Amino Acid and sucrose content determined in the cytosolic, chloroplastic, and vacuolar compartments and in the Phloem sap of...
Amino acid and sucrose contents were analyzed in the chloroplastic, cytosolic, and vacuolar compartments and in the phloem sap of illuminated spinach leaves (Spinacia oleracea L.). The determination of subcellular metabolite distribution was carriedhttp://www.biomedsearch.com/nih/Amino-Acid-Sucrose-Content-Determined/16668375.html
The cell. 5. Vesicular traffic. Vacuoles. Atlas of plant and animal histology.
Vacuoles are membrane-bound organelles found in plant cells, fungi and yeasts. They are usually large compartments that in mature cells may be up to 90 % of the total cell volume. The name vacuole is derived from the Latin word "vacuus", which means empty. This was clearly a misunderstanding because vacuoles are not empty, but filled with a more or less concentrated aqueous solution. The membrane of the vacuole is known as tonoplast, and is an essential part for the function of this organelle. In plants, there are several types of vacuoles according to the role they carry out. A plant cell may contain different types of vacuoles, and even a vacuole can modify its enzyme repertory and then change its function. Vacuoles are usually rounded, but the final shape is influenced by the cell morphology. One large vacuole is often observed in mature plant cells, but sometimes the membrane of the vacuole gets deeply and profusely ...http://mmegias.webs.uvigo.es/02-english/5-celulas/5-vacuolas.php
Remodeling of organelle-bound actin is required for yeast vacuole fusion | JCB
Our studies show that vacuole-bound actin is needed for homotypic fusion of this organelle in the absence of cytoskeleton or cytosol. Proteins of the well-established pathways of actin cytoskeleton regulation are needed for normal vacuole structure in vivo (Fig. 2 A) and are found on purified vacuoles at levels which cannot be due to cytosolic contamination (Fig. 2 B). Antibody to the Las17p/Bee1p, the yeast WASp homologue, inhibits vacuole fusion (Fig. 3), and this inhibition can be modulated (Fig. 3 C) by high levels of either the WCA domain of Las17p or by calmodulin, which are known to interact directly with Arp2/3 complex. Antibody to Arp3p itself also blocks vacuole fusion (Fig. 3 D). Mutations in actin have striking effects on vacuole structure in vivo (Fig. 2 A) and fusion in vitro (Fig. 4), and well-studied actin ligands (Morton et al., 2000) show fusion stage-specific inhibition of the vacuole fusion reaction (Figs. 5 and 6). We found that blocking F-actin depolymerization ...http://jcb.rupress.org/content/158/4/669
Rho1p and Cdc42p act after Ypt7p to regulate vacuole docking | The EMBO Journal
Previous studies indicated that, in addition to the Rab GTPase Ypt7p, vacuole fusion requires a late‐acting, GTPγS‐sensitive factor (Eitzen et al., 2000). We have now identified two additional GTPases, Rho1p and Cdc42p, which are required for homotypic vacuole fusion, although each acts before the GTPγS‐sensitive step. Four lines of evidence prove that both Rho1p and Cdc42p are required for the fusion reaction: (i) Rho1p and Cdc42p antibodies inhibit vacuole fusion (Figure 1A; Müller et al., 2001); (ii) Rdi1p treatment, which extracts Rho1p and Cdc42p from vacuole membranes, blocks vacuole fusion (Figures 2A and 3A); (iii) vacuoles isolated from RHO1 and CDC42 temperature‐sensitive strains are thermolabile for fusion (Figure 1B and C); and (iv) these strains show vacuole fragmentation after a brief incubation at the non‐permissive temperature (Figure 1E and F).. Our results and those of Müller et al. (2001) show that Cdc42p is required for vacuole docking, functioning between ...http://emboj.embopress.org/content/20/20/5650
Osmoregulation in the alga Vacuolaria virescens. Structure of the contractile vacuole and the nature of its association with...
