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Marquez CA, Oh CI, Ahn G, Shin WR, Kim YH, Ahn JY. Synergistic vesicle-vector systems for targeted delivery. J Nanobiotechnology 2024; 22:6. [PMID: 38167116 PMCID: PMC10763086 DOI: 10.1186/s12951-023-02275-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Accepted: 12/14/2023] [Indexed: 01/05/2024] Open
Abstract
With the immense progress in drug delivery systems (DDS) and the rise of nanotechnology, challenges such as target specificity remain. The vesicle-vector system (VVS) is a delivery system that uses lipid-based vesicles as vectors for a targeted drug delivery. When modified with target-probing materials, these vesicles become powerful vectors for drug delivery with high target specificity. In this review, we discuss three general types of VVS based on different modification strategies: (1) vesicle-probes; (2) vesicle-vesicles; and (3) genetically engineered vesicles. The synthesis of each VVS type and their corresponding properties that are advantageous for targeted drug delivery, are also highlighted. The applications, challenges, and limitations of VVS are briefly examined. Finally, we share a number of insights and perspectives regarding the future of VVS as a targeted drug delivery system at the nanoscale.
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Affiliation(s)
- Christine Ardelle Marquez
- Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
| | - Cho-Im Oh
- Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
| | - Gna Ahn
- Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
- Center for Ecology and Environmental Toxicology, Chungbuk National University, Cheongju, 28644, Republic of Korea
| | - Woo-Ri Shin
- Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju, 28644, Republic of Korea
- Department of Bioengineering, University of Pennsylvania, 210 S 33rd St, Philadelphia, PA, 19104, USA
| | - Yang-Hoon Kim
- Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju, 28644, Republic of Korea.
- Center for Ecology and Environmental Toxicology, Chungbuk National University, Cheongju, 28644, Republic of Korea.
| | - Ji-Young Ahn
- Department of Microbiology, Chungbuk National University, 1 Chungdae-Ro, Seowon-Gu, Cheongju, 28644, Republic of Korea.
- Center for Ecology and Environmental Toxicology, Chungbuk National University, Cheongju, 28644, Republic of Korea.
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2
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Davies-Jones J, Davies PR, Graf A, Hewes D, Hill KE, Pascoe M. Photoinduced force microscopy as a novel method for the study of microbial nanostructures. NANOSCALE 2023; 16:223-236. [PMID: 38053416 DOI: 10.1039/d3nr03499b] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/07/2023]
Abstract
A detailed comparison of the capabilities of electron microscopy and nano-infrared (IR) microscopy for imaging microbial nanostructures has been carried out for the first time. The surface sensitivity, chemical specificity, and non-destructive nature of spectroscopic mapping is shown to offer significant advantages over transmission electron microscopy (TEM) for the study of biological samples. As well as yielding important topographical information, the distribution of amides, lipids, and carbohydrates across cross-sections of bacterial (Escherichia coli, Staphylococcus aureus) and fungal (Candida albicans) cells was demonstrated using PiFM. The unique information derived from this new mode of spectroscopic mapping of the surface chemistry and biology of microbial cell walls and membranes, may provide new insights into fungal/bacterial cell function as well as having potential use in determining mechanisms of antimicrobial resistance, especially those targeting the cell wall.
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Affiliation(s)
- Josh Davies-Jones
- Cardiff Catalysis Institute, Cardiff School of Chemistry, Cardiff University, Cardiff, CF10 3A, UK.
| | - Philip R Davies
- Cardiff Catalysis Institute, Cardiff School of Chemistry, Cardiff University, Cardiff, CF10 3A, UK.
| | - Arthur Graf
- Cardiff Catalysis Institute, Cardiff School of Chemistry, Cardiff University, Cardiff, CF10 3A, UK.
| | - Dan Hewes
- Cardiff Catalysis Institute, Cardiff School of Chemistry, Cardiff University, Cardiff, CF10 3A, UK.
| | - Katja E Hill
- Advanced Therapies Group, School of Dentistry, Cardiff University, Cardiff, CF14 4XY, UK.
| | - Michael Pascoe
- Cardiff Catalysis Institute, Cardiff School of Chemistry, Cardiff University, Cardiff, CF10 3A, UK.
- School of Pharmacy and Pharmaceutical Sciences, Cardiff University, Cardiff, CF10 3BN, UK.
