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Yang X, Wang Q, Xiao B, Wang Q, Deng W, Osherov N, Li R, Liu W. The cyclase-associated protein contributes to antifungal susceptibility and virulence in Aspergillus fumigatus. Emerg Microbes Infect 2025:2506795. [PMID: 40396792 DOI: 10.1080/22221751.2025.2506795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/22/2025]
Abstract
ABSTRACTAspergillus fumigatus is the most prevalent pathogenic mould that contributes to high morbidity and mortality in immunocompromised patients. Here, we characterized the functions of the cyclase-associated protein (CAP) in A. fumigatus. To study the role of CAP in virulence and antifungal susceptibility of A. fumigatus, CAP gene knockout strain (△CAP) and complemented strain (R-△CAP) were constructed. △CAP showed a reduced growth rate, abnormal hyphal development, and increased susceptibility to cell wall-perturbing agents (Congo red, calcofluor white, and SDS), oxidative stress-inducing agents (H2O2 and menadione), calcineurin inhibitors (FK506 and CsA), and voriconazole (VRC) and itraconazole. Transcriptome analysis revealed that differentially expressed genes responsible for regulating growth, hyphal development, cell wall synthesis, stress responses and antifungal susceptibility were identified in △CAP. To identify CAP-interacting proteins, an A. fumigatus strain expressing the CAP protein fused with a C-terminus 6×his tag was constructed and designated Afcap6his. After extracting Afcap6his and Af293 proteins, actin and adenylate cyclase were identified by coimmunoprecipitation (co-IP) and liquid chromatography-tandem mass spectrometry (LC-MS/MS). Additionally, △CAP showed downregulated actin expression, AC-cAMP-PKA pathway activity and efflux pump genes (AfuMDR1, AfuMDR2, AfuMDR3, AfuMDR4, and cdr1B) expression as well as increased calcineurin activity. By using an invasive pulmonary aspergillosis (IPA) murine model, △CAP exhibited attenuated virulence and increased VRC therapeutic efficiency. Thus, CAP plays an important role in regulating antifungal susceptibility and virulence of A. fumigatus.
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Affiliation(s)
- Xinyu Yang
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China
- National Clinical Research Center for Skin and Immune Diseases, Beijing, China
- Research Center for Medical Mycology, Peking University, Beijing, China
| | - Qian Wang
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China
- National Clinical Research Center for Skin and Immune Diseases, Beijing, China
- Research Center for Medical Mycology, Peking University, Beijing, China
| | - Binghan Xiao
- State Key Laboratory of Microbial Resources, Institute of Microbiology, Chinese Academy of Sciences, Beijing, China
| | - Qiqi Wang
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China
- National Clinical Research Center for Skin and Immune Diseases, Beijing, China
- Research Center for Medical Mycology, Peking University, Beijing, China
| | - Weiwei Deng
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China
- National Clinical Research Center for Skin and Immune Diseases, Beijing, China
- Research Center for Medical Mycology, Peking University, Beijing, China
| | - Nir Osherov
- Department of Clinical Microbiology and Immunology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Ruoyu Li
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China
- National Clinical Research Center for Skin and Immune Diseases, Beijing, China
- Research Center for Medical Mycology, Peking University, Beijing, China
| | - Wei Liu
- Department of Dermatology and Venerology, Peking University First Hospital, Beijing, China
- National Clinical Research Center for Skin and Immune Diseases, Beijing, China
- Research Center for Medical Mycology, Peking University, Beijing, China
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Bresinsky M, Goepferich A. Control of biomedical nanoparticle distribution and drug release in vivo by complex particle design strategies. Eur J Pharm Biopharm 2025; 208:114634. [PMID: 39826847 DOI: 10.1016/j.ejpb.2025.114634] [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: 10/16/2024] [Revised: 01/06/2025] [Accepted: 01/14/2025] [Indexed: 01/22/2025]
Abstract
The utilization of targeted nanoparticles as a selective drug delivery system is a powerful tool to increase the amount of active substance reaching the target site. This can increase therapeutic efficacy while reducing adverse drug effects. However, nanoparticles face several challenges: upon injection, the immediate adhesion of plasma proteins may mask targeting ligands, thereby diminishing the target cell selectivity. In addition, opsonization can lead to premature clearance and the widespread presence of receptors or enzymes limits the accuracy of target cell recognition. Nanoparticles may also suffer from endosomal entrapment, and controlled drug release can be hindered by premature burst release or insufficient particle retention at the target site. Various strategies have been developed to address these adverse events, such as the implementation of switchable particle properties, regulating the composition of the formed protein corona, or using click-chemistry based targeting approaches. This has resulted in increasingly complex particle designs, raising the question of whether this development actually improves the therapeutic efficacy in vivo. This review provides an overview of the challenges in targeted drug delivery and explores potential solutions described in the literature. Subsequently, appropriate strategies for the development of nanoparticular drug delivery concepts are discussed.
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Affiliation(s)
- Melanie Bresinsky
- Department of Pharmaceutical Technology, University of Regensburg 93053 Regensburg, Bavaria, Germany
| | - Achim Goepferich
- Department of Pharmaceutical Technology, University of Regensburg 93053 Regensburg, Bavaria, Germany.
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3
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Li YY, Murai K, Lyu J, Honda M. Roles Played by DOCK11, a Guanine Nucleotide Exchange Factor, in HBV Entry and Persistence in Hepatocytes. Viruses 2024; 16:745. [PMID: 38793626 PMCID: PMC11125634 DOI: 10.3390/v16050745] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2024] [Revised: 04/28/2024] [Accepted: 05/05/2024] [Indexed: 05/26/2024] Open
Abstract
HBV infection is challenging to cure due to the persistence of viral covalently closed circular viral DNA (cccDNA). The dedicator of cytokinesis 11 (DOCK11) is recognized as a guanine nucleotide exchange factor (GEF) for CDC42 that has been reported to be required for HBV persistence. DOCK11 is expressed in both the cytoplasm and nucleus of human hepatocytes and is functionally associated with retrograde trafficking proteins Arf-GAP with GTPase domain, ankyrin repeat, and pleckstrin homology domain-containing protein 2 (AGAP2), and ADP-ribosylation factor 1 (ARF1), together with the HBV capsid, in the trans-Golgi network (TGN). This opens an alternative retrograde trafficking route for HBV from early endosomes (EEs) to the TGN and then to the endoplasmic reticulum (ER), thereby avoiding lysosomal degradation. DOCK11 also facilitates the association of cccDNA with H3K4me3 and RNA Pol II for activating cccDNA transcription. In addition, DOCK11 plays a crucial role in the host DNA repair system, being essential for cccDNA synthesis. This function can be inhibited by 10M-D42AN, a novel DOCK11-binding peptide, leading to the suppression of HBV replication both in vitro and in vivo. Treatment with a combination of 10M-D42AN and entecavir may represent a promising therapeutic strategy for patients with chronic hepatitis B (CHB). Consequently, DOCK11 may be seen as a potential candidate molecule in the development of molecularly targeted drugs against CHB.
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Affiliation(s)
- Ying-Yi Li
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
| | - Kazuhisa Murai
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
| | - Junyan Lyu
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
| | - Masao Honda
- Department of Gastroenterology, Kanazawa University Graduate School of Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
- Department of Clinical Laboratory Medicine, Kanazawa University Graduate School of Health Medicine, 13-1, Takaramachi, Kanazawa 920-8640, Japan
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4
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Riachy L, Ferrand T, Chasserot-Golaz S, Galas L, Alexandre S, Montero-Hadjadje M. Advanced Imaging Approaches to Reveal Molecular Mechanisms Governing Neuroendocrine Secretion. Neuroendocrinology 2023; 113:107-119. [PMID: 34915491 DOI: 10.1159/000521457] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Accepted: 12/09/2021] [Indexed: 11/19/2022]
Abstract
Identification of the molecular mechanisms governing neuroendocrine secretion and resulting intercellular communication is one of the great challenges of cell biology to better understand organism physiology and neurosecretion disruption-related pathologies such as hypertension, neurodegenerative, or metabolic diseases. To visualize molecule distribution and dynamics at the nanoscale, many imaging approaches have been developed and are still emerging. In this review, we provide an overview of the pioneering studies using transmission electron microscopy, atomic force microscopy, total internal reflection microscopy, and super-resolution microscopy in neuroendocrine cells to visualize molecular mechanisms driving neurosecretion processes, including exocytosis and associated fusion pores, endocytosis and associated recycling vesicles, and protein-protein or protein-lipid interactions. Furthermore, the potential and the challenges of these different advanced imaging approaches for application in the study of neuroendocrine cell biology are discussed, aiming to guide researchers to select the best approach for their specific purpose around the crucial but not yet fully understood neurosecretion process.
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Affiliation(s)
- Lina Riachy
- Laboratoire de Différenciation et Communication Neuronale et Neuroendocrine, Institut de Recherche et d'Innovation Biomédicale de Normandie, Normandie University, UNIROUEN, INSERM, U1239, Rouen, France
| | - Thomas Ferrand
- Laboratoire de Différenciation et Communication Neuronale et Neuroendocrine, Institut de Recherche et d'Innovation Biomédicale de Normandie, Normandie University, UNIROUEN, INSERM, U1239, Rouen, France
| | - Sylvette Chasserot-Golaz
- Institut des Neurosciences Cellulaires et Intégratives, Centre National de la Recherche Scientifique, Strasbourg University, Strasbourg, France
| | - Ludovic Galas
- Normandie University, UNIROUEN, INSERM, PRIMACEN, Rouen, France
| | - Stéphane Alexandre
- Polymères, Biopolymères, Surfaces Laboratory, CNRS, Normandie University, UNIROUEN, UMR 6270, Rouen, France
| | - Maité Montero-Hadjadje
- Laboratoire de Différenciation et Communication Neuronale et Neuroendocrine, Institut de Recherche et d'Innovation Biomédicale de Normandie, Normandie University, UNIROUEN, INSERM, U1239, Rouen, France
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Pain C, Tolmie F, Wojcik S, Wang P, Kriechbaumer V. intER-ACTINg: the structure and dynamics of ER and actin are interlinked. J Microsc 2022. [PMID: 35985796 DOI: 10.1111/jmi.13139] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/09/2022] [Accepted: 08/10/2022] [Indexed: 11/30/2022]
Abstract
The actin cytoskeleton is the driver of gross ER remodelling and the movement and positioning of other membrane-bound organelles such as Golgi bodies. Rapid ER membrane remodelling is a feature of most plant cells and is important for normal cellular processes, including targeted secretion, immunity and signalling. Modifications to the actin cytoskeleton, through pharmacological agents such as Latrunculin B and phalloidin, or disruption of normal myosin function also affect ER structure and/or dynamics. Here, we investigate the impact of changes in the actin cytoskeleton on structure and dynamics on the ER as well as in return the impact of modified ER structure on the architecture of the actin cytoskeleton. By expressing actin markers that affect actin dynamics, or expressing of ER-shaping proteins that influence ER architecture, we found that the structure of ER-actin networks is closely inter-related; affecting one component is likely to have a direct effect on the other. Therefore, our results indicate that a complicated regulatory machinery and cross-talk between these two structures must exist in plants to co-ordinate the function of ER-actin network during multiple subcellular processes. In addition, when considering organelle structure and dynamics, the choice of actin marker is essential in preventing off-target organelle structure and dynamics modifications. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Charlotte Pain
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Frances Tolmie
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Stefan Wojcik
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
| | - Pengwei Wang
- Key Laboratory of Horticultural Plant Biology (Ministry of Education), College of Horticulture and Forestry Science, Huazhong Agricultural University, Wuhan, 430070, China
| | - Verena Kriechbaumer
- Plant Cell Biology, Department of Biological and Medical Sciences, Oxford Brookes University, Oxford, OX3 0BP, UK
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Kannan G, Saraswathi MS, Thangavelu R, Kumar PS, Bathrinath M, Uma S, Backiyarani S, Chandrasekar A, Ganapathi TR. Development of fusarium wilt resistant mutants of Musa spp. cv.Rasthali (AAB, Silk subgroup) and comparative proteomic analysis along with its wild type. PLANTA 2022; 255:80. [PMID: 35249170 DOI: 10.1007/s00425-022-03860-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2021] [Accepted: 02/16/2022] [Indexed: 06/14/2023]
Abstract
Induced mutagenesis using embryogenic cell suspension (ECS) explants with toxin based screening is an effective tool to create non-chimeral Fusarium wilt resistant mutants in banana. Global proteomics unravel the molecular mechanism behind resistance. Race 1 of Fusarium wilt is a serious threat to Musa spp. cv.Rasthali (AAB, Silk subgroup) which is a choice variety traditionally grown in most of the south East Asian countries. Resistant gene introgression into susceptible varieties through conventional breeding has several limitations and the predominant ones being sterility and long generation time. Under such circumstances, induced mutagenesis combined with toxin based in vitro screening remains as the viable alternative for the development of fusarium wilt resistant Rasthali. Therefore, induced mutagenesis was attempted by using ethylmethane sulfonate (EMS) in embryogenic cell suspension (ECS) of Rasthali followed by in vitro screening for fusarium wilt resistance using new generation toxins and pot screening through challenge inoculation with Foc race 1. This ultimately resulted in the identification of 15 resistant lines. Global proteomic analysis in one of the resistant mutant lines namely NRCBRM15 and its wild type revealed 37 proteins, of which 20 showed differential expression. Out of 20 proteins, nineteen were significantly abundant in NRCBRM15 and only one was abundant in wild Rasthali. A total of nine genes based on protein expression were further validated using quantitative real time polymerase chain reaction (qRT-PCR). Annotation results revealed that some of the genes namely Enolase, ATP synthase-alpha subunit, Actin 2, Actin 3,-glucanase, UTP-glucose-1-phosphate uridylyltransferase, Respiratory burst oxidase homolog, V type proton ATPase catalytic subunit A and DUF292 domain containing protein are involved in diverse functions such as carbohydrate metabolism, energy production, electron carrier, response to wounding, binding proteins, cytoskeleton organization, extracellular region, structural molecule and defense.
