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a tiny cavity filled with fluid in the cytoplasm of a cell

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空胞,液胞(細胞内にあり分泌液を含む小腔)

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出典(authority):フリー百科事典『ウィキペディア（Wikipedia）』「2014/01/18 12:03:09」(JST)

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Not to be confused with vesicle.

Plant cell structure

Animal cell structure

A vacuole is a membrane-bound organelle which is present in all plant and fungal cells and some protist, animal^[1] and bacterial cells.^[2] Vacuoles are essentially enclosed compartments which are filled with water containing inorganic and organic molecules including enzymes in solution, though in certain cases they may contain solids which have been engulfed. Vacuoles are formed by the fusion of multiple membrane vesicles and are effectively just larger forms of these.^[3] The organelle has no basic shape or size; its structure varies according to the needs of the cell.

The function and significance of vacuoles varies greatly according to the type of cell in which they are present, having much greater prominence in the cells of plants, fungi and certain protists than those of animals and bacteria. In general, the functions of the vacuole include:

Isolating materials that might be harmful or a threat to the cell
Containing waste products
Containing water in plant cells
Maintaining internal hydrostatic pressure or turgor within the cell
Maintaining an acidic internal pH
Containing small molecules
Exporting unwanted substances from the cell
Allows plants to support structures such as leaves and flowers due to the pressure of the central vacuole
In seeds, stored proteins needed for germination are kept in 'protein bodies', which are modified vacuoles.^[4]

Vacuoles also play a major role in autophagy, maintaining a balance between biogenesis (production) and degradation (or turnover), of many substances and cell structures in certain organisms. They also aid in the lysis and recycling of misfolded proteins that have begun to build up within the cell. Thomas Boller ^[5] and others proposed that the vacuole participates in the destruction of invading bacteria and Robert B Mellor proposed organ-specific forms have a role in 'housing' symbiotic bacteria. In protists, vacuoles have the additional function of storing food which has been absorbed by the organism and assisting in the digestive and waste management process for the cell.^[6]

The vacuole probably evolved several times independently, even within the Viridiplantae.^[7]

Bacteria

Large vacuoles are found in three genera of filamentous sulfur bacteria, the Thioploca, Beggiatoa and Thiomargarita. The cytosol is extremely reduced in these genera and the vacuole can occupy between 40–98% of the cell.^[8] The vacuole contains high concentrations of nitrate ions and is therefore thought to be a storage organelle.^[2]

Gas vacuoles, which are freely permeable to gas,^[9] are present in some species of Cyanobacteria. They allow the bacteria to control their buoyancy.

Plants

The anthocyanin-storing vacuoles of Rhoeo spathacea, a spiderwort, in cells that have plasmolyzed

Most mature plant cells have one large vacuole that typically occupies more than 30% of the cell's volume, and that can occupy as much as 80% of the volume for certain cell types and conditions.^[10] Strands of cytoplasm often run through the vacuole.

A vacuole is surrounded by a membrane called the tonoplast (word origin: Gk tón(os) + -o-, meaning “stretching”, “tension”, “tone” + comb. form repr. Gk plastós formed, molded). Also called the vacuolar membrane, the tonoplast is the cytoplasmic membrane surrounding a vacuole, separating the vacuolar contents from the cell's cytoplasm. As a membrane, it is mainly involved in regulating the movements of ions around the cell, and isolating materials that might be harmful or a threat to the cell.^[11]

Transport of protons from the cytosol to the vacuole stabilizes cytoplasmic pH, while making the vacuolar interior more acidic creating a proton motive force which the cell can use to transport nutrients into or out of the vacuole. The low pH of the vacuole also allows degradative enzymes to act. Although single large vacuoles are most common, the size and number of vacuoles may vary in different tissues and stages of development. For example, developing cells in the meristems contain small provacuoles and cells of the vascular cambium have many small vacuoles in the winter and one large one in the summer.

Aside from storage, the main role of the central vacuole is to maintain turgor pressure against the cell wall. Proteins found in the tonoplast (aquaporins) control the flow of water into and out of the vacuole through active transport, pumping potassium (K⁺) ions into and out of the vacuolar interior. Due to osmosis, water will diffuse into the vacuole, placing pressure on the cell wall. If water loss leads to a significant decline in turgor pressure, the cell will plasmolyze. Turgor pressure exerted by vacuoles is also required for cellular elongation: as the cell wall is partially degraded by the action of expansins, the less rigid wall is expanded by the pressure coming from within the vacuole. Turgor pressure exerted by the vacuole is also essential in supporting plants in an upright position. Another function of a central vacuole is that it pushes all contents of the cell's cytoplasm against the cellular membrane, and thus keeps the chloroplasts closer to light.^[12] Most plants store chemicals in the vacuole that react with chemicals in the cytosol. If the cell is broken, for example by a herbivore, then the two chemicals can react forming toxic chemicals. In garlic, alliin and the enzyme alliinase are normally separated but form allicin if the vacuole is broken. A similar reaction is responsible for the production of syn-propanethial-S-oxide when onions are cut.^{[citation needed]}

