
| | - Hiroki Miyajima
- Department of Otolaryngology, Shinshu University School of Medicine, Matsumoto, 390-8621, Japan
- Department of Otolaryngology, Aizawa Hospital, Matsumoto, 390-8510, Japan
| | - Shin-Ya Nishio
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 390-8621, Matsumoto, Japan
| | - Shin-Ichi Usami
- Department of Hearing Implant Sciences, Shinshu University School of Medicine, 390-8621, Matsumoto, Japan
| | - Bong Jik Kim
- Department of Otolaryngology-Head and Neck Surgery, Chungnam National University College of Medicine, Chungnam National University Sejong Hospital, Sejong, 30099, South Korea
- Brain Research Institute, Chungnam National University College of Medicine, Daejeon, 35015, South Korea
| | - Byung Yoon Choi
- Department of Otorhinolaryngology, Seoul National University Bundang Hospital, Seongnam, 13620, South Korea
| | - Koichi Omori
- Department of Otolaryngology-Head and Neck Surgery, Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan
| | - Hari Shroff
- Laboratory of High Resolution Optical Imaging, National Institute of Biomedical Imaging and Bioengineering, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Thomas B Friedman
- Laboratory of Molecular Genetics, National Institute on Deafness and Other Communication Disorders, National Institutes of Health, Porter Neuroscience Research Center, Room 1F-143A, Bethesda, MD, 20892, USA
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39
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Bullard B. Kenneth Charles Holmes 1934–2021. Front Mol Biosci 2022; 9:855014. [PMID: 35372521 PMCID: PMC8972166 DOI: 10.3389/fmolb.2022.855014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2022] [Accepted: 02/09/2022] [Indexed: 11/13/2022] Open
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40
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Kenneth C. Holmes (1934-1921). Structure 2022. [PMID: 35120594 DOI: 10.1016/j.str.2022.01.004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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41
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Ramos-León F, Ramamurthi K. Cytoskeletal proteins: Lessons learned from bacteria. Phys Biol 2022; 19. [PMID: 35081523 DOI: 10.1088/1478-3975/ac4ef0] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2021] [Accepted: 01/26/2022] [Indexed: 11/11/2022]
Abstract
Cytoskeletal proteins are classified as a group that is defined functionally, whose members are capable of polymerizing into higher order structures, either dynamically or statically, to perform structural roles during a variety of cellular processes. In eukaryotes, the most well-studied cytoskeletal proteins are actin, tubulin, and intermediate filaments, and are essential for cell shape and movement, chromosome segregation, and intracellular cargo transport. Prokaryotes often harbor homologs of these proteins, but in bacterial cells, these homologs are usually not employed in roles that can be strictly defined as "cytoskeletal". However, several bacteria encode other proteins capable of polymerizing which, although they do not appear to have a eukaryotic counterpart, nonetheless appear to perform a more traditional "cytoskeletal" function. In this review, we discuss recent reports that cover the structure and functions of prokaryotic proteins that are broadly termed as cytoskeletal, either by sequence homology or by function, to highlight how the enzymatic properties of traditionally studied cytoskeletal proteins may be used for other types of cellular functions; and to demonstrate how truly "cytoskeletal" functions may be performed by uniquely bacterial proteins that do not display homology to eukaryotic proteins.
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Affiliation(s)
- Félix Ramos-León
- National Institutes of Health, 37 Convent Dr., Bldg 37, Room 5132, Bethesda, Maryland, 20892, UNITED STATES
| | - Kumaran Ramamurthi
- Laboratory of Molecular Biology, National Cancer Institute, 37 Convent Dr, Bldg 37, Room 5132, Bethesda, Maryland, 20892, UNITED STATES
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42
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Actomyosin Complex. Subcell Biochem 2022; 99:421-470. [PMID: 36151385 PMCID: PMC9710302 DOI: 10.1007/978-3-031-00793-4_14] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Formation of cross-bridges between actin and myosin occurs ubiquitously in eukaryotic cells and mediates muscle contraction, intracellular cargo transport, and cytoskeletal remodeling. Myosin motors repeatedly bind to and dissociate from actin filaments in a cycle that transduces the chemical energy from ATP hydrolysis into mechanical force generation. While the general layout of surface elements within the actin-binding interface is conserved among myosin classes, sequence divergence within these motifs alters the specific contacts involved in the actomyosin interaction as well as the kinetics of mechanochemical cycle phases. Additionally, diverse lever arm structures influence the motility and force production of myosin molecules during their actin interactions. The structural differences generated by myosin's molecular evolution have fine-tuned the kinetics of its isoforms and adapted them for their individual cellular roles. In this chapter, we will characterize the structural and biochemical basis of the actin-myosin interaction and explain its relationship with myosin's cellular roles, with emphasis on the structural variation among myosin isoforms that enables their functional specialization. We will also discuss the impact of accessory proteins, such as the troponin-tropomyosin complex and myosin-binding protein C, on the formation and regulation of actomyosin cross-bridges.
