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International Journal of Molecular... Jan 2019Autophagy is a catabolic process by which eukaryotic cells eliminate cytosolic materials through vacuole-mediated sequestration and subsequent delivery to lysosomes for... (Review)
Review
Autophagy is a catabolic process by which eukaryotic cells eliminate cytosolic materials through vacuole-mediated sequestration and subsequent delivery to lysosomes for degradation, thus maintaining cellular homeostasis and the integrity of organelles. Autophagy has emerged as playing a critical role in the regulation of liver physiology and the balancing of liver metabolism. Conversely, numerous recent studies have indicated that autophagy may disease-dependently participate in the pathogenesis of liver diseases, such as liver hepatitis, steatosis, fibrosis, cirrhosis, and hepatocellular carcinoma. This review summarizes the current knowledge on the functions of autophagy in hepatic metabolism and the contribution of autophagy to the pathophysiology of liver-related diseases. Moreover, the impacts of autophagy modulation on the amelioration of the development and progression of liver diseases are also discussed.
Topics: Animals; Autophagy; Disease Progression; Humans; Liver; Liver Diseases; Signal Transduction; Vacuoles
PubMed: 30642133
DOI: 10.3390/ijms20020300 -
Journal of Experimental Botany Jun 2017
Topics: Homeostasis; Membrane Transport Proteins; Membranes; Plant Physiological Phenomena; Plant Proteins; Vacuoles
PubMed: 28899083
DOI: 10.1093/jxb/erx229 -
Trends in Microbiology Aug 2022Invasive bacteria colonise their host tissues by establishing niches inside eukaryotic cells, where they grow either in the cytosol or inside a specialised vacuole.... (Review)
Review
Invasive bacteria colonise their host tissues by establishing niches inside eukaryotic cells, where they grow either in the cytosol or inside a specialised vacuole. These two distinct intracellular lifestyles both present benefits but also impose various constraints on pathogenic microorganisms, in terms of nutrient acquisition, space requirements, exposure to immune responses, and ability to disseminate. Here we review the major characteristics of cytosolic and vacuolar lifestyles and the strategies used by bacteria to overcome challenges specific to each compartment. Recent research providing evidence that these scenarios are not mutually exclusive is presented, with the dual lifestyles of two foodborne pathogens, Listeria monocytogenes and Salmonella Typhimurium, discussed in detail. Finally, we elaborate on the conceptual implications of polyvalence from the perspective of host-pathogen interactions.
Topics: Cytosol; Host-Pathogen Interactions; Listeria monocytogenes; Salmonella typhimurium; Vacuoles
PubMed: 35168833
DOI: 10.1016/j.tim.2022.01.015 -
Plant Physiology Mar 2022Stomatal movement is essential for plants to optimize transpiration and therefore photosynthesis. Rapid changes in the stomatal aperture are accompanied by adjustment of...
Stomatal movement is essential for plants to optimize transpiration and therefore photosynthesis. Rapid changes in the stomatal aperture are accompanied by adjustment of vacuole volume and morphology in guard cells (GCs). In Arabidopsis (Arabidopsis thaliana) leaf epidermis, stomatal development undergoes a cell-fate transition including four stomatal lineage cells: meristemoid, guard mother cell, young GC, and GC. Little is known about the mechanism underlying vacuole dynamics and vacuole formation during stomatal development. Here, we utilized whole-cell electron tomography (ET) analysis to elucidate vacuole morphology, formation, and development in different stages of stomatal lineage cells at nanometer resolution. The whole-cell ET models demonstrated that large vacuoles were generated from small vacuole stepwise fusion/maturation along stomatal development stages. Further ET analyses verified the existence of swollen intraluminal vesicles inside distinct vacuoles at certain developmental stages of stomatal lineage cells, implying a role of multivesicular body fusion in stomatal vacuole formation. Collectively, our findings demonstrate a mechanism mediating vacuole formation in Arabidopsis stomatal development and may shed light on the role of vacuoles in stomatal movement.
Topics: Arabidopsis; Arabidopsis Proteins; Electron Microscope Tomography; Plant Stomata; Vacuoles
PubMed: 35134219
DOI: 10.1093/plphys/kiac028 -
Nature Communications Jun 2023Liquid droplets of biomolecules play key roles in organizing cellular behavior, and are also technologically relevant, yet physical studies of dynamic processes of such...
