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Autophagy Sep 2019Based on my reading, and on my own experience, I have come to realize that people learn in different ways, and this can include the use of different media. This is one...
Based on my reading, and on my own experience, I have come to realize that people learn in different ways, and this can include the use of different media. This is one reason I have worked with various artists to portray the topic of autophagy through paintings, music and dance. Indeed, comments from members of the audience who have attended one of my seminars often suggest that a particular artistic approach 'hit home' and added meaning to them about the topic. In this issue of the journal I describe another such project-'the-found-art vacuole'-that utilized the talents of an amazing watercolor painter, Scott Hartley. The object of Scott's painting is the only artophagy composition that I have 'made'-assembled is a more accurate word. Doing so was quite fun, but after examining many of the 'antique' items that form the 'found-art vacuole', I realized that it would be nice to have a painting that was done in exquisite detail. The requirement for detail immediately made me think of Scott, whose work I was familiar with from the Ann Arbor Art Fair. To quote a line from the Belleville News-Democrat describing Scott's taking first place in an art competition, 'He began by doing landscapes, and eventually found a different style for his work: the intricacies of urban architecture, of alleys and fire escapes in a city neighborhood.' This does describe the nature of Scott's work, but you have to see these paintings to appreciate the detail.
Topics: Autophagy; Music; Paintings; Saccharomyces cerevisiae; Vacuoles
PubMed: 31238790
DOI: 10.1080/15548627.2019.1630225 -
Plant Molecular Biology Nov 2019Short review focussing on the role and targeting of vacuolar substructure in plant immunity and pathogenesis. Plants lack specialized immune cells, therefore each plant... (Review)
Review
Short review focussing on the role and targeting of vacuolar substructure in plant immunity and pathogenesis. Plants lack specialized immune cells, therefore each plant cell must defend itself against invading pathogens. A typical plant defense strategy is the hypersensitive response that results in host cell death at the site of infection, a process largely regulated by the vacuole. In plant cells, the vacuole is a vital organelle that plays a central role in numerous fundamental processes, such as development, reproduction, and cellular responses to biotic and abiotic stimuli. It shows divergent membranous structures that are continuously transforming. Recent technical advances in visualization and live-cell imaging have significantly altered our view of the vacuolar structures and their dynamics. Understanding the active nature of the vacuolar structures and the mechanisms of vacuole-mediated defense responses is of great importance in understanding plant-pathogen interactions. In this review, we present an overview of the current knowledge about the vacuole and its internal structures, as well as their role in plant-microbe interactions. There is so far limited information on the modulation of the vacuolar structures by pathogens, but recent research has identified the vacuole as a possible target of microbial interference.
Topics: Biomarkers; Cell Death; Host-Pathogen Interactions; Intracellular Membranes; Plant Immunity; Plant Proteins; Plants; Vacuoles
PubMed: 31621005
DOI: 10.1007/s11103-019-00921-y -
Cellular Microbiology Oct 2020Intracellular bacterial pathogens harbour genes, the closest homologues of which are found in eukaryotes. Regulator of chromosome condensation 1 (RCC1) repeat proteins... (Review)
Review
Intracellular bacterial pathogens harbour genes, the closest homologues of which are found in eukaryotes. Regulator of chromosome condensation 1 (RCC1) repeat proteins are phylogenetically widespread and implicated in protein-protein interactions, such as the activation of the small GTPase Ran by its cognate guanine nucleotide exchange factor, RCC1. Legionella pneumophila and Coxiella burnetii, the causative agents of Legionnaires' disease and Q fever, respectively, harbour RCC1 repeat coding genes. Legionella pneumophila secretes the RCC1 repeat 'effector' proteins LegG1, PpgA and PieG into eukaryotic host cells, where they promote the activation of the pleiotropic small GTPase Ran, microtubule stabilisation, pathogen vacuole motility and intracellular bacterial growth as well as host cell migration. The RCC1 repeat effectors localise to the pathogen vacuole or the host plasma membrane and target distinct components of the Ran GTPase cycle, including Ran modulators and the small GTPase itself. Coxiella burnetii translocates the RCC1 repeat effector NopA into host cells, where the protein localises to nucleoli. NopA binds to Ran GTPase and promotes the nuclear accumulation of Ran(GTP), thus pertubing the import of the transcription factor NF-κB and innate immune signalling. Hence, divergent evolution of bacterial RCC1 repeat effectors defines the range of Ran GTPase cycle targets and likely allows fine-tuning of Ran GTPase activation by the pathogens at different cellular sites.
