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PLoS Computational Biology 2013The generation of two non-identical membrane compartments via exchange of vesicles is considered to require two types of vesicles specified by distinct cytosolic coats...
The generation of two non-identical membrane compartments via exchange of vesicles is considered to require two types of vesicles specified by distinct cytosolic coats that selectively recruit cargo, and two membrane-bound SNARE pairs that specify fusion and differ in their affinities for each type of vesicles. The mammalian Golgi complex is composed of 6-8 non-identical cisternae that undergo gradual maturation and replacement yet features only two SNARE pairs. We present a model that explains how distinct composition of Golgi cisternae can be generated with two and even a single SNARE pair and one vesicle coat. A decay of active SNARE concentration in aging cisternae provides the seed for a cis[Formula: see text]trans SNARE gradient that generates the predominantly retrograde vesicle flux which further enhances the gradient. This flux in turn yields the observed inhomogeneous steady-state distribution of Golgi enzymes, which compete with each other and with the SNAREs for incorporation into transport vesicles. We show analytically that the steady state SNARE concentration decays exponentially with the cisterna number. Numerical solutions of rate equations reproduce the experimentally observed SNARE gradients, overlapping enzyme peaks in cis, medial and trans and the reported change in vesicle nature across the Golgi: Vesicles originating from younger cisternae mostly contain Golgi enzymes and SNAREs enriched in these cisternae and extensively recycle through the Endoplasmic Reticulum (ER), while the other subpopulation of vesicles contains Golgi proteins prevalent in older cisternae and hardly reaches the ER.
Topics: Golgi Apparatus; Models, Biological; Proteins
PubMed: 23874173
DOI: 10.1371/journal.pcbi.1003125 -
International Journal of Molecular... Sep 2013The Golgi complex lies at the heart of the secretory pathway and is responsible for modifying proteins and lipids, as well as sorting newly synthesized molecules to... (Review)
Review
The Golgi complex lies at the heart of the secretory pathway and is responsible for modifying proteins and lipids, as well as sorting newly synthesized molecules to their correct destination. As a consequence of these important roles, any changes in its proteome can negatively affect its function and in turn lead to disease. Recently, a number of proteins have been identified, which when either depleted or mutated, result in diseases that affect various organ systems. Here we describe how these proteins have been linked to the Golgi complex, and specifically how they affect either the morphology, membrane traffic or glycosylation ability of this organelle.
Topics: Glycosylation; Golgi Apparatus; Humans; Proteome
PubMed: 24025425
DOI: 10.3390/ijms140918670 -
Plant Physiology Jun 2015The endoplasmic reticulum (ER) is the gateway to the secretory pathway in all eukaryotic cells. Its products subsequently pass through the Golgi apparatus on the way to... (Review)
Review
The endoplasmic reticulum (ER) is the gateway to the secretory pathway in all eukaryotic cells. Its products subsequently pass through the Golgi apparatus on the way to the cell surface (true secretion) or to the lytic compartment of the cell (vacuolar protein transport). In animal cells, the Golgi apparatus is present as a stationary larger order complex near the nucleus, and transport between the cortical ER and the Golgi complex occurs via an intermediate compartment which is transported on microtubules. By contrast, higher plant cells have discrete mobile Golgi stacks that move along the cortical ER, and the intermediate compartment is absent. Although many of the major molecular players involved in ER-Golgi trafficking in mammalian and yeast (Saccharomyces cerevisiae) cells have homologs in higher plants, the narrow interface (less than 500 nm) between the Golgi and the ER, together with the motility factor, makes the identification of the transport vectors responsible for bidirectional traffic between these two organelles much more difficult. Over the years, a controversy has arisen over the two major possibilities by which transfer can occur: through vesicles or direct tubular connections. In this article, four leading plant cell biologists attempted to resolve this issue. Unfortunately, their opinions are so divergent and often opposing that it was not possible to reach a consensus. Thus, we decided to let each tell his or her version individually. The review begins with an article by Federica Brandizzi that provides the necessary molecular background on coat protein complexes in relation to the so-called secretory units model for ER-Golgi transport in highly vacuolated plant cells. The second article, written by Chris Hawes, presents the evidence in favor of tubules. It is followed by an article from David Robinson defending the classical notion that transport occurs via vesicles. The last article, by Akihiko Nakano, introduces the reader to possible alternatives to vesicles or tubules, which are now emerging as a result of exciting new developments in high-resolution light microscopy in yeast.