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3
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Kimura Y, Tsuji T, Shimizu Y, Watanabe Y, Kimura M, Fujimoto T, Higuchi M. Physicochemical properties of the vacuolar membrane and cellular factors determine formation of vacuolar invaginations. Sci Rep 2023; 13:16187. [PMID: 37759072 PMCID: PMC10533490 DOI: 10.1038/s41598-023-43232-5] [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: 02/26/2023] [Accepted: 09/21/2023] [Indexed: 09/29/2023] Open
Abstract
Vacuoles change their morphology in response to stress. In yeast exposed to chronically high temperatures, vacuolar membranes get deformed and invaginations are formed. We show that phase-separation of vacuolar membrane occurred after heat stress leading to the formation of the invagination. In addition, Hfl1, a vacuolar membrane-localized Atg8-binding protein, was found to suppress the excess vacuolar invaginations after heat stress. At that time, Hfl1 formed foci at the neck of the invaginations in wild-type cells, whereas it was efficiently degraded in the vacuole in the atg8Δ mutant. Genetic analysis showed that the endosomal sorting complex required for transport machinery was necessary to form the invaginations irrespective of Atg8 or Hfl1. In contrast, a combined mutation with the vacuole BAR domain protein Ivy1 led to vacuoles in hfl1Δivy1Δ and atg8Δivy1Δ mutants having constitutively invaginated structures; moreover, these mutants showed stress-sensitive phenotypes. Our findings suggest that vacuolar invaginations result from the combination of changes in the physiochemical properties of the vacuolar membrane and other cellular factors.
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Affiliation(s)
- Yoko Kimura
- Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan.
- Department of Agriculture, Shizuoka University, Shizuoka, 422-8529, Japan.
| | - Takuma Tsuji
- Laboratory of Molecular Cell Biology, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Yosuke Shimizu
- Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Yuki Watanabe
- Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Masafumi Kimura
- Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Toyoshi Fujimoto
- Laboratory of Molecular Cell Biology, Research Institute for Diseases of Old Age, Juntendo University Graduate School of Medicine, Tokyo, Japan
| | - Miyuki Higuchi
- Department of Agriculture, Shizuoka University, Shizuoka, 422-8529, Japan
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4
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Fatty Acyl Coenzyme A Synthetase Fat1p Regulates Vacuolar Structure and Stationary-Phase Lipophagy in Saccharomyces cerevisiae. Microbiol Spectr 2023; 11:e0462522. [PMID: 36598223 PMCID: PMC9927365 DOI: 10.1128/spectrum.04625-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
During yeast stationary phase, a single spherical vacuole (lysosome) is created by the fusion of several small ones. Moreover, the vacuolar membrane is reconstructed into two distinct microdomains. Little is known, however, about how cells maintain vacuolar shape or regulate their microdomains. Here, we show that Fat1p, a fatty acyl coenzyme A (acyl-CoA) synthetase and fatty acid transporter, and not the synthetases Faa1p and Faa4p, is essential for vacuolar shape preservation, the development of vacuolar microdomains, and cell survival in stationary phase of the yeast Saccharomyces cerevisiae. Furthermore, Fat1p negatively regulates general autophagy in both log- and stationary-phase cells. In contrast, Fat1p promotes lipophagy, as the absence of FAT1 limits the entry of lipid droplets into the vacuole and reduces the degradation of liquid droplet (LD) surface proteins. Notably, supplementing with unsaturated fatty acids or overexpressing the desaturase Ole1p can reverse all aberrant phenotypes caused by FAT1 deficiency. We propose that Fat1p regulates stationary phase vacuolar morphology, microdomain differentiation, general autophagy, and lipophagy by controlling the degree of fatty acid saturation in membrane lipids. IMPORTANCE The ability to sense environmental changes and adjust the levels of cellular metabolism is critical for cell viability. Autophagy is a recycling process that makes the most of already-existing energy resources, and the vacuole/lysosome is the ultimate autophagic processing site in cells. Lipophagy is an autophagic process to select degrading lipid droplets. In yeast cells in stationary phase, vacuoles fuse and remodel their membranes to create a single spherical vacuole with two distinct membrane microdomains, which are required for yeast lipophagy. In this study, we discovered that Fat1p was capable of rapidly responding to changes in nutritional status and preserving cell survival by regulating membrane lipid saturation to maintain proper vacuolar morphology and the level of lipophagy in the yeast S. cerevisiae. Our findings shed light on how cells maintain vacuolar structure and promote the differentiation of vacuole surface microdomains for stationary-phase lipophagy.
