1
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Schuldt C, Khudayberdiev S, Chandra BD, Linne U, Rust MB. Cyclase-associated protein (CAP) inhibits inverted formin 2 (INF2) to induce dendritic spine maturation. Cell Mol Life Sci 2024; 81:353. [PMID: 39154297 PMCID: PMC11335277 DOI: 10.1007/s00018-024-05393-y] [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: 03/12/2024] [Revised: 07/09/2024] [Accepted: 08/02/2024] [Indexed: 08/19/2024]
Abstract
The morphology of dendritic spines, the postsynaptic compartment of most excitatory synapses, decisively modulates the function of neuronal circuits as also evident from human brain disorders associated with altered spine density or morphology. Actin filaments (F-actin) form the backbone of spines, and a number of actin-binding proteins (ABP) have been implicated in shaping the cytoskeleton in mature spines. Instead, only little is known about the mechanisms that control the reorganization from unbranched F-actin of immature spines to the complex, highly branched cytoskeleton of mature spines. Here, we demonstrate impaired spine maturation in hippocampal neurons upon genetic inactivation of cyclase-associated protein 1 (CAP1) and CAP2, but not of CAP1 or CAP2 alone. We found a similar spine maturation defect upon overactivation of inverted formin 2 (INF2), a nucleator of unbranched F-actin with hitherto unknown synaptic function. While INF2 overactivation failed in altering spine density or morphology in CAP-deficient neurons, INF2 inactivation largely rescued their spine defects. From our data we conclude that CAPs inhibit INF2 to induce spine maturation. Since we previously showed that CAPs promote cofilin1-mediated cytoskeletal remodeling in mature spines, we identified them as a molecular switch that control transition from filopodia-like to mature spines.
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Affiliation(s)
- Cara Schuldt
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, 35032, Marburg, Germany
| | - Sharof Khudayberdiev
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, 35032, Marburg, Germany
| | - Ben-David Chandra
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany
| | - Uwe Linne
- Department of Chemistry, Philipps-University Marburg, 35032, Marburg, Germany
| | - Marco B Rust
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032, Marburg, Germany.
- Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, 35032, Marburg, Germany.
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2
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Labat-de-Hoz L, Fernández-Martín L, Correas I, Alonso MA. INF2 formin variants linked to human inherited kidney disease reprogram the transcriptome, causing mitotic chaos and cell death. Cell Mol Life Sci 2024; 81:279. [PMID: 38916773 PMCID: PMC11335204 DOI: 10.1007/s00018-024-05323-y] [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: 03/01/2024] [Revised: 06/13/2024] [Accepted: 06/14/2024] [Indexed: 06/26/2024]
Abstract
Mutations in the human INF2 gene cause autosomal dominant focal segmental glomerulosclerosis (FSGS)-a condition characterized by podocyte loss, scarring, and subsequent kidney degeneration. To understand INF2-linked pathogenicity, we examined the effect of pathogenic INF2 on renal epithelial cell lines and human primary podocytes. Our study revealed an increased incidence of mitotic cells with surplus microtubule-organizing centers fostering multipolar spindle assembly, leading to nuclear abnormalities, particularly multi-micronucleation. The levels of expression of exogenous pathogenic INF2 were similar to those of endogenous INF2. The aberrant nuclear phenotypes were observed regardless of the expression method used (retrovirus infection or plasmid transfection) or the promoter (LTR or CMV) used, and were absent with exogenous wild type INF2 expression. This indicates that the effect of pathogenic INF2 is not due to overexpression or experimental cell manipulation, but instead to the intrinsic properties of pathogenic INF2. Inactivation of the INF2 catalytic domain prevented aberrant nuclei formation. Pathogenic INF2 triggered the translocation of the transcriptional cofactor MRTF into the nucleus. RNA sequencing revealed a profound alteration in the transcriptome that could be primarily attributed to the sustained activation of the MRTF-SRF transcriptional complex. Cells eventually underwent mitotic catastrophe and death. Reducing MRTF-SRF activation mitigated multi-micronucleation, reducing the extent of cell death. Our results, if validated in animal models, could provide insights into the mechanism driving glomerular degeneration in INF2-linked FSGS and may suggest potential therapeutic strategies for impeding FSGS progression.
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Affiliation(s)
- Leticia Labat-de-Hoz
- Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Autónoma de Madrid (UAM), 28049, Madrid, Spain
| | - Laura Fernández-Martín
- Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Autónoma de Madrid (UAM), 28049, Madrid, Spain
| | - Isabel Correas
- Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Autónoma de Madrid (UAM), 28049, Madrid, Spain
- Department of Molecular Biology, UAM, 28049, Madrid, Spain
| | - Miguel A Alonso
- Centro de Biología Molecular Severo Ochoa (CBMSO), Consejo Superior de Investigaciones Científicas (CSIC) and Universidad Autónoma de Madrid (UAM), 28049, Madrid, Spain.
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3
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Subramanian B, Williams S, Karp S, Hennino MF, Jacas S, Lee M, Riella CV, Alper SL, Higgs HN, Pollak MR. Missense Mutant Gain-of-Function Causes Inverted Formin 2 (INF2)-Related Focal Segmental Glomerulosclerosis (FSGS). BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.08.598088. [PMID: 38915495 PMCID: PMC11195136 DOI: 10.1101/2024.06.08.598088] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Inverted formin-2 (INF2) gene mutations are among the most common causes of genetic focal segmental glomerulosclerosis (FSGS) with or without Charcot-Marie-Tooth (CMT) disease. Recent studies suggest that INF2, through its effects on actin and microtubule arrangement, can regulate processes including vesicle trafficking, cell adhesion, mitochondrial calcium uptake, mitochondrial fission, and T-cell polarization. Despite roles for INF2 in multiple cellular processes, neither the human pathogenic R218Q INF2 point mutation nor the INF2 knock-out allele is sufficient to cause disease in mice. This discrepancy challenges our efforts to explain the disease mechanism, as the link between INF2-related processes, podocyte structure, disease inheritance pattern, and their clinical presentation remains enigmatic. Here, we compared the kidney responses to puromycin aminonucleoside (PAN) induced injury between R218Q INF2 point mutant knock-in and INF2 knock-out mouse models and show that R218Q INF2 mice are susceptible to developing proteinuria and FSGS. This contrasts with INF2 knock-out mice, which show only a minimal kidney phenotype. Co-localization and co-immunoprecipitation analysis of wild-type and mutant INF2 coupled with measurements of cellular actin content revealed that the R218Q INF2 point mutation confers a gain-of-function effect by altering the actin cytoskeleton, facilitated in part by alterations in INF2 localization. Differential analysis of RNA expression in PAN-stressed heterozygous R218Q INF2 point-mutant and heterozygous INF2 knock-out mouse glomeruli showed that the adhesion and mitochondria-related pathways were significantly enriched in the disease condition. Mouse podocytes with R218Q INF2, and an INF2-mutant human patient's kidney organoid-derived podocytes with an S186P INF2 mutation, recapitulate the defective adhesion and mitochondria phenotypes. These results link INF2-regulated cellular processes to the onset and progression of glomerular disease. Thus, our data demonstrate that gain-of-function mechanisms drive INF2-related FSGS and explain the autosomal dominant inheritance pattern of this disease.
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4
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Tu X, Yin S, Zang J, Zhang T, Lv C, Zhao G. Understanding the Role of Filamentous Actin in Food Quality: From Structure to Application. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2024; 72:11885-11899. [PMID: 38747409 DOI: 10.1021/acs.jafc.4c01877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2024]
Abstract
Actin, a multifunctional protein highly expressed in eukaryotes, is widely distributed throughout cells and serves as a crucial component of the cytoskeleton. Its presence is integral to maintaining cell morphology and participating in various biological processes. As an irreplaceable component of myofibrillar proteins, actin, including G-actin and F-actin, is highly related to food quality. Up to now, purification of actin at a moderate level remains to be overcome. In this paper, we have reviewed the structures and functions of actin, the methods to obtain actin, and the relationships between actin and food texture, color, and flavor. Moreover, actin finds applications in diverse fields such as food safety, bioengineering, and nanomaterials. Developing an actin preparation method at the industrial level will help promote its further applications in food science, nutrition, and safety.