Liquid droplets of biomolecules play key roles in organizing cellular behavior, and are also technologically relevant, yet physical studies of dynamic processes of such droplets have generally been lacking. Here, we investigate and quantify the dynamics of formation of dilute internal inclusions, i.e., vacuoles, within a model system consisting of liquid droplets of DNA 'nanostar' particles. When acted upon by DNA-cleaving restriction enzymes, these DNA droplets exhibit cycles of appearance, growth, and bursting of internal vacuoles. Analysis of vacuole growth shows their radius increases linearly in time. Further, vacuoles pop upon reaching the droplet interface, leading to droplet motion driven by the osmotic pressure of restriction fragments captured in the vacuole. We develop a model that accounts for the linear nature of vacuole growth, and the pressures associated with motility, by describing the dynamics of diffusing restriction fragments. The results illustrate the complex non-equilibrium dynamics possible in biomolecular condensates.
Topics: Vacuoles; DNA
PubMed: 37328453
DOI: 10.1038/s41467-023-39175-0 -
International Journal of Medical... Jan 2018Guanylate-binding proteins (GBP) are a family of dynamin-related large GTPases which are expressed in response to interferons and other pro-inflammatory cytokines. GBPs... (Review)
Review
Guanylate-binding proteins (GBP) are a family of dynamin-related large GTPases which are expressed in response to interferons and other pro-inflammatory cytokines. GBPs mediate a broad spectrum of innate immune functions against intracellular pathogens ranging from viruses to bacteria and protozoa. Several binding partners for individual GBPs have been identified and several different mechanisms of action have been proposed depending on the organisms, the cell type and the pathogen used. Many of these anti-pathogenic functions of GBPs involve the recruitment to and the subsequent destruction of pathogen containing vacuolar compartments, the assembly of large oligomeric innate immune complexes such as the inflammasome, or the induction of autophagy. Furthermore, GBPs often cooperate with immunity-related GTPases (IRGs), another family of dynamin-related GTPases, to exert their anti-pathogenic function, but since most IRGs have been lost in the evolution of higher primates, the anti-pathogenic function of human GBPs seems to be IRG-independent. GBPs and IRGs share biochemical and structural properties with the other members of the dynamin superfamily such as low nucleotide affinity and a high intrinsic GTPase activity which can be further enhanced by oligomerisation. Furthermore, GBPs and IRGs can interact with lipid membranes. In the case of three human and murine GBP isoforms this interaction is mediated by C-terminal isoprenylation. Based on cell biological studies, and in analogy to the function of other dynamins in membrane scission events, it has been postulated that both GBPs and IRGs might actively disrupt the outer membrane of pathogen-containing vacuole leading to the detection and destruction of the pathogen by the cytosolic innate immune system of the host. Recent evidence, however, indicates that GBPs might rather function by mediating membrane tethering events similar to the dynamin-related atlastin and mitofusin proteins, which mediate fusion of the ER and mitochondria, respectively. The aim of this review is to highlight the current knowledge on the function of GBPs in innate immunity and to combine it with the recent progress in the biochemical characterisation of this protein family.
Topics: Animals; Autophagy; Cytoplasm; GTP Phosphohydrolases; GTP-Binding Proteins; Humans; Immunity, Innate; Inflammasomes; Interferons; Vacuoles
PubMed: 29174633
DOI: 10.1016/j.ijmm.2017.10.013 -
International Journal of Molecular... Feb 2023Large vacuoles are a predominant cell organelle throughout the plant body. They maximally account for over 90% of cell volume and generate turgor pressure that acts as a... (Review)
Review
Large vacuoles are a predominant cell organelle throughout the plant body. They maximally account for over 90% of cell volume and generate turgor pressure that acts as a driving force of cell growth, which is essential for plant development. The plant vacuole also acts as a reservoir for sequestering waste products and apoptotic enzymes, thereby enabling plants to rapidly respond to fluctuating environments. Vacuoles undergo dynamic transformation through repeated enlargement, fusion, fragmentation, invagination, and constriction, eventually resulting in the typical 3-dimensional complex structure in each cell type. Previous studies have indicated that such dynamic transformations of plant vacuoles are governed by the plant cytoskeletons, which consist of F-actin and microtubules. However, the molecular mechanism of cytoskeleton-mediated vacuolar modifications remains largely unclear. Here we first review the behavior of cytoskeletons and vacuoles during plant development and in response to environmental stresses, and then introduce candidates that potentially play pivotal roles in the vacuole-cytoskeleton nexus. Finally, we discuss factors hampering the advances in this research field and their possible solutions using the currently available cutting-edge technologies.
