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The American Journal of Anatomy Apr 1982The reactivity of the various components of the Golgi apparatus of rat spermatids for three phosphatase activities (nicotinamide adenine dinucleotide phosphatase,...
The reactivity of the various components of the Golgi apparatus of rat spermatids for three phosphatase activities (nicotinamide adenine dinucleotide phosphatase, NADPase; thiamine pyrophosphatase, TPPase; cytidine monophosphatase, CMPase) and the incorporation of 3H-fucose by the spermatids was analyzed at the 19 steps of spermiogenesis, i.e., during and after this organelle elaborated the glycoprotein-rich acrosomic system. During steps 1-3, the Golgi apparatus produced, in addition to the proacrosomic granules, multivesicular bodies that became associated with the chromatoid body. NADPase was located within the four of five intermediate saccules of Golgi stacks, and TPPase was found in the last one or two saccules on the trans aspect of the stacks from steps 1 to 17 of spermiogenesis. CMPase was located within the thick saccular GERL elements found in the trans region of the Golgi apparatus from steps 1 to 7 of spermiogenesis, but the CMPase-positive GERL disappeared from the Golgi apparatus after its detachment from the acrosomic system at step 8. Th acrosomic system itself was reactive from CMPase and TPPase but was negative for NADPase, while the multivesicular bodies were CMPase and NADPase positive but unreactive for TPPase. Tritiated-fucose was readily incorporated within the Golgi apparatus of steps 1-17 spermatids; in steps 1-7 it was subsequently incorporated within the acrosomic system and multivesicular bodies. These various data indicated (1) that the Golgi apparatus of spermatids, although it loses its CMPase-positive GERL element in step 8, retains evidence of functional capacity until it degenerates in step 17; (2) that in early spermatids the various saccular components of the Golgi are specialized with respect to enzymatic activities; and (3) that each Golgi region may contribute in a coordinated fashion to the formation of the acrosomic system and multivesicular bodies.
Topics: Animals; Fucose; Golgi Apparatus; Histocytochemistry; Male; Nucleotidases; Rats; Sperm Maturation; Spermatids; Spermatogenesis; Spermatozoa; Thiamine Pyrophosphatase; Tritium
PubMed: 6124118
DOI: 10.1002/aja.1001630402 -
Theory in Biosciences = Theorie in Den... Jun 2008Many complex cellular processes involve major changes in topology and geometry. We have developed a method using topology-based geometric modelling in which the edge... (Review)
Review
Many complex cellular processes involve major changes in topology and geometry. We have developed a method using topology-based geometric modelling in which the edge labels of an n-dimensional generalized map (a subclass of graphs) represent the relations between neighbouring biological compartments. We illustrate our method using two topological models of the Golgi apparatus. These models can be animated using transformation rules, which depend on geometric and/or biochemical data and which modify both these data and the topology. Both models constitute plausible topological representations of the Golgi apparatus, but only the model based on a recent hypothesis about the Golgi apparatus is fully compatible with data from electron microscopy. Finally, we outline how our method may help biologists to choose between different hypotheses.
Topics: Animals; Golgi Apparatus; Humans; Models, Anatomic; Models, Biological; Protein Transport; Signal Transduction; Systems Biology
PubMed: 18458977
DOI: 10.1007/s12064-008-0030-3 -
Cell Dec 1999
Review
Topics: Animals; Cell Division; Endoplasmic Reticulum; Golgi Apparatus; Microscopy, Fluorescence
PubMed: 10612391
DOI: 10.1016/s0092-8674(00)81544-5 -
Microscopic morphology and the origins of the membrane maturation model of Golgi apparatus function.International Review of Cytology 2007The membrane maturation (flow differentiation) model of Golgi apparatus function embodies concepts of saccule formation at one face of the Golgi apparatus from membranes... (Review)
Review
The membrane maturation (flow differentiation) model of Golgi apparatus function embodies concepts of saccule formation at one face of the Golgi apparatus from membranes derived from endoplasmic reticulum and utilization of saccules in vesicle formation at the opposite face for delivery to the plasma membrane as existing saccules are displaced from one position within the stack to another. Derivation of the model came almost entirely from light and electron microscopy. Especially important were observations that passage through the Golgi apparatus was accompanied by differentiation of membranes from endoplasmic reticulum-like to plasma membrane-like across the polarity axis of the stacked saccules. The concept of coparticipation of endoplasmic reticulum and/or nuclear envelope, transition, and secretory vesicles and other pre- and post-Golgi apparatus structures through the operation of an integrated endomembrane system was essential to the model. Dynamic aspects confirmed initially by autoradiographing and cell fractionation studies have been corroborated in newer approaches of fluorescent labeling and with living cells.