The contractile vacuole of the chloromonadophycean alga Vacuolaria virescens is a permanent structure that possesses a specialized membrane: subunits of this membrane have a diameter of 21-24 nm and in places are arranged in a regular hexagonal pattern. The lateral walls of these subunits form regularly spaced bristles or pegs which extend inwards from the trilaminar membrane for a distance of 13-15 nm. The contractile vacuole is situated immediately above an extensive Golgi apparatus that covers most of the anterior surface of the nucleus. Vesicles of Golgi origin give rise to subsidiary vacuoles which in turn empty into the contractile vacuole. Golgi vesicles, subsidiary vacuoles and the contractile vacuole contain similar electron-dense material. It is suggested that this material might be a highly hydrophilic substance which will attract water from the cytoplasm into the Golgi vesicles, subsidiary vacuoles and contractile vacuole from whence it is ...http://jcs.biologists.org/content/31/1/213
The role of Ca2+ influx in endocytic vacuole formation in pancreatic acinar cells | Biochemical Journal
Endocytic vacuoles can be up to 10 μm in diameter and appear specifically in pathological conditions as a result of aberrant retrieval of structures formed by compound endocytosis . The co-localization hypothesis of trypsinogen activation suggests intracellular/intra-organellar activation of trypsinogen and the formation of active (and potentially damaging) trypsin as a result of fusion of trypsinogen containing organelles with organelles containing lysosomal proteases (reviewed in ). In our previous study, we have indeed detected trypsin activity in the endocytic vacuoles and observed that some of the vacuoles have lysosomal markers . In the present study, we specifically addressed the question about the role of SOCE in the formation of these vacuoles. The results of our experiments revealed that the SOCE-mediated Ca2+ plateaus produced by CCK or TLC-S (two commonly used inducers of experimental pancreatitis) are effectively ...http://www.biochemj.org/content/465/3/405
Endocytic vacuole | Article about endocytic vacuole by The Free Dictionary
Looking for endocytic vacuole? Find out information about endocytic vacuole. A membrane-bound cellular organelle containing extracellular particles engulfed by the mechanisms of endocytosis Explanation of endocytic vacuolehttps://encyclopedia2.thefreedictionary.com/endocytic+vacuole
Na+/H+ Antiporter in Tonoplast Vesicles from Rice Roots1 : Plant and Cell Physiology - oi
The Na+/H + antiporter in vacuolar membranes transports Na+ from the cytoplasm to vacuoles using a pH gradient generated by proton pumps; it is considered to be related to salinity tolerance. Rice (Oryza sativa L.) is a salt-sensitive crop whose vacuolar antiporter is unknown. The vacuolar pH of rice roots, determined by 31P-nuclear magnetic resonance (NMR), increased from 5.34 to 5.58 in response to 0.1 M NaCl treatment. Transport of protons into the tonoplast vesicles from rice roots was fluorometrically measured. Efflux of protons was accelerated by the addition of Na+. Furthermore, the influx of 22Na+ into the tonoplast vesicles was accelerated by a pH gradient generated by proton-translocating adenosine 5'-triphosphatase (H+-ATPase) and proton-translocating inorganic pyro-phosphatase (H+-PPase). We concluded that this Na+/H+antiporter functioned as a Na+ transporter in the vacuolar membranes. The antiporter had a Km of 10 mM for Na+ and was competitively inhibited by amiloride and its ...http://oxfordindex.oup.com/view/10.1093/oxfordjournals.pcp.a029357
YEB3/VAC8 encodes a myristylated armadillo protein of the Saccharomyces cerevisiae vacuolar membrane that functions in vacuole...
Armadillo (Arm) repeat proteins such as beta-catenin and alpha-karyopherin (importin) are thought to mediate the docking of cargo at membrane-associated cytoskeletal elements. YEB3 encodes an uncharacterized Saccharomyces cerevisiae protein that contains eleven tandem Arm repeats. While YEB3 is nonessential for growth, yeb3delta cells accumulated numerous small vacuoles and are defective in vacuolar inheritance. A functional Yeb3p-green fluorescent protein (GFP) chimera localized to vacuolar membranes. Confocal microscopy revealed that Yeb3p-GFP is localized over the surface of the vacuole, but is concentrated approximately 5- to 7-fold in bands located between clustered vacuoles. N-terminal myristylation of Yeb3p is required for vacuolar localization. The first 69 amino acids of Yeb3p were sufficient to target a GFP reporter protein to the vacuolar membrane; however, this fusion protein also localized to the plasma membrane, indicating that additional sequence is required ...http://jcs.biologists.org/content/111/15/2137
Plant Life: Vacuoles