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Affiliation(s)
- Gandhi Kannan
- Crop Improvement Division, ICAR, National Research Centre for Banana, Thogamalai Road, Thayanur (post), Tiruchirappalli, Tamil Nadu, 620 102, India
| | - Marimuthu Somasundaram Saraswathi
- Crop Improvement Division, ICAR, National Research Centre for Banana, Thogamalai Road, Thayanur (post), Tiruchirappalli, Tamil Nadu, 620 102, India.
| | - Raman Thangavelu
- Crop Improvement Division, ICAR, National Research Centre for Banana, Thogamalai Road, Thayanur (post), Tiruchirappalli, Tamil Nadu, 620 102, India
| | - Parasuraman Subesh Kumar
- Crop Improvement Division, ICAR, National Research Centre for Banana, Thogamalai Road, Thayanur (post), Tiruchirappalli, Tamil Nadu, 620 102, India
| | - Murugesan Bathrinath
- Crop Improvement Division, ICAR, National Research Centre for Banana, Thogamalai Road, Thayanur (post), Tiruchirappalli, Tamil Nadu, 620 102, India
| | - Subbaraya Uma
- Crop Improvement Division, ICAR, National Research Centre for Banana, Thogamalai Road, Thayanur (post), Tiruchirappalli, Tamil Nadu, 620 102, India
| | - Suthanthiram Backiyarani
- Crop Improvement Division, ICAR, National Research Centre for Banana, Thogamalai Road, Thayanur (post), Tiruchirappalli, Tamil Nadu, 620 102, India
| | - Arumugam Chandrasekar
- Crop Improvement Division, ICAR, National Research Centre for Banana, Thogamalai Road, Thayanur (post), Tiruchirappalli, Tamil Nadu, 620 102, India
| | - Thumballi R Ganapathi
- Plant Cell Culture Technology Section Nuclear Agriculture and Biotechnology Division Bhabha Atomic Research Centre, Trombay, Mumbai, 400 085, India
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7
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Weichseldorfer M, Tagaya Y, Reitz M, DeVico AL, Latinovic OS. Identifying CCR5 coreceptor populations permissive for HIV-1 entry and productive infection: implications for in vivo studies. J Transl Med 2022; 20:39. [PMID: 35073923 PMCID: PMC8785515 DOI: 10.1186/s12967-022-03243-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/10/2022] [Indexed: 12/15/2022] Open
Abstract
Background The chemokine receptor CCR5 is the major coreceptor for HIV-1 cell entry. We previously observed that not all CCR5 mAbs reduce HIV-1 infection, suggesting that only some CCR5 populations are permissive for HIV-1 entry. This study aims to better understand the relevant conformational states of the cellular coreceptor, CCR5, involved in HIV entry. We hypothesized that CCR5 assumes multiple configurations during normal cycling on the plasma membrane, but only particular forms facilitate HIV-1 infection. Methods To this end, we quantified different CCR5 populations using six CCR5 monoclonal antibodies (mAbs) with different epitope specificities and visualized them with super-resolution microscopy. We quantified each surface CCR5 population before and after HIV-1 infection. Results Based on CCR5 conformational changes, down-modulation, and trafficking rates (internalization and recycling kinetics), we were able to distinguish among heterogeneous CCR5 populations and thus which populations might best be targeted to inhibit HIV-1 entry. We assume that a decreased surface presence of a particular CCR5 subpopulation following infection means that it has been internalized due to HIV-1 entry, and that it therefore represents a highly relevant target for future antiviral therapy strategies. Strikingly, this was most true for antibody CTC8, which targets the N-terminal region of CCR5 and blocks viral entry more efficiently than it blocks chemokine binding. Conclusions Defining the virus-host interactions responsible for HIV-1 transmission, including specific coreceptor populations capable of establishing de novo infections, is essential for the development of an HIV-1 vaccine. This study hopefully will facilitate further development of inhibitors to block CCR5 usage by HIV-1, as well as inform future HIV-1 vaccine design. Supplementary Information The online version contains supplementary material available at 10.1186/s12967-022-03243-8.
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Affiliation(s)
- Matthew Weichseldorfer
- Institute of Human Virology, School of Medicine, University of Maryland, 725 W. Lombard St., Baltimore, MD, 21201, USA
| | - Yutaka Tagaya
- Institute of Human Virology, School of Medicine, University of Maryland, 725 W. Lombard St., Baltimore, MD, 21201, USA.,Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Marvin Reitz
- Institute of Human Virology, School of Medicine, University of Maryland, 725 W. Lombard St., Baltimore, MD, 21201, USA.,Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Anthony L DeVico
- Institute of Human Virology, School of Medicine, University of Maryland, 725 W. Lombard St., Baltimore, MD, 21201, USA.,Department of Medicine, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA
| | - Olga S Latinovic
- Institute of Human Virology, School of Medicine, University of Maryland, 725 W. Lombard St., Baltimore, MD, 21201, USA. .,Department of Microbiology and Immunology, School of Medicine, University of Maryland, Baltimore, MD, 21201, USA.
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8
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Wang D, Ye Z, Wei W, Yu J, Huang L, Zhang H, Yue J. Capping protein regulates endosomal trafficking by controlling F-actin density around endocytic vesicles and recruiting RAB5 effectors. eLife 2021; 10:e65910. [PMID: 34796874 PMCID: PMC8654373 DOI: 10.7554/elife.65910] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Accepted: 11/18/2021] [Indexed: 12/30/2022] Open
Abstract
Actin filaments (F-actin) have been implicated in various steps of endosomal trafficking, and the length of F-actin is controlled by actin capping proteins, such as CapZ, which is a stable heterodimeric protein complex consisting of α and β subunits. However, the role of these capping proteins in endosomal trafficking remains elusive. Here, we found that CapZ docks to endocytic vesicles via its C-terminal actin-binding motif. CapZ knockout significantly increases the F-actin density around immature early endosomes, and this impedes fusion between these vesicles, manifested by the accumulation of small endocytic vesicles in CapZ-knockout cells. CapZ also recruits several RAB5 effectors, such as Rabaptin-5 and Rabex-5, to RAB5-positive early endosomes via its N-terminal domain, and this further activates RAB5. Collectively, our results indicate that CapZ regulates endosomal trafficking by controlling actin density around early endosomes and recruiting RAB5 effectors.
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Affiliation(s)
- Dawei Wang
- City University of Hong Kong Shenzhen Research InstituteShenzhenChina
- Department of Biomedical Sciences, City University of Hong KongHong KongChina
| | - Zuodong Ye
- City University of Hong Kong Shenzhen Research InstituteShenzhenChina
- Department of Biomedical Sciences, City University of Hong KongHong KongChina
| | - Wenjie Wei
- Core Research Facilities, Southern University of Science and TechnologyShenzhenChina
| | - Jingting Yu
- City University of Hong Kong Shenzhen Research InstituteShenzhenChina
| | - Lihong Huang
- City University of Hong Kong Shenzhen Research InstituteShenzhenChina
- Department of Biomedical Sciences, City University of Hong KongHong KongChina
| | - Hongmin Zhang
- Department of Biology, Guangdong Provincial Key Laboratory of Cell Microenvironment and Disease Research and Shenzhen Key Laboratory of Cell Microenvironment, Southern University of Science and TechnologyShenzhenChina
| | - Jianbo Yue
- City University of Hong Kong Shenzhen Research InstituteShenzhenChina
- Department of Biomedical Sciences, City University of Hong KongHong KongChina
- City University of Hong Kong Chengdu Research InstituteChengduChina
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9
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Tyler JJ, Smaczynska-de Rooij II, Abugharsa L, Palmer JS, Hancock LP, Allwood EG, Ayscough KR. Phosphorylation of the WH2 domain in yeast Las17/WASP regulates G-actin binding and protein function during endocytosis. Sci Rep 2021; 11:9718. [PMID: 33958621 PMCID: PMC8102491 DOI: 10.1038/s41598-021-88826-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Accepted: 04/12/2021] [Indexed: 11/29/2022] Open
Abstract
Actin nucleation is the key rate limiting step in the process of actin polymerization, and tight regulation of this process is critical to ensure actin filaments form only at specific times and at defined regions of the cell. WH2 domains are short sequence motifs found in many different actin binding proteins including WASP family proteins which regulate the actin nucleating complex Arp2/3. In this study we reveal a phosphorylation site, Serine 554, within the WH2 domain of the yeast WASP homologue Las17. Both phosphorylation and a phospho-mimetic mutation reduce actin monomer binding affinity while an alanine mutation, generated to mimic the non-phosphorylated state, increases actin binding affinity. The effect of these mutations on the Las17-dependent process of endocytosis in vivo was analysed and leads us to propose that switching of Las17 phosphorylation states may allow progression through distinct phases of endocytosis from site assembly through to the final scission stage. While the study is focused on Las17, the sole WASP family protein in yeast, our results have broad implications for our understanding of how a key residue in this conserved motif can underpin the many different actin regulatory roles with which WH2 domains have been associated.
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Affiliation(s)
- J J Tyler
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, S10 2TN, UK
| | - I I Smaczynska-de Rooij
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, S10 2TN, UK
| | - L Abugharsa
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, S10 2TN, UK
| | - J S Palmer
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, S10 2TN, UK
| | - L P Hancock
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, S10 2TN, UK
| | - E G Allwood
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, S10 2TN, UK
| | - K R Ayscough
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield, S10 2TN, UK.
