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Trends in Biochemical Sciences Dec 2020It has been demonstrated that two Golgi stacking proteins, GRASP55 and GRASP65, self-interact to form trans-oligomers that tether adjacent Golgi membranes into stacks... (Review)
Review
It has been demonstrated that two Golgi stacking proteins, GRASP55 and GRASP65, self-interact to form trans-oligomers that tether adjacent Golgi membranes into stacks and ribbons in mammalian cells. This ensures proper functioning of the Golgi apparatus in protein trafficking and processing. More recently, GRASP proteins have drawn extensive attention from researchers due to their diverse and essential roles in and out of the Golgi in different organisms. In this review, we summarize their established roles in Golgi structure formation and function under physiological conditions. We then highlight the emerging and divergent roles for individual GRASP proteins, focusing on GRASP65 in cell migration and apoptosis and GRASP55 in unconventional protein secretion and autophagy under stress or pathological conditions.
Topics: Animals; Cell Movement; Golgi Apparatus; Golgi Matrix Proteins; Protein Transport
PubMed: 32893104
DOI: 10.1016/j.tibs.2020.08.001 -
IUBMB Life Apr 2022Organelles can easily be disrupted by intracellular and extracellular factors. Studies on ER and mitochondria indicate that a wide range of responses are elicited upon...
Organelles can easily be disrupted by intracellular and extracellular factors. Studies on ER and mitochondria indicate that a wide range of responses are elicited upon organelle disruption. One response thought to be of particular importance is autophagy. Cells can target entire organelles into autophagosomes for removal. This wholesale nature makes autophagy a robust means for eliminating compromised organelles. Recently, it was demonstrated that the Golgi apparatus is a substrate of autophagy. On the other hand, various reports have shown that components traffic away from the Golgi for elimination in an autophagosome-independent manner when the Golgi apparatus is stressed. Future studies will reveal how these different pieces of machinery coordinate to drive Golgi degradation. Quantitative measurements will be needed to determine how much autophagy contributes to the maintenance of the Golgi apparatus.
Topics: Autophagosomes; Autophagy; Endoplasmic Reticulum; Golgi Apparatus; Quality Control
PubMed: 35274438
DOI: 10.1002/iub.2611 -
FEBS Letters Sep 2019Organelles have been studied traditionally as single units, but a novel concept is now emerging: each organelle has distinct functional zones that regulate specific... (Review)
Review
Organelles have been studied traditionally as single units, but a novel concept is now emerging: each organelle has distinct functional zones that regulate specific functions. The Golgi apparatus seems to have various zones, including zones for: glycosylphosphatidylinositol-anchored proteins; proteoglycan, mucin and lipid glycosylation; transport of cholesterol and ceramides; protein degradation (Golgi membrane-associated degradation); and signalling for apoptosis. The capacity for these specific functions and the size of the corresponding zones appear to be tightly regulated by the Golgi stress response to accommodate cellular demands. For instance, the proteoglycan and mucin zones seem to be separately augmented during the differentiation of chondrocytes and goblet cells, respectively. The mammalian Golgi stress response consists of several response pathways. The TFE3 pathway regulates the general function of the Golgi, such as structural maintenance, N-glycosylation and vesicular transport, whereas the proteoglycan pathway increases the expression of glycosylation enzymes for proteoglycans. The CREB3 and HSP47 pathways regulate pro- and anti-apoptotic functions, respectively. These observations indicate that the Golgi is a dynamic organelle, the capacity of which is upregulated according to cellular needs.