Topics: Animals; Bacterial Proteins; Biological Evolution; Cell Nucleolus; Coxiella burnetii; Enzyme Activation; Genes, Bacterial; Guanine Nucleotide Exchange Factors; Host-Pathogen Interactions; Humans; Legionella; Legionella pneumophila; Legionnaires' Disease; Protein Transport; Q Fever; Vacuoles; ran GTP-Binding Protein
PubMed: 32720355
DOI: 10.1111/cmi.13246 -
Nature Reviews. Microbiology Jul 2020The pathology of malaria is caused by infection of red blood cells with unicellular Plasmodium parasites. During blood-stage development, the parasite replicates within... (Review)
Review
The pathology of malaria is caused by infection of red blood cells with unicellular Plasmodium parasites. During blood-stage development, the parasite replicates within a membrane-bound parasitophorous vacuole. A central nexus for host-parasite interactions, this unique parasite shelter functions in nutrient acquisition, subcompartmentalization and the export of virulence factors, making its functional molecules attractive targets for the development of novel intervention strategies to combat the devastating impact of malaria. In this Review, we explore the origin, development, molecular composition and functions of the parasitophorous vacuole of Plasmodium blood stages. We also discuss the relevance of the malaria parasite's intravacuolar lifestyle for successful erythrocyte infection and provide perspectives for future research directions in parasitophorous vacuole biology.
Topics: Erythrocytes; Host-Parasite Interactions; Humans; Life Cycle Stages; Malaria, Falciparum; Merozoites; Plasmodium falciparum; Vacuoles
PubMed: 31980807
DOI: 10.1038/s41579-019-0321-3 -
Biochimica Et Biophysica Acta.... Dec 2020Vacuole is a prominent organelle that often occupies most of the plant cell volume. The vacuolar accumulation of secondary metabolites, also called specialized... (Review)
Review
Vacuole is a prominent organelle that often occupies most of the plant cell volume. The vacuolar accumulation of secondary metabolites, also called specialized metabolites, plays important roles in environmental responses such as protecting against insect herbivores and attracting pollinators. The compartmentation of xenobiotics in the vacuole is also essential for adaptation to environmental stresses. These accumulations involve several transport systems, for which some responsible transporter proteins have been reported. Furthermore, studies on biosynthetic enzymes and transporters of secondary metabolites have revealed that vacuoles, which have been recognized for many years as a site for accumulation, also function as a site for biosynthesis of secondary metabolites and are thus actively involved in the entire biosynthetic process. In this review, we briefly summarize recent findings on vacuolar transporters involved in secondary metabolites and xenobiotics, and discuss their roles in plant adaptation to biotic and abiotic stresses, through vacuolar dynamism.
Topics: Alkaloids; Anthocyanins; Biological Transport; Multidrug Resistance-Associated Proteins; Organic Cation Transport Proteins; Phenols; Plant Proteins; Plants; Vacuoles; Xenobiotics
PubMed: 31738903
DOI: 10.1016/j.bbamem.2019.183127 -
Cells Jun 2022Cells rely on autophagy to degrade cytosolic material and maintain homeostasis. During autophagy, content to be degraded is encapsulated in double membrane vesicles,... (Review)
Review
Cells rely on autophagy to degrade cytosolic material and maintain homeostasis. During autophagy, content to be degraded is encapsulated in double membrane vesicles, termed autophagosomes, which fuse with the yeast vacuole for degradation. This conserved cellular process requires the dynamic rearrangement of membranes. As such, the process of autophagy requires many soluble proteins that bind to membranes to restructure, tether, or facilitate lipid transfer between membranes. Here, we review the methods that have been used to investigate membrane binding by the core autophagy machinery and additional accessory proteins involved in autophagy in yeast. We also review the key experiments demonstrating how each autophagy protein was shown to interact with membranes.
Topics: Autophagosomes; Autophagy; Proteins; Saccharomyces cerevisiae; Vacuoles
PubMed: 35741004
DOI: 10.3390/cells11121876 -
Cells Aug 2022Recent studies have highlighted the importance of autophagy and particularly non-canonical autophagy in the development and progression of acute pancreatitis (a frequent... (Review)
Review
Recent studies have highlighted the importance of autophagy and particularly non-canonical autophagy in the development and progression of acute pancreatitis (a frequent disease with considerable morbidity and significant mortality). An important early event in the development of acute pancreatitis is the intrapancreatic activation of trypsinogen, (i.e., formation of trypsin) leading to the autodigestion of the organ. Another prominent phenomenon associated with the initiation of this disease is vacuolisation and specifically the formation of giant endocytic vacuoles in pancreatic acinar cells. These organelles develop in acinar cells exposed to several inducers of acute pancreatitis (including taurolithocholic acid and high concentrations of secretagogues cholecystokinin and acetylcholine). Notably, early trypsinogen activation occurs in the endocytic vacuoles. These trypsinogen-activating organelles undergo activation, long-distance trafficking, and non-canonical autophagy. In this review, we will discuss the role of autophagy in acute pancreatitis and particularly focus on the recently discovered LAP-like non-canonical autophagy (LNCA) of endocytic vacuoles.