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Affiliation(s)
- Xinyi Tu
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing Key Laboratory of Functional Food from Plant Resources, Beijing 100083, People's Republic of China
| | - Shuhua Yin
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing Key Laboratory of Functional Food from Plant Resources, Beijing 100083, People's Republic of China
| | - Jiachen Zang
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing Key Laboratory of Functional Food from Plant Resources, Beijing 100083, People's Republic of China
| | - Tuo Zhang
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing Key Laboratory of Functional Food from Plant Resources, Beijing 100083, People's Republic of China
| | - Chenyan Lv
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing Key Laboratory of Functional Food from Plant Resources, Beijing 100083, People's Republic of China
| | - Guanghua Zhao
- College of Food Science & Nutritional Engineering, China Agricultural University, Beijing Key Laboratory of Functional Food from Plant Resources, Beijing 100083, People's Republic of China
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5
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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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6
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Rajan S, Aguirre R, Hong Zhou Z, Hauser P, Reisler E. Drebrin Protects Assembled Actin from INF2-FFC-mediated Severing and Stabilizes Cell Protrusions. J Mol Biol 2024; 436:168421. [PMID: 38158176 DOI: 10.1016/j.jmb.2023.168421] [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: 09/20/2023] [Revised: 12/21/2023] [Accepted: 12/21/2023] [Indexed: 01/03/2024]
Abstract
Highly specialized cells, such as neurons and podocytes, have arborized morphologies that serve their specific functions. Actin cytoskeleton and its associated proteins are responsible for the distinctive shapes of cells. The mechanism of their cytoskeleton regulation - contributing to cell shape maintenance - is yet to be fully clarified. Inverted formin 2 (INF2), one of the modulators of the cytoskeleton, is an atypical formin that can both polymerize and depolymerize actin filaments depending on its molar ratio to actin. Prior work has established that INF2 binds to the sides of actin filaments and severs them. Drebrin is another actin-binding protein that also binds filaments laterally and stabilizes them, but the interplay between drebrin and INF2 on actin filament stabilization is not well understood. Here, we have used biochemical assays, electron microscopy, and total internal reflection fluorescence microscopy imaging to show that drebrin protects actin filaments from severing by INF2 without inhibiting its polymerization activity. Notably, truncated drebrin - DrbA1-300 - is sufficient for this protection, though not as effective as the full-length protein. INF2 and drebrin are abundantly expressed in highly specialized cells and are crucial for the temporal regulation of their actin cytoskeleton, consistent with their involvement in peripheral neuropathy.
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Affiliation(s)
- Sudeepa Rajan
- Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA
| | - Roman Aguirre
- Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA; Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA
| | - Z Hong Zhou
- Department of Microbiology, Immunology and Molecular Genetics, UCLA, Los Angeles, CA 90095, USA
| | - Peter Hauser
- Medical and Research Services, Greater Los Angeles Veterans Affairs Healthcare System at Sepulveda, North Hills, CA 91344, USA; Department of Medicine, David Geffen School of Medicine, UCLA, Los Angeles, CA 90095, USA
| | - Emil Reisler
- Department of Chemistry and Biochemistry, University of California, Los Angeles (UCLA), Los Angeles, CA 90095, USA; Molecular Biology Institute, UCLA, Los Angeles, CA 90095, USA.
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7
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Ma M, Zhou H, Zhang Y, Yuan W, Chen C. The DNA-dependent protein kinase catalytic subunit promotes sepsis-induced cardiac dysfunction through disrupting INF-2-dependent mitochondrial dynamics. Int J Med Sci 2024; 21:714-724. [PMID: 38464839 PMCID: PMC10920849 DOI: 10.7150/ijms.91894] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2023] [Accepted: 02/03/2024] [Indexed: 03/12/2024] Open
Abstract
Sepsis-induced cardiomyopathy (SIC) represents a severe complication of systemic infection, characterized by significant cardiac dysfunction. This study examines the role of DNA-dependent protein kinase catalytic subunit (DNA-PKcs) and Inverted Formin 2 (INF2) in the pathogenesis of SIC, focusing on their impact on mitochondrial homeostasis and dynamics. Our research demonstrates that silencing DNA-PKcs alleviates lipopolysaccharide (LPS)-induced cardiomyocyte death and dysfunction. Using HL-1 cardiomyocytes treated with LPS, we observed that DNA-PKcs knockdown notably reverses LPS-induced cytotoxicity, indicating a protective role against cellular damage. This effect is further substantiated by the reduction in caspase-3 and caspase-9 activation, key markers of apoptosis, upon DNA-PKcs knockdown. Besides, our data further reveal that DNA-PKcs knockdown attenuates LPS-induced mitochondrial dysfunction, evidenced by improved ATP production, enhanced activities of mitochondrial respiratory complexes, and preserved mitochondrial membrane potential. Moreover, DNA-PKcs deletion counteracts LPS-induced shifts towards mitochondrial fission, indicating its regulatory influence on mitochondrial dynamics. Conclusively, our research elucidates the intricate interplay between DNA-PKcs and INF2 in the modulation of mitochondrial function and dynamics during sepsis-induced cardiomyopathy. These findings offer new insights into the molecular mechanisms underpinning SIC and suggest potential therapeutic targets for mitigating mitochondrial dysfunction in this critical condition.
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Affiliation(s)
- Mudi Ma
- Shenshan Medical Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Shanwei, Guangdong, China
- Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Guangzhou, China
| | - Hao Zhou
- Senior Department of Cardiology, The Sixth Medical Center of People's Liberation Army General Hospital, Beijing, China
| | - Ying Zhang
- Shenshan Medical Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Shanwei, Guangdong, China
| | - Woliang Yuan
- Shenshan Medical Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Shanwei, Guangdong, China
| | - Chaoxiong Chen
- Shenshan Medical Center, Sun Yat-sen Memorial Hospital, Sun Yat-sen University, Shanwei, Guangdong, China
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8
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Kast DJ, Jansen S. Purification of modified mammalian actin isoforms for in vitro reconstitution assays. Eur J Cell Biol 2023; 102:151363. [PMID: 37778219 PMCID: PMC10872616 DOI: 10.1016/j.ejcb.2023.151363] [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: 06/19/2023] [Revised: 08/19/2023] [Accepted: 09/26/2023] [Indexed: 10/03/2023] Open
Abstract
In vitro reconstitution assays using purified actin have greatly improved our understanding of cytoskeletal dynamics and their regulation by actin-binding proteins. However, early purification methods consisted of harsh conditions to obtain pure actin and often did not include correct maturation and obligate modification of the isolated actin monomers. Novel insights into the folding requirements and N-terminal processing of actin as well as a better understanding of the interaction of actin with monomer sequestering proteins such as DNaseI, profilin and gelsolin, led to the development of more gentle approaches to obtain pure recombinant actin isoforms with known obligate modifications. This review summarizes the approaches that can be employed to isolate natively folded endogenous and recombinant actin from tissues and cells. We further emphasize the use and limitations of each method and describe how these methods can be implemented to study actin PTMs, disease-related actin mutations and novel actin-like proteins.
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Affiliation(s)
- David J Kast
- Department of Cell Biology and Physiology, Washington University in St. Louis, Saint Louis, MO, 63110, United States.
| | - Silvia Jansen
- Department of Cell Biology and Physiology, Washington University in St. Louis, Saint Louis, MO, 63110, United States.
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9
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Duan C, Liu R, Kuang L, Zhang Z, Hou D, Zheng D, Xiang X, Huang H, Liu L, Li T. Activated Drp1 Initiates the Formation of Endoplasmic Reticulum-Mitochondrial Contacts via Shrm4-Mediated Actin Bundling. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2304885. [PMID: 37909346 PMCID: PMC10754141 DOI: 10.1002/advs.202304885] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/18/2023] [Revised: 08/24/2023] [Indexed: 11/03/2023]
Abstract
Excessive mitochondrial fission following ischemia and hypoxia relies on the formation of contacts between the endoplasmic reticulum and mitochondria (ER-Mito); however, the specific mechanisms behind this process remain unclear. Confocal microscopy and time course recording are used to investigate how ischemia and hypoxia affect the activation of dynamin-related protein 1 (Drp1), a protein central to mitochondrial dynamics, ER-Mito interactions, and the consequences of modifying the expression of Drp1, shroom (Shrm) 4, and inverted formin (INF) 2 on ER-Mito contact establishment. Both Drp1 activation and ER-Mito contact initiation cause excessive mitochondrial fission and dysfunction under ischemic-hypoxic conditions. The activated form of Drp1 aids in ER-Mito contact initiation by recruiting Shrm4 and promoting actin bundling between the ER and mitochondria. This process relies on the structural interplay between INF2 and scattered F-actin on the ER. This study uncovers new roles of cytoplasmic Drp1, providing valuable insights for devising strategies to manage mitochondrial imbalances in the context of ischemic-hypoxic injury.