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Choi W, Kim YH, Min J. Inhibition of Enveloped Virus Surrogate Phi6 Infection Using Yeast-Derived Vacuoles. Microbiol Spectr 2023; 11:e0266122. [PMID: 36688634 PMCID: PMC9927162 DOI: 10.1128/spectrum.02661-22] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023] Open
Abstract
The periodic emergence of infectious disease poses a serious threat to human life. Among the causative agents, including pathogenic bacteria and fungi, enveloped viruses have caused global pandemics. In the last 10 years, outbreaks of severe acute respiratory syndrome coronavirus 2 disease, severe acute respiratory syndrome, and Middle East respiratory syndrome have all been caused by enveloped viruses. Among several paths of secondary transmission, inhalation of aerosols containing saliva with sputum droplets from infected patients is the major path. To prevent these infectious diseases, mass use of antiviral agents is essential. The yeast-derived vacuole is a small organelle in which hydrolytic enzymes are concentrated. It is an intracellular organ with an excellent ability to process old organelles and bacteria and viruses that have invaded from the outside and can be present in sufficient quantity to be called a kind of enzyme bomb. We confirmed the inhibition of virus infection and structural collapse by vacuole treatment. Among several enzymes, proteases affected Phi6 infectivity. This study tried to isolate these vacuoles from yeast and use them as an antiviral agent for virus treatment, which is a recent issue. We confirmed that viral infectivity was inactivated, and structure collapsed through vacuole treatment. This paper is meaningful in that extracellularly isolated yeast-derived vacuoles are a first attempt to utilize vacuoles for viral treatment. IMPORTANCE The study assesses the vacuoles isolated from the yeast Saccharomyces cerevisiae as green antiviral agents to decrease the concerns about massive use of chemical antiviral agents and its side effects. To prevent the spreading of infectious diseases, personal or public use of antiviral agents is encouraged. The concern about the active compounds of these chemical antiviral agents has grown. Active compounds of antiviral agents have potential side effects on human health and the environment. Our proposed approach suggests effective and green antivirus material from a nonhazardous yeast strain. Also, large-scale production using a fermentation process can allow cost-effectiveness. The results showed sufficient reduced infectivity by vacuole treatment. The exposed vacuole can play the roles of both enzyme bomb to the virus and renewable nutrient source in the ecosystem.
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Affiliation(s)
- Wooil Choi
- Graduate School of Semiconductor and Chemical Engineering, Jeonbuk National University, Jeonbuk, South Korea
| | - Yang-Hoon Kim
- School of Biological Sciences, Chungbuk National University, Cheongju, South Korea
| | - Jiho Min
- Graduate School of Semiconductor and Chemical Engineering, Jeonbuk National University, Jeonbuk, South Korea
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Refinement of Singer-Nicolson fluid-mosaic model by microscopy imaging: Lipid rafts and actin-induced membrane compartmentalization. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2023; 1865:184093. [PMID: 36423676 DOI: 10.1016/j.bbamem.2022.184093] [Citation(s) in RCA: 17] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2022] [Revised: 11/09/2022] [Accepted: 11/10/2022] [Indexed: 11/22/2022]
Abstract
This year celebrates the 50th anniversary of the Singer-Nicolson fluid mosaic model for biological membranes. The next level of sophistication we have achieved for understanding plasma membrane (PM) structures, dynamics, and functions during these 50 years includes the PM interactions with cortical actin filaments and the partial demixing of membrane constituent molecules in the PM, particularly raft domains. Here, first, we summarize our current knowledge of these two structures and emphasize that they are interrelated. Second, we review the structure, molecular dynamics, and function of raft domains, with main focuses on raftophilic glycosylphosphatidylinositol-anchored proteins (GPI-APs) and their signal transduction mechanisms. We pay special attention to the results obtained by single-molecule imaging techniques and other advanced microscopy methods. We also clarify the limitations of present optical microscopy methods for visualizing raft domains, but emphasize that single-molecule imaging techniques can "detect" raft domains associated with molecules of interest in the PM.