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Gao Q, Yang JL, Zhao XR, Liu SC, Liu ZJ, Wei LJ, Hua Q. Yarrowia lipolytica as a Metabolic Engineering Platform for the Production of Very-Long-Chain Wax Esters. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2020; 68:10730-10740. [PMID: 32896122 DOI: 10.1021/acs.jafc.0c04393] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
The oleaginous yeast Yarrowia lipolytica is an attractive cell factory platform strain and can be used for sustainable production of high-value oleochemical products. Wax esters (WEs) have a good lubricating property and are usually used as a base for the production of advanced lubricants and emollient oils. In this study, we reported the metabolic engineering of Y. lipolytica to heterologously biosynthesize high-content very-long-chain fatty acids (VLCFAs) and fatty alcohols and efficiently esterify them to obtain very-long-chain WEs. Co-expression of fatty acid elongases from different sources in Y. lipolytica could yield VLCFAs with carbon chain lengths up to 24. Combining with optimization of the central metabolic modules could further enhance the biosynthesis of VLCFAs. Furthermore, through the screening of heterologous fatty acyl reductases (FARs), we enabled high-level production of fatty alcohols. Genomic integration and heterologous expression of wax synthase (WS) and FAR in a VLCFA-producing Y. lipolytica strain yielded 95-650 mg/L WEs with carbon chain lengths from 32 to 44. Scaled-up fermentation in 5 L laboratory bioreactors significantly increased the production of WEs to 2.0 g/L, the highest content so far in yeasts. This study contributes to the further efficient biosynthesis of VLCFAs and their derivatives.
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Affiliation(s)
- Qi Gao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Jing-Lin Yang
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Xin-Ru Zhao
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Shun-Cheng Liu
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Zhi-Jie Liu
- Key Laboratory of Fermentation Engineering (Ministry of Education), Hubei Key Laboratory of Industrial Microbiology, Hubei Collaborative Innovation Center of Industrial Fermentation, Hubei University of Technology, Wuhan 430068, P. R. China
| | - Liu-Jing Wei
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
| | - Qiang Hua
- State Key Laboratory of Bioreactor Engineering, East China University of Science and Technology, 130 Meilong Road, Shanghai 200237, P. R. China
- Shanghai Collaborative Innovation Center for Biomanufacturing Technology, 130 Meilong Road, Shanghai 200237, P. R. China
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11
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Fernández-Del-Río L, Kelly ME, Contreras J, Bradley MC, James AM, Murphy MP, Payne GS, Clarke CF. Genes and lipids that impact uptake and assimilation of exogenous coenzyme Q in Saccharomyces cerevisiae. Free Radic Biol Med 2020; 154:105-118. [PMID: 32387128 PMCID: PMC7611304 DOI: 10.1016/j.freeradbiomed.2020.04.029] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/26/2020] [Revised: 04/18/2020] [Accepted: 04/28/2020] [Indexed: 12/13/2022]
Abstract
Coenzyme Q (CoQ) is an essential player in the respiratory electron transport chain and is the only lipid-soluble antioxidant synthesized endogenously in mammalian and yeast cells. In humans, genetic mutations, pathologies, certain medical treatments, and aging, result in CoQ deficiencies, which are linked to mitochondrial, cardiovascular, and neurodegenerative diseases. The only strategy available for these patients is CoQ supplementation. CoQ supplements benefit a small subset of patients, but the poor solubility of CoQ greatly limits treatment efficacy. Consequently, the efficient delivery of CoQ to the mitochondria and restoration of respiratory function remains a major challenge. A better understanding of CoQ uptake and mitochondrial delivery is crucial to make this molecule a more efficient and effective therapeutic tool. In this study, we investigated the mechanism of CoQ uptake and distribution using the yeast Saccharomyces cerevisiae as a model organism. The addition of exogenous CoQ was tested for the ability to restore growth on non-fermentable medium in several strains that lack CoQ synthesis (coq mutants). Surprisingly, we discovered that the presence of CoQ biosynthetic intermediates impairs assimilation of CoQ into a functional respiratory chain in yeast cells. Moreover, a screen of 40 gene deletions considered to be candidates to prevent exogenous CoQ from rescuing growth of the CoQ-less coq2Δ mutant, identified six novel genes (CDC10, RTS1, RVS161, RVS167, VPS1, and NAT3) as necessary for efficient trafficking of CoQ to mitochondria. The proteins encoded by these genes represent essential steps in the pathways responsible for transport of exogenously supplied CoQ to its functional sites in the cell, and definitively associate CoQ distribution with endocytosis and intracellular vesicular trafficking pathways conserved from yeast to human cells.
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Affiliation(s)
- Lucía Fernández-Del-Río
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA
| | - Miranda E Kelly
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA
| | - Jaime Contreras
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA
| | - Michelle C Bradley
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA
| | - Andrew M James
- MRC Mitochondrial Biology Unit, University of Cambridge, UK
| | - Michael P Murphy
- MRC Mitochondrial Biology Unit, University of Cambridge, UK; Department of Medicine, University of Cambridge, UK
| | - Gregory S Payne
- Department of Biological Chemistry, David Geffen School of Medicine, University of California, Los Angeles, USA
| | - Catherine F Clarke
- Department of Chemistry and Biochemistry and the Molecular Biology Institute, University of California, Los Angeles, USA.
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12
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Donahue ND, Acar H, Wilhelm S. Concepts of nanoparticle cellular uptake, intracellular trafficking, and kinetics in nanomedicine. Adv Drug Deliv Rev 2019; 143:68-96. [PMID: 31022434 DOI: 10.1016/j.addr.2019.04.008] [Citation(s) in RCA: 574] [Impact Index Per Article: 95.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2019] [Revised: 04/14/2019] [Accepted: 04/19/2019] [Indexed: 12/12/2022]
Abstract
Nanoparticle-based therapeutics and diagnostics are commonly referred to as nanomedicine and may significantly impact the future of healthcare. However, the clinical translation of these technologies is challenging. One of these challenges is the efficient delivery of nanoparticles to specific cell populations and subcellular targets in the body to elicit desired biological and therapeutic responses. It is critical for researchers to understand the fundamental concepts of how nanoparticles interact with biological systems to predict and control in vivo nanoparticle transport for improved clinical benefit. In this overview article, we review and discuss cellular internalization pathways, summarize the field`s understanding of how nanoparticle physicochemical properties affect cellular interactions, and explore and discuss intracellular nanoparticle trafficking and kinetics. Our overview may provide a valuable resource for researchers and may inspire new studies to expand our current understanding of nanotechnology-biology interactions at cellular and subcellular levels with the goal to improve clinical translation of nanomedicines.
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Affiliation(s)
- Nathan D Donahue
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma 73019, United States
| | - Handan Acar
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma 73019, United States; Stephenson Cancer Center, Oklahoma City, Oklahoma 73104, United States.
| | - Stefan Wilhelm
- Stephenson School of Biomedical Engineering, University of Oklahoma, Norman, Oklahoma 73019, United States; Stephenson Cancer Center, Oklahoma City, Oklahoma 73104, United States.
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Cellular Uptake Mechanisms and Detection of Nanoparticle Uptake by Advanced Imaging Methods. BIOLOGICAL RESPONSES TO NANOSCALE PARTICLES 2019. [DOI: 10.1007/978-3-030-12461-8_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
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14
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Genth H, Junemann J, Lämmerhirt CM, Lücke AC, Schelle I, Just I, Gerhard R, Pich A. Difference in Mono-O-Glucosylation of Ras Subtype GTPases Between Toxin A and Toxin B From Clostridioides difficile Strain 10463 and Lethal Toxin From Clostridium sordellii Strain 6018. Front Microbiol 2018; 9:3078. [PMID: 30622517 PMCID: PMC6308379 DOI: 10.3389/fmicb.2018.03078] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 11/29/2018] [Indexed: 12/18/2022] Open
Abstract
Clostridioides difficile toxin A (TcdA) and Toxin B (TcdB) trigger inflammasome activation with caspase-1 activation in cultured cells, which in turn induce the release of IL-6, IFN-γ, and IL-8. Release of these proinflammatory responses is positively regulated by Ras-GTPases, which leads to the hypothesis that Ras glucosylation by glucosylating toxins results in (at least) reduced proinflammatory responses. Against this background, data on toxin-catalyzed Ras glucosylation are required to estimate of pro-inflammatory effect of the glucosylating toxins. In this study, a quantitative evaluation of the GTPase substrate profiles glucosylated in human colonic (Caco-2) cells treated with either TcdA, TcdB, or the related Clostridium sordellii lethal toxin (TcsL) was performed using multiple reaction monitoring (MRM) mass spectrometry. (H/K/N)Ras are presented to be glucosylated by TcsL and TcdA but by neither TcdB isoform tested. Furthermore, the glucosylation of (H/K/N)Ras was detected in TcdA-(not TcdB)-treated cells, as analyzed exploiting immunoblot analysis using the Ras glucosylation-sensitive 27H5 antibody. Furthermore, [14C]glucosylation of substrate GTPase was found to be increased in a cell-free system complemented with Caco-2 lysates. Under these conditions, (H/K/N)Ras glucosylation by TcdA was detected. In contrast, TcdB-catalyzed (H/K/N)Ras glucosylation was detected by neither MRM analysis, immunoblot analysis nor [14C]glucosylation in a cell-free system. The observation that TcdA (not TcdB) glucosylates Ras subtype GTPases correlates with the fact that TcdB (not TcdA) is primarily responsible for inflammatory responses in CDI. Finally, TcsL more efficaciously glucosylated Ras subtype GTPase as compared with TcdA, reinforcing the paradigm that TcsL is the prototype of a Ras glucosylating toxin.
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Affiliation(s)
- Harald Genth
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
| | | | | | | | - Ilona Schelle
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
| | - Ingo Just
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
| | - Ralf Gerhard
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
| | - Andreas Pich
- Institute of Toxicology, Hannover Medical School, Hanover, Germany
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15
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Grosjean N, Gross EM, Le Jean M, Blaudez D. Global Deletome Profile of Saccharomyces cerevisiae Exposed to the Technology-Critical Element Yttrium. Front Microbiol 2018; 9:2005. [PMID: 30233513 PMCID: PMC6131306 DOI: 10.3389/fmicb.2018.02005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Accepted: 08/08/2018] [Indexed: 11/14/2022] Open
Abstract
The emergence of the technology-critical-element yttrium as a contaminant in the environment raises concern regarding its toxicological impact on living organisms. The molecular mechanisms underlying yttrium toxicity must be delineated. We considered the genomic phenotyping of a mutant collection of Saccharomyces cerevisiae to be of particular interest to decipher key cellular pathways involved either in yttrium toxicity or detoxification mechanisms. Among the 4733 mutants exposed to yttrium, 333 exhibited modified growth, of which 56 were sensitive and 277 were resistant. Several functions involved in yttrium toxicity mitigation emerged, primarily vacuolar acidification and retrograde transport. Conversely, functional categories overrepresented in the yttrium toxicity response included cytoskeleton organization and endocytosis, protein transport and vesicle trafficking, lipid metabolism, as well as signaling pathways. Comparison with similar studies carried out using other metals and stressors showed a response pattern similar to nickel stress. One third of the identified mutants highlighted peculiar cellular effects triggered by yttrium, specifically those affecting the pheromone-dependent signaling pathway or sphingolipid metabolic processes. Taken together, these data emphasize the role of the plasma membrane as a hotspot for yttrium toxicity. The up-to-now lack of data concerning yttrium toxicity at the cellular and molecular levels makes this pioneer study using the model S. cerevisiae an excellent first basis for the assessment of yttrium toxicity toward eukaryotes.