Topics: Acute Disease; Autophagy; Humans; Pancreatitis; Trypsinogen; Vacuoles
PubMed: 36010591
DOI: 10.3390/cells11162514 -
FEBS Letters Sep 2022Seed storage proteins (SSPs) accumulated within plant seeds constitute the major protein nutrition sources for human and livestock. SSPs are synthesized on the... (Review)
Review
Seed storage proteins (SSPs) accumulated within plant seeds constitute the major protein nutrition sources for human and livestock. SSPs are synthesized on the endoplasmic reticulum and are then deposited in plant-specific protein bodies, including endoplasmic reticulum-derived protein bodies and protein storage vacuoles. Plant seeds have evolved a distinct endomembrane system to accomplish SSP transport. There are two distinct types of trafficking pathways contributing to SSP delivery to protein storage vacuoles: one is Golgi-dependent and the other is Golgi-independent. In recent years, molecular, genetic, and biochemical studies have shed light on the complex network controlling SSP trafficking, to which both evolutionarily conserved molecular machineries and plant-unique regulators contribute. In this review, we discuss current knowledge of protein body biogenesis and endomembrane-mediated SSP transport, focusing on endoplasmic reticulum export and post-Golgi traffic. This knowledge supports a dominant role for the Golgi-dependent pathways in SSP transport in Arabidopsis and rice. In addition, we describe cutting-edge strategies for dissecting the endomembrane trafficking system in plant seeds to advance the field.
Topics: Arabidopsis; Golgi Apparatus; Plant Proteins; Plants; Protein Transport; Seed Storage Proteins; Seeds; Vacuoles
PubMed: 35615915
DOI: 10.1002/1873-3468.14374 -
International Journal of Molecular... Mar 2020Autophagy is an evolutionarily conserved process that occurs in yeast, plants, and animals. Despite many years of research, some aspects of autophagy are still not fully... (Review)
Review
Autophagy is an evolutionarily conserved process that occurs in yeast, plants, and animals. Despite many years of research, some aspects of autophagy are still not fully explained. This mostly concerns the final stages of autophagy, which have not received as much interest from the scientific community as the initial stages of this process. The final stages of autophagy that we take into consideration in this review include the formation and degradation of the autophagic bodies as well as the efflux of metabolites from the vacuole to the cytoplasm. The autophagic bodies are formed through the fusion of an autophagosome and vacuole during macroautophagy and by vacuolar membrane invagination or protrusion during microautophagy. Then they are rapidly degraded by vacuolar lytic enzymes, and products of the degradation are reused. In this paper, we summarize the available information on the trafficking of the autophagosome towards the vacuole, the fusion of the autophagosome with the vacuole, the formation and decomposition of autophagic bodies inside the vacuole, and the efflux of metabolites to the cytoplasm. Special attention is given to the formation and degradation of autophagic bodies and metabolite salvage in plant cells.
Topics: Autophagosomes; Autophagy; Biological Transport; Cytoplasm; Phagosomes; Plant Physiological Phenomena; Proteolysis; Vacuoles
PubMed: 32210003
DOI: 10.3390/ijms21062205 -
Journal of Cell Science Jun 2023The Saccharomyces cerevisiae casein kinase protein Yck3 is a central regulator at the vacuole that phosphorylates several proteins involved in membrane trafficking....
The Saccharomyces cerevisiae casein kinase protein Yck3 is a central regulator at the vacuole that phosphorylates several proteins involved in membrane trafficking. Here, we set out to identify novel substrates of this protein. We found that endogenously tagged Yck3 localized not only at the vacuole, but also on endosomes. To disable Yck3 function, we generated a kinase-deficient mutant and thus identified the I-BAR-protein Ivy1 as a novel Yck3 substrate. Ivy1 localized to both endosomes and vacuoles, and Yck3 controlled this localization. A phosphomimetic Ivy1-SD mutant was found primarily on vacuoles, whereas its non-phosphorylatable SA variant strongly localized to endosomes, similar to what was observed upon deletion of Yck3. In vitro analysis revealed that Yck3-mediated phosphorylation strongly promoted Ivy1 recruitment to liposomes carrying the Rab7-like protein Ypt7. Modeling of Ivy1 with Ypt7 identified binding sites for Ypt7 and a positively charged patch, which were both required for Ivy1 localization. Strikingly, Ivy1 mutations in either site resulted in more cells with multilobed vacuoles, suggesting a partial defect in its membrane biogenesis. Our data thus indicate that Yck3-mediated phosphorylation controls both localization and function of Ivy1 in endolysosomal biogenesis.
Topics: Vacuoles; Phosphorylation; Saccharomyces cerevisiae; Saccharomyces cerevisiae Proteins; rab GTP-Binding Proteins; Endosomes; Casein Kinases
PubMed: 37259913
DOI: 10.1242/jcs.260889