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7
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Choi SY, Choi W, Park YS, Kim HK, Kim YH, Min J. Vacuoles isolated from Saccharomyces cerevisiae inhibit differentiation of 3T3-L1 adipocyte. Enzyme Microb Technol 2023; 163:110165. [DOI: 10.1016/j.enzmictec.2022.110165] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 11/01/2022] [Accepted: 11/21/2022] [Indexed: 11/25/2022]
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TOR complex 2 is a master regulator of plasma membrane homeostasis. Biochem J 2022; 479:1917-1940. [PMID: 36149412 PMCID: PMC9555796 DOI: 10.1042/bcj20220388] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2022] [Revised: 08/30/2022] [Accepted: 09/01/2022] [Indexed: 11/17/2022]
Abstract
As first demonstrated in budding yeast (Saccharomyces cerevisiae), all eukaryotic cells contain two, distinct multi-component protein kinase complexes that each harbor the TOR (Target Of Rapamycin) polypeptide as the catalytic subunit. These ensembles, dubbed TORC1 and TORC2, function as universal, centrally important sensors, integrators, and controllers of eukaryotic cell growth and homeostasis. TORC1, activated on the cytosolic surface of the lysosome (or, in yeast, on the cytosolic surface of the vacuole), has emerged as a primary nutrient sensor that promotes cellular biosynthesis and suppresses autophagy. TORC2, located primarily at the plasma membrane, plays a major role in maintaining the proper levels and bilayer distribution of all plasma membrane components (sphingolipids, glycerophospholipids, sterols, and integral membrane proteins). This article surveys what we have learned about signaling via the TORC2 complex, largely through studies conducted in S. cerevisiae. In this yeast, conditions that challenge plasma membrane integrity can, depending on the nature of the stress, stimulate or inhibit TORC2, resulting in, respectively, up-regulation or down-regulation of the phosphorylation and thus the activity of its essential downstream effector the AGC family protein kinase Ypk1. Through the ensuing effect on the efficiency with which Ypk1 phosphorylates multiple substrates that control diverse processes, membrane homeostasis is maintained. Thus, the major focus here is on TORC2, Ypk1, and the multifarious targets of Ypk1 and how the functions of these substrates are regulated by their Ypk1-mediated phosphorylation, with emphasis on recent advances in our understanding of these processes.
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Ochoa-Gutiérrez D, Reyes-Torres AM, de la Fuente-Colmenares I, Escobar-Sánchez V, González J, Ortiz-Hernández R, Torres-Ramírez N, Segal-Kischinevzky C. Alternative CUG Codon Usage in the Halotolerant Yeast Debaryomyces hansenii: Gene Expression Profiles Provide New Insights into Ambiguous Translation. J Fungi (Basel) 2022; 8:jof8090970. [PMID: 36135695 PMCID: PMC9502446 DOI: 10.3390/jof8090970] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2022] [Revised: 09/10/2022] [Accepted: 09/12/2022] [Indexed: 12/04/2022] Open
Abstract
The halotolerant yeast Debaryomyces hansenii belongs to the CTG-Ser1 clade of fungal species that use the CUG codon to translate as leucine or serine. The ambiguous decoding of the CUG codon is relevant for expanding protein diversity, but little is known about the role of leucine–serine ambiguity in cellular adaptations to extreme environments. Here, we examine sequences and structures of tRNACAG from the CTG-Ser1 clade yeasts, finding that D. hansenii conserves the elements to translate ambiguously. Then, we show that D. hansenii has tolerance to conditions of salinity, acidity, alkalinity, and oxidative stress associated with phenotypic and ultrastructural changes. In these conditions, we found differential expression in both the logarithmic and stationary growth phases of tRNASer, tRNALeu, tRNACAG, LeuRS, and SerRS genes that could be involved in the adaptive process of this yeast. Finally, we compare the proteomic isoelectric points and hydropathy profiles, detecting that the most important variations among the physicochemical characteristics of D. hansenii proteins are in their hydrophobic and hydrophilic interactions with the medium. We propose that the ambiguous translation, i.e., leucylation or serynation, on translation of the CUG-encoded residues, could be linked to adaptation processes in extreme environments.