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Affiliation(s)
- Nicolas Grosjean
- Université de Lorraine, CNRS, LIEC, Nancy, France.,Université de Lorraine, CNRS, LIEC, Metz, France
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16
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Lažetić V, Joseph BB, Bernazzani SM, Fay DS. Actin organization and endocytic trafficking are controlled by a network linking NIMA-related kinases to the CDC-42-SID-3/ACK1 pathway. PLoS Genet 2018; 14:e1007313. [PMID: 29608564 PMCID: PMC5897031 DOI: 10.1371/journal.pgen.1007313] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 04/12/2018] [Accepted: 03/19/2018] [Indexed: 01/07/2023] Open
Abstract
Molting is an essential process in the nematode Caenorhabditis elegans during which the epidermal apical extracellular matrix, termed the cuticle, is detached and replaced at each larval stage. The conserved NIMA-related kinases NEKL-2/NEK8/NEK9 and NEKL-3/NEK6/NEK7, together with their ankyrin repeat partners, MLT-2/ANKS6, MLT-3/ANKS3, and MLT-4/INVS, are essential for normal molting. In nekl and mlt mutants, the old larval cuticle fails to be completely shed, leading to entrapment and growth arrest. To better understand the molecular and cellular functions of NEKLs during molting, we isolated genetic suppressors of nekl molting-defective mutants. Using two independent approaches, we identified CDC-42, a conserved Rho-family GTPase, and its effector protein kinase, SID-3/ACK1. Notably, CDC42 and ACK1 regulate actin dynamics in mammals, and actin reorganization within the worm epidermis has been proposed to be important for the molting process. Inhibition of NEKL-MLT activities led to strong defects in the distribution of actin and failure to form molting-specific apical actin bundles. Importantly, this phenotype was reverted following cdc-42 or sid-3 inhibition. In addition, repression of CDC-42 or SID-3 also suppressed nekl-associated defects in trafficking, a process that requires actin assembly and disassembly. Expression analyses indicated that components of the NEKL-MLT network colocalize with both actin and CDC-42 in specific regions of the epidermis. Moreover, NEKL-MLT components were required for the normal subcellular localization of CDC-42 in the epidermis as well as wild-type levels of CDC-42 activation. Taken together, our findings indicate that the NEKL-MLT network regulates actin through CDC-42 and its effector SID-3. Interestingly, we also observed that downregulation of CDC-42 in a wild-type background leads to molting defects, suggesting that there is a fine balance between NEKL-MLT and CDC-42-SID-3 activities in the epidermis.
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Affiliation(s)
- Vladimir Lažetić
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY
| | - Braveen B. Joseph
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY
| | - Sarina M. Bernazzani
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY
| | - David S. Fay
- Department of Molecular Biology, College of Agriculture and Natural Resources, University of Wyoming, Laramie, WY
- * E-mail:
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17
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Endosomal Trafficking During Mitosis and Notch-Dependent Asymmetric Division. ENDOCYTOSIS AND SIGNALING 2018; 57:301-329. [DOI: 10.1007/978-3-319-96704-2_11] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
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18
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Chen K, Gu Y, Sun W, Bin Dong, Wang G, Fan X, Xia T, Fang N. Characteristic rotational behaviors of rod-shaped cargo revealed by automated five-dimensional single particle tracking. Nat Commun 2017; 8:887. [PMID: 29026088 PMCID: PMC5638882 DOI: 10.1038/s41467-017-01001-9] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2017] [Accepted: 08/09/2017] [Indexed: 01/03/2023] Open
Abstract
We report an automated single particle tracking technique for tracking the x, y, z coordinates, azimuthal and elevation angles of anisotropic plasmonic gold nanorod probes in live cells. These five spatial coordinates are collectively referred to as 5D. This method overcomes a long-standing challenge in distinguishing rotational motions from translational motions in the z-axis in differential interference contrast microscopy to result in full disclosure of nanoscale motions with high accuracy. Transferrin-coated endocytic gold nanorod cargoes initially undergo active rotational diffusion and display characteristic rotational motions on the membrane. Then as the cargoes being enclosed in clathrin-coated pits, they slow down the active rotation and experience a quiet period before they restore active rotational diffusion after fission and eventually being transported away from the original entry spots. Finally, the 3D trajectories and the accompanying rotational motions of the cargoes are resolved accurately to render the intracellular transport process in live cells.Distinguishing rotational motions from translational motions in the z-axis has been a long-standing challenge. Here the authors develop a five-dimensional single particle tracking method to detect rotational behaviors of nanocargos during clathrin-mediated endocytosis and intracellular transport.
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Affiliation(s)
- Kuangcai Chen
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
- Department of Chemistry, Iowa State University, Ames, IA, 50011, USA
| | - Yan Gu
- Department of Chemistry, Iowa State University, Ames, IA, 50011, USA
- The Bristol-Myers Squibb Company, Devens, MA, 01434, USA
| | - Wei Sun
- Department of Chemistry, Iowa State University, Ames, IA, 50011, USA
- Corning Inc., Painted Post, NY, 14870, USA
| | - Bin Dong
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA
- Department of Chemistry, Iowa State University, Ames, IA, 50011, USA
| | - Gufeng Wang
- Department of Chemistry, Iowa State University, Ames, IA, 50011, USA
- Department of Chemistry, North Carolina State University, Rayleigh, NC, 27695, USA
| | - Xinxin Fan
- Department of Electronics and Information Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China
| | - Tian Xia
- Department of Electronics and Information Engineering, Huazhong University of Science and Technology, Wuhan, 430074, China.
| | - Ning Fang
- Department of Chemistry, Georgia State University, Atlanta, GA, 30303, USA.
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19
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Sun H, Merrill D, An R, Turek J, Matei D, Nolte DD. Biodynamic imaging for phenotypic profiling of three-dimensional tissue culture. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:16007. [PMID: 28301634 PMCID: PMC5221565 DOI: 10.1117/1.jbo.22.1.016007] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 11/28/2016] [Indexed: 05/04/2023]
Abstract
Three-dimensional (3-D) tissue culture represents a more biologically relevant environment for testing new drugs compared to conventional two-dimensional cancer cell culture models. Biodynamic imaging is a high-content 3-D optical imaging technology based on low-coherence interferometry and digital holography that uses dynamic speckle as high-content image contrast to probe deep inside 3-D tissue. Speckle contrast is shown to be a scaling function of the acquisition time relative to the persistence time of intracellular transport and hence provides a measure of cellular activity. Cellular responses of 3-D multicellular spheroids to paclitaxel are compared among three different growth techniques: rotating bioreactor (BR), hanging-drop (HD), and nonadherent (U-bottom, UB) plate spheroids, compared with ex vivo living tissues. HD spheroids have the most homogeneous tissue, whereas BR spheroids display large sample-to-sample variability as well as spatial heterogeneity. The responses of BR-grown tumor spheroids to paclitaxel are more similar to those of ex vivo biopsies than the responses of spheroids grown using HD or plate methods. The rate of mitosis inhibition by application of taxol is measured through tissue dynamics spectroscopic imaging, demonstrating the ability to monitor antimitotic chemotherapy. These results illustrate the potential use of low-coherence digital holography for 3-D pharmaceutical screening applications.
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Affiliation(s)
- Hao Sun
- Purdue University, Department of Physics, 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States
| | - Daniel Merrill
- Purdue University, Department of Physics, 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States
| | - Ran An
- Animated Dynamics, Inc., 5770 Decatur Boulevard Suite A, Indianapolis, Indiana 46241, United States
| | - John Turek
- Purdue University, Department of Basic Medical Sciences, West Lafayette, 625 Harrison Street, Indiana 47907, United States
| | - Daniela Matei
- Northwestern University School of Medicine, 303 East SuperiorChicago, Illinois 60611, United States
| | - David D. Nolte
- Purdue University, Department of Physics, 525 Northwestern Avenue, West Lafayette, Indiana 47907, United States
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20
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Anjum NA, Rodrigo MAM, Moulick A, Heger Z, Kopel P, Zítka O, Adam V, Lukatkin AS, Duarte AC, Pereira E, Kizek R. Transport phenomena of nanoparticles in plants and animals/humans. ENVIRONMENTAL RESEARCH 2016; 151:233-243. [PMID: 27504871 DOI: 10.1016/j.envres.2016.07.018] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Revised: 07/12/2016] [Accepted: 07/13/2016] [Indexed: 06/06/2023]
Abstract
The interaction of a plethora nanoparticles with major biota such as plants and animals/humans has been the subject of various multidisciplinary studies with special emphasis on toxicity aspects. However, reports are meager on the transport phenomena of nanoparticles in the plant-animal/human system. Since plants and animals/humans are closely linked via food chain, discussion is imperative on the main processes and mechanisms underlying the transport phenomena of nanoparticles in the plant-animal/human system, which is the main objective of this paper. Based on the literature appraised herein, it is recommended to perform an exhaustive exploration of so far least explored aspects such as reproducibility, predictability, and compliance risks of nanoparticles, and insights into underlying mechanisms in context with their transport phenomenon in the plant-animal/human system. The outcomes of the suggested studies can provide important clues for fetching significant benefits of rapidly expanding nanotechnology to the plant-animal/human health-improvements and protection as well.
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Affiliation(s)
- Naser A Anjum
- CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal.
| | - Miguel Angel Merlos Rodrigo
- Department of Chemistry and Biochemistry, Laboratory of Metallomics and Nanotechnologies, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic
| | - Amitava Moulick
- Department of Chemistry and Biochemistry, Laboratory of Metallomics and Nanotechnologies, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic
| | - Zbynek Heger
- Department of Chemistry and Biochemistry, Laboratory of Metallomics and Nanotechnologies, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic
| | - Pavel Kopel
- Department of Chemistry and Biochemistry, Laboratory of Metallomics and Nanotechnologies, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic
| | - Ondřej Zítka
- Department of Chemistry and Biochemistry, Laboratory of Metallomics and Nanotechnologies, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
| | - Vojtech Adam
- Department of Chemistry and Biochemistry, Laboratory of Metallomics and Nanotechnologies, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic
| | - Alexander S Lukatkin
- Department of Botany, Physiology and Ecology of Plants, N.P. Ogarev Mordovia State University, Bolshevistskaja Str., 68, Saransk 430005, Russia
| | - Armando C Duarte
- CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Eduarda Pereira
- CESAM-Centre for Environmental and Marine Studies & Department of Chemistry, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Rene Kizek
- Department of Chemistry and Biochemistry, Laboratory of Metallomics and Nanotechnologies, Mendel University in Brno, Zemedelska 1, CZ-613 00 Brno, Czech Republic; Central European Institute of Technology, Brno University of Technology, Technicka 3058/10, CZ-616 00 Brno, Czech Republic.
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21
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Tyler JJ, Allwood EG, Ayscough KR. WASP family proteins, more than Arp2/3 activators. Biochem Soc Trans 2016; 44:1339-1345. [PMID: 27911716 PMCID: PMC5095904 DOI: 10.1042/bst20160176] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 07/14/2016] [Accepted: 07/21/2016] [Indexed: 01/19/2023]
Abstract
Wiskott-Aldrich syndrome protein (WASP) family proteins have been extensively characterized as factors that promote the nucleation of actin through the activation of the protein complex Arp2/3. While yeast mostly have a single member of the family, mammalian cells have at least six different members, often with multiple isoforms. Members of the family are characterized by a common structure. Their N-termini are varied and are considered to confer spatial and temporal regulation of Arp2/3-activating activity, whereas their C-terminal half contains a polyproline-rich region, one or more WASP homology-2 (WH2) actin-binding domains and motifs that bind directly to Arp2/3. Recent studies, however, indicate that the yeast WASP homologue Las17 is able to nucleate actin independently of Arp2/3 through the function of novel G-actin-binding activities in its polyproline region. This allows Las17 to generate the mother filaments that are needed for subsequent Arp2/3 recruitment and activation during the actin polymerization that drives endocytic invagination in yeast. In this review, we consider how motifs within the polyproline region of Las17 support nucleation of actin filaments, and whether similar mechanisms might exist among other family members.