Topics: Biological Transport; Endoplasmic Reticulum; Eukaryota; Golgi Apparatus; Models, Biological; Plants
PubMed: 25883241
DOI: 10.1104/pp.15.00124 -
Nature Protocols Apr 2010The Golgi apparatus undergoes extensive disassembly during mitosis and reassembly in post-mitotic daughter cells. This process has been mimicked in vitro by treating...
The Golgi apparatus undergoes extensive disassembly during mitosis and reassembly in post-mitotic daughter cells. This process has been mimicked in vitro by treating Golgi membranes with mitotic and interphase cytosol. To determine the minimal machinery that controls the morphological change, we have developed a defined Golgi disassembly and reassembly assay that reconstitutes this process using purified proteins instead of cytosol. Treatment of Golgi membranes with mitotic kinases and COPI coat proteins efficiently disassembles the membranes into mitotic Golgi fragments, whereas further incubation with p97 or N-ethylmaleimide-sensitive factor (two AAA ATPases involved in membrane fusion) and their cofactors, in combination with protein phosphatase PP2A, leads to reassembly of the membranes into new Golgi stacks. The whole process takes 3-4 d and is applicable for identification and determination of novel cytosolic and membrane proteins that regulate Golgi membrane dynamics in the cell cycle.
Topics: Animals; Cell Cycle; Cell Fractionation; Cell-Free System; Coat Protein Complex I; Cytosol; Golgi Apparatus; HeLa Cells; Humans; In Vitro Techniques; Interphase; Liver; Membrane Proteins; Microscopy, Electron, Transmission; Mitosis; Protein Kinases; Rats
PubMed: 20360770
DOI: 10.1038/nprot.2010.38 -
Oncotarget Oct 2015
Topics: Animals; Endocytosis; Endoplasmic Reticulum; Golgi Apparatus; Humans; Protein Transport; Receptors, Peptide; Signal Transduction; Virion; Virus Internalization
PubMed: 26356567
DOI: 10.18632/oncotarget.5444 -
Biochimica Et Biophysica Acta Aug 1998The plant Golgi apparatus has an important role in protein glycosylation and sorting, but is also a major biosynthetic organelle that synthesises large quantities of... (Review)
Review
The plant Golgi apparatus has an important role in protein glycosylation and sorting, but is also a major biosynthetic organelle that synthesises large quantities of cell wall polysaccharides. This is reflected in the organisation of the Golgi apparatus as numerous individual stacks of cisternae that are dispersed through the cell. Each stack is polarised: the shape of the cisternae and the staining of the membranes change in a cis to trans direction, and the cisternae on the trans side contain more polysaccharides. Numerous glycosyltransferases are required for the synthesis of the complex cell wall polysaccharides. Microscopy and biochemical fractionation studies suggest that these enzymes are compartmentalised within the stack. Although there is no obvious cis Golgi network, the trans-most cisterna or trans Golgi network often buds clathrin-coated and sometimes smooth dense vesicles as well. Here, vacuolar proteins are sorted from the secreted proteins and polysaccharides. This review highlights unique aspects of the organisation and function of the plant Golgi apparatus. Fundamentally similar processes probably underlie Golgi organisation in all organisms, and consideration of the plant Golgi specialisations can therefore be generally informative, as well as being of central importance to plant cell biology.
Topics: Animals; Cell Compartmentation; Golgi Apparatus; Plant Physiological Phenomena; Plants
PubMed: 9714825
DOI: 10.1016/s0167-4889(98)00061-5 -
Arthritis Research 2002Anti-Golgi complex autoantibodies are found primarily in patients with Sjögren's syndrome and systemic lupus erythematosus, although they are not restricted to these...