Topics: Animals; Endoplasmic Reticulum Stress; Golgi Apparatus; Humans
PubMed: 31344260
DOI: 10.1002/1873-3468.13554 -
Cold Spring Harbor Perspectives in... Jan 2013Enriched endoplasmic reticulum (ER) and Golgi membranes subjected to mass spectrometry have uncovered over a thousand different proteins assigned to the ER and Golgi... (Review)
Review
Enriched endoplasmic reticulum (ER) and Golgi membranes subjected to mass spectrometry have uncovered over a thousand different proteins assigned to the ER and Golgi apparatus of rat liver. This, in turn, led to the uncovering of several hundred proteins of poorly understood function and, through hierarchical clustering, showed that proteins distributed in patterns suggestive of microdomains in cognate organelles. This has led to new insights with respect to their intracellular localization and function. Another outcome has been the critical testing of the cisternal maturation hypothesis showing overwhelming support for a predominant role of COPI vesicles in the transport of resident proteins of the ER and Golgi apparatus (as opposed to biosynthetic cargo). Here we will discuss new insights gained and also highlight new avenues undertaken to further explore the cell biology of the ER and the Golgi apparatus through tandem mass spectrometry.
Topics: Animals; Calnexin; Cell Biology; Cell Separation; Cluster Analysis; Endoplasmic Reticulum; Golgi Apparatus; Humans; Protein Transport; Proteomics; Rats; Tandem Mass Spectrometry
PubMed: 23284051
DOI: 10.1101/cshperspect.a015073 -
Traffic (Copenhagen, Denmark) Sep 2001Eukaryotic cells use a variety of strategies to inherit the Golgi apparatus. During vertebrate mitosis, the Golgi reorganizes dramatically in a process that seems to be... (Review)
Review
Eukaryotic cells use a variety of strategies to inherit the Golgi apparatus. During vertebrate mitosis, the Golgi reorganizes dramatically in a process that seems to be driven by the reversible fragmentation of existing Golgi structures and the temporary redistribution of Golgi components to the endoplasmic reticulum. Several proteins that participate in vertebrate Golgi inheritance have been identified, but their detailed functions remain unknown. A comparison between vertebrates and other eukaryotes reveals common mechanisms of Golgi inheritance. In many cell types, Golgi stacks undergo fission early in mitosis. Some cells exhibit a further Golgi breakdown that is probably due to a mitotic inhibition of membrane traffic. In all eukaryotes examined, Golgi inheritance involves either the partitioning of pre-existing Golgi elements between the daughter cells or the emergence of new Golgi structures from the endoplasmic reticulum, or some combination of these two pathways.
Topics: Animals; Biological Transport; Cell Cycle Proteins; Endoplasmic Reticulum; Fungi; Golgi Apparatus; Mitosis; Models, Biological; Plant Physiological Phenomena; Protein Kinases; Protein Serine-Threonine Kinases; Proto-Oncogene Proteins; Polo-Like Kinase 1
PubMed: 11555412
DOI: 10.1034/j.1600-0854.2001.20901.x -
Traffic (Copenhagen, Denmark) Apr 2012The Golgi apparatus is an organelle that has been extensively studied in the model eukaryote, yeast. Its morphology varies among yeast species; the Golgi exists as a... (Review)
Review
The Golgi apparatus is an organelle that has been extensively studied in the model eukaryote, yeast. Its morphology varies among yeast species; the Golgi exists as a system of dispersed cisternae in the case of the budding yeast Saccharomyces cerevisiae, whereas the Golgi cisternae in Pichia pastoris and Schizosaccharomyces pombe are organized into stacks. In spite of the different organization, the mechanism of trafficking through the Golgi apparatus is believed to be similar, involving cisternal maturation, in which the resident Golgi proteins are transported backwards while secretory cargo proteins can stay in the cisternae. Questions remain regarding the organization of the yeast Golgi, the regulatory mechanisms that underlie cisternal maturation of the Golgi and transport machinery of cargo proteins through this organelle. Studies using different yeast species have provided hints to these mechanisms.