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Affiliation(s)
- Joe J Tyler
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield S10 2TN, U.K
| | - Ellen G Allwood
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield S10 2TN, U.K
| | - Kathryn R Ayscough
- Department of Biomedical Science, Firth Court, University of Sheffield, Sheffield S10 2TN, U.K
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22
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Target shape dependence in a simple model of receptor-mediated endocytosis and phagocytosis. Proc Natl Acad Sci U S A 2016; 113:6113-8. [PMID: 27185939 DOI: 10.1073/pnas.1521974113] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Phagocytosis and receptor-mediated endocytosis are vitally important particle uptake mechanisms in many cell types, ranging from single-cell organisms to immune cells. In both processes, engulfment by the cell depends critically on both particle shape and orientation. However, most previous theoretical work has focused only on spherical particles and hence disregards the wide-ranging particle shapes occurring in nature, such as those of bacteria. Here, by implementing a simple model in one and two dimensions, we compare and contrast receptor-mediated endocytosis and phagocytosis for a range of biologically relevant shapes, including spheres, ellipsoids, capped cylinders, and hourglasses. We find a whole range of different engulfment behaviors with some ellipsoids engulfing faster than spheres, and that phagocytosis is able to engulf a greater range of target shapes than other types of endocytosis. Further, the 2D model can explain why some nonspherical particles engulf fastest (not at all) when presented to the membrane tip-first (lying flat). Our work reveals how some bacteria may avoid being internalized simply because of their shape, and suggests shapes for optimal drug delivery.
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23
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Porter K, Day B. From filaments to function: The role of the plant actin cytoskeleton in pathogen perception, signaling and immunity. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2016; 58:299-311. [PMID: 26514830 DOI: 10.1111/jipb.12445] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Accepted: 10/28/2015] [Indexed: 05/23/2023]
Abstract
The eukaryotic actin cytoskeleton is required for numerous cellular processes, including cell shape, development and movement, gene expression and signal transduction, and response to biotic and abiotic stress. In recent years, research in both plants and animal systems have described a function for actin as the ideal surveillance platform, linking the function and activity of primary physiological processes to the immune system. In this review, we will highlight recent advances that have defined the regulation and breadth of function of the actin cytoskeleton as a network required for defense signaling following pathogen infection. Coupled with an overview of recent work demonstrating specific targeting of the plant actin cytoskeleton by a diversity of pathogens, including bacteria, fungi and viruses, we will highlight the importance of actin as a key signaling hub in plants, one that mediates surveillance of cellular homeostasis and the activation of specific signaling responses following pathogen perception. Based on the studies highlighted herein, we propose a working model that posits changes in actin filament organization is in and of itself a highly specific signal, which induces, regulates and physically directs stimulus-specific signaling processes, most importantly, those associated with response to pathogens.
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Affiliation(s)
- Katie Porter
- Graduate Program in Cell and Molecular Biology, Michigan State University, East Lansing, MI, 48823, USA
| | - Brad Day
- Graduate Program in Cell and Molecular Biology, Michigan State University, East Lansing, MI, 48823, USA
- Department of Plant, Soil and Microbial Sciences, Michigan State University, East Lansing, MI, 48823, USA
- Graduate Program in Genetics, Michigan State University, East Lansing, MI, 48823, USA
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Smaczynska-de Rooij II, Marklew CJ, Allwood EG, Palmer SE, Booth WI, Mishra R, Goldberg MW, Ayscough KR. Phosphorylation Regulates the Endocytic Function of the Yeast Dynamin-Related Protein Vps1. Mol Cell Biol 2015; 36:742-55. [PMID: 26711254 PMCID: PMC4760221 DOI: 10.1128/mcb.00833-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2015] [Revised: 10/08/2015] [Accepted: 12/10/2015] [Indexed: 12/25/2022] Open
Abstract
The family of dynamin proteins is known to function in many eukaryotic membrane fusion and fission events. The yeast dynamin-related protein Vps1 functions at several stages of membrane trafficking, including Golgi apparatus to endosome and vacuole, peroxisomal fission, and endocytic scission. We have previously shown that in its endocytic role, Vps1 functions with the amphiphysin heterodimer Rvs161/Rvs167 to facilitate scission and release of vesicles. Phosphoproteome studies of Saccharomyces cerevisiae have identified a phosphorylation site in Vps1 at serine 599. In this study, we confirmed this phosphorylation event, and we reveal that, like Rvs167, Vps1 can be phosphorylated by the yeast cyclin-associated kinase Pho85 in vivo and in vitro. The importance of this posttranslational modification was revealed when mutagenesis of S599 to a phosphomimetic or nonphosphorylatable form caused defects in endocytosis but not in other functions associated with Vps1. Mutation to nonphosphorylatable valine inhibited the Rvs167 interaction, while both S599V and S599D caused defects in vesicle scission, as shown by both live-cell imaging and electron microscopy of endocytic invaginations. Our data support a model in which phosphorylation and dephosphorylation of Vps1 promote distinct interactions and highlight the importance of such regulatory events in facilitating sequential progression of the endocytic process.
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Affiliation(s)
| | - Christopher J Marklew
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Ellen G Allwood
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Sarah E Palmer
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Wesley I Booth
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
| | - Ritu Mishra
- School of Biological and Biomedical Sciences, Durham University, Durham, United Kingdom
| | - Martin W Goldberg
- School of Biological and Biomedical Sciences, Durham University, Durham, United Kingdom
| | - Kathryn R Ayscough
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
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25
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New Regulators of Clathrin-Mediated Endocytosis Identified in Saccharomyces cerevisiae by Systematic Quantitative Fluorescence Microscopy. Genetics 2015; 201:1061-70. [PMID: 26362318 DOI: 10.1534/genetics.115.180729] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2015] [Accepted: 09/07/2015] [Indexed: 11/18/2022] Open
Abstract
Despite the importance of clathrin-mediated endocytosis (CME) for cell biology, it is unclear if all components of the machinery have been discovered and many regulatory aspects remain poorly understood. Here, using Saccharomyces cerevisiae and a fluorescence microscopy screening approach we identify previously unknown regulatory factors of the endocytic machinery. We further studied the top scoring protein identified in the screen, Ubx3, a member of the conserved ubiquitin regulatory X (UBX) protein family. In vivo and in vitro approaches demonstrate that Ubx3 is a new coat component. Ubx3-GFP has typical endocytic coat protein dynamics with a patch lifetime of 45 ± 3 sec. Ubx3 contains a W-box that mediates physical interaction with clathrin and Ubx3-GFP patch lifetime depends on clathrin. Deletion of the UBX3 gene caused defects in the uptake of Lucifer Yellow and the methionine transporter Mup1 demonstrating that Ubx3 is needed for efficient endocytosis. Further, the UBX domain is required both for localization and function of Ubx3 at endocytic sites. Mechanistically, Ubx3 regulates dynamics and patch lifetime of the early arriving protein Ede1 but not later arriving coat proteins or actin assembly. Conversely, Ede1 regulates the patch lifetime of Ubx3. Ubx3 likely regulates CME via the AAA-ATPase Cdc48, a ubiquitin-editing complex. Our results uncovered new components of the CME machinery that regulate this fundamental process.
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26
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Rispal D, Eltschinger S, Stahl M, Vaga S, Bodenmiller B, Abraham Y, Filipuzzi I, Movva NR, Aebersold R, Helliwell SB, Loewith R. Target of Rapamycin Complex 2 Regulates Actin Polarization and Endocytosis via Multiple Pathways. J Biol Chem 2015; 290:14963-78. [PMID: 25882841 DOI: 10.1074/jbc.m114.627794] [Citation(s) in RCA: 63] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Indexed: 11/06/2022] Open
Abstract
Target of rapamycin is a Ser/Thr kinase that operates in two conserved multiprotein complexes, TORC1 and TORC2. Unlike TORC1, TORC2 is insensitive to rapamycin, and its functional characterization is less advanced. Previous genetic studies demonstrated that TORC2 depletion leads to loss of actin polarization and loss of endocytosis. To determine how TORC2 regulates these readouts, we engineered a yeast strain in which TORC2 can be specifically and acutely inhibited by the imidazoquinoline NVP-BHS345. Kinetic analyses following inhibition of TORC2, supported with quantitative phosphoproteomics, revealed that TORC2 regulates these readouts via distinct pathways as follows: rapidly through direct protein phosphorylation cascades and slowly through indirect changes in the tensile properties of the plasma membrane. The rapid signaling events are mediated in large part through the phospholipid flippase kinases Fpk1 and Fpk2, whereas the slow signaling pathway involves increased plasma membrane tension resulting from a gradual depletion of sphingolipids. Additional hits in our phosphoproteomic screens highlight the intricate control TORC2 exerts over diverse aspects of eukaryote cell physiology.
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Affiliation(s)
- Delphine Rispal
- From the Department of Molecular Biology and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211 Geneva
| | - Sandra Eltschinger
- From the Department of Molecular Biology and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211 Geneva
| | - Michael Stahl
- From the Department of Molecular Biology and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211 Geneva
| | - Stefania Vaga
- the Department of Biology, Institute of Molecular Systems Biology, ETH Zürich, 8093 Zürich
| | - Bernd Bodenmiller
- the Institute of Molecular Life Sciences, University of Zürich, 8057 Zürich
| | - Yann Abraham
- the Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel
| | - Ireos Filipuzzi
- the Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel
| | - N Rao Movva
- the Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel
| | - Ruedi Aebersold
- the Department of Biology, Institute of Molecular Systems Biology, ETH Zürich, 8093 Zürich, the Faculty of Science, University of Zürich, 8057 Zürich, and
| | - Stephen B Helliwell
- the Novartis Institutes for Biomedical Research, Novartis Campus, 4056 Basel,
| | - Robbie Loewith
- From the Department of Molecular Biology and Institute of Genetics and Genomics of Geneva (iGE3), University of Geneva, 1211 Geneva, the National Centre for Competence in Research Chemical Biology, 1211 Geneva, Switzerland
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27
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Ecologically Driven Competence for Exogenous DNA Uptake in Yeast. Curr Microbiol 2015; 70:883-93. [DOI: 10.1007/s00284-015-0808-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2014] [Accepted: 02/20/2015] [Indexed: 01/03/2023]
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28
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Palmer SE, Smaczynska-de Rooij II, Marklew CJ, Allwood EG, Mishra R, Johnson S, Goldberg MW, Ayscough KR. A dynamin-actin interaction is required for vesicle scission during endocytosis in yeast. Curr Biol 2015; 25:868-78. [PMID: 25772449 PMCID: PMC4386032 DOI: 10.1016/j.cub.2015.01.061] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 11/23/2014] [Accepted: 01/23/2015] [Indexed: 12/29/2022]
Abstract
Actin is critical for endocytosis in yeast cells, and also in mammalian cells under tension. However, questions remain as to how force generated through actin polymerization is transmitted to the plasma membrane to drive invagination and scission. Here, we reveal that the yeast dynamin Vps1 binds and bundles filamentous actin. Mutational analysis of Vps1 in a helix of the stalk domain identifies a mutant RR457-458EE that binds actin more weakly. In vivo analysis of Vps1 function demonstrates that the mutation disrupts endocytosis but not other functions of Vps1 such as vacuolar trafficking or peroxisome fission. The mutant Vps1 is stably expressed in cells and co-localizes with the endocytic reporters Abp1 and the amphiphysin Rvs167. Detailed analysis of individual endocytic patch behavior indicates that the mutation causes aberrant movements in later stages of endocytosis, consistent with a scission defect. Ultrastructural analysis of yeast cells using electron microscopy reveals a significant increase in invagination depth, further supporting a role for the Vps1-actin interaction during scission. In vitro analysis of the mutant protein demonstrates that--like wild-type Vps1--it is able to form oligomeric rings, but, critically, it has lost its ability to bundle actin filaments into higher-order structures. A model is proposed in which actin filaments bind Vps1 during invagination, and this interaction is important to transduce the force of actin polymerization to the membrane to drive successful scission.