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43
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Rall JA. Investigation of the molecular motor of muscle: from generating life in a test tube to myosin structure over beers. ADVANCES IN PHYSIOLOGY EDUCATION 2021; 45:730-743. [PMID: 34498938 DOI: 10.1152/advan.00077.2021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Accepted: 07/22/2021] [Indexed: 06/13/2023]
Abstract
This article traces 60 years of investigation of the molecular motor of skeletal muscle from the 1940s through the 1990s. It started with the discovery that myosin interaction with actin in the presence of ATP caused shortening of threads of actin and myosin. In 1957, structures protruding from myosin filaments were seen for the first time and called "cross bridges." A combination of techniques led to the proposal in 1969 of the "swinging-tilting cross bridge" model of contraction. In the early 1980s, a major problem arose when it was shown that a probe attached to the cross bridges did not move during contraction. A spectacular breakthrough came when it was discovered that only the cross bridge was required to support movement in an in vitro motility assay. Next it was determined that single myosin molecules caused the movement of actin filaments in 10-nm steps. The atomic structure of the cross bridge was published in 1993, and this discovery supercharged the muscle field. The cross bridge contained a globular head or motor domain that bound actin and ATP. But the most striking feature was the long tail of the cross bridge surrounded by two subunits of the myosin molecule. This structure suggested that the tail might act as a lever arm magnifying head movement. Consistent with this proposal, genetic techniques that lengthened the lever arm resulted in larger myosin steps. Thus the molecular motor of muscle operated not by the tilting of the globular head of myosin but by tilting of the lever arm generating the driving force for contraction.
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Affiliation(s)
- Jack A Rall
- Department of Physiology and Cell Biology, College of Medicine, Ohio State University, Columbus, Ohio
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44
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Doran MH, Lehman W. The Central Role of the F-Actin Surface in Myosin Force Generation. BIOLOGY 2021; 10:1221. [PMID: 34943138 PMCID: PMC8698748 DOI: 10.3390/biology10121221] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/08/2021] [Revised: 11/17/2021] [Accepted: 11/19/2021] [Indexed: 11/17/2022]
Abstract
Actin is one of the most abundant and versatile proteins in eukaryotic cells. As discussed in many contributions to this Special Issue, its transition from a monomeric G-actin to a filamentous F-actin form plays a critical role in a variety of cellular processes, including control of cell shape and cell motility. Once polymerized from G-actin, F-actin forms the central core of muscle-thin filaments and acts as molecular tracks for myosin-based motor activity. The ATP-dependent cross-bridge cycle of myosin attachment and detachment drives the sliding of myosin thick filaments past thin filaments in muscle and the translocation of cargo in somatic cells. The variation in actin function is dependent on the variation in muscle and non-muscle myosin isoform behavior as well as interactions with a plethora of additional actin-binding proteins. Extensive work has been devoted to defining the kinetics of actin-based force generation powered by the ATPase activity of myosin. In addition, over the past decade, cryo-electron microscopy has revealed the atomic-evel details of the binding of myosin isoforms on the F-actin surface. Most accounts of the structural interactions between myosin and actin are described from the perspective of the myosin molecule. Here, we discuss myosin-binding to actin as viewed from the actin surface. We then describe conserved structural features of actin required for the binding of all or most myosin isoforms while also noting specific interactions unique to myosin isoforms.