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Affiliation(s)
- Chenyang Duan
- Department of Shock and TransfusionState Key Laboratory of TraumaBurns and Combined InjuryDaping HospitalArmy Medical UniversityChongqing400042P. R. China
- Department of AnesthesiologyThe Second Affiliated Hospital of Chongqing Medical UniversityChongqing400010P. R. China
| | - Ruixue Liu
- Department of AnesthesiologyThe Second Affiliated Hospital of Chongqing Medical UniversityChongqing400010P. R. China
| | - Lei Kuang
- Department of Shock and TransfusionState Key Laboratory of TraumaBurns and Combined InjuryDaping HospitalArmy Medical UniversityChongqing400042P. R. China
| | - Zisen Zhang
- Department of Shock and TransfusionState Key Laboratory of TraumaBurns and Combined InjuryDaping HospitalArmy Medical UniversityChongqing400042P. R. China
| | - Dongyao Hou
- Department of AnesthesiologyThe Second Affiliated Hospital of Chongqing Medical UniversityChongqing400010P. R. China
| | - Danyang Zheng
- Department of Shock and TransfusionState Key Laboratory of TraumaBurns and Combined InjuryDaping HospitalArmy Medical UniversityChongqing400042P. R. China
| | - Xinming Xiang
- Department of Shock and TransfusionState Key Laboratory of TraumaBurns and Combined InjuryDaping HospitalArmy Medical UniversityChongqing400042P. R. China
| | - He Huang
- Department of AnesthesiologyThe Second Affiliated Hospital of Chongqing Medical UniversityChongqing400010P. R. China
| | - Liangming Liu
- Department of Shock and TransfusionState Key Laboratory of TraumaBurns and Combined InjuryDaping HospitalArmy Medical UniversityChongqing400042P. R. China
| | - Tao Li
- Department of Shock and TransfusionState Key Laboratory of TraumaBurns and Combined InjuryDaping HospitalArmy Medical UniversityChongqing400042P. R. China
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10
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Martin JL, Khan A, Grintsevich EE. Actin Isoform Composition and Binding Factors Fine-Tune Regulatory Impact of Mical Enzymes. Int J Mol Sci 2023; 24:16651. [PMID: 38068973 PMCID: PMC10705957 DOI: 10.3390/ijms242316651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Revised: 11/20/2023] [Accepted: 11/20/2023] [Indexed: 12/18/2023] Open
Abstract
Mical family enzymes are unusual actin regulators that prime filaments (F-actin) for disassembly via the site-specific oxidation of M44/M47. Filamentous actin acts as a substrate of Mical enzymes, as well as an activator of their NADPH oxidase activity, which leads to hydrogen peroxide generation. Mical enzymes are required for cytokinesis, muscle and heart development, dendritic pruning, and axonal guidance, among other processes. Thus, it is critical to understand how this family of actin regulators functions in different cell types. Vertebrates express six actin isoforms in a cell-specific manner, but MICALs' impact on their intrinsic properties has never been systematically investigated. Our data reveal the differences in the intrinsic dynamics of Mical-oxidized actin isoforms. Furthermore, our results connect the intrinsic dynamics of actin isoforms and their redox state with the patterns of hydrogen peroxide (H2O2) generation by MICALs. We documented that the differential properties of actin isoforms translate into the distinct patterns of hydrogen peroxide generation in Mical/NADPH-containing systems. Moreover, our results establish a conceptual link between actin stabilization by interacting factors and its ability to activate MICALs' NADPH oxidase activity. Altogether, our results suggest that the regulatory impact of MICALs may differ depending on the isoform-related identities of local actin networks.
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Affiliation(s)
| | | | - Elena E. Grintsevich
- Department of Chemistry and Biochemistry, California State University, Long Beach (CSULB), Long Beach, CA 90840, USA
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11
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Wu F, Muskat NH, Dvilansky I, Koren O, Shahar A, Gazit R, Elia N, Arbely E. Acetylation-dependent coupling between G6PD activity and apoptotic signaling. Nat Commun 2023; 14:6208. [PMID: 37798264 PMCID: PMC10556143 DOI: 10.1038/s41467-023-41895-2] [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: 03/27/2023] [Accepted: 09/14/2023] [Indexed: 10/07/2023] Open
Abstract
Lysine acetylation has been discovered in thousands of non-histone human proteins, including most metabolic enzymes. Deciphering the functions of acetylation is key to understanding how metabolic cues mediate metabolic enzyme regulation and cellular signaling. Glucose-6-phosphate dehydrogenase (G6PD), the rate-limiting enzyme in the pentose phosphate pathway, is acetylated on multiple lysine residues. Using site-specifically acetylated G6PD, we show that acetylation can activate (AcK89) and inhibit (AcK403) G6PD. Acetylation-dependent inactivation is explained by structural studies showing distortion of the dimeric structure and active site of G6PD. We provide evidence for acetylation-dependent K95/97 ubiquitylation of G6PD and Y503 phosphorylation, as well as interaction with p53 and induction of early apoptotic events. Notably, we found that the acetylation of a single lysine residue coordinates diverse acetylation-dependent processes. Our data provide an example of the complex roles of acetylation as a posttranslational modification that orchestrates the regulation of enzymatic activity, posttranslational modifications, and apoptotic signaling.
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Affiliation(s)
- Fang Wu
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Natali H Muskat
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Inbar Dvilansky
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Omri Koren
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Anat Shahar
- Macromolecular Crystallography Research Center (MCRC), Ilse Katz Institute for Nanoscale Science & Technology, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Roi Gazit
- The Shraga Segal Department of Microbiology, Immunology and Genetics, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Natalie Elia
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel
| | - Eyal Arbely
- Department of Chemistry, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel.
- Department of Life Sciences, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel.
- The National Institute for Biotechnology in the Negev, Ben-Gurion University of the Negev, Beer-Sheva, 8410501, Israel.
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12
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Ueda H, Tran QTH, Tran LNT, Higasa K, Ikeda Y, Kondo N, Hashiyada M, Sato C, Sato Y, Ashida A, Nishio S, Iwata Y, Iida H, Matsuoka D, Hidaka Y, Fukui K, Itami S, Kawashita N, Sugimoto K, Nozu K, Hattori M, Tsukaguchi H. Characterization of cytoskeletal and structural effects of INF2 variants causing glomerulopathy and neuropathy. Sci Rep 2023; 13:12003. [PMID: 37491439 PMCID: PMC10368640 DOI: 10.1038/s41598-023-38588-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2023] [Accepted: 07/11/2023] [Indexed: 07/27/2023] Open
Abstract
Focal segmental glomerulosclerosis (FSGS) is a common glomerular injury leading to end-stage renal disease. Monogenic FSGS is primarily ascribed to decreased podocyte integrity. Variants between residues 184 and 245 of INF2, an actin assembly factor, produce the monogenic FSGS phenotype. Meanwhile, variants between residues 57 and 184 cause a dual-faceted disease involving peripheral neurons and podocytes (Charcot-Marie-Tooth CMT/FSGS). To understand the molecular basis for INF2 disorders, we compared structural and cytoskeletal effects of INF2 variants classified into two subgroups: One (G73D, V108D) causes the CMT/FSGS phenotype, and the other (T161N, N202S) produces monogenic FSGS. Molecular dynamics analysis revealed that all INF2 variants show distinct flexibility compared to the wild-type INF2 and could affect stability of an intramolecular interaction between their N- and C-terminal segments. Immunocytochemistry of cells expressing INF2 variants showed fewer actin stress fibers, and disorganization of cytoplasmic microtubule arrays. Notably, CMT/FSGS variants caused more prominent changes in mitochondrial distribution and fragmentation than FSGS variants and these changes correlated with the severity of cytoskeletal disruption. Our results indicate that CMT/FSGS variants are associated with more severe global cellular defects caused by disrupted cytoskeleton-organelle interactions than are FSGS variants. Further study is needed to clarify tissue-specific pathways and/or cellular functions implicated in FSGS and CMT phenotypes.
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Affiliation(s)
- Hiroko Ueda
- Division of Nephrology, Second Department of Internal Medicine, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka, 573-1191, Japan
| | - Quynh Thuy Huong Tran
- Division of Nephrology, Second Department of Internal Medicine, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka, 573-1191, Japan
| | - Linh Nguyen Truc Tran
- Division of Nephrology, Second Department of Internal Medicine, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka, 573-1191, Japan
| | - Koichiro Higasa
- Department of Genome Analysis, Institute of Biomedical Science, Kansai Medical University, Hirakata, Japan
| | - Yoshiki Ikeda
- Department of Molecular Genetics, Kansai Medical University, Hirakata, Japan
| | - Naoyuki Kondo
- Department of Molecular Genetics, Kansai Medical University, Hirakata, Japan
| | - Masaki Hashiyada
- Department of Legal Medicine, Kansai Medical University, Hirakata, Japan
| | - Chika Sato
- Department of Gynecology and Obstetrics, Kansai Medical University, Hirakata, Japan
| | - Yoshinori Sato
- Division of Nephrology, Department of Medicine, Showa University Fujigaoka Hospital, Yokohama, Kanagawa, Japan
| | - Akira Ashida
- Department of Pediatrics, Osaka Medical and Pharmaceutical University, Takatsuki, Japan
| | - Saori Nishio
- Department of Rheumatology, Endocrinology and Nephrology, Faculty of Medicine and Graduate School of Medicine, Hokkaido University, Sapporo, Japan
| | - Yasunori Iwata
- Department of Nephrology and Laboratory Medicine, Kanazawa University, Kanazawa, Japan
| | - Hiroyuki Iida
- Department of Internal Medicine, Toyama Prefectural Central Hospital, Toyama, Japan
- Toyama Transplantation Promotion Foundation, Toyama, Japan
| | - Daisuke Matsuoka
- Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Yoshihiko Hidaka
- Department of Pediatrics, Shinshu University School of Medicine, Matsumoto, Japan
| | - Kenji Fukui
- Department of Biochemistry, Faculty of Medicine, Osaka Medical and Pharmaceutical University, Takatsuki, Japan
| | - Suzu Itami
- Major in Science, Graduate School of Science and Engineering, Kindai University, Higashiosaka, Japan
| | - Norihito Kawashita
- Department of Energy and Materials, Faculty of Science and Engineering, Kindai University, Higashiosaka, Japan
| | - Keisuke Sugimoto
- Department of Pediatrics, Kindai University Faculty of Medicine, Osakasayama, Japan
| | - Kandai Nozu
- Department of Pediatrics, Kobe University Graduate School of Medicine, Kobe, Japan
| | - Motoshi Hattori
- Department of Pediatric Nephrology, Tokyo Women's Medical University, Tokyo, Japan
| | - Hiroyasu Tsukaguchi
- Division of Nephrology, Second Department of Internal Medicine, Kansai Medical University, 2-5-1 Shinmachi, Hirakata, Osaka, 573-1191, Japan.