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Affiliation(s)
- Sarah E Palmer
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK
| | | | | | - Ellen G Allwood
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK
| | - Ritu Mishra
- Department of Biological Science, Durham University, Durham DH1 3LE, UK
| | - Simeon Johnson
- Department of Biological Science, Durham University, Durham DH1 3LE, UK
| | - Martin W Goldberg
- Department of Biological Science, Durham University, Durham DH1 3LE, UK
| | - Kathryn R Ayscough
- Department of Biomedical Science, University of Sheffield, Sheffield S10 2TN, UK.
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29
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Grefner NM, Gromova LV, Gruzdkov AA, Komissarchik YY. Interaction of glucose transporters SGLT1 and GLUT2 with cytoskeleton in enterocytes and Caco2 cells during hexose absorption. ACTA ACUST UNITED AC 2015. [DOI: 10.1134/s1990519x15010034] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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30
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Pathways and Mechanisms of Yeast Competence: A New Frontier of Yeast Genetics. Fungal Biol 2015. [DOI: 10.1007/978-3-319-10142-2_22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
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31
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Souza LCK, Pinho REGG, Lima CVDP, Fragoso SP, Soares MJ. Actin expression in trypanosomatids (Euglenozoa: Kinetoplastea). Mem Inst Oswaldo Cruz 2014; 108:631-6. [PMID: 23903980 PMCID: PMC3970605 DOI: 10.1590/0074-0276108052013015] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 02/26/2013] [Indexed: 11/23/2022] Open
Abstract
Heteroxenic and monoxenic trypanosomatids were screened for the
presence of actin using a mouse polyclonal antibody produced against the entire
sequence of the Trypanosoma cruzi actin gene, encoding a 41.9
kDa protein. Western blot analysis showed that this antibody reacted with a
polypeptide of approximately 42 kDa in the whole-cell lysates of parasites
targeting mammals (T. cruzi, Trypanosoma
brucei and Leishmania major), insects
(Angomonas deanei, Crithidia fasciculata,
Herpetomonas samuelpessoai and Strigomonas
culicis) and plants (Phytomonas serpens). A single
polypeptide of approximately 42 kDa was detected in the whole-cell lysates of
T. cruzi cultured epimastigotes, metacyclic trypomastigotes
and amastigotes at similar protein expression levels. Confocal microscopy showed
that actin was expressed throughout the cytoplasm of all the tested
trypanosomatids. These data demonstrate that actin expression is widespread in
trypanosomatids.
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32
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Yameen B, Choi WI, Vilos C, Swami A, Shi J, Farokhzad OC. Insight into nanoparticle cellular uptake and intracellular targeting. J Control Release 2014; 190:485-99. [PMID: 24984011 PMCID: PMC4153400 DOI: 10.1016/j.jconrel.2014.06.038] [Citation(s) in RCA: 541] [Impact Index Per Article: 49.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Revised: 06/20/2014] [Accepted: 06/21/2014] [Indexed: 12/27/2022]
Abstract
Collaborative efforts from the fields of biology, materials science, and engineering are leading to exciting progress in the development of nanomedicines. Since the targets of many therapeutic agents are localized in subcellular compartments, modulation of nanoparticle-cell interactions for efficient cellular uptake through the plasma membrane and the development of nanomedicines for precise delivery to subcellular compartments remain formidable challenges. Cellular internalization routes determine the post-internalization fate and intracellular localization of nanoparticles. This review highlights the cellular uptake routes most relevant to the field of non-targeted nanomedicine and presents an account of ligand-targeted nanoparticles for receptor-mediated cellular internalization as a strategy for modulating the cellular uptake of nanoparticles. Ligand-targeted nanoparticles have been the main impetus behind the progress of nanomedicines towards the clinic. This strategy has already resulted in remarkable progress towards effective oral delivery of nanomedicines that can overcome the intestinal epithelial barrier. A detailed overview of the recent developments in subcellular targeting as a novel platform for next-generation organelle-specific nanomedicines is also provided. Each section of the review includes prospects, potential, and concrete expectations from the field of targeted nanomedicines and strategies to meet those expectations.
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Affiliation(s)
- Basit Yameen
- Laboratory of Nanomedicine and Biomaterials, Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA
| | - Won Il Choi
- Laboratory of Nanomedicine and Biomaterials, Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA
| | - Cristian Vilos
- Laboratory of Nanomedicine and Biomaterials, Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA; Universidad Andres Bello, Facultad de Medicina, Center for Integrative Medicine and Innovative Science (CIMIS), Echaurren 183, Santiago, Chile
| | - Archana Swami
- Laboratory of Nanomedicine and Biomaterials, Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA
| | - Jinjun Shi
- Laboratory of Nanomedicine and Biomaterials, Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA
| | - Omid C Farokhzad
- Laboratory of Nanomedicine and Biomaterials, Department of Anesthesiology, Brigham and Women's Hospital, Harvard Medical School, 75 Francis St., Boston, MA 02115, USA; King Abdulaziz University, Jeddah, Saudi Arabia.
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33
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Sattlegger E, Chernova TA, Gogoi NM, Pillai IV, Chernoff YO, Munn AL. Yeast studies reveal moonlighting functions of the ancient actin cytoskeleton. IUBMB Life 2014; 66:538-45. [PMID: 25138357 DOI: 10.1002/iub.1294] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2014] [Accepted: 07/21/2014] [Indexed: 11/12/2022]
Abstract
Classic functions of the actin cytoskeleton include control of cell size and shape and the internal organization of cells. These functions are manifest in cellular processes of fundamental importance throughout biology such as the generation of cell polarity, cell migration, cell adhesion, and cell division. However, studies in the unicellular model eukaryote Saccharomyces cerevisiae (Baker's yeast) are giving insights into other functions in which the actin cytoskeleton plays a critical role. These include endocytosis, control of protein translation, and determination of protein 3-dimensional shape (especially conversion of normal cellular proteins into prions). Here, we present a concise overview of these new "moonlighting" roles for the actin cytoskeleton and how some of these roles might lie at the heart of important molecular switches. This is an exciting time for researchers interested in the actin cytoskeleton. We show here how studies of actin are leading us into many new and exciting realms at the interface of genetics, biochemistry, and cell biology. While many of the pioneering studies have been conducted using yeast, the conservation of the actin cytoskeleton and its component proteins throughout eukaryotes suggests that these new roles for the actin cytoskeleton may not be restricted to yeast cells but rather may reflect new roles for the actin cytoskeleton of all eukaryotes.
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Affiliation(s)
- Evelyn Sattlegger
- Institute of Natural and Mathematical Sciences, Massey University, Albany, New Zealand
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34
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Encinar del Dedo J, Idrissi FZ, Arnáiz-Pita Y, James M, Dueñas-Santero E, Orellana-Muñoz S, del Rey F, Sirotkin V, Geli MI, Vázquez de Aldana CR. Eng2 is a component of a dynamic protein complex required for endocytic uptake in fission yeast. Traffic 2014; 15:1122-42. [PMID: 25040903 DOI: 10.1111/tra.12198] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 07/14/2014] [Accepted: 07/14/2014] [Indexed: 11/29/2022]
Abstract
Eng2 is a glucanase required for spore release, although it is also expressed during vegetative growth, suggesting that it might play other cellular functions. Its homology to the Saccharomyces cerevisiae Acf2 protein, previously shown to promote actin polymerization at endocytic sites in vitro, prompted us to investigate its role in endocytosis. Interestingly, depletion of Eng2 caused profound defects in endocytic uptake, which were not due to the absence of its glucanase activity. Analysis of the dynamics of endocytic proteins by fluorescence microscopy in the eng2Δ strain unveiled a previously undescribed phenotype, in which assembly of the Arp2/3 complex appeared uncoupled from the internalization of the endocytic coat and resulted in a fission defect. Strikingly also, we found that Eng2-GFP dynamics did not match the pattern of other endocytic proteins. Eng2-GFP localized to bright cytosolic spots that moved around the cellular poles and occasionally contacted assembling endocytic patches just before recruitment of Wsp1, the Schizosaccharomyces pombe WASP. Interestingly, Csh3-YFP, a WASP-interacting protein, interacted with Eng2 by co-immunoprecipitation and was recruited to Eng2 in bright cytosolic spots. Altogether, our work defines a novel endocytic functional module, which probably couples the endocytic coat to the actin module.
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Affiliation(s)
- Javier Encinar del Dedo
- Instituto de Biología Funcional y Genómica, CSIC/Universidad de Salamanca, c/ Zacarías González 2, 37007, Salamanca, Spain
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35
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Aghamohammadzadeh S, Smaczynska-de Rooij II, Ayscough KR. An Abp1-dependent route of endocytosis functions when the classical endocytic pathway in yeast is inhibited. PLoS One 2014; 9:e103311. [PMID: 25072293 PMCID: PMC4114835 DOI: 10.1371/journal.pone.0103311] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2014] [Accepted: 06/30/2014] [Indexed: 12/04/2022] Open
Abstract
Clathrin-mediated endocytosis (CME) is a well characterized pathway in both yeast and mammalian cells. An increasing number of alternative endocytic pathways have now been described in mammalian cells that can be both clathrin, actin, and Arf6- dependent or independent. In yeast, a single clathrin-mediated pathway has been characterized in detail. However, disruption of this pathway in many mutant strains indicates that other uptake pathways might exist, at least for bulk lipid and fluid internalization. Using a combination of genetics and live cell imaging, here we show evidence for a novel endocytic pathway in S. cerevisiae that does not involve several of the proteins previously shown to be associated with the ‘classic’ pathway of endocytosis. This alternative pathway functions in the presence of low levels of the actin-disrupting drug latrunculin-A which inhibits movement of the proteins Sla1, Sla2, and Sac6, and is independent of dynamin function. We reveal that in the absence of the ‘classic’ pathway, the actin binding protein Abp1 is now essential for bulk endocytosis. This novel pathway appears to be distinct from another described alternative endocytic route in S. cerevisiae as it involves at least some proteins known to be associated with cortical actin patches rather than being mediated at formin-dependent endocytic sites. These data indicate that cells have the capacity to use overlapping sets of components to facilitate endocytosis under a range of conditions.