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Affiliation(s)
- Matthew H. Doran
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118, USA
| | - William Lehman
- Department of Physiology & Biophysics, Boston University School of Medicine, Boston, MA 02118, USA
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45
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Perfilov MM, Gavrikov AS, Lukyanov KA, Mishin AS. Transient Fluorescence Labeling: Low Affinity-High Benefits. Int J Mol Sci 2021; 22:11799. [PMID: 34769228 PMCID: PMC8583718 DOI: 10.3390/ijms222111799] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2021] [Revised: 10/15/2021] [Accepted: 10/28/2021] [Indexed: 12/20/2022] Open
Abstract
Fluorescent labeling is an established method for visualizing cellular structures and dynamics. The fundamental diffraction limit in image resolution was recently bypassed with the development of super-resolution microscopy. Notably, both localization microscopy and stimulated emission depletion (STED) microscopy impose tight restrictions on the physico-chemical properties of labels. One of them-the requirement for high photostability-can be satisfied by transiently interacting labels: a constant supply of transient labels from a medium replenishes the loss in the signal caused by photobleaching. Moreover, exchangeable tags are less likely to hinder the intrinsic dynamics and cellular functions of labeled molecules. Low-affinity labels may be used both for fixed and living cells in a range of nanoscopy modalities. Nevertheless, the design of optimal labeling and imaging protocols with these novel tags remains tricky. In this review, we highlight the pros and cons of a wide variety of transiently interacting labels. We further discuss the state of the art and future perspectives of low-affinity labeling methods.
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Affiliation(s)
| | | | | | - Alexander S. Mishin
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, 117997 Moscow, Russia; (M.M.P.); (A.S.G.); (K.A.L.)
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46
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Rosenbloom AD, Kovar EW, Kovar DR, Loew LM, Pollard TD. Mechanism of actin filament nucleation. Biophys J 2021; 120:4399-4417. [PMID: 34509503 DOI: 10.1016/j.bpj.2021.09.006] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 07/23/2021] [Accepted: 09/07/2021] [Indexed: 11/16/2022] Open
Abstract
We used computational methods to analyze the mechanism of actin filament nucleation. We assumed a pathway where monomers form dimers, trimers, and tetramers that then elongate to form filaments but also considered other pathways. We aimed to identify the rate constants for these reactions that best fit experimental measurements of polymerization time courses. The analysis showed that the formation of dimers and trimers is unfavorable because the association reactions are orders of magnitude slower than estimated in previous work rather than because of rapid dissociation of dimers and trimers. The 95% confidence intervals calculated for the four rate constants spanned no more than one order of magnitude. Slow nucleation reactions are consistent with published high-resolution structures of actin filaments and molecular dynamics simulations of filament ends. One explanation for slow dimer formation, which we support with computational analysis, is that actin monomers are in a conformational equilibrium with a dominant conformation that cannot participate in the nucleation steps.
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Affiliation(s)
| | - Elizabeth W Kovar
- Biological Sciences Collegiate Division, The University of Chicago, Chicago, Illinois; R. D. Berlin Center for Cell Analysis and Modeling, The University of Connecticut School of Medicine, Farmington, Connecticut
| | - David R Kovar
- Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois; and
| | - Leslie M Loew
- R. D. Berlin Center for Cell Analysis and Modeling, The University of Connecticut School of Medicine, Farmington, Connecticut
| | - Thomas D Pollard
- Departments of Molecular Cellular and Developmental Biology, of Molecular Biophysics and Biochemistry, and of Cell Biology, Yale University, New Haven, Connecticut.
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DFNA20/26 and Other ACTG1-Associated Phenotypes: A Case Report and Review of the Literature. Audiol Res 2021; 11:582-593. [PMID: 34698053 PMCID: PMC8544197 DOI: 10.3390/audiolres11040052] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/10/2021] [Accepted: 10/13/2021] [Indexed: 02/08/2023] Open
Abstract
Since the early 2000s, an ever-increasing subset of missense pathogenic variants in the ACTG1 gene has been associated with an autosomal-dominant, progressive, typically post-lingual non-syndromic hearing loss (NSHL) condition designed as DFNA20/26. ACTG1 gene encodes gamma actin, the predominant actin protein in the cytoskeleton of auditory hair cells; its normal expression and function are essential for the stereocilia maintenance. Different gain-of-function pathogenic variants of ACTG1 have been associated with two major phenotypes: DFNA20/26 and Baraitser-Winter syndrome, a multiple congenital anomaly disorder. Here, we report a novel ACTG1 variant [c.625G>A (p. Val209Met)] in an adult patient with moderate-severe NSHL characterized by a downsloping audiogram. The patient, who had a clinical history of slowly progressive NSHL and tinnitus, was referred to our laboratory for the analysis of a large panel of NSHL-associated genes by next generation sequencing. An extensive review of previously reported ACTG1 variants and their associated phenotypes was also performed.