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13
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Haarer BK, Pimm ML, de Jong EP, Amberg DC, Henty-Ridilla JL. Purification of human β- and γ-actin from budding yeast. J Cell Sci 2023; 136:jcs260540. [PMID: 37070275 PMCID: PMC10184827 DOI: 10.1242/jcs.260540] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Accepted: 04/04/2023] [Indexed: 04/19/2023] Open
Abstract
Biochemical studies of human actin and its binding partners rely heavily on abundant and easily purified α-actin from skeletal muscle. Therefore, muscle actin has been used to evaluate and determine the activities of most actin regulatory proteins but there is an underlying concern that these proteins perform differently from actin present in non-muscle cells. To provide easily accessible and relatively abundant sources of human β- or γ-actin (i.e. cytoplasmic actins), we developed Saccharomyces cerevisiae strains that express each as their sole source of actin. Both β- or γ-actin purified in this system polymerize and interact with various binding partners, including profilin, mDia1 (formin), fascin and thymosin-β4 (Tβ4). Notably, Tβ4 and profilin bind to β- or γ-actin with higher affinity than to α-actin, emphasizing the value of testing actin ligands with specific actin isoforms. These reagents will make specific isoforms of actin more accessible for future studies on actin regulation.
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Affiliation(s)
- Brian K. Haarer
- Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY 13210, USA
| | - Morgan L. Pimm
- Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY 13210, USA
| | | | - David C. Amberg
- Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY 13210, USA
| | - Jessica L. Henty-Ridilla
- Department of Biochemistry and Molecular Biology, State University of New York (SUNY) Upstate Medical University, Syracuse, NY 13210, USA
- Department of Neuroscience and Physiology, SUNY Upstate Medical University, Syracuse, NY 13210, USA
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14
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Lakha R, Hachicho C, Mehlenbacher MR, Wilcox DE, Austin RN, Vizcarra CL. Metallothionein-3 attenuates the effect of Cu 2+ ions on actin filaments. J Inorg Biochem 2023; 242:112157. [PMID: 36801620 DOI: 10.1016/j.jinorgbio.2023.112157] [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: 12/19/2022] [Revised: 02/01/2023] [Accepted: 02/02/2023] [Indexed: 02/10/2023]
Abstract
Metallothionein 3 (MT-3) is a cysteine-rich metal-binding protein that is expressed in the mammalian central nervous system and kidney. Various reports have posited a role for MT-3 in regulating the actin cytoskeleton by promoting the assembly of actin filaments. We generated purified, recombinant mouse MT-3 of known metal compositions, either with zinc (Zn), lead (Pb), or copper/zinc (Cu/Zn) bound. None of these forms of MT-3 accelerated actin filament polymerization in vitro, either with or without the actin binding protein profilin. Furthermore, using a co-sedimentation assay, we did not observe Zn-bound MT-3 in complex with actin filaments. Cu2+ ions on their own induced rapid actin polymerization, an effect that we attribute to filament fragmentation. This effect of Cu2+ is reversed by adding either EGTA or Zn-bound MT-3, indicating that either molecule can chelate Cu2+ from actin. Altogether, our data indicate that purified recombinant MT-3 does not directly bind actin but it does attenuate the Cu-induced fragmentation of actin filaments.
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Affiliation(s)
- Rabina Lakha
- Department of Chemistry, Barnard College, New York, NY 10027, USA
| | - Carla Hachicho
- Department of Chemistry, Barnard College, New York, NY 10027, USA
| | | | - Dean E Wilcox
- Department of Chemistry, Dartmouth College, Hanover, NH 03755, USA
| | - Rachel N Austin
- Department of Chemistry, Barnard College, New York, NY 10027, USA
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15
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Chin SM, Hatano T, Sivashanmugam L, Suchenko A, Kashina AS, Balasubramanian MK, Jansen S. N-terminal acetylation and arginylation of actin determines the architecture and assembly rate of linear and branched actin networks. J Biol Chem 2022; 298:102518. [PMID: 36152749 PMCID: PMC9597890 DOI: 10.1016/j.jbc.2022.102518] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2022] [Revised: 09/16/2022] [Accepted: 09/17/2022] [Indexed: 11/27/2022] Open
Abstract
The great diversity in actin network architectures and dynamics is exploited by cells to drive fundamental biological processes, including cell migration, endocytosis, and cell division. While it is known that this versatility is the result of the many actin-remodeling activities of actin-binding proteins, such as Arp2/3 and cofilin, recent work also implicates posttranslational acetylation or arginylation of the actin N terminus itself as an equally important regulatory mechanism. However, the molecular mechanisms by which acetylation and arginylation alter the properties of actin are not well understood. Here, we directly compare how processing and modification of the N terminus of actin affects its intrinsic polymerization dynamics and its remodeling by actin-binding proteins that are essential for cell migration. We find that in comparison to acetylated actin, arginylated actin reduces intrinsic as well as formin-mediated elongation and Arp2/3-mediated nucleation. By contrast, there are no significant differences in cofilin-mediated severing. Taken together, these results suggest that cells can employ these differently modified actins to regulate actin dynamics. In addition, unprocessed actin with an N-terminal methionine residue shows very different effects on formin-mediated elongation, Arp2/3-mediated nucleation, and severing by cofilin. Altogether, this study shows that the nature of the N terminus of actin can promote distinct actin network dynamics, which can be differentially used by cells to locally finetune actin dynamics at distinct cellular locations, such as at the leading edge.
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Affiliation(s)
- Samantha M Chin
- Department of Cell Biology and Physiology, Washington University in St Louis, Saint Louis, Missouri, USA
| | - Tomoyuki Hatano
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Lavanya Sivashanmugam
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Andrejus Suchenko
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Anna S Kashina
- Department of Biomedical Sciences, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Mohan K Balasubramanian
- Centre for Mechanochemical Cell Biology and Division of Biomedical Sciences, Warwick Medical School, University of Warwick, Coventry, UK
| | - Silvia Jansen
- Department of Cell Biology and Physiology, Washington University in St Louis, Saint Louis, Missouri, USA.
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16
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Labat-de-Hoz L, Comas L, Rubio-Ramos A, Casares-Arias J, Fernández-Martín L, Pantoja-Uceda D, Martín MT, Kremer L, Jiménez MA, Correas I, Alonso MA. Structure and function of the N-terminal extension of the formin INF2. Cell Mol Life Sci 2022; 79:571. [PMID: 36306014 PMCID: PMC9616786 DOI: 10.1007/s00018-022-04581-y] [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: 06/30/2022] [Revised: 09/19/2022] [Accepted: 09/29/2022] [Indexed: 11/16/2022]
Abstract
In INF2—a formin linked to inherited renal and neurological disease in humans—the DID is preceded by a short N-terminal extension of unknown structure and function. INF2 activation is achieved by Ca2+-dependent association of calmodulin (CaM). Here, we show that the N-terminal extension of INF2 is organized into two α-helices, the first of which is necessary to maintain the perinuclear F-actin ring and normal cytosolic F-actin content. Biochemical assays indicated that this helix interacts directly with CaM and contains the sole CaM-binding site (CaMBS) detected in INF2. The residues W11, L14 and L18 of INF2, arranged as a 1-4-8 motif, were identified as the most important residues for the binding, W11 being the most critical of the three. This motif is conserved in vertebrate INF2 and in the human population. NMR and biochemical analyses revealed that CaM interacts directly through its C-terminal lobe with the INF2 CaMBS. Unlike control cells, INF2 KO cells lacked the perinuclear F-actin ring, had little cytosolic F-actin content, did not respond to increased Ca2+ concentrations by making more F-actin, and maintained the transcriptional cofactor MRTF predominantly in the cytoplasm. Whereas expression of intact INF2 restored all these defects, INF2 with inactivated CaMBS did not. Our study reveals the structure of the N-terminal extension, its interaction with Ca2+/CaM, and its function in INF2 activation.
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Affiliation(s)
- Leticia Labat-de-Hoz
- Centro de Biología Molecular (CBM) Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Laura Comas
- Instituto de Química Física Rocasolano (IQFR), Consejo Superior de Investigaciones Científicas, 28006, Madrid, Spain
| | - Armando Rubio-Ramos
- Centro de Biología Molecular (CBM) Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Javier Casares-Arias
- Centro de Biología Molecular (CBM) Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - Laura Fernández-Martín
- Centro de Biología Molecular (CBM) Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049, Madrid, Spain
| | - David Pantoja-Uceda
- Instituto de Química Física Rocasolano (IQFR), Consejo Superior de Investigaciones Científicas, 28006, Madrid, Spain
| | - M Teresa Martín
- Centro Nacional de Biotecnología (CNB), Consejo Superior de Investigaciones Científicas, 28049, Madrid, Spain
| | - Leonor Kremer
- Centro Nacional de Biotecnología (CNB), Consejo Superior de Investigaciones Científicas, 28049, Madrid, Spain
| | - M Angeles Jiménez
- Instituto de Química Física Rocasolano (IQFR), Consejo Superior de Investigaciones Científicas, 28006, Madrid, Spain
| | - Isabel Correas
- Centro de Biología Molecular (CBM) Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049, Madrid, Spain.,Department of Molecular Biology, Universidad Autónoma de Madrid (UAM), 28049, Madrid, Spain
| | - Miguel A Alonso
- Centro de Biología Molecular (CBM) Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, 28049, Madrid, Spain.