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Affiliation(s)
| | | | - Kathryn R. Ayscough
- Department of Biomedical Science, University of Sheffield, Sheffield, United Kingdom
- * E-mail:
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36
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37
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Yang JA, Lohse SE, Murphy CJ. Tuning cellular response to nanoparticles via surface chemistry and aggregation. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:1642-1651. [PMID: 24323847 DOI: 10.1002/smll.201302835] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/30/2013] [Revised: 10/03/2013] [Indexed: 05/28/2023]
Abstract
The aggregation of gold nanoparticles (Au NPs) in cell media is a common phenomenon that can influence NP-cell interactions. Here, we control Au NP aggregation in cell media and study the impact of Au NP aggregation on human dermal fibroblast (HDF) cells. By first adding Au NPs to fetal bovine serum (FBS) and then subsequently to a buffer, aggregation can be avoided. Aggregation of Au NPs also can be avoided by coating Au NPs with other biomolecules such as lipids. The aggregation state of the Au NPs influences cellular toxicity and Au NP uptake: non-aggregated cationic Au NPs are four-fold less toxic to HDF cells than aggregated cationic Au NPs, and the uptake of non-aggregated anionic citrate Au NPs is three orders of magnitude less than that of aggregated citrate Au NPs. Upon uptake of Au NPs, cellular F-actin fiber formation is disrupted and actin dots are predominant. When lipid-coated Au NPs are doped with a fluorescent lipid (F-lipid) and incubated with HDF cells, the fluorescence from the F-lipid was found throughout the cell, showing that lipids can dissociate from the Au NP surface upon entering the cell.
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Affiliation(s)
- Jie An Yang
- Department of Chemistry, University of Illinois at Urbana-Champaign, 600 S. Mathews Avenue, Urbana, IL, 61801, USA
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38
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Briguglio JS, Turkewitz AP. Tetrahymena thermophila: a divergent perspective on membrane traffic. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2014; 322:500-16. [PMID: 24634411 DOI: 10.1002/jez.b.22564] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Revised: 01/13/2014] [Accepted: 01/22/2014] [Indexed: 12/12/2022]
Abstract
Tetrahymena thermophila, a member of the Ciliates, represents a class of organisms distantly related from commonly used model organisms in cell biology, and thus offers an opportunity to explore potentially novel mechanisms and their evolution. Ciliates, like all eukaryotes, possess a complex network of organelles that facilitate both macromolecular uptake and secretion. The underlying endocytic and exocytic pathways are key mediators of a cell's interaction with its environment, and may therefore show niche-specific adaptations. Our laboratory has taken a variety of approaches to identify key molecular determinants for membrane trafficking pathways in Tetrahymena. Studies of Rab GTPases, dynamins, and sortilin-family receptors substantiate the widespread conservation of some features but also uncover surprising roles for lineage-restricted innovation.
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Affiliation(s)
- Joseph S Briguglio
- The Department of Molecular Genetics and Cell Biology, The University of Chicago, Chicago, Illinois
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39
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Flegler AJ, Cianci GC, Hope TJ. CCR5 conformations are dynamic and modulated by localization, trafficking and G protein association. PLoS One 2014; 9:e89056. [PMID: 24586501 PMCID: PMC3938464 DOI: 10.1371/journal.pone.0089056] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2013] [Accepted: 01/15/2014] [Indexed: 11/19/2022] Open
Abstract
CCR5 acts as the principal coreceptor during HIV-1 transmission and early stages of infection. Efficient HIV-1 entry requires a series of processes, many dependent on the conformational state of both viral envelope protein and cellular receptor. Monoclonal antibodies (MAbs) are able to identify different CCR5 conformations, allowing for their use as probes to distinguish CCR5 populations. Not all CCR5 MAbs are able to reduce HIV-1 infection, suggesting the use of select CCR5 populations for entry. In the U87.CD4.CCR5-GFP cell line, we used such HIV-1-restricting MAbs to probe the relation between localization, trafficking and G protein association for individual CCR5 conformations. We find that CCR5 conformations not only exhibit different localization and abundance patterns throughout the cell, but that they also display distinct sensitivities to endocytosis inhibition. Using chemokine analogs that vary in their HIV-1 inhibitory mechanisms, we also illustrate that responses to ligand engagement are conformation-specific. Additionally, we provide supporting evidence for the select sensitivity of conformations to G protein association. Characterizing the link between the function and dynamics of CCR5 populations has implications for understanding their selective targeting by HIV-1 and for the development of inhibitors that will block CCR5 utilization by the virus.
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Affiliation(s)
- Ayanna J. Flegler
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Gianguido C. Cianci
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
| | - Thomas J. Hope
- Department of Cell and Molecular Biology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, United States of America
- * E-mail:
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40
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Kaur S, Fielding AB, Gassner G, Carter NJ, Royle SJ. An unmet actin requirement explains the mitotic inhibition of clathrin-mediated endocytosis. eLife 2014; 3:e00829. [PMID: 24550251 PMCID: PMC3924242 DOI: 10.7554/elife.00829] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Clathrin-mediated endocytosis (CME) is the major internalisation route for many different receptor types in mammalian cells. CME is shut down during early mitosis, but the mechanism of this inhibition is unclear. In this study, we show that the mitotic shutdown is due to an unmet requirement for actin in CME. In mitotic cells, membrane tension is increased and this invokes a requirement for the actin cytoskeleton to assist the CME machinery to overcome the increased load. However, the actin cytoskeleton is engaged in the formation of a rigid cortex in mitotic cells and is therefore unavailable for deployment. We demonstrate that CME can be ‘restarted’ in mitotic cells despite high membrane tension, by allowing actin to engage in endocytosis. Mitotic phosphorylation of endocytic proteins is maintained in mitotic cells with restored CME, indicating that direct phosphorylation of the CME machinery does not account for shutdown. DOI:http://dx.doi.org/10.7554/eLife.00829.001 The plasma membrane that surrounds a cell acts as a protective barrier that regulates what can enter or exit the cell. However, large molecules and other ‘cargo’ can get into a cell in a variety of ways. One of these routes—known as clathrin-mediated endocytosis—involves a receptor on the outside of the membrane grabbing hold of the cargo while a protein called clathrin forms a ‘pit’ beneath the receptor. This pit becomes deeper and deeper until the cargo is completely surrounded by clathrin-lined membrane and is brought inside the cell. This process has been studied over the past 50 years, and it is known that clathrin-mediated endocytosis is turned off when a cell begins to divide to produce new cells, and then turned back on when cell division has come to an end. However, there are competing theories as to exactly why this process stops when cell division starts. Now, Kaur et al. have investigated these theories by looking at the role that another protein, called actin, plays in turning off clathrin-mediated endocytosis. Actin is a molecule that forms a sort of scaffolding within the cell (called the cytoskeleton), and it also guides the movement of molecules and larger structures within the cell. Further, when the cell membrane is being stretched, the actin cytoskeleton can assist the clathrin-mediated endocytosis machinery to pull cargo into the cell. So why doesn’t actin help with endocytosis during cell division? The answer, Kaur et al. suggest, is that all the actin in the cell is needed by the cytoskeleton during cell division, so there is no actin available to perform other tasks such as clathrin-mediated endocytosis. Further experiments demonstrated that this form of endocytosis can be ‘restarted’ in dividing cells by treating the cells in a way that frees up some additional actin. The work of Kaur et al. also ruled out the theory that chemical changes to the endocytosis machinery disabled it during cell division. These findings have implications for the delivery of drugs, via endocytosis, to the rapidly dividing cells that are involved in diseases such as cancer. DOI:http://dx.doi.org/10.7554/eLife.00829.002
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Affiliation(s)
- Satdip Kaur
- Division of Biomedical Cell Biology, Warwick Medical School, University of Warwick, Coventry, United Kingdom
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41
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Abstract
Yeast and other walled cells possess high internal turgor pressure that allows them to grow and survive in the environment. This turgor pressure, however, may oppose the invagination of the plasma membrane needed for endocytosis. Here we study the effects of turgor pressure on endocytosis in the fission yeast Schizosaccharomyces pombe by time-lapse imaging of individual endocytic sites. Decreasing effective turgor pressure by addition of sorbitol to the media significantly accelerates early steps in the endocytic process before actin assembly and membrane ingression but does not affect the velocity or depth of ingression of the endocytic pit in wild-type cells. Sorbitol also rescues endocytic ingression defects of certain endocytic mutants and of cells treated with a low dose of the actin inhibitor latrunculin A. Endocytosis proceeds after removal of the cell wall, suggesting that the cell wall does not contribute mechanically to this process. These studies suggest that endocytosis is governed by a mechanical balance between local actin-dependent inward forces and opposing forces from high internal turgor pressure on the plasma membrane.
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Affiliation(s)
- Roshni Basu
- Department of Microbiology and Immunology, Columbia University College of Physicians and Surgeons, New York, NY 10032
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42
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Montefusco DJ, Matmati N, Hannun YA. The yeast sphingolipid signaling landscape. Chem Phys Lipids 2014; 177:26-40. [PMID: 24220500 PMCID: PMC4211598 DOI: 10.1016/j.chemphyslip.2013.10.006] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Revised: 10/18/2013] [Accepted: 10/19/2013] [Indexed: 12/13/2022]
Abstract
Sphingolipids are recognized as signaling mediators in a growing number of pathways, and represent potential targets to address many diseases. The study of sphingolipid signaling in yeast has created a number of breakthroughs in the field, and has the potential to lead future advances. The aim of this article is to provide an inclusive view of two major frontiers in yeast sphingolipid signaling. In the first section, several key studies in the field of sphingolipidomics are consolidated to create a yeast sphingolipidome that ranks nearly all known sphingolipid species by their level in a resting yeast cell. The second section presents an overview of most known phenotypes identified for sphingolipid gene mutants, presented with the intention of illuminating not yet discovered connections outside and inside of the field.
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Affiliation(s)
- David J Montefusco
- Dept. Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC, United States.
| | - Nabil Matmati
- Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, United States
| | - Yusuf A Hannun
- Stony Brook Cancer Center, Stony Brook University, Stony Brook, NY, United States.
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43
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Tuo S, Nakashima K, Pringle JR. Role of endocytosis in localization and maintenance of the spatial markers for bud-site selection in yeast. PLoS One 2013; 8:e72123. [PMID: 24039741 PMCID: PMC3764181 DOI: 10.1371/journal.pone.0072123] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2013] [Accepted: 07/06/2013] [Indexed: 11/19/2022] Open
Abstract
The yeast Saccharomyces cerevisiae normally selects bud sites (and hence axes of cell polarization) in one of two distinct patterns, the axial pattern of haploid cells and the bipolar pattern of diploid cells. These patterns depend on distinct sets of cortical-marker proteins that transmit positional information through a common signaling pathway based on a Ras-type GTPase. It has been reported previously that various proteins of the endocytic pathway may be involved in determining the bipolar pattern but not the axial pattern. To explore this question systematically, we constructed and analyzed congenic haploid and diploid deletion mutants for 14 genes encoding proteins that are involved in endocytosis. The mutants displayed a wide range of severities in their overall endocytosis defects, as judged by their growth rates and abilities to take up the lipophilic dye FM 4-64. Consistent with the previous reports, none of the mutants displayed a significant defect in axial budding, but they displayed defects in bipolar budding that were roughly correlated with the severities of their overall endocytosis defects. Both the details of the mutant budding patterns and direct examination of GFP-tagged marker proteins suggested that both initial formation and maintenance of the normally persistent bipolar marks depend on endocytosis, as well as polarized exocytosis, in actively growing cells. Interestingly, maintenance of the bipolar marks in non-growing cells did not appear to require normal levels of endocytosis. In some cases, there was a striking lack of correlation between the overall severities of the general-endocytosis defect and the bud-site selection defect, suggesting that various endocytosis proteins may differ in their importance for the uptake of various plasma-membrane targets.