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Pe KBA, Yatsuzuka K, Hakariya H, Kida T, Katsuda Y, Fukuda M, Sato SI. RNA-based cooperative protein labeling that permits direct monitoring of the intracellular concentration change of an endogenous protein. Nucleic Acids Res 2021; 49:e132. [PMID: 34581825 PMCID: PMC8682759 DOI: 10.1093/nar/gkab839] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2021] [Revised: 08/24/2021] [Accepted: 09/09/2021] [Indexed: 11/13/2022] Open
Abstract
Imaging the dynamics of proteins in living cells is a powerful means for understanding cellular functions at a deeper level. Here, we report a versatile method for spatiotemporal imaging of specific endogenous proteins in living mammalian cells. The method employs a bifunctional aptamer capable of selective protein recognition and fluorescent probe-binding, which is induced only when the aptamer specifically binds to its target protein. An aptamer for β-actin protein preferentially recognizes its monomer forms over filamentous forms, resulting in selective G-actin staining in both fixed and living cells. Through actin-drug treatment, the method permitted direct monitoring of the intracellular concentration change of endogenous G-actin. This protein-labeling method, which is highly selective and non-covalent, provides rich insights into the study of spatiotemporal protein dynamics in living cells.
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Affiliation(s)
| | - Kenji Yatsuzuka
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Hayase Hakariya
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Tomoki Kida
- Division of Materials Science and Chemistry, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan
| | - Yousuke Katsuda
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University, Kyoto 606-8501, Japan.,Division of Materials Science and Chemistry, Faculty of Advanced Science and Technology, Kumamoto University, 2-39-1 Kurokami, Chuo-ku, Kumamoto 860-8555, Japan
| | - Masatora Fukuda
- Department of Chemistry, Faculty of Science, Fukuoka University, 8-19-1 Nanakuma, Jonan-ku, Fukuoka 814-0180, Japan
| | - Shin-Ichi Sato
- Institute for Chemical Research, Kyoto University, Uji, Kyoto 611-0011, Japan
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49
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Kumar A, Zhong Y, Albrecht A, Sang PB, Maples A, Liu Z, Vinayachandran V, Reja R, Lee CF, Kumar A, Chen J, Xiao J, Park B, Shen J, Liu B, Person MD, Trybus KM, Zhang KYJ, Pugh BF, Kamm KE, Milewicz DM, Shen X, Kapoor P. Actin R256 Mono-methylation Is a Conserved Post-translational Modification Involved in Transcription. Cell Rep 2021; 32:108172. [PMID: 32997990 PMCID: PMC8860185 DOI: 10.1016/j.celrep.2020.108172] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2019] [Revised: 07/11/2020] [Accepted: 08/27/2020] [Indexed: 12/19/2022] Open
Abstract
Nuclear actin has been elusive due to the lack of knowledge about molecular mechanisms. From actin-containing chromatin remodeling complexes, we discovered an arginine mono-methylation mark on an evolutionarily conserved R256 residue of actin (R256me1). Actin R256 mutations in yeast affect nuclear functions and cause diseases in human. Interestingly, we show that an antibody specific for actin R256me1 preferentially stains nuclear actin over cytoplasmic actin in yeast, mouse, and human cells. We also show that actin R256me1 is regulated by protein arginine methyl transferase-5 (PRMT5) in HEK293 cells. A genome-wide survey of actin R256me1 mark provides a landscape for nuclear actin correlated with transcription. Further, gene expression and protein interaction studies uncover extensive correlations between actin R256me1 and active transcription. The discovery of actin R256me1 mark suggests a fundamental mechanism to distinguish nuclear actin from cytoplasmic actin through post-translational modification (PTM) and potentially implicates an actin PTM mark in transcription and human diseases. Nuclear actin and actin PTMs are poorly understood. Kumar et al. discover a system of actin PTMs similar to histone PTMs, including a conserved mark on nuclear actin (R256me1) with potential implications for transcription and human diseases.