Fungi

Vacuoles in fungal cells perform similar functions to those in plants and there can be more than one vacuole per cell. In yeast cells the vacuole is a dynamic structure that can rapidly modify its morphology. They are involved in many processes including the homeostasis of cell pH and the concentration of ions, osmoregulation, storing amino acids and polyphosphate and degradative processes. Toxic ions, such as strontium (Sr2+
), cobalt(II) (Co2+
), and lead(II) (Pb2+
) are transported into the vacuole to isolate them from the rest of the cell.^[13]

Animals

In animal cells, vacuoles perform mostly subordinate roles, assisting in larger processes of exocytosis and endocytosis.

Animal vacuoles are smaller than their plant counterparts but also usually greater in number.^[14] There are also animal cells that do not have any vacuoles.^[15]

Exocytosis is the extrusion process of proteins and lipids from the cell. These materials are absorbed into secretory granules within the Golgi apparatus before being transported to the cell membrane and secreted into the extracellular environment. In this capacity, vacuoles are simply storage vesicles which allow for the containment, transport and disposal of selected proteins and lipids to the extracellular environment of the cell.

Endocytosis is the reverse of exocytosis and can occur in a variety of forms. Phagocytosis ("cell eating") is the process by which bacteria, dead tissue, or other bits of material visible under the microscope are engulfed by cells. The material makes contact with the cell membrane, which then invaginates. The invagination is pinched off, leaving the engulfed material in the membrane-enclosed vacuole and the cell membrane intact. Pinocytosis ("cell drinking") is essentially the same process, the difference being that the substances ingested are in solution and not visible under the microscope.^[16] Phagocytosis and pinocytosis are both undertaken in association with lysosomes which complete the breakdown of the material which has been engulfed.^[17]

Salmonella is able to survive and reproduce in the vacuoles of several mammal species after being engulfed.^[18]

References

Wikimedia Commons has media related to Vacuole.

^ Venes, Donald (2001). Taber's Cyclopedic Medical Dictionary (Twentieth Edition), (F.A. Davis Company, Philadelphia), p. 2287 ISBN 0-9762548-3-2.
^ ^a ^b Heide N. Schulz-Vogt (2006). Vacuoles. Microbiology Monographs 1. doi:10.1007/3-540-33774-1_10. ISBN 3-540-26205-9.
^ Brooker, Robert J, et al. (2007). Biology (First Edition), (McGraw-Hill, New York), p. 79 ISBN 0-07-326807-0.
^ Matile, Phillipe (1993) Chapter 18: Vacuoles, discovery of lysosomal origin in Discoveries in Plant Biology: v. 1 (World Scientific Publishing Co Pte Ltd)
^ Thomas Boller. Plantbiology.unibas.ch. Retrieved on 2011-09-02.
^ Jezbera Jan, Karel Hornak, Karel Simek (2005). "Food selection by bacterivorous protists: insight from the analysis of the food vacuole by means of fluorescence in situ hybridization". FEMS Microbiology Ecology 52 (3): 351–363. doi:10.1016/j.femsec.2004.12.001. PMID 16329920.
^ http://www.uni-koeln.de/math-nat-fak/botanik/bot1/AGBecker/Publikationen/pdfs/IRC2007.pdf
^ Kalanetra KM, Huston SL, Nelson DC (December 2004). "Novel, attached, sulfur-oxidizing bacteria at shallow hydrothermal vents possess vacuoles not involved in respiratory nitrate accumulation". Appl. Environ. Microbiol. 70 (12): 7487–96. doi:10.1128/AEM.70.12.7487-7496.2004. PMC 5351775. PMID 15574952. Cite uses deprecated parameters (help)
^ Walsby AE (1969). "The Permeability of Blue-Green Algal Gas-Vacuole Membranes to Gas". Proceedings of the Royal Society of London. Series B, Biological Sciences 173 (1031): 235–255. ISSN 0080-4649. Unknown parameter |olcl= ignored (help)
^ Alberts, Bruce, Johnson, Alexander, Lewis, Julian, Raff, Martin, Roberts, Keith, and Walter, Peter (2008). Molecular Biology of the Cell (Fifth Edition), (Garland Science, New York), p. 781 ISBN 978-0-8153-4111-6.
^ Li, WING-YEN; FUK-LING WONG, SAU-NA TSAI , TSUI-HUNG PHANG , GUIHUA SHAO, HON-MING LAM (June 2006). "Tonoplast-located GmCLC1 and GmNHX1 from soybean enhance NaCl tolerance in transgenic bright yellow (BY)-2 cells". Plant, Cell and Environment 29 (6): 1122–1137. doi:10.1111/j.1365-3040.2005.01487.x. PMID 17080938. Retrieved 23 October 2011. Cite uses deprecated parameters (help)
^ Lincoln Taiz and Eduardo Zeiger Plant Physiology 3rd Edition SINAUER 2002 p.13 and 14 ISBN 0-87893-856-7
^ D J Klionsky, P K Herman, and S D Emr (1990). "The fungal vacuole: composition, function, and biogenesis". Microbiol Rev. 54 (3): 266–292. PMC 372777. PMID 2215422.
^ Differences Between Plant and Animal|Cell Procaryotic and Eucaryotic Cell. iCBSE.org. 2011
^ Plant cells vs. Animal cells. Biology-Online.org
^ William F. Ganong, MD (2003). Review of medical physiology (21st ed.).
^ Reggiori F (2006). "Membrane Origin for Autophagy". Current Topics in Developmental Biology 74: 1–30. doi:10.1016/S0070-2153(06)74001-7. PMID 16860663.
^ Leigh A. Knodler, Olivia Steele-Mortimer (2003). "Taking Possession: Biogenesis of the Salmonella-Containing Vacuole". Traffic 4 (9): 587–599. doi:10.1034/j.1600-0854.2003.00118.x. PMID 12911813.