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17
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Calabrese B, Jones SL, Shiraishi-Yamaguchi Y, Lingelbach M, Manor U, Svitkina TM, Higgs HN, Shih AY, Halpain S. INF2-mediated actin filament reorganization confers intrinsic resilience to neuronal ischemic injury. Nat Commun 2022; 13:6037. [PMID: 36229429 PMCID: PMC9558009 DOI: 10.1038/s41467-022-33268-y] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2021] [Accepted: 09/09/2022] [Indexed: 12/24/2022] Open
Abstract
During early ischemic brain injury, glutamate receptor hyperactivation mediates neuronal death via osmotic cell swelling. Here we show that ischemia and excess NMDA receptor activation cause actin to rapidly and extensively reorganize within the somatodendritic compartment. Normally, F-actin is concentrated within dendritic spines. However, <5 min after bath-applied NMDA, F-actin depolymerizes within spines and polymerizes into stable filaments within the dendrite shaft and soma. A similar actinification occurs after experimental ischemia in culture, and photothrombotic stroke in mouse. Following transient NMDA incubation, actinification spontaneously reverses. Na+, Cl-, water, and Ca2+ influx, and spine F-actin depolymerization are all necessary, but not individually sufficient, for actinification, but combined they induce activation of the F-actin polymerization factor inverted formin-2 (INF2). Silencing of INF2 renders neurons vulnerable to cell death and INF2 overexpression is protective. Ischemia-induced dendritic actin reorganization is therefore an intrinsic pro-survival response that protects neurons from death induced by cell edema.
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Affiliation(s)
- Barbara Calabrese
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, and Sanford Consortium for Regenerative Medicine, La Jolla, CA, 92093, USA
| | - Steven L Jones
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104-4544, USA
| | | | - Michael Lingelbach
- Neurosciences Interdepartmental Program, Stanford University, Stanford, CA, 94305, USA
| | - Uri Manor
- The Salk Institute for Biological Studies, La Jolla, CA, 92037, USA
| | - Tatyana M Svitkina
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104-4544, USA
| | - Henry N Higgs
- Department of Biochemistry, Geisel School of Medicine, Hanover, NH, 03755, USA
| | - Andy Y Shih
- Center for Developmental Biology and Regenerative Medicine, Seattle Children's Research Institute, Seattle, WA, 98101, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Shelley Halpain
- Department of Neurobiology, School of Biological Sciences, University of California, San Diego, and Sanford Consortium for Regenerative Medicine, La Jolla, CA, 92093, USA.
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18
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A solution to the long-standing problem of actin expression and purification. Proc Natl Acad Sci U S A 2022; 119:e2209150119. [PMID: 36197995 PMCID: PMC9565351 DOI: 10.1073/pnas.2209150119] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Actin is the most abundant protein in the cytoplasm of eukaryotic cells and interacts with hundreds of proteins to perform essential functions, including cell motility and cytokinesis. Numerous diseases are caused by mutations in actin, but studying the biochemistry of actin mutants is difficult without a reliable method to obtain recombinant actin. Moreover, biochemical studies have typically used tissue-purified α-actin, whereas humans express six isoforms that are nearly identical but perform specialized functions and are difficult to obtain in isolation from natural sources. Here, we describe a solution to the problem of actin expression and purification. We obtain high yields of actin isoforms in human Expi293F cells. Experiments along the multistep purification protocol demonstrate the removal of endogenous actin and the functional integrity of recombinant actin isoforms. Proteomics analysis of endogenous vs. recombinant actin isoforms confirms the presence of native posttranslational modifications, including N-terminal acetylation achieved after affinity-tag removal using the actin-specific enzyme Naa80. The method described facilitates studies of actin under fully native conditions to determine differences among isoforms and the effects of disease-causing mutations that occur in all six isoforms.
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19
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Singh AK, Rai A, Weber A, Posern G. miRNA mediated downregulation of cyclase-associated protein 1 (CAP1) is required for myoblast fusion. Front Cell Dev Biol 2022; 10:899917. [PMID: 36246999 PMCID: PMC9562714 DOI: 10.3389/fcell.2022.899917] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/19/2022] [Accepted: 09/14/2022] [Indexed: 11/13/2022] Open
Abstract
Myoblast fusion is essential for the formation, growth, and regeneration of skeletal muscle, but the molecular mechanisms that govern fusion and myofiber formation remain poorly understood. Past studies have shown an important role of the actin cytoskeleton and actin regulators in myoblast fusion. The Cyclase-Associated Proteins (CAP) 1 and 2 recently emerged as critical regulators of actin treadmilling in higher eukaryotes including mammals. Whilst the role of CAP2 in skeletal muscle development and function is well characterized, involvement of CAP1 in this process remains elusive. Here we report that CAP1, plays a critical role in cytoskeletal remodeling during myoblast fusion and formation of myotubes. Cap1 mRNA and protein are expressed in both murine C2C12 and human LHCN-M2 myoblasts, but their abundance decreases during myogenic differentiation. Perturbing the temporally controlled expression of CAP1 by overexpression or CRISPR-Cas9 mediated knockout impaired actin rearrangement, myoblast alignment, expression of profusion molecules, differentiation into multinucleated myotubes, and myosin heavy chain expression. Endogenous Cap1 expression is post-transcriptionally downregulated during differentiation by canonical myomiRs miR-1, miR-133, and miR-206, which have conserved binding sites at the 3′ UTR of the Cap1 mRNA. Deletion of the endogenous 3′ UTR by CRISPR-Cas9 in C2C12 cells phenocopies overexpression of CAP1 by inhibiting myotube formation. Our findings implicates Cap1 and its myomiR-mediated downregulation in the myoblast fusion process and the generation of skeletal muscle.
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Affiliation(s)
- Anurag Kumar Singh
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- Department of Internal Medicine I, University Hospital Halle, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- *Correspondence: Anurag Kumar Singh, ; Guido Posern,
| | - Amrita Rai
- Department of Structural Biochemistry, Max Planck Institute of Molecular Physiology, Dortmund, Germany
| | - Anja Weber
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Guido Posern
- Institute for Physiological Chemistry, Medical Faculty, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
- *Correspondence: Anurag Kumar Singh, ; Guido Posern,
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20
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Kage F, Vicente-Manzanares M, McEwan BC, Kettenbach AN, Higgs HN. Myosin II proteins are required for organization of calcium-induced actin networks upstream of mitochondrial division. Mol Biol Cell 2022; 33:ar63. [PMID: 35427150 PMCID: PMC9561854 DOI: 10.1091/mbc.e22-01-0005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022] Open
Abstract
The formin INF2 polymerizes a calcium-activated cytoplasmic network of actin filaments, which we refer to as calcium-induced actin polymerization (CIA). CIA plays important roles in multiple cellular processes, including mitochondrial dynamics and vesicle transport. Here, we show that nonmuscle myosin II (NMII) is activated within 60 s of calcium stimulation and rapidly recruited to the CIA network. Knockout of any individual NMII in U2OS cells affects the organization of the CIA network, as well as three downstream effects: endoplasmic-reticulum-to-mitochondrial calcium transfer, mitochondrial Drp1 recruitment, and mitochondrial division. Interestingly, while NMIIC is the least abundant NMII in U2OS cells (>200-fold less than NMIIA and >10-fold less than NMIIB), its knockout is equally deleterious to CIA. On the basis of these results, we propose that myosin II filaments containing all three NMII heavy chains exert organizational and contractile roles in the CIA network. In addition, NMIIA knockout causes a significant decrease in myosin regulatory light chain levels, which might have additional effects.
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Affiliation(s)
- Frieda Kage
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Miguel Vicente-Manzanares
- Centro de Investigacion del Cancer/Instituto de Biologia Molecular y Celular del Cancer, Centro Mixto Universidad de Salamanca, 37007 Salamanca, Spain
| | - Brennan C. McEwan
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
- Program in Cancer Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Arminja N. Kettenbach
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
- Program in Cancer Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
| | - Henry N. Higgs
- Department of Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover NH 03755, USA
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21
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Rust MB, Marcello E. Disease association of cyclase-associated protein (CAP): Lessons from gene-targeted mice and human genetic studies. Eur J Cell Biol 2022; 101:151207. [PMID: 35150966 DOI: 10.1016/j.ejcb.2022.151207] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Revised: 02/04/2022] [Accepted: 02/07/2022] [Indexed: 11/03/2022] Open
Abstract
Cyclase-associated protein (CAP) is an actin binding protein that has been initially described as partner of the adenylyl cyclase in yeast. In all vertebrates and some invertebrate species, two orthologs, named CAP1 and CAP2, have been described. CAP1 and CAP2 are characterized by a similar multidomain structure, but different expression patterns. Several molecular studies clarified the biological function of the different CAP domains, and they shed light onto the mechanisms underlying CAP-dependent regulation of actin treadmilling. However, CAPs are crucial elements not only for the regulation of actin dynamics, but also for signal transduction pathways. During recent years, human genetic studies and the analysis of gene-targeted mice provided important novel insights into the physiological roles of CAPs and their involvement in the pathogenesis of several diseases. In the present review, we summarize and discuss recent progress in our understanding of CAPs' physiological functions, focusing on heart, skeletal muscle and central nervous system as well as their involvement in the mechanisms controlling metabolism. Remarkably, loss of CAPs or impairment of CAPs-dependent pathways can contribute to the pathogenesis of different diseases. Overall, these studies unraveled CAPs complexity highlighting their capability to orchestrate structural and signaling pathways in the cells.