Almost all plant cells contain vacuoles. Not all mature cells of plants, however, contain a single vacuole. For example, the cells of the tissue that produces the wood and bark of trees contain many small vacuoles during winter, when the tissue is dormant.When the tissue becomes active in spring and summer, these small vacuoles fuse into single, large vacuoles ...http://lifeofplant.blogspot.co.id/2010/12/vacuoles.html
Yeast vacuoles: more than a model lysosome : Sussex Research Online
Thanks to their amenability to both genetic and biochemical analysis, vacuoles of S. cerevisiae are valuable models for trafficking processes to mammalian lysosomes. They also have additional functions to lysosomes, and all of these processes can influence the size and number of vacuoles. Several recent papers have indicated that some vacuolar proteins participate in more than one process, and hence could be regulatory points to balance the processes and control vacuole dimensions. Studies of vacuoles from other yeasts and fungi are uncovering further roles for vacuoles, increasing the apparent requirement for such regulation. Having served as models in the past, yeast vacuoles are now well suited to develop the next generation of quantitative methods to understand organelle functions and dynamics.. ...http://sro.sussex.ac.uk/19033/
Actin and myosin function in directed vacuole movement during cell division in Saccharomyces cerevisiae. | JCB
During cell division, cytoplasmic organelles are not synthesized de novo, rather they are replicated and partitioned between daughter cells. Partitioning of the vacuole in the budding yeast Saccharomyces cerevisiae is coordinated with the cell cycle and involves a dramatic translocation of a portion of the parental organelle from the mother cell into the bud. While the molecular mechanisms that mediate this event are unknown, the vacuole's rapid and directed movements suggest cytoskeleton involvement. To identify cytoskeletal components that function in this process, vacuole inheritance was examined in a collection of actin mutants. Six strains were identified as being defective in vacuole inheritance. Tetrad analysis verified that the defect cosegregates with the mutant actin gene. One strain with a deletion in a myosin-binding region was analyzed further. The vacuole inheritance defect in this strain appears to result from the loss of a specific actin function; the actin cytoskeleton is intact ...http://jcb.rupress.org/content/135/6/1535
Identification of a cytoplasm to vacuole targeting determinant in aminopeptidase I. | JCB
Aminopeptidase I (API) is a soluble leucine aminopeptidase resident in the yeast vacuole (Frey, J., and K.H. Rohm. 1978. Biochim. Biophys. Acta. 527:31-41). The precursor form of API contains an amino-terminal 45-amino acid propeptide, which is removed by proteinase B (PrB) upon entry into the vacuole. The propeptide of API lacks a consensus signal sequence and it has been demonstrated that vacuolar localization of API is independent of the secretory pathway (Klionsky, D.J., R. Cueva, and D.S. Yaver. 1992. J. Cell Biol. 119:287-299). The predicted secondary structure for the API propeptide is composed of an amphipathic alpha-helix followed by a beta-turn and another alpha-helix, forming a helix-turn-helix structure. With the use of mutational analysis, we determined that the API propeptide is essential for proper transport into the vacuole. Deletion of the entire propeptide from the API molecule resulted in accumulation of a mature-sized protein in the cytosol. A more detailed examination using ...http://jcb.rupress.org/content/132/6/999
The Toxoplasma Blog: Ubiquitin systems mark pathogen-containing vacuoles as targets for host defense by guanylate binding...
Many microbes create and maintain pathogen-containing vacuoles (PVs) as an intracellular niche permissive for microbial growth and survival. The destruction of PVs by IFNγ-inducible guanylate binding protein (GBP) and immunity-related GTPase (IRG) host proteins is central to a successful immune response directed against numerous PV-resident pathogens. However, the mechanism by which IRGs and GBPs cooperatively detect and destroy PVs is unclear. We find that host cell priming with IFNγ prompts IRG-dependent association of Toxoplasma- and Chlamydia-containing vacuoles with ubiquitin through regulated translocation of the E3 ubiquitin ligase tumor necrosis factor (TNF) receptor associated factor 6 (TRAF6). This initial ubiquitin labeling elicits p62-mediated escort and deposition of GBPs to PVs, thereby conferring cell-autonomous immunity. Hypervirulent strains of Toxoplasma gondii evade this process via specific rhoptry protein kinases that inhibit IRG function, resulting in ...http://toxoplasmaparasite.blogspot.com/2015/09/ubiquitin-systems-mark-pathogen.html
Phytochelatin-metal(loid) transport into vacuoles shows different substrate preferences in barley and Arabidopsis - Zurich...