Anti-Golgi complex autoantibodies are found primarily in patients with Sjögren's syndrome and systemic lupus erythematosus, although they are not restricted to these diseases. Several Golgi autoantigens have been identified that represent a small family of proteins. Common features of all Golgi autoantigens appear to be their distinct structural organization of multiple alpha-helical coiled-coil rods in the central domains flanked by non-coiled-coil N-termini and C-termini, and their localization to the cytoplasmic face of Golgi cisternae. Many autoantigens in systemic autoimmune diseases have distinct cleavage products in apoptosis or necrosis and this has raised the possibility that cell death may play a role in the generation of potentially immunostimulatory forms of autoantigens. In the present study, we examined changes in the Golgi complex and associated autoantigens during apoptosis and necrosis. Immunofluorescence analysis showed that the Golgi complex was altered and developed distinctive characteristics during apoptosis and necrosis. In addition, immunoblotting analysis showed the generation of antigenic fragments of each Golgi autoantigen, suggesting that they may play a role in sustaining autoantibody production. Further studies are needed to determine whether the differences observed in the Golgi complex during apoptosis or necrosis may account for the production of anti-Golgi complex autoantibodies.
Topics: Apoptosis; Autoantigens; Autoimmunity; Dose-Response Relationship, Drug; Fluorescent Antibody Technique, Indirect; Golgi Apparatus; Hepatocytes; Humans; Immunoblotting; Jurkat Cells; Membrane Proteins; Necrosis; Staurosporine
PubMed: 12106502
DOI: 10.1186/ar422 -
Biochemistry. Biokhimiia Sep 2014Microtubules, actin filaments, and Golgi apparatus are connected both directly and indirectly, but it is manifested differently depending on the cell organization and... (Review)
Review
Microtubules, actin filaments, and Golgi apparatus are connected both directly and indirectly, but it is manifested differently depending on the cell organization and specialization, and these connections are considered in many original studies and reviews. In this review we would like to discuss what underlies differences in the structural organization of the Golgi apparatus in animal and plant cells: specific features of the microtubule cytoskeleton organization, the use of different cytoskeleton components for Golgi apparatus movement and maintenance of its integrity, or specific features of synthetic and secretory processes. We suppose that a dispersed state of the Golgi apparatus in higher plant cells cannot be explained only by specific features of the microtubule system organization and by the absence of centrosome as an active center of their organization because the Golgi apparatus is organized similarly in the cells of other organisms that possess the centrosome and centrosomal microtubules. One of the key factors determining the Golgi apparatus state in plant cells is the functional uniformity or functional specialization of stacks. The functional specialization does not suggest the joining of the stacks to form a ribbon; therefore, the disperse state of the Golgi apparatus needs to be supported, but it also can exist "by default". We believe that the dispersed state of the Golgi apparatus in plants is supported, on one hand, by dynamic connections of the Golgi apparatus stacks with the actin filament system and, on the other hand, with the endoplasmic reticulum exit sites distributed throughout the endoplasmic reticulum.
Topics: Golgi Apparatus; Plant Cells
PubMed: 25385017
DOI: 10.1134/S0006297914090065 -
Traffic (Copenhagen, Denmark) Sep 2008The interface between the endoplasmic reticulum (ER) and the Golgi apparatus is a critical junction in the secretory pathway mediating the transport of both soluble and... (Review)
Review
The interface between the endoplasmic reticulum (ER) and the Golgi apparatus is a critical junction in the secretory pathway mediating the transport of both soluble and membrane cargo between the two organelles. Such transport can be bidirectional and is mediated by coated membranes. In this review, we consider the organization and dynamics of this interface in plant cells, the putative structure of which has caused some controversy in the literature, and we speculate on the stages of Golgi biogenesis from the ER and the role of the Golgi and ER on each other's motility.
Topics: COP-Coated Vesicles; Endoplasmic Reticulum; Golgi Apparatus; Plant Physiological Phenomena; Plant Proteins; Protein Transport; Secretory Pathway
PubMed: 18513377
DOI: 10.1111/j.1600-0854.2008.00773.x -
Histochemistry and Cell Biology Sep 2013The organization, assembly and remodeling of the actin cytoskeleton provide force and tracks for a variety of (endo)membrane-associated events such as membrane... (Review)
Review
The organization, assembly and remodeling of the actin cytoskeleton provide force and tracks for a variety of (endo)membrane-associated events such as membrane trafficking. This review illustrates in different cellular models how actin and many of its numerous binding and regulatory proteins (actin and co-workers) participate in the structural organization of the Golgi apparatus and in trafficking-associated processes such as sorting, biogenesis and motion of Golgi-derived transport carriers.
Topics: Actins; Animals; Golgi Apparatus; Humans; Models, Biological
PubMed: 23807268
DOI: 10.1007/s00418-013-1115-8