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Affiliation(s)
- Marco B Rust
- Molecular Neurobiology Group, Institute of Physiological Chemistry, Philipps-University of Marburg, 35032 Marburg, Germany; Center for Mind, Brain and Behavior (CMBB), University of Marburg and Justus-Liebig-University Giessen, 35032 Marburg, Germany; DFG Research Training Group 'Membrane Plasticity in Tissue Development and Remodeling', GRK 2213, Philipps-University of Marburg, 35032 Marburg, Germany.
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, Università degli Studi di Milano, 20133 Milan, Italy.
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22
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Zhao Y, Zhang H, Wang H, Ye M, Jin X. Role of formin INF2 in human diseases. Mol Biol Rep 2021; 49:735-746. [PMID: 34698992 DOI: 10.1007/s11033-021-06869-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 10/21/2021] [Indexed: 01/08/2023]
Abstract
Formin proteins catalyze actin nucleation and microfilament polymerization. Inverted formin 2 (INF2) is an atypical diaphanous-related formin characterized by polymerization and depolymerization of actin. Accumulating evidence showed that INF2 is associated with kidney disease focal segmental glomerulosclerosis and cancers, such as colorectal and thyroid cancer where it functions as a tumor suppressor, glioblastoma, breast, prostate, and gastric cancer, via its oncogenic function. However, studies on the underlying molecular mechanisms of the different roles of INF2 in diverse cancers are limited. This review comprehensively describes the structure, biochemical features, and primary pathogenic mutations of INF2.
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Affiliation(s)
- Yiting Zhao
- Department of Hepato-Biliary-Pancreatic Surgery, The Affiliated Ningbo Medical Center of LiHuiLi Hospital of Medical School of Ningbo University, Ningbo, 315048, China.,The Affiliated Hospital of Medical School, Ningbo University, Ningbo, 315020, China
| | - Hui Zhang
- Department of Biochemistry and Molecular Biology, and Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, 315211, China.,The Affiliated Hospital of Medical School, Ningbo University, Ningbo, 315020, China
| | - Haibiao Wang
- Department of Hepato-Biliary-Pancreatic Surgery, The Affiliated Ningbo Medical Center of LiHuiLi Hospital of Medical School of Ningbo University, Ningbo, 315048, China. .,Department of Biochemistry and Molecular Biology, and Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, 315211, China.
| | - Meng Ye
- Department of Biochemistry and Molecular Biology, and Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, 315211, China. .,The Affiliated Hospital of Medical School, Ningbo University, Ningbo, 315020, China.
| | - Xiaofeng Jin
- Department of Biochemistry and Molecular Biology, and Zhejiang Key Laboratory of Pathophysiology, Medical School of Ningbo University, Ningbo, 315211, China. .,The Affiliated Hospital of Medical School, Ningbo University, Ningbo, 315020, China.
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23
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Bamburg JR, Minamide LS, Wiggan O, Tahtamouni LH, Kuhn TB. Cofilin and Actin Dynamics: Multiple Modes of Regulation and Their Impacts in Neuronal Development and Degeneration. Cells 2021; 10:cells10102726. [PMID: 34685706 PMCID: PMC8534876 DOI: 10.3390/cells10102726] [Citation(s) in RCA: 51] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 10/06/2021] [Accepted: 10/07/2021] [Indexed: 02/06/2023] Open
Abstract
Proteins of the actin depolymerizing factor (ADF)/cofilin family are ubiquitous among eukaryotes and are essential regulators of actin dynamics and function. Mammalian neurons express cofilin-1 as the major isoform, but ADF and cofilin-2 are also expressed. All isoforms bind preferentially and cooperatively along ADP-subunits in F-actin, affecting the filament helical rotation, and when either alone or when enhanced by other proteins, promotes filament severing and subunit turnover. Although self-regulating cofilin-mediated actin dynamics can drive motility without post-translational regulation, cells utilize many mechanisms to locally control cofilin, including cooperation/competition with other proteins. Newly identified post-translational modifications function with or are independent from the well-established phosphorylation of serine 3 and provide unexplored avenues for isoform specific regulation. Cofilin modulates actin transport and function in the nucleus as well as actin organization associated with mitochondrial fission and mitophagy. Under neuronal stress conditions, cofilin-saturated F-actin fragments can undergo oxidative cross-linking and bundle together to form cofilin-actin rods. Rods form in abundance within neurons around brain ischemic lesions and can be rapidly induced in neurites of most hippocampal and cortical neurons through energy depletion or glutamate-induced excitotoxicity. In ~20% of rodent hippocampal neurons, rods form more slowly in a receptor-mediated process triggered by factors intimately connected to disease-related dementias, e.g., amyloid-β in Alzheimer’s disease. This rod-inducing pathway requires a cellular prion protein, NADPH oxidase, and G-protein coupled receptors, e.g., CXCR4 and CCR5. Here, we will review many aspects of cofilin regulation and its contribution to synaptic loss and pathology of neurodegenerative diseases.
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Affiliation(s)
- James R. Bamburg
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
- Correspondence: ; Tel.: +1-970-988-9120; Fax: +1-970-491-0494
| | - Laurie S. Minamide
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
| | - O’Neil Wiggan
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
| | - Lubna H. Tahtamouni
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
- Department of Biology and Biotechnology, The Hashemite University, Zarqa 13115, Jordan
| | - Thomas B. Kuhn
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins, CO 80523, USA; (L.S.M.); (O.W.); (L.H.T.); (T.B.K.)
- Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, AK 99775, USA
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24
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MacTaggart B, Kashina A. Posttranslational modifications of the cytoskeleton. Cytoskeleton (Hoboken) 2021; 78:142-173. [PMID: 34152688 DOI: 10.1002/cm.21679] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2021] [Revised: 06/13/2021] [Accepted: 06/16/2021] [Indexed: 12/12/2022]
Abstract
The cytoskeleton plays important roles in many essential processes at the cellular and organismal levels, including cell migration and motility, cell division, and the establishment and maintenance of cell and tissue architecture. In order to facilitate these varied functions, the main cytoskeletal components-microtubules, actin filaments, and intermediate filaments-must form highly diverse intracellular arrays in different subcellular areas and cell types. The question of how this diversity is conferred has been the focus of research for decades. One key mechanism is the addition of posttranslational modifications (PTMs) to the major cytoskeletal proteins. This posttranslational addition of various chemical groups dramatically increases the complexity of the cytoskeletal proteome and helps facilitate major global and local cytoskeletal functions. Cytoskeletal proteins undergo many PTMs, most of which are not well understood. Recent technological advances in proteomics and cell biology have allowed for the in-depth study of individual PTMs and their functions in the cytoskeleton. Here, we provide an overview of the major PTMs that occur on the main structural components of the three cytoskeletal systems-tubulin, actin, and intermediate filament proteins-and highlight the cellular function of these modifications.
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Affiliation(s)
- Brittany MacTaggart
- School of Veterinary Medicine, Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Anna Kashina
- School of Veterinary Medicine, Department of Biomedical Sciences, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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25
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Functional Redundancy of Cyclase-Associated Proteins CAP1 and CAP2 in Differentiating Neurons. Cells 2021; 10:cells10061525. [PMID: 34204261 PMCID: PMC8234816 DOI: 10.3390/cells10061525] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2021] [Revised: 06/11/2021] [Accepted: 06/14/2021] [Indexed: 01/03/2023] Open
Abstract
Cyclase-associated proteins (CAPs) are evolutionary-conserved actin-binding proteins with crucial functions in regulating actin dynamics, the spatiotemporally controlled assembly and disassembly of actin filaments (F-actin). Mammals possess two family members (CAP1 and CAP2) with different expression patterns. Unlike most other tissues, both CAPs are expressed in the brain and present in hippocampal neurons. We recently reported crucial roles for CAP1 in growth cone function, neuron differentiation, and neuron connectivity in the mouse brain. Instead, CAP2 controls dendritic spine morphology and synaptic plasticity, and its dysregulation contributes to Alzheimer's disease pathology. These findings are in line with a model in which CAP1 controls important aspects during neuron differentiation, while CAP2 is relevant in differentiated neurons. We here report CAP2 expression during neuron differentiation and its enrichment in growth cones. We therefore hypothesized that CAP2 is relevant not only in excitatory synapses, but also in differentiating neurons. However, CAP2 inactivation neither impaired growth cone morphology and motility nor neuron differentiation. Moreover, CAP2 mutant mice did not display any obvious changes in brain anatomy. Hence, differently from CAP1, CAP2 was dispensable for neuron differentiation and brain development. Interestingly, overexpression of CAP2 rescued not only growth cone size in CAP1-deficient neurons, but also their morphology and differentiation. Our data provide evidence for functional redundancy of CAP1 and CAP2 in differentiating neurons, and they suggest compensatory mechanisms in single mutant neurons.