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Affiliation(s)
- Shanshan Tuo
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - Kenichi Nakashima
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
| | - John R. Pringle
- Department of Genetics, Stanford University School of Medicine, Stanford, California, United States of America
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44
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Abstract
Clathrin-mediated endocytosis (CME) is conserved among eukaryotes and has been extensively analyzed at a molecular level. Here, we present an analysis of CME in the human fungal pathogen Candida albicans that shows the same modular structure as those in other fungi and mammalian cells. Intriguingly, C. albicans is perfectly viable in the absence of Arp2/3, an essential component of CME in other systems. In C. albicans, Arp2/3 function remains essential for CME as all 15 proteins tested that participate in CME, including clathrin, lose their characteristic dynamics observed in wild-type (WT) cells. However, since arp2/3 cells are still able to endocytose lipids and fluid-phase markers, but not the Ste2 and Mup1 plasma membrane proteins, there must be an alternate clathrin-independent pathway we term Arp2/3-independent endocytosis (AIE). Characterization of AIE shows that endocytosis in arp2 mutants relies on actin cables and other Arp2/3-independent actin structures, as inhibition of actin functions prevented cargo uptake in arp2/3 mutants. Transmission electron microscopy (TEM) showed that arp2/3 mutants still formed invaginating tubules, cell structures whose proper functions are believed to heavily rely on Arp2/3. Finally, Prk1 and Sjl2, two proteins involved in patch disassembly during CME, were not correctly localized to sites of endocytosis in arp2 mutants, implying a role of Arp2/3 in CME patch disassembly. Overall, C. albicans contains an alternative endocytic pathway (AIE) that relies on actin cable function to permit clathrin-independent endocytosis (CIE) and provides a system to further explore alternate endocytic routes that likely exist in fungal species. There is a well-established process of endocytosis that is generally used by eukaryotic cells termed clathrin-mediated endocytosis (CME). Although the details are somewhat different between lower and higher eukaryotes, CME appears to be the dominant endocytic process in all eukaryotes. While fungi such as Saccharomyces cerevisiae have proven excellent models for dissecting the molecular details of endocytosis, loss of CME is so detrimental that it has been difficult to study alternate pathways functioning in its absence. Although the fungal pathogen Candida albicans has a CME pathway that functions similarly to that of S. cerevisiae, inactivation of this pathway does not compromise growth of yeast-form C. albicans. In these cells, lipids and fluid-phase molecules are still endocytosed in an actin-dependent manner, but membrane proteins are not. Thus, C. albicans provides a powerful model for the analysis of CME-independent endocytosis in lower eukaryotes.
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45
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Vevea JD, Swayne TC, Boldogh IR, Pon LA. Inheritance of the fittest mitochondria in yeast. Trends Cell Biol 2013; 24:53-60. [PMID: 23932848 DOI: 10.1016/j.tcb.2013.07.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 07/02/2013] [Accepted: 07/08/2013] [Indexed: 01/01/2023]
Abstract
Eukaryotic cells compartmentalize their biochemical processes within organelles, which have specific functions that must be maintained for overall cellular health. As the site of aerobic energy mobilization and essential biosynthetic activities, mitochondria are critical for cell survival and proliferation. Here, we describe mechanisms to control the quality and quantity of mitochondria within cells with an emphasis on findings from the budding yeast Saccharomyces cerevisiae. We also describe how mitochondrial quality and quantity control systems that operate during cell division affect lifespan and cell cycle progression.
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Affiliation(s)
- Jason D Vevea
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Theresa C Swayne
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, USA
| | - Istvan R Boldogh
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA
| | - Liza A Pon
- Department of Pathology and Cell Biology, Columbia University, New York, NY, USA; Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, USA.
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46
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Nogalski MT, Chan GCT, Stevenson EV, Collins-McMillen DK, Yurochko AD. The HCMV gH/gL/UL128-131 complex triggers the specific cellular activation required for efficient viral internalization into target monocytes. PLoS Pathog 2013; 9:e1003463. [PMID: 23853586 PMCID: PMC3708883 DOI: 10.1371/journal.ppat.1003463] [Citation(s) in RCA: 72] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2012] [Accepted: 05/13/2013] [Indexed: 12/18/2022] Open
Abstract
We have established that HCMV acts as a specific ligand engaging and activating cellular integrins on monocytes. As a result, integrin signaling via Src activation leads to the functional activation of paxillin required for efficient viral entry and for the biological changes in monocytes needed for viral dissemination. These biological/molecular changes allow HCMV to use monocytes as "vehicles" for systemic spread and the establishment of lifelong persistence. However, it remains unresolved how HCMV specifically induces this observed monocyte activation. It was previously demonstrated that the HCMV gH/gL/UL128-131 glycoprotein complex facilitates viral entry into biologically relevant cell types. Nevertheless, the mechanism by which the gH/gL/UL128-131 complex promotes this process is unknown. We now show that only HCMV virions possessing the gH/gL/UL128-131 complex are capable of activating integrin/Src/paxillin-signaling in monocytes. In fibroblasts, this signaling is reversed, such that virus lacking the gH/gL/UL128-131 complex is the only virus able to induce the paxillin activation cascade. The presence of the gH/gL/UL128-131 complex also may have an inhibitory effect on integrin-mediated signaling pathway in fibroblasts. Furthermore, we demonstrate that the presence of the gH/gL/UL128-131 complex on the viral envelope, through its activation of the integrin/Src/paxillin pathway, is necessary for efficient HCMV internalization into monocytes and that appropriate actin and dynamin regulation is critical for this entry process. Importantly, productive infection in monocyte-derived macrophages was seen only in cells exposed to HCMV expressing the gH/gL/UL128-131 complex. From our data, the HCMV gH/gL/U128-131 complex emerges as the specific ligand driving the activation of the receptor-mediated signaling required for the regulation of the actin cytoskeleton and, consequently, for efficient and productive internalization of HCMV into monocytes. To our knowledge, our studies demonstrate a possible molecular mechanism for why the gH/gL/UL128-131 complex dictates HCMV tropism and why the complex is lost as clinical isolates are passaged in the laboratory.
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Affiliation(s)
- Maciej T. Nogalski
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America
| | - Gary C. T. Chan
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America
| | - Emily V. Stevenson
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America
| | - Donna K. Collins-McMillen
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America
| | - Andrew D. Yurochko
- Department of Microbiology and Immunology, Center for Molecular and Tumor Virology, Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America
- Feist-Weiller Cancer Center, Louisiana State University Health Sciences Center, Shreveport, Louisiana, United States of America
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47
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Chen X, Ni F, Tian X, Kondrashkina E, Wang Q, Ma J. Structural basis of actin filament nucleation by tandem W domains. Cell Rep 2013; 3:1910-20. [PMID: 23727244 DOI: 10.1016/j.celrep.2013.04.028] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 03/23/2013] [Accepted: 04/26/2013] [Indexed: 11/17/2022] Open
Abstract
Spontaneous nucleation of actin is very inefficient in cells. To overcome this barrier, cells have evolved a set of actin filament nucleators to promote rapid nucleation and polymerization in response to specific stimuli. However, the molecular mechanism of actin nucleation remains poorly understood. This is hindered largely by the fact that actin nucleus, once formed, rapidly polymerizes into filament, thus making it impossible to capture stable multisubunit actin nucleus. Here, we report an effective double-mutant strategy to stabilize actin nucleus by preventing further polymerization. Employing this strategy, we solved the crystal structure of AMPPNP-actin in complex with the first two tandem W domains of Cordon-bleu (Cobl), a potent actin filament nucleator. Further sequence comparison and functional studies suggest that the nucleation mechanism of Cobl is probably shared by the p53 cofactor JMY, but not Spire. Moreover, the double-mutant strategy opens the way for atomic mechanistic study of actin nucleation and polymerization.
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Affiliation(s)
- Xiaorui Chen
- Graduate Program of Structural and Computational Biology and Molecular Biophysics, Baylor College of Medicine, One Baylor Plaza, Houston, TX 77030, USA
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48
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Yoshida M, Ohnuki S, Yashiroda Y, Ohya Y. Profilin is required for Ca2+ homeostasis and Ca2+-modulated bud formation in yeast. Mol Genet Genomics 2013; 288:317-28. [PMID: 23708467 DOI: 10.1007/s00438-013-0752-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Accepted: 05/10/2013] [Indexed: 12/11/2022]
Abstract
A cls5-1 mutant of Saccharomyces cerevisiae is specifically sensitive to high concentrations of Ca2+, with elevated intracellular calcium content and altered cell morphology in the presence of 100 mM Ca2+. To reveal the mechanisms of the Ca2+-sensitive phenotype, we investigated the gene responsible and its interacting network. We demonstrated that CLS5 is identical to PFY1, encoding profilin. Involvement of profilin in the maintenance of intracellular Ca2+ homeostasis was supported by the fact that both exchangeable and non-exchangeable intracellular Ca2+ pools in the cls5-1 mutant are higher than those of the wild-type strain. Several mutations of the genes whose proteins physically interact with profilin resulted in the Ca2+-sensitive phenotype. Examination of the intracellular Ca2+ pools indicated that Bni1p, Bem1p, Rho1p, and Cla4p are also required for the maintenance of Ca2+ homeostasis. Quantitative morphological analysis revealed that the Ca2+-induced morphological changes in cls5-1 cells are similar to bem1 and cls4-1 cells. Common Ca2+-induced morphological changes were an increase in cell size and a decrease of the ratio of budded cells in the population. Since a mutation allele of cls4-1 is located in the CDC24 gene, we suggest that profilin, Bem1p, and Cdc24p are required for Ca2+-modulated bud formation. Thus, profilin is involved in Ca2+ regulation in two ways: the first is Ca2+ homeostasis by coordination with Bni1p, Bem1p, Rho1p, and Cla4p, and the second is the requirement of Ca2+ for bud formation by coordination with Bem1p and Cdc24p.
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Affiliation(s)
- Mitsunori Yoshida
- Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Building FBS-101, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan
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49
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Yeast competence for exogenous DNA uptake: towards understanding its genetic component. Antonie van Leeuwenhoek 2013; 103:1181-207. [DOI: 10.1007/s10482-013-9905-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2012] [Accepted: 03/14/2013] [Indexed: 12/20/2022]
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50
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Patel FB, Soto MC. WAVE/SCAR promotes endocytosis and early endosome morphology in polarized C. elegans epithelia. Dev Biol 2013; 377:319-32. [PMID: 23510716 DOI: 10.1016/j.ydbio.2013.03.012] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 02/28/2013] [Accepted: 03/05/2013] [Indexed: 12/20/2022]
Abstract
Cells can use the force of actin polymerization to drive intracellular transport, but the role of actin in endocytosis is not clear. Studies in single-celled yeast demonstrate the essential role of the branched actin nucleator, Arp2/3, and its activating nucleation promoting factors (NPFs) in the process of invagination from the cell surface through endocytosis. However, some mammalian studies have disputed the need for F-actin and Arp2/3 in Clathrin-Mediated Endocytosis (CME) in multicellular organisms. We investigate the role of Arp2/3 during endocytosis in Caenorhabditis elegans, a multicellular organism with polarized epithelia. Arp2/3 and its NPF, WAVE/SCAR, are essential for C. elegans embryonic morphogenesis. We show that WAVE/SCAR and Arp2/3 regulate endocytosis and early endosome morphology in diverse tissues of C. elegans. Depletion of WAVE/SCAR or Arp2/3, but not of the NPF Wasp, severely disrupts the distribution of molecules proposed to be internalized via CME, and alters the subcellular enrichment of the early endosome regulator RAB-5. Loss of WAVE/SCAR or of the GEFs that regulate RAB-5 results in similar defects in endocytosis in the intestine and coelomocyte cells. This study in a multicellular organism supports an essential role for branched actin regulators in endocytosis, and identifies WAVE/SCAR as a key NPF that promotes Arp2/3 endocytic function in C. elegans.
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Affiliation(s)
- Falshruti B Patel
- Department of Pathology and Laboratory Medicine, UMDNJ--Robert Wood Johnson Medical School, 675 Hoes Lane, Piscataway, NJ 08854, USA
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