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Affiliation(s)
- Daniel Ochoa-Gutiérrez
- Laboratorio de Biología Molecular y Genómica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad # 3000, Cd. Universitaria, Coyoacán, Mexico City 04510, Mexico
- Posgrado en Ciencias Biológicas, Universidad Nacional Autónoma de México, Avenida Universidad # 3000, Cd. Universitaria, Coyoacán, Mexico City 04510, Mexico
| | - Anya M. Reyes-Torres
- Laboratorio de Biología Molecular y Genómica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad # 3000, Cd. Universitaria, Coyoacán, Mexico City 04510, Mexico
| | - Ileana de la Fuente-Colmenares
- Laboratorio de Biología Molecular y Genómica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad # 3000, Cd. Universitaria, Coyoacán, Mexico City 04510, Mexico
| | - Viviana Escobar-Sánchez
- Laboratorio de Biología Molecular y Genómica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad # 3000, Cd. Universitaria, Coyoacán, Mexico City 04510, Mexico
| | - James González
- Laboratorio de Biología Molecular y Genómica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad # 3000, Cd. Universitaria, Coyoacán, Mexico City 04510, Mexico
| | - Rosario Ortiz-Hernández
- Laboratorio de Microscopía Electrónica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad # 3000, Cd. Universitaria, Coyoacán, Mexico City 04510, Mexico
| | - Nayeli Torres-Ramírez
- Laboratorio de Microscopía Electrónica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad # 3000, Cd. Universitaria, Coyoacán, Mexico City 04510, Mexico
| | - Claudia Segal-Kischinevzky
- Laboratorio de Biología Molecular y Genómica, Departamento de Biología Celular, Facultad de Ciencias, Universidad Nacional Autónoma de México, Avenida Universidad # 3000, Cd. Universitaria, Coyoacán, Mexico City 04510, Mexico
- Correspondence:
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10
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Yeast cells actively tune their membranes to phase separate at temperatures that scale with growth temperatures. Proc Natl Acad Sci U S A 2022; 119:2116007119. [PMID: 35046036 PMCID: PMC8795566 DOI: 10.1073/pnas.2116007119] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/06/2021] [Indexed: 02/06/2023] Open
Abstract
Phase separation in membranes creates domains enriched in specific components. To date, the best example of micrometer-scale phase separation in the membrane of an unperturbed, living cell occurs in a yeast (Saccharomyces cerevisiae) organelle called the vacuole. Recent studies indicate that the phases are functionally important, enabling yeast survival during periods of stress. We discovered that yeast regulate this phase transition; the temperature at which membrane components mix into a single phase is ∼15 °C above the growth temperature. To maintain this offset, yeast may tune the level of ergosterol (a molecule that is structurally similar to cholesterol) in their membranes. Surprisingly, depleting sterols in vacuole membranes causes them to phase separate, in contrast to previous assumptions. Membranes of vacuoles, the lysosomal organelles of Saccharomyces cerevisiae (budding yeast), undergo extraordinary changes during the cell’s normal growth cycle. The cycle begins with a stage of rapid cell growth. Then, as glucose becomes scarce, growth slows, and vacuole membranes phase separate into micrometer-scale domains of two liquid phases. Recent studies suggest that these domains promote yeast survival by organizing membrane proteins that play key roles in a central signaling pathway conserved among eukaryotes (TORC1). An outstanding question in the field has been whether cells regulate phase transitions in response to new physical conditions and how this occurs. Here, we measure transition temperatures and find that after an increase of roughly 15 °C, vacuole membranes appear uniform, independent of growth temperature. Moreover, populations of cells grown at a single temperature regulate this transition to occur over a surprisingly narrow temperature range. Remarkably, the transition temperature scales linearly with the growth temperature, demonstrating that the cells physiologically adapt to maintain proximity to the transition. Next, we ask how yeast adjust their membranes to achieve phase separation. We isolate vacuoles from yeast during the rapid stage of growth, when their membranes do not natively exhibit domains. Ergosterol is the major sterol in yeast. We find that domains appear when ergosterol is depleted, contradicting the prevalent assumption that increases in sterol concentration generally cause membrane phase separation in vivo, but in agreement with previous studies using artificial and cell-derived membranes.