Topics: Vacuoles; Cytoskeleton; Microtubules; Plants; Actin Cytoskeleton
PubMed: 36835552
DOI: 10.3390/ijms24044143 -
Journal of Experimental Botany Dec 2017Due to the numerous roles plant vacuoles play in cell homeostasis, detoxification, and protein storage, the trafficking pathways to this organelle have been extensively... (Review)
Review
Due to the numerous roles plant vacuoles play in cell homeostasis, detoxification, and protein storage, the trafficking pathways to this organelle have been extensively studied. Recent evidence, however, suggests that our vision of transport to the vacuole is not as simple as previously imagined. Alternative routes have been identified and are being characterized. Intricate interconnections between routes seem to occur in various cases, complicating the interpretation of data. In this review, we aim to summarize the published evidence and link the emerging data with previous findings. We discuss the current state of information on alternative and classical trafficking routes to the plant vacuole.
Topics: Plant Proteins; Plants; Protein Transport; Secretory Pathway; Vacuoles
PubMed: 29096031
DOI: 10.1093/jxb/erx376 -
Plant & Cell Physiology Jun 2022Fruit flesh cell vacuoles play a pivotal role in fruit growth and quality formation. In the present study, intact vacuoles were carefully released and collected from...
Fruit flesh cell vacuoles play a pivotal role in fruit growth and quality formation. In the present study, intact vacuoles were carefully released and collected from protoplasts isolated from flesh cells at five sampling times along fig fruit development. Label-free quantification and vacuole proteomic analysis identified 1,251 proteins, 1,137 of which were recruited as differentially abundant proteins (DAPs) by fold change ≥ 1.5, P < 0.05. DAPs were assigned to 10 functional categories; among them, 238, 186, 109, 93 and 90 were annotated as metabolism, transport proteins, membrane fusion or vesicle trafficking, protein fate and stress response proteins, respectively. Decreased numbers of DAPs were uncovered along fruit development. The overall changing pattern of DAPs revealed two major proteome landscape conversions in fig flesh cell vacuoles: the first occurred when fruit developed from late-stage I to mid-stage II, and the second occurred when the fruit started ripening. Metabolic proteins related to glycosidase, lipid and extracellular proteins contributing to carbohydrate storage and vacuole expansion, and protein-degrading proteins determining vacuolar lytic function were revealed. Key tonoplast proteins contributing to vacuole expansion, cell growth and fruit quality formation were also identified. The revealed comprehensive changes in the vacuole proteome during flesh development were compared with our previously published vacuole proteome of grape berry. The information expands our knowledge of the vacuolar proteome and the protein basis of vacuole functional evolution during fruit development and quality formation.
Topics: Ficus; Fruit; Plant Proteins; Proteome; Proteomics; Vacuoles
PubMed: 35348748
DOI: 10.1093/pcp/pcac039 -
Frontiers in Cellular and Infection... 2017A common strategy among intracellular bacterial pathogens is to enter into a vacuolar environment upon host cell invasion. One such pathogen, , resides within the... (Review)
Review
A common strategy among intracellular bacterial pathogens is to enter into a vacuolar environment upon host cell invasion. One such pathogen, , resides within the -containing vacuole (SCV) inside epithelial cells and macrophages. hijacks the host endosomal system to establish this unique intracellular replicative niche, forming a highly complex and dynamic network of -induced filaments (SIFs). SIFs radiate outwards from the SCV upon onset of bacterial replication. SIF biogenesis is dependent on the activity of bacterial effector proteins secreted by the -pathogenicity island-2 (SPI-2) encoded type III secretion system. While the presence of SIFs has been known for almost 25 years, their precise role during infection remains elusive. This review summarizes our current knowledge of SCV maturation and SIF biogenesis, and recent advances in our understanding of the role of SIFs inside cells.
Topics: Animals; Cytoskeleton; Epithelial Cells; Host-Pathogen Interactions; Humans; Macrophages; Salmonella enterica; Vacuoles
PubMed: 28791257
DOI: 10.3389/fcimb.2017.00335