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English Journal

The effects of engineered nanoparticles on the cellular structure and growth of Saccharomyces cerevisiae.

Bayat N1, Rajapakse K, Marinsek-Logar R, Drobne D, Cristobal S.Author information 1Department of Biochemistry and Biophysics, Stockholm University , Stockholm , Sweden.AbstractIn order to study the effects of nanoparticles (NPs) with different physicochemical properties on cellular viability and structure, Saccharomyces cerevisiae were exposed to different concentrations of TiO2-NPs (1-3 nm), ZnO-NPs (<100 nm), CuO-NPs (<50 nm), their bulk forms, Ag-NPs (10 nm) and single-walled carbon nanotubes (SWCNTs). The GreenScreen assay was used to measure cyto- and genotoxicity, and transmission electron microscopy (TEM) used to assess ultrastructure. CuO-NPs were highly cytotoxic, reducing the cell density by 80% at 9 cm(2)/ml, and inducing lipid droplet formation. Cells exposed to Ag-NPs (19 cm(2)/ml) and TiO2-NPs (147 cm(2)/ml) contained dark deposits in intracellular vacuoles, the cell wall and vesicles, and reduced cell density (40 and 30%, respectively). ZnO-NPs (8 cm(2)/ml) caused an increase in the size of intracellular vacuoles, despite not being cytotoxic. SWCNTs did not cause cytotoxicity or significant alterations in ultrastructure, despite high oxidative potential. Two genotoxicity assays, GreenScreen and the comet assay, produced different results and the authors discuss the reasons for this discrepancy. Classical assays of toxicity may not be the most suitable for studying the effects of NPs in cellular systems, and the simultaneous assessment of other measures of the state of cells, such as TEM are highly recommended.
Nanotoxicology.Nanotoxicology.2014 Jun;8(4):363-73. doi: 10.3109/17435390.2013.788748. Epub 2013 Apr 22.
In order to study the effects of nanoparticles (NPs) with different physicochemical properties on cellular viability and structure, Saccharomyces cerevisiae were exposed to different concentrations of TiO2-NPs (1-3 nm), ZnO-NPs (<100 nm), CuO-NPs (<50 nm), their bulk forms, Ag-NPs (10 nm) and
PMID 23521755

The prosurvival role of autophagy in resveratrol-induced cytotoxicity in GH3 cells.