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26
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Zhang X, Pizzoni A, Hong K, Naim N, Qi C, Korkhov V, Altschuler DL. CAP1 binds and activates adenylyl cyclase in mammalian cells. Proc Natl Acad Sci U S A 2021; 118:e2024576118. [PMID: 34099549 PMCID: PMC8214675 DOI: 10.1073/pnas.2024576118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
CAP1 (Cyclase-Associated Protein 1) is highly conserved in evolution. Originally identified in yeast as a bifunctional protein involved in Ras-adenylyl cyclase and F-actin dynamics regulation, the adenylyl cyclase component seems to be lost in mammalian cells. Prompted by our recent identification of the Ras-like small GTPase Rap1 as a GTP-independent but geranylgeranyl-specific partner for CAP1, we hypothesized that CAP1-Rap1, similar to CAP-Ras-cyclase in yeast, might play a critical role in cAMP dynamics in mammalian cells. In this study, we report that CAP1 binds and activates mammalian adenylyl cyclase in vitro, modulates cAMP in live cells in a Rap1-dependent manner, and affects cAMP-dependent proliferation. Utilizing deletion and mutagenesis approaches, we mapped the interaction of CAP1-cyclase with CAP's N-terminal domain involving critical leucine residues in the conserved RLE motifs and adenylyl cyclase's conserved catalytic loops (e.g., C1a and/or C2a). When combined with a FRET-based cAMP sensor, CAP1 overexpression-knockdown strategies, and the use of constitutively active and negative regulators of Rap1, our studies highlight a critical role for CAP1-Rap1 in adenylyl cyclase regulation in live cells. Similarly, we show that CAP1 modulation significantly affected cAMP-mediated proliferation in an RLE motif-dependent manner. The combined study indicates that CAP1-cyclase-Rap1 represents a regulatory unit in cAMP dynamics and biology. Since Rap1 is an established downstream effector of cAMP, we advance the hypothesis that CAP1-cyclase-Rap1 represents a positive feedback loop that might be involved in cAMP microdomain establishment and localized signaling.
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Affiliation(s)
- Xuefeng Zhang
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Alejandro Pizzoni
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Kyoungja Hong
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Nyla Naim
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261
| | - Chao Qi
- Institute of Molecular Biology and Biophysics, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Volodymyr Korkhov
- Institute of Molecular Biology and Biophysics, Paul Scherrer Institute, 5232 Villigen PSI, Switzerland
| | - Daniel L Altschuler
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA 15261;
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27
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Kodera N, Abe H, Nguyen PDN, Ono S. Native cyclase-associated protein and actin from Xenopus laevis oocytes form a unique 4:4 complex with a tripartite structure. J Biol Chem 2021; 296:100649. [PMID: 33839148 PMCID: PMC8113726 DOI: 10.1016/j.jbc.2021.100649] [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: 10/01/2020] [Revised: 04/01/2021] [Accepted: 04/07/2021] [Indexed: 11/26/2022] Open
Abstract
Cyclase-associated protein (CAP) is a conserved actin-binding protein that regulates multiple aspects of actin dynamics, including polymerization, depolymerization, filament severing, and nucleotide exchange. CAP has been isolated from different cells and tissues in an equimolar complex with actin, and previous studies have shown that a CAP–actin complex contains six molecules each of CAP and actin. Intriguingly, here, we successfully isolated a complex of Xenopus cyclase-associated protein 1 (XCAP1) with actin from oocyte extracts, which contained only four molecules each of XCAP1 and actin. This XCAP1–actin complex remained stable as a single population of 340 kDa species during hydrodynamic analyses using gel filtration or analytical ultracentrifugation. Examination of the XCAP1–actin complex by high-speed atomic force microscopy revealed a tripartite structure: one middle globular domain and two globular arms. The two arms were observed in high and low states. The arms at the high state were spontaneously converted to the low state by dissociation of actin from the complex. However, when extra G-actin was added, the arms at the low state were converted to the high state. Based on the known structures of the N-terminal helical-folded domain and C-terminal CARP domain, we hypothesize that the middle globular domain corresponds to a tetramer of the N-terminal helical-folded domain of XCAP1 and that each arm in the high state corresponds to a heterotetramer containing a dimer of the C-terminal CARP domain of XCAP1 and two G-actin molecules. This novel configuration of a CAP–actin complex should help to understand how CAP promotes actin filament disassembly.
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Affiliation(s)
- Noriyuki Kodera
- WPI-Nano Life Science Institute, Kanazawa University, Kanazawa, Ishikawa, Japan
| | - Hiroshi Abe
- Department of Biology, Graduate School of Science, Chiba University, Chiba, Japan
| | | | - Shoichiro Ono
- Departments of Pathology and Cell Biology, Emory University School of Medicine, Atlanta, Georgia, USA; Winship Cancer Institute, Emory University School of Medicine, Atlanta, Georgia, USA.
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28
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Colpan M, Iwanski J, Gregorio CC. CAP2 is a regulator of actin pointed end dynamics and myofibrillogenesis in cardiac muscle. Commun Biol 2021; 4:365. [PMID: 33742108 PMCID: PMC7979805 DOI: 10.1038/s42003-021-01893-w] [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: 10/17/2020] [Accepted: 02/22/2021] [Indexed: 01/31/2023] Open
Abstract
The precise assembly of actin-based thin filaments is crucial for muscle contraction. Dysregulation of actin dynamics at thin filament pointed ends results in skeletal and cardiac myopathies. Here, we discovered adenylyl cyclase-associated protein 2 (CAP2) as a unique component of thin filament pointed ends in cardiac muscle. CAP2 has critical functions in cardiomyocytes as it depolymerizes and inhibits actin incorporation into thin filaments. Strikingly distinct from other pointed-end proteins, CAP2's function is not enhanced but inhibited by tropomyosin and it does not directly control thin filament lengths. Furthermore, CAP2 plays an essential role in cardiomyocyte maturation by modulating pre-sarcomeric actin assembly and regulating α-actin composition in mature thin filaments. Identification of CAP2's multifunctional roles provides missing links in our understanding of how thin filament architecture is regulated in striated muscle and it reveals there are additional factors, beyond Tmod1 and Lmod2, that modulate actin dynamics at thin filament pointed ends.
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Affiliation(s)
- Mert Colpan
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, USA
| | - Jessika Iwanski
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, USA
| | - Carol C Gregorio
- Department of Cellular and Molecular Medicine and Sarver Molecular Cardiovascular Research Program, The University of Arizona, Tucson, AZ, USA.
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29
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Hao Y, Yan G, Ma R, Hasan MT. Linking dynamic patterns of COVID-19 spreads in Italy with regional characteristics: a two level longitudinal modelling approach. MATHEMATICAL BIOSCIENCES AND ENGINEERING : MBE 2021; 18:2579-2598. [PMID: 33892561 DOI: 10.3934/mbe.2021131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
The current statistical modeling of coronavirus (COVID-19) spread has mainly focused on spreading patterns and forecasting of COVID-19 development; these patterns have been found to vary among locations. As the survival time of coronaviruses on surfaces depends on temperature, some researchers have explored the association of daily confirmed cases with environmental factors. Furthermore, some researchers have studied the link between daily fatality rates with regional factors such as health resources, but found no significant factors. As the spreading patterns of COVID-19 development vary a lot among locations, fitting regression models of daily confirmed cases or fatality rates directly with regional factors might not reveal important relationships. In this study, we investigate the link between regional spreading patterns of COVID-19 development in Italy and regional factors in two steps. First, we characterize regional spreading patterns of COVID-19 daily confirmed cases by a special patterned Poisson regression model for longitudinal count; the varying growth and declining patterns as well as turning points among regions in Italy have been well captured by regional regression parameters. We then associate these regional regression parameters with regional factors. The effects of regional factors on spreading patterns of COVID-19 daily confirmed cases have been effectively evaluated.
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Affiliation(s)
- Youtian Hao
- Department of Mathematics and Statistics, University of New Brunswick, P.O. Box 4400, Fredericton, NB, E3B 5A3, Canada
| | - Guohua Yan
- Department of Mathematics and Statistics, University of New Brunswick, P.O. Box 4400, Fredericton, NB, E3B 5A3, Canada
| | - Renjun Ma
- Department of Mathematics and Statistics, University of New Brunswick, P.O. Box 4400, Fredericton, NB, E3B 5A3, Canada
| | - M Tariqul Hasan
- Department of Mathematics and Statistics, University of New Brunswick, P.O. Box 4400, Fredericton, NB, E3B 5A3, Canada
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30
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Ulferts S, Prajapati B, Grosse R, Vartiainen MK. Emerging Properties and Functions of Actin and Actin Filaments Inside the Nucleus. Cold Spring Harb Perspect Biol 2021; 13:cshperspect.a040121. [PMID: 33288541 PMCID: PMC7919393 DOI: 10.1101/cshperspect.a040121] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Recent years have provided considerable insights into the dynamic nature of the cell nucleus, which is constantly reorganizing its genome, controlling its size and shape, as well as spatiotemporally orchestrating chromatin remodeling and transcription. Remarkably, it has become clear that the ancient and highly conserved cytoskeletal protein actin plays a crucial part in these processes. However, the underlying mechanisms, regulations, and properties of actin functions inside the nucleus are still not well understood. Here we summarize the diverse and distinct roles of monomeric and filamentous actin as well as the emerging roles for actin dynamics inside the nuclear compartment for genome organization and nuclear architecture.