Topics: Biological Transport; Golgi Apparatus; Models, Biological; Saccharomyces cerevisiae; Signal Transduction
PubMed: 22132734
DOI: 10.1111/j.1600-0854.2011.01316.x -
BMC Biology Sep 2011
Review
Topics: Animals; Biological Evolution; Golgi Apparatus; Intracellular Membranes; Protein Transport; Saccharomyces cerevisiae
PubMed: 21961959
DOI: 10.1186/1741-7007-9-63 -
FEBS Letters Sep 2019Glycosylphosphatidylinositol-anchored proteins (GPI-APs) are lipid APs attached to the extracellular leaflet of the plasma membrane (PM) via a glycolipid anchor. GPI-APs... (Review)
Review
Glycosylphosphatidylinositol-anchored proteins (GPI-APs) are lipid APs attached to the extracellular leaflet of the plasma membrane (PM) via a glycolipid anchor. GPI-APs are commonly associated with cholesterol- and sphingolipid-enriched membrane microdomains. These microdomains help regulating various biological activities, by segregating different proteins and lipids in (nanoscale) membrane compartments. In fibroblasts, GPI-APs form actin- and cholesterol-dependent nanoclusters directly at the PM. In contrast, in polarized epithelial cells GPI-APs cluster in the Golgi apparatus, the major protein-sorting hub for the secretory pathway. Golgi clustering is required for the selective sorting of GPI-APs to the apical PM domain, but also regulates their organization and biological activities at the cell surface. In this review, we discuss recent advances in our understanding of the mechanism of GPI-AP sorting to the apical membrane. We focus on the roles of the protein moiety and lipids in the regulation of the clustering of GPI-APs in the Golgi apparatus.
Topics: Animals; Epithelial Cells; Golgi Apparatus; Humans; Membrane Proteins; Protein Transport
PubMed: 31400147
DOI: 10.1002/1873-3468.13573 -
Journal of Cerebral Blood Flow and... Apr 2023Glycosylation of lipids and proteins significantly increases the molecular diversity in the brain. Membrane-localized glycoconjugates facilitate critical neuro-immune... (Review)
Review
Glycosylation of lipids and proteins significantly increases the molecular diversity in the brain. Membrane-localized glycoconjugates facilitate critical neuro-immune interactions. Therefore, glycodysregulation is increasingly recognized as a novel hallmark of various acute and chronic neurological diseases. Although RNAs are heavily modified, they are never thought to be substrates for glycosylation due to their inaccessibility to the glycosylation machinery in the Golgi apparatus. The astonishing discovery of cell surface glycoRNAs opened new avenues for glycomedicine. This review highlighted the key features of GlycoRNAs and further discussed their potential immunomodulatory role in the brain, particularly focusing on post-stroke neuroinflammation.
Topics: Glycosylation; Golgi Apparatus; Cell Membrane; Brain
PubMed: 36644904
DOI: 10.1177/0271678X231151995 -
Traffic (Copenhagen, Denmark) Nov 2010The Golgi apparatus lies at the heart of the secretory pathway where it receives, modifies and sorts protein cargo to the proper intracellular or extracellular location.... (Review)
Review
The Golgi apparatus lies at the heart of the secretory pathway where it receives, modifies and sorts protein cargo to the proper intracellular or extracellular location. Although this secretory function is highly conserved throughout the eukaryotic kingdom, the structure of the Golgi complex is arranged very differently among species. In particular, Golgi membranes in vertebrate cells are integrated into a single compact entity termed the Golgi ribbon that is normally localized in the perinuclear area and in close vicinity to the centrosomes. This organization poses a challenge for cell division when the single Golgi ribbon needs to be partitioned into the two daughter cells. To ensure faithful inheritance in the progeny, the Golgi ribbon is divided in three consecutive steps in mitosis, namely disassembly, partitioning and reassembly. However, the structure of the Golgi ribbon is only present in higher animals and Golgi disassembly during mitosis is not ubiquitous in all organisms. Therefore, there must be unique reasons to build up the Golgi in this particular conformation and to preserve it over generations. In this review, we first highlight the diversity of the Golgi architecture in different organisms and revisit the concept of the Golgi ribbon. Following on, we discuss why the ribbon is needed and how it forms in vertebrate cells. Lastly, we conclude with likely purposes of mitotic ribbon disassembly and further propose mechanisms by which it regulates mitosis.
Topics: Animals; Golgi Apparatus; Humans; Interphase; Mitosis
PubMed: 21040294
DOI: 10.1111/j.1600-0854.2010.01114.x