Zhang X1, Xu W2, Su J1, Chu M3, Jin H1, Li G1, Tan C1, Wang X1, Wang C4.Author information 1Department of Neurosurgery, The Third Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.2Department of Urology, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.3Department of Neurosurgery, The First Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.4Department of Neurosurgery, The Fourth Affiliated Hospital of Harbin Medical University, Harbin, Heilongjiang 150001, P.R. China.AbstractIn a previous study, we reported that resveratrol exerts antitumor effects through the estrogen receptor in prolactinoma. The autophagy/lysosomal degradation pathway plays an important role in damage control and energy efficiency. In this study, we investigated the involvement of autophagy and the related signaling pathways in resveratrol-induced apoptosis of GH3 cells. We demonstrate that resveratrol inhibits cell proliferation and induces apoptosis in a dose-dependent manner in GH3 cells. The cleavage of PARP was also observed, and the activation of caspase-3 and caspase-8 was detected. Consistent with this finding, the inhibition of caspase activation effectively attenuated resveratrol-induced cell apoptosis. In addition, the decreased level of Bcl-2 was also observed. The induction of autophagy was confirmed by the detection of the formation of autophagic vacuoles, and the increase in microtubule-associated protein 1 light chain 3 (LC3)-II and beclin-1 levels, two hallmarks of autophagy. Pre-treatment with bafilomycin A1 or 3-methyladenine, inhibitors of autophagy, enhanced the resveratrol-mediated caspase activation and cell death. Moreover, resveratrol induced the activation of ERK1/2, as well as the downregulation of Akt and mTOR phosphorylation. Taken together, these findings indicate that resveratrol induces caspase-dependent apoptosis and decreases Bcl-2 levels. In addition, resveratrol-induced autophagy is regulated by the PI3K/Akt/mTOR and ERK1/2 pathways. Furthermore, the inhibition of autophagy increases the cytotoxicity of resveratrol to GH3 cells.
International journal of molecular medicine.Int J Mol Med.2014 Apr;33(4):987-93. doi: 10.3892/ijmm.2014.1660. Epub 2014 Feb 17.
In a previous study, we reported that resveratrol exerts antitumor effects through the estrogen receptor in prolactinoma. The autophagy/lysosomal degradation pathway plays an important role in damage control and energy efficiency. In this study, we investigated the involvement of autophagy and the r
PMID 24534837

Interaction between silver nanoparticles of 20 nm (AgNP20 ) and human neutrophils: induction of apoptosis and inhibition of de novo protein synthesis by AgNP20 aggregates.

Poirier M1, Simard JC, Antoine F, Girard D.Author information 1Laboratoire de recherche en inflammation et physiologie des granulocytes, Université du Québec, INRS-Institut Armand-Frappier, Laval, QC, Canada.AbstractCytotoxic and proinflammatory properties of silver nanoparticles (AgNPs) have been reported in few studies but the direct interaction between AgNPs and neutrophils, which play a key role in inflammation, has never been documented. Here, we examined the role of AgNPs with a starting size of 20 nm (AgNP20 ) in human neutrophils. Using dynamic light scattering for the characterization of NPs suspended under identical conditions to those used for in vitro experiments, we found that, at 10 µg ml(-1) , 92% of AgNP20 possess a diameter of 17.1 nm but, at 100 µg ml(-1) , a tri-modal size distribution with large aggregates was observed (> 500 nm). Neutrophil cell size increased when treated with AgNP20 and transmission electronic microscopy experiments revealed that AgNP20 can rapidly interact with the cell membrane, penetrate neutrophils, localize in vacuole-like structures, and be randomly distributed in the cytosol after 24 h. Treatment with 100 µg ml(-1) AgNP20 for 24 h (but not 10 µg ml(-1) ) increased the neutrophil apoptotic rate and inhibited de novo protein synthesis. We conclude that AgNP20 induced apoptosis and can act as potent inhibitors of de novo protein synthesis at 100, but not 10 µg ml(-1) in human neutrophils. Copyright © 2013 John Wiley & Sons, Ltd.
Journal of applied toxicology : JAT.J Appl Toxicol.2014 Apr;34(4):404-12. doi: 10.1002/jat.2956. Epub 2013 Nov 15.
Cytotoxic and proinflammatory properties of silver nanoparticles (AgNPs) have been reported in few studies but the direct interaction between AgNPs and neutrophils, which play a key role in inflammation, has never been documented. Here, we examined the role of AgNPs with a starting size of 20 nm (
PMID 24243556

Japanese Journal

Effects on vesicular transport pathways at the late endosome in cells with limited very long-chain fatty acids

Obara Keisuke,Kojima Ryo,Kihara Akio
Journal of Lipid Research 54(3), 831-842, 2013-03-00
… In addition, the sur4Δ mutant also exhibited a synthetic growth defect when combined with the deletion of VPS3, which encodes a subunit of the CORVET (class C core vacuole/endosome tethering) complex that tethers transport vesicles to the late endosome/multivesicular body (MVB). …
NAID 120005228358

Phospholipid Flippases Lem3p-Dnf1p and Lem3p-Dnf2p Are Involved in the Sorting of the Tryptophan Permease Tat2p in Yeast

Hachiro Takeru,Yamamoto Takaharu,Nakano Kenji,Tanaka Kazuma
Journal of Biological Chemistry 288(5), 3594-3608, 2013-02-01
… Tat2p is not ubiquitinated when the NH2-terminal region is bound to membrane phospholipids, but if it dissociates from the membrane due to a low level of phosphatidylserine caused by perturbation of phospholipid asymmetry in the lem3Δ mutant, Tat2p is ubiquitinated and then transported from the TGN to the vacuole. …
NAID 120005228251

Functional roles of YPT31 and YPT32 in clotrimazole resistance of Saccharomyces cerevisiae through effects on vacuoles and ATP-binding cassette transporter(s)