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Affiliation(s)
- Svenja Ulferts
- Institute for Clinical and Experimental Pharmacology and Toxicology I, University of Freiburg, 79104 Freiburg, Germany
| | - Bina Prajapati
- Institute of Biotechnology, Helsinki Institute for Life Science, University of Helsinki, 00014 Helsinki, Finland
| | - Robert Grosse
- Institute for Clinical and Experimental Pharmacology and Toxicology I, University of Freiburg, 79104 Freiburg, Germany,Centre for Integrative Biological Signalling Studies (CIBSS), 79104 Freiburg, Germany
| | - Maria K. Vartiainen
- Institute of Biotechnology, Helsinki Institute for Life Science, University of Helsinki, 00014 Helsinki, Finland
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31
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Schneider R, Deutsch K, Hoeprich GJ, Marquez J, Hermle T, Braun DA, Seltzsam S, Kitzler TM, Mao Y, Buerger F, Majmundar AJ, Onuchic-Whitford AC, Kolvenbach CM, Schierbaum L, Schneider S, Halawi AA, Nakayama M, Mann N, Connaughton DM, Klämbt V, Wagner M, Riedhammer KM, Renders L, Katsura Y, Thumkeo D, Soliman NA, Mane S, Lifton RP, Shril S, Khokha MK, Hoefele J, Goode BL, Hildebrandt F. DAAM2 Variants Cause Nephrotic Syndrome via Actin Dysregulation. Am J Hum Genet 2020; 107:1113-1128. [PMID: 33232676 DOI: 10.1016/j.ajhg.2020.11.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/05/2020] [Indexed: 01/10/2023] Open
Abstract
The discovery of >60 monogenic causes of nephrotic syndrome (NS) has revealed a central role for the actin regulators RhoA/Rac1/Cdc42 and their effectors, including the formin INF2. By whole-exome sequencing (WES), we here discovered bi-allelic variants in the formin DAAM2 in four unrelated families with steroid-resistant NS. We show that DAAM2 localizes to the cytoplasm in podocytes and in kidney sections. Further, the variants impair DAAM2-dependent actin remodeling processes: wild-type DAAM2 cDNA, but not cDNA representing missense variants found in individuals with NS, rescued reduced podocyte migration rate (PMR) and restored reduced filopodia formation in shRNA-induced DAAM2-knockdown podocytes. Filopodia restoration was also induced by the formin-activating molecule IMM-01. DAAM2 also co-localizes and co-immunoprecipitates with INF2, which is intriguing since variants in both formins cause NS. Using in vitro bulk and TIRF microscopy assays, we find that DAAM2 variants alter actin assembly activities of the formin. In a Xenopus daam2-CRISPR knockout model, we demonstrate actin dysregulation in vivo and glomerular maldevelopment that is rescued by WT-DAAM2 mRNA. We conclude that DAAM2 variants are a likely cause of monogenic human SRNS due to actin dysregulation in podocytes. Further, we provide evidence that DAAM2-associated SRNS may be amenable to treatment using actin regulating compounds.
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32
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Labat-de-Hoz L, Alonso MA. The formin INF2 in disease: progress from 10 years of research. Cell Mol Life Sci 2020; 77:4581-4600. [PMID: 32451589 PMCID: PMC11104792 DOI: 10.1007/s00018-020-03550-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Revised: 05/04/2020] [Accepted: 05/13/2020] [Indexed: 02/07/2023]
Abstract
Formins are a conserved family of proteins that primarily act to form linear polymers of actin. Despite their importance to the normal functioning of the cytoskeleton, for a long time, the only two formin genes known to be a genetic cause of human disorders were DIAPH1 and DIAPH3, whose mutation causes two distinct forms of hereditary deafness. In the last 10 years, however, the formin INF2 has emerged as an important target of mutations responsible for the appearance of focal segmental glomerulosclerosis, which are histological lesions associated with glomerulus degeneration that often leads to end-stage renal disease. In some rare cases, focal segmental glomerulosclerosis concurs with Charcot-Marie-Tooth disease, which is a degenerative neurological disorder affecting peripheral nerves. All known INF2 gene mutations causing disease map to the exons encoding the amino-terminal domain. In this review, we summarize the structure, biochemical features and functions of INF2, conduct a systematic and comprehensive analysis of the pathogenic INF2 mutations, including a detailed study exon-by-exon of patient cases and mutations, address the impact of the pathogenic mutations on the structure, regulation and known functions of INF2, draw a series of conclusions that could be useful for INF2-related disease diagnosis, and suggest lines of research for future work on the molecular mechanisms by which INF2 causes disease.
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Affiliation(s)
- Leticia Labat-de-Hoz
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain
| | - Miguel A Alonso
- Centro de Biología Molecular Severo Ochoa, Consejo Superior de Investigaciones Científicas and Universidad Autónoma de Madrid, Madrid, Spain.
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33
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A M, Latario CJ, Pickrell LE, Higgs HN. Lysine acetylation of cytoskeletal proteins: Emergence of an actin code. J Biophys Biochem Cytol 2020; 219:211455. [PMID: 33044556 PMCID: PMC7555357 DOI: 10.1083/jcb.202006151] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2020] [Revised: 08/26/2020] [Accepted: 09/02/2020] [Indexed: 02/06/2023] Open
Abstract
Reversible lysine acetylation of nuclear proteins such as histones is a long-established important regulatory mechanism for chromatin remodeling and transcription. In the cytoplasm, acetylation of a number of cytoskeletal proteins, including tubulin, cortactin, and the formin mDia2, regulates both cytoskeletal assembly and stability. More recently, acetylation of actin itself was revealed to regulate cytoplasmic actin polymerization through the formin INF2, with downstream effects on ER-to-mitochondrial calcium transfer, mitochondrial fission, and vesicle transport. This finding raises the possibility that actin acetylation, along with other post-translational modifications to actin, might constitute an "actin code," similar to the "histone code" or "tubulin code," controlling functional shifts to these central cellular proteins. Given the multiple roles of actin in nuclear functions, its modifications might also have important roles in gene expression.
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34
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Rust MB, Khudayberdiev S, Pelucchi S, Marcello E. CAPt'n of Actin Dynamics: Recent Advances in the Molecular, Developmental and Physiological Functions of Cyclase-Associated Protein (CAP). Front Cell Dev Biol 2020; 8:586631. [PMID: 33072768 PMCID: PMC7543520 DOI: 10.3389/fcell.2020.586631] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Accepted: 08/26/2020] [Indexed: 12/11/2022] Open
Abstract
Cyclase-associated protein (CAP) has been discovered three decades ago in budding yeast as a protein that associates with the cyclic adenosine monophosphate (cAMP)-producing adenylyl cyclase and that suppresses a hyperactive RAS2 variant. Since that time, CAP has been identified in all eukaryotic species examined and it became evident that the activity in RAS-cAMP signaling is restricted to a limited number of species. Instead, its actin binding activity is conserved among eukaryotes and actin cytoskeleton regulation emerged as its primary function. However, for many years, the molecular functions as well as the developmental and physiological relevance of CAP remained unknown. In the present article, we will compile important recent progress on its molecular functions that identified CAP as a novel key regulator of actin dynamics, i.e., the spatiotemporally controlled assembly and disassembly of actin filaments (F-actin). These studies unraveled a cooperation with ADF/Cofilin and Twinfilin in F-actin disassembly, a nucleotide exchange activity on globular actin monomers (G-actin) that is required for F-actin assembly and an inhibitory function towards the F-actin assembly factor INF2. Moreover, by focusing on selected model organisms, we will review current literature on its developmental and physiological functions, and we will present studies implicating CAP in human pathologies. Together, this review article summarizes and discusses recent achievements in understanding the molecular, developmental and physiological functions of CAP, which led this protein emerge as a novel CAPt'n of actin dynamics.
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Affiliation(s)
- Marco B Rust
- Molecular Neurobiology Group, Institute of Physiological Chemistry, University of Marburg, Marburg, Germany.,DFG Research Training Group, Membrane Plasticity in Tissue Development and Remodeling, GRK 2213, University of Marburg, Marburg, Germany.,Center for Mind, Brain and Behavior, University of Marburg and Justus-Liebig-University Giessen, Giessen, Germany
| | - Sharof Khudayberdiev
- Molecular Neurobiology Group, Institute of Physiological Chemistry, University of Marburg, Marburg, Germany
| | - Silvia Pelucchi
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
| | - Elena Marcello
- Department of Pharmacological and Biomolecular Sciences, University of Milan, Milan, Italy
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