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11
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Ahmed T, Nisler CR, Fluck EC, Walujkar S, Sotomayor M, Moiseenkova-Bell VY. Structure of the ancient TRPY1 channel from Saccharomyces cerevisiae reveals mechanisms of modulation by lipids and calcium. Structure 2022; 30:139-155.e5. [PMID: 34453887 PMCID: PMC8741645 DOI: 10.1016/j.str.2021.08.003] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2021] [Revised: 06/29/2021] [Accepted: 08/10/2021] [Indexed: 01/14/2023]
Abstract
Transient receptor potential (TRP) channels emerged in fungi as mechanosensitive osmoregulators. The Saccharomyces cerevisiae vacuolar TRP yeast 1 (TRPY1) is the most studied TRP channel from fungi, but the structure and details of channel modulation remain elusive. Here, we describe the full-length cryoelectron microscopy structure of TRPY1 at 3.1 Å resolution in a closed state. The structure, despite containing an evolutionarily conserved and archetypical transmembrane domain, reveals distinctive structural folds for the cytosolic N and C termini, compared with other eukaryotic TRP channels. We identify an inhibitory phosphatidylinositol 3-phosphate (PI(3)P) lipid-binding site, along with two Ca2+-binding sites: a cytosolic site, implicated in channel activation and a vacuolar lumen site, implicated in inhibition. These findings, together with data from microsecond-long molecular dynamics simulations and a model of a TRPY1 open state, provide insights into the basis of TRPY1 channel modulation by lipids and Ca2+, and the molecular evolution of TRP channels.
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Affiliation(s)
- Tofayel Ahmed
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Collin R Nisler
- Biophysics Graduate Program, The Ohio State University, Columbus, OH 43210, USA; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA
| | - Edwin C Fluck
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA; Biochemistry and Molecular Biophysics Graduate Group, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sanket Walujkar
- Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Chemical Physics Graduate Program, The Ohio State University, Columbus, OH 43210, USA
| | - Marcos Sotomayor
- Biophysics Graduate Program, The Ohio State University, Columbus, OH 43210, USA; Department of Chemistry and Biochemistry, The Ohio State University, Columbus, OH 43210, USA; Chemical Physics Graduate Program, The Ohio State University, Columbus, OH 43210, USA
| | - Vera Y Moiseenkova-Bell
- Department of Systems Pharmacology and Translational Therapeutics, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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12
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Oliveira MC, Yusupov M, Bogaerts A, Cordeiro RM. Distribution of lipid aldehydes in phase-separated membranes: A molecular dynamics study. Arch Biochem Biophys 2022; 717:109136. [DOI: 10.1016/j.abb.2022.109136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2021] [Revised: 01/19/2022] [Accepted: 01/21/2022] [Indexed: 11/02/2022]
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13
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Schlarmann P, Ikeda A, Funato K. Membrane Contact Sites in Yeast: Control Hubs of Sphingolipid Homeostasis. MEMBRANES 2021; 11:971. [PMID: 34940472 PMCID: PMC8707754 DOI: 10.3390/membranes11120971] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 12/03/2021] [Accepted: 12/06/2021] [Indexed: 01/02/2023]
Abstract
Sphingolipids are the most diverse class of membrane lipids, in terms of their structure and function. Structurally simple sphingolipid precursors, such as ceramides, act as intracellular signaling molecules in various processes, including apoptosis, whereas mature and complex forms of sphingolipids are important structural components of the plasma membrane. Supplying complex sphingolipids to the plasma membrane, according to need, while keeping pro-apoptotic ceramides in check is an intricate task for the cell and requires mechanisms that tightly control sphingolipid synthesis, breakdown, and storage. As each of these processes takes place in different organelles, recent studies, using the budding yeast Saccharomyces cerevisiae, have investigated the role of membrane contact sites as hubs that integrate inter-organellar sphingolipid transport and regulation. In this review, we provide a detailed overview of the findings of these studies and put them into the context of established regulatory mechanisms of sphingolipid homeostasis. We have focused on the role of membrane contact sites in sphingolipid metabolism and ceramide transport, as well as the mechanisms that prevent toxic ceramide accumulation.
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Affiliation(s)
| | | | - Kouichi Funato
- Graduate School of Integrated Sciences for Life, Hiroshima University, Kagamiyama 1-4-4, Higashi-Hiroshima 739-8528, Japan; (P.S.); (A.I.)