Cadmium (Cd) and arsenic (As) are toxic to all living organisms, including plants and humans. In plants, Cd and As are detoxified by phytochelatins (PCs) and metal(loid)-chelating peptides and by sequestering PC-metal(loid) complexes in vacuoles. Consistent differences have been observed between As and Cd detoxification. Whereas chelation of Cd by PCs is largely sufficient to detoxify Cd, As-PC complexes must be sequestered into vacuoles to be fully detoxified. It is not clear whether this difference in detoxification pathways is ubiquitous among plants or varies across species. Here, we have conducted a PC transport study using vacuoles isolated from Arabidopsis and barley. Arabidopsis vacuoles accumulated low levels of PC2 -Cd, and vesicles from yeast cells expressing either AtABCC1 or AtABCC2 exhibited negligible PC2 -Cd transport activity compared with PC2 -As. In contrast, barley vacuoles readily accumulated comparable ...http://www.zora.uzh.ch/id/eprint/106508/
Structure of Cell: Vacuoles MCQs - Quiz Questions - Biology MCQ Answers
Structure of cell vacuoles MCQs quiz, learn structure of cell vacuoles multiple choice questions answers, online biology quiz MCQs, vacuoles of animal cells are with answer.http://www.mcqslearn.com/o-level/biology/structure-of-cell-vacuoles.php
Cell Biology/Organelles - Wikibooks, open books for an open world
Vacuoles are cellular storage places. Like the cell membrane, they are comprised of a lipid bilayer that functions as a selectively permeable barrier to regulate movement of materials into and out of the compartment. They can serve a variety of purposes, storing food, water, or waste products, or immune functions such as containing dangerous materials or maintaining turgor pressure (in plants). Vacuoles serve very different purposes in plant cells than they do in animal cells.. Plant Cells In plants, vacuoles comprise a significant portion of the cell's total volume and often contribute significantly to the function of a differentiated cell. For example, vacuoles in stomata cells contain large numbers of potassium ions, which can be pumped in or out to open or close the stomata.. Animal Cells In animal cells, vacuoles serve more subordinate roles, such as assisting in endo- and exocytosis or basic storage of food and waste.. ...https://en.m.wikibooks.org/wiki/Cell_Biology/Organelles
Vacuoles: Non-Living Inclusions of Cytoplasm (794 Words)
The enlargement of the vacuoles is accompanied by the entry of water into the cell. It becomes quite evident that with the entry of water into the cell, the size of the cell will increase, and, in fact, the cell attains a volume many times greater than the volume of the original meristematic cell.. During this process of cell enlargement by vacuolation the nucleus and cytoplasm do not greatly increase in size, and in the fully vucuolated cell the cytoplasm forms a parietal layer which lines the cell wall internally, and a number of strands which extend from this parietal layer across the central vacuole. The nucleus may be suspended in the centre of the vacuole by these cytoplasmic strands or it may be embedded in the parietal layer of cytoplasm.. The cell-sap which fills the vacuole consists of an aqueous solution of various inorganic and organic compounds. Inorganic ions are always present, especially those resulting from the dissociation of the nitrates, sulphates and phosphates of ...http://www.yourarticlelibrary.com/biology/vacuoles-non-living-inclusions-of-cytoplasm-794-words/6716/
VMP1 - Vacuole membrane protein 1 - Homo sapiens (Human) - VMP1 gene & protein
Stress-induced protein that, when overexpressed, promotes formation of intracellular vacuoles followed by cell death. May be involved in the cytoplasmic vacuolization of acinar cells during the early stage of acute pancreatitis. Plays a role in the initial stages of the autophagic process through its interaction with BECN1 (By similarity). Involved in cell-cell adhesion. Plays an essential role in formation of cell junctions.http://www.uniprot.org/uniprot/Q96GC9
IDEALS @ Illinois: The regulation of yeast homotypic membrane fusion by class C ABC transporters
Maintenance of eukaryotic cellular homeostasis requires the fusion of vesicle membranes that is accomplished by a SNARE-mediated mechanism. Membrane fusion is the merger of two lipid bilayers into one continuous membrane. Multiprotein complexes that have been conserved in eukaryotes carry out the basic reactions of fusion. In Saccharomyces cerevisiae, homotypic vacuole fusion occurs in experimentally defined phases. Fusion priming does not involve contact between vacuoles but includes the disassembly of complexes of SNAREs on the same membrane (cis) by Sec18p (NSF) and its cochaperone Sec17p (a-SNAP). Tethering requires Ypt7p (a Rab GTPase) and the HOPS effecter complex. SNARE complexes, including one R SNARE from a donor vacuole and three Q SNAREs from the acceptor vacuole, are formed in trans during docking of vacuoles. The membranes of the docked vacuoles are drawn together to form the "boundary domain" that resembles flat discs. The outer membranes are ...https://www.ideals.illinois.edu/handle/2142/44801