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Affiliation(s)
- Ashok Kumar
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708, USA
| | - Yuan Zhong
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA
| | - Amelie Albrecht
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA; The University of Texas M.D. Anderson Cancer Center UTHealth Graduate School of Biomedical Sciences, Houston, TX 77030, USA
| | - Pau Biak Sang
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708, USA
| | - Adrian Maples
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708, USA
| | - Zhenan Liu
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Vinesh Vinayachandran
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Rohit Reja
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Chia-Fang Lee
- ICMB Proteomics Facility, The University of Texas at Austin, Austin, TX 78712, USA
| | - Ashutosh Kumar
- Laboratory for Structural Bioinformatics, Center for Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - Jiyuan Chen
- Department of Internal Medicine, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, USA
| | - Jing Xiao
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA
| | - Bongsoo Park
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Jianjun Shen
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA
| | - Bin Liu
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA
| | - Maria D Person
- ICMB Proteomics Facility, The University of Texas at Austin, Austin, TX 78712, USA
| | - Kathleen M Trybus
- Department of Molecular Physiology and Biophysics, University of Vermont, Burlington, VT 05405, USA
| | - Kam Y J Zhang
- Laboratory for Structural Bioinformatics, Center for Biosystems Dynamics Research, RIKEN, 1-7-22 Suehiro, Tsurumi, Yokohama, Kanagawa 230-0045, Japan
| | - B Franklin Pugh
- Center for Eukaryotic Gene Regulation, Department of Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, PA 16802, USA
| | - Kristine E Kamm
- Department of Physiology, The University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Dianna M Milewicz
- Department of Internal Medicine, University of Texas Health Science Center at Houston, McGovern Medical School, Houston, TX, USA
| | - Xuetong Shen
- Department of Epigenetics and Molecular Carcinogenesis, Science Park Research Division, The University of Texas M.D. Anderson Cancer Center, Smithville, TX 78957, USA.
| | - Prabodh Kapoor
- Department of Cellular and Molecular Biology, The University of Texas Health Science Center at Tyler, Tyler, TX 75708, USA.
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50
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Stewart TJ, Murthy V, Dugan SP, Baker JE. Velocity of myosin-based actin sliding depends on attachment and detachment kinetics and reaches a maximum when myosin-binding sites on actin saturate. J Biol Chem 2021; 297:101178. [PMID: 34508779 PMCID: PMC8560993 DOI: 10.1016/j.jbc.2021.101178] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 09/02/2021] [Accepted: 09/07/2021] [Indexed: 11/22/2022] Open
Abstract
Molecular motors such as kinesin and myosin often work in groups to generate the directed movements and forces critical for many biological processes. Although much is known about how individual motors generate force and movement, surprisingly, little is known about the mechanisms underlying the macroscopic mechanics generated by multiple motors. For example, the observation that a saturating number, N, of myosin heads move an actin filament at a rate that is influenced by actin–myosin attachment and detachment kinetics is accounted for neither experimentally nor theoretically. To better understand the emergent mechanics of actin–myosin mechanochemistry, we use an in vitro motility assay to measure and correlate the N-dependence of actin sliding velocities, actin-activated ATPase activity, force generation against a mechanical load, and the calcium sensitivity of thin filament velocities. Our results show that both velocity and ATPase activity are strain dependent and that velocity becomes maximized with the saturation of myosin-binding sites on actin at a value that is 40% dependent on attachment kinetics and 60% dependent on detachment kinetics. These results support a chemical thermodynamic model for ensemble motor mechanochemistry and imply molecularly explicit mechanisms within this framework, challenging the assumption of independent force generation.
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Affiliation(s)
- Travis J Stewart
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, Nevada, USA
| | - Vidya Murthy
- Department of Biomedical Engineering, University of Nevada, Reno, Nevada, USA
| | - Sam P Dugan
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, Nevada, USA
| | - Josh E Baker
- Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno, Nevada, USA.
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