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14
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Liao PC, Garcia EJ, Tan G, Tsang CA, Pon LA. Roles for L o microdomains and ESCRT in ER stress-induced lipid droplet microautophagy in budding yeast. Mol Biol Cell 2021; 32:br12. [PMID: 34668753 PMCID: PMC8694086 DOI: 10.1091/mbc.e21-04-0179] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Microlipophagy (µLP), degradation of lipid droplets (LDs) by microautophagy, occurs by autophagosome-independent direct uptake of LDs at lysosomes/vacuoles in response to nutrient limitations and ER stressors in Saccharomyces cerevisiae. In nutrient-limited yeast, liquid-ordered (Lo) microdomains, sterol-rich raftlike regions in vacuolar membranes, are sites of membrane invagination during LD uptake. The endosome sorting complex required for transport (ESCRT) is required for sterol transport during Lo formation under these conditions. However, ESCRT has been implicated in mediating membrane invagination during µLP induced by ER stressors or the diauxic shift from glycolysis- to respiration-driven growth. Here we report that ER stress induced by lipid imbalance and other stressors induces Lo microdomain formation. This process is ESCRT independent and dependent on Niemann-Pick type C sterol transfer proteins. Inhibition of ESCRT or Lo microdomain formation partially inhibits lipid imbalance-induced µLP, while inhibition of both blocks this µLP. Finally, although the ER stressors dithiothreitol or tunicamycin induce Lo microdomains, µLP in response to these stressors is ESCRT dependent and Lo microdomain independent. Our findings reveal that Lo microdomain formation is a yeast stress response, and stress-induced Lo microdomain formation occurs by stressor-specific mechanisms. Moreover, ESCRT and Lo microdomains play functionally distinct roles in LD uptake during stress-induced µLP.
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Affiliation(s)
- Pin-Chao Liao
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032
| | - Enrique J Garcia
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032
| | - Gary Tan
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032
| | - Catherine A Tsang
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032
| | - Liza A Pon
- Department of Pathology and Cell Biology, Columbia University, New York, NY 10032
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15
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Hurst LR, Fratti RA. Lipid Rafts, Sphingolipids, and Ergosterol in Yeast Vacuole Fusion and Maturation. Front Cell Dev Biol 2020; 8:539. [PMID: 32719794 PMCID: PMC7349313 DOI: 10.3389/fcell.2020.00539] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2020] [Accepted: 06/09/2020] [Indexed: 01/15/2023] Open
Abstract
The Saccharomyces cerevisiae lysosome-like vacuole is a useful model for studying membrane fusion events and organelle maturation processes utilized by all eukaryotes. The vacuolar membrane is capable of forming micrometer and nanometer scale domains that can be visualized using microscopic techniques and segregate into regions with surprisingly distinct lipid and protein compositions. These lipid raft domains are liquid-ordered (L o ) like regions that are rich in sphingolipids, phospholipids with saturated acyl chains, and ergosterol. Recent studies have shown that these lipid rafts contain an enrichment of many different proteins that function in essential activities such as nutrient transport, organelle contact, membrane trafficking, and homotypic fusion, suggesting that they are biologically relevant regions within the vacuole membrane. Here, we discuss recent developments and the current understanding of sphingolipid and ergosterol function at the vacuole, the composition and function of lipid rafts at this organelle and how the distinct lipid and protein composition of these regions facilitates the biological processes outlined above.
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Affiliation(s)
- Logan R Hurst
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Rutilio A Fratti
- Department of Biochemistry, University of Illinois at Urbana-Champaign, Urbana, IL, United States.,Center for Biophysics and Quantitative Biology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
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16
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Ishii A, Kurokawa K, Hotta M, Yoshizaki S, Kurita M, Koyama A, Nakano A, Kimura Y. Role of Atg8 in the regulation of vacuolar membrane invagination. Sci Rep 2019; 9:14828. [PMID: 31616012 PMCID: PMC6794316 DOI: 10.1038/s41598-019-51254-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 09/26/2019] [Indexed: 01/23/2023] Open
Abstract
Cellular heat stress can cause damage, and significant changes, to a variety of cellular structures. When exposed to chronically high temperatures, yeast cells invaginate vacuolar membranes. In this study, we found that the expression of Atg8, an essential autophagy factor, is induced after chronic heat stress. In addition, without Atg8, vacuolar invaginations are induced conspicuously, beginning earlier and invaginating vacuoles more frequently after heat stress. Our results indicate that Atg8's invagination-suppressing functions do not require Atg8 lipidation, in contrast with autophagy, which requires Atg8 lipidation. Genetic analyses of vps24 and vps23 further suggest that full ESCRT machinery is necessary to form vacuolar invaginations irrespective of Atg8. In contrast, through a combined mutation with the vacuole BAR domain protein Ivy1, vacuoles show constitutively enhanced invaginated structures. Finally, we found that the atg8Δivy1Δ mutant is sensitive against agents targeting functions of the vacuole and/or plasma membrane (cell wall). Collectively, our findings revealed that Atg8 maintains vacuolar membrane homeostasis in an autophagy-independent function by coordinating with other cellular factors.