Instituto de Biotecnologia UNAM
Barkla,B.J. Pantoja,O. 2011. Plasma Membrane and Abiotic Stress en: Murphy,A. Plant Plasma Membrane, Plant Cell Monographs. Springer. pags. 457-470 Barkla,B.J. Vera-Estrella,R. Balderas,E. Pantoja,O. 2008. Mecanismos de tolerancia a la salinidad en plantas en: Lopez-Munguia,A. Una ventana al quehacer cient fico. Instituto de Biotecnolog a de la UNAM 25 aniversario, cap 23. Mexico, D.F.. UNAM. pags. 263-272 Pantoja,O. Barkla,B.J. Vera-Estrella,R. 2000. Ion channels and ion co-transporters in the tonoplast en: Rogers,J.C. Vacuolar Compartments. Sheffield Academic Press. pags. 199-220 ...http://www.ibt.unam.mx/server/PRG.base?tipo:doc,dir:PRG.curriculum,par:omar
Biology-Online • View topic - Functions of Vacuoles
Until about 30-40 years ago, nobody really knew much about how intracellular vesicular traffic really worked. Thus, they designated cellular structures by their shape in the microscope. That is why old books make confusions for such term as that of vacuole. Any modern cellular biology course will tell you that vacuoles are the counterparts of lysosomes. Actually, they are pretty much the same thing, only they have different sizes. They both employ the mannose-phosphate tag, the targeting sequences are similar, they both use proton pumps to generate a low pH etc. Of course, they have many different functions and proteins because they evolved for different purposes, but for the most part they are very similar. You will never find both lysosomes and vacuoles in the same cell. It just makes no sense ...http://www.biology-online.org/biology-forum/about14603.html?hilit=Vesicular
Biology-Online • View topic - Functions of Vacuoles
Until about 30-40 years ago, nobody really knew much about how intracellular vesicular traffic really worked. Thus, they designated cellular structures by their shape in the microscope. That is why old books make confusions for such term as that of vacuole. Any modern cellular biology course will tell you that vacuoles are the counterparts of lysosomes. Actually, they are pretty much the same thing, only they have different sizes. They both employ the mannose-phosphate tag, the targeting sequences are similar, they both use proton pumps to generate a low pH etc. Of course, they have many different functions and proteins because they evolved for different purposes, but for the most part they are very similar. You will never find both lysosomes and vacuoles in the same cell. It just makes no sense ...http://www.biology-online.org/biology-forum/post-104501.html
The vacuole system is a significant intracellular pathway for longitudinal solute transport in basidiomycete fungi. - Oxford...
Mycelial fungi have a growth form which is unique among multicellular organisms. The data presented here suggest that they have developed a unique solution to internal solute translocation involving a complex, extended vacuole. In all filamentous fungi examined, this extended vacuole forms an interconnected network, dynamically linked by tubules, which has been hypothesized to act as an internal distribution system. We have tested this hypothesis directly by quantifying solute movement within the organelle by photobleaching a fluorescent vacuolar marker. Predictive simulation models were then used to determine the transport characteristics over extended length scales. This modeling showed that the vacuolar organelle forms a functionally important, bidirectional diffusive transport pathway over distances of millimeters to centimeters. Flux through the pathway is regulated by the dynamic tubular connections involving homotypic fusion and fission. There is also a strongly predicted interaction amonghttps://www.neuroscience.ox.ac.uk/publications/33540
Copine A, a calcium-dependent membrane-binding protein, transiently localizes to the plasma membrane and intracellular vacuoles...
Copines make up a family of soluble, calcium-dependent membrane binding proteins found in a wide variety of eukaryotic organisms. Copines are characterized as having two C2 domains at the N-terminal region followed by an "A domain," similar to the von Willebrand A (VWA) domain found in integrins, in the C-terminal region . Copines appear to be absent from the Sacchromyces cerevisae genome, while the genomes of Paramecium, Arabidopsis, C. elegans, and human have two, three, five, and nine, respectively [13, 4, 24]. Tomsig and Creutz  have hypothesized that copines play a role in calcium signaling by binding to target proteins with their A domains and then bringing those target proteins to a particular membrane through the action of their C2 domains in response to a rise in calcium concentration. Because copines have two C2 domains, they have also been hypothesized to have a role in membrane trafficking. It is possible that both ideas could be correct; copines may provide links between ...https://bmccellbiol.biomedcentral.com/articles/10.1186/1471-2121-6-46