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Affiliation(s)
- Ayane Ishii
- Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Kazuo Kurokawa
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, Wako, Saitama, 351-0198, Japan
| | - Miyuu Hotta
- Department of Agriculture, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Suzuka Yoshizaki
- Department of Agriculture, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Maki Kurita
- Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Aya Koyama
- Department of Agriculture, Shizuoka University, Shizuoka, 422-8529, Japan
| | - Akihiko Nakano
- Live Cell Super-Resolution Imaging Research Team, RIKEN Center for Advanced Photonics, Wako, Saitama, 351-0198, Japan
| | - Yoko Kimura
- Graduate School of Integrated Science and Technology, Shizuoka University, Shizuoka, 422-8529, Japan. .,Department of Agriculture, Shizuoka University, Shizuoka, 422-8529, Japan.
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17
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Hilgemann DW, Lin MJ, Fine M, Deisl C. On the existence of endocytosis driven by membrane phase separations. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2019; 1862:183007. [PMID: 31202864 DOI: 10.1016/j.bbamem.2019.06.006] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/29/2019] [Revised: 05/31/2019] [Accepted: 06/06/2019] [Indexed: 01/15/2023]
Abstract
Large endocytic responses can occur rapidly in diverse cell types without dynamins, clathrin, or actin remodeling. Our experiments suggest that membrane phase separations are crucial with more ordered plasma membrane domains being internalized. Not only do these endocytic processes rely on coalescence of membrane domains, they are promoted by participation of membrane proteins in such domains, one important regulatory influence being palmitoylation. Membrane actin cytoskeleton in general resists membrane phase transitions, and its remodeling may play many roles. Besides membrane 'caging' and 'pinching' roles, typically ascribed to clathrin and dynamins, cytoskeleton remodeling may modify local membrane tension and buckling, as well as the presence and location of actin- and tension-free membrane patches. Endocytosis that depends on membrane phase separations becomes activated in metabolic stress and in response to Ca and PI3 kinase signaling. Internalized membrane traffics normally, and the secretory pathway eventually resupplies membrane to the plasmalemma or directs internalized membrane to other locations, including the extracellular space as exosomes. We describe here that endocytosis driven by membrane phase transitions is regulated by the same signaling mechanisms that regulate macropinocytosis, and it may play diverse roles in cells from nutrient assimilation to membrane recycling, cell migration, and the initiation of quiescent or hibernating cell states. Membrane ordering and phase separations have been shown to promote endocytosis in diverse cell types, including fibroblasts, myocytes, glial cells, and immune cells. We propose that clathrin/dynamin-independent endocytosis represents a continuum of related mechanisms with variable but universal dependence on membrane ordering and actin remodeling. This article is part of a Special Issue entitled: Molecular biophysics of membranes and membrane proteins.
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Affiliation(s)
- Donald W Hilgemann
- University of Texas Southwestern Medical Center, Department of Physiology, 5323 Harry Hines Boulevard, Dallas, TX 75235-9040, USA.
| | - Mei-Jung Lin
- University of Texas Southwestern Medical Center, Department of Physiology, 5323 Harry Hines Boulevard, Dallas, TX 75235-9040, USA
| | - Michael Fine
- University of Texas Southwestern Medical Center, Department of Physiology, 5323 Harry Hines Boulevard, Dallas, TX 75235-9040, USA
| | - Christine Deisl
- University of Texas Southwestern Medical Center, Department of Physiology, 5323 Harry Hines Boulevard, Dallas, TX 75235-9040, USA
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