Topics: Animals; Cell Membrane; Endoplasmic Reticulum; Golgi Apparatus; Intracellular Membranes; Microscopy, Electron; Models, Biological; Plants; Secretory Vesicles
PubMed: 17631189
DOI: 10.1016/S0074-7696(07)62004-X -
Histochemistry and Cell Biology Sep 2013The central organelle within the secretory pathway is the Golgi apparatus, a collection of flattened membranes organized into stacks. The cisternal maturation model of... (Review)
Review
The central organelle within the secretory pathway is the Golgi apparatus, a collection of flattened membranes organized into stacks. The cisternal maturation model of intra-Golgi transport depicts Golgi cisternae that mature from cis to medial to trans by receiving resident proteins, such as glycosylation enzymes via retrograde vesicle-mediated recycling. The conserved oligomeric Golgi (COG) complex, a multi-subunit tethering complex of the complexes associated with tethering containing helical rods family, organizes vesicle targeting during intra-Golgi retrograde transport. The COG complex, both physically and functionally, interacts with all classes of molecules maintaining intra-Golgi trafficking, namely SNAREs, SNARE-interacting proteins, Rabs, coiled-coil tethers, vesicular coats, and molecular motors. In this report, we will review the current state of the COG interactome and analyze possible scenarios for the molecular mechanism of the COG orchestrated vesicle targeting, which plays a central role in maintaining glycosylation homeostasis in all eukaryotic cells.
Topics: Adaptor Proteins, Vesicular Transport; Animals; Biological Transport; Eukaryotic Cells; Glycosylation; Golgi Apparatus; Homeostasis; Humans; Intracellular Membranes
PubMed: 23839779
DOI: 10.1007/s00418-013-1117-6 -
Bioconjugate Chemistry Nov 2022Despite the enormous progress in genomics and proteomics, it is still challenging to assess the states of organelles in living cells with high spatiotemporal resolution....
Despite the enormous progress in genomics and proteomics, it is still challenging to assess the states of organelles in living cells with high spatiotemporal resolution. Based on our recent finding of enzyme-instructed self-assembly of a thiophosphopeptide that targets the Golgi Apparatus (GA) instantly, we use the thiophosphopeptide, which is enzymatically responsive and redox active, as an integrative probe for revealing the state of the GA of live cells at the single cell level. By imaging the probe in the GA of live cells over time, our results show that the accumulation of the probe at the GA depends on cell types. By comparison to a conventional Golgi probe, this self-assembling probe accumulates at the GA much faster and are sensitive to the expression of alkaline phosphatases. In addition, subtle changes of the fluorophore results in slightly different GA responses. This work illustrates a novel class of active molecular probes that combine enzyme-instructed self-assembly and redox reaction for high-resolution imaging of the states of subcellular organelles over a large area and extended times.
Topics: Golgi Apparatus; Fluorescent Dyes; Microscopy, Fluorescence; Organelles; Alkaline Phosphatase
PubMed: 35312281
DOI: 10.1021/acs.bioconjchem.2c00084 -
Trends in Cell Biology Jan 1998The intermediate compartment residing between the endoplasmic reticulum (ER) and the Golgi is now recognized to be a dynamic structure that captures cargo released from... (Review)
Review
The intermediate compartment residing between the endoplasmic reticulum (ER) and the Golgi is now recognized to be a dynamic structure that captures cargo released from the ER in COPII vesicular carriers and promotes recycling by COPI vesicular carriers. These and other findings now provide compelling evidence for the importance of this intermediate in balancing anterograde and retrograde flow through the early secretory pathway and in the formation and maintenance of the Golgi stack.
Topics: Amino Acid Sequence; Animals; Biological Transport; Golgi Apparatus; Humans; Membrane Proteins; Molecular Sequence Data
PubMed: 9695803
DOI: 10.1016/s0962-8924(97)01184-7 -
Methods in Enzymology 2010Proteins and glycolipids are modified by various modes of glycosylation in the endoplasmic reticulum (ER) and the Golgi apparatus. It is well known that the lumen of the... (Review)
Review
Proteins and glycolipids are modified by various modes of glycosylation in the endoplasmic reticulum (ER) and the Golgi apparatus. It is well known that the lumen of the Golgi is acidic and compromising acidification by chemical compounds causes impaired glycosylation and transport of proteins (Axelsson et al., 2001; Chapman and Munro, 1994; Palokangas et al., 1994; Presley et al., 1997; Puri et al., 2002; Reaves and Banting, 1994; Rivinoja et al., 2006; Tartakoff et al., 1978). The mechanisms by which glycosylation and transport are regulated by an acidic pH remain largely unknown. Recent findings that the impaired regulation of an acidic environment may be implicated in the pathology of several diseases emphasize the importance of pH regulation (Jentsch, 2007; Kasper et al., 2005; Kornak et al., 2001; Kornak et al., 2008; Piwon et al., 2000; Stobrawa et al., 2001; Teichgraber et al., 2008). We recently established a mutant cell line in which Golgi acidification was selectively impaired and the raised luminal Golgi pH caused impaired transport and glycosylation of proteins and altered Golgi morphology (Maeda et al., 2008). As alkalinizing compounds nonselectively affect all acidic organelles including lysosomes, endosomes, and the Golgi, the mutant cell is thought to be useful in analyzing how the acidic environment of the Golgi regulates glycosylation. In this chapter, we have introduced how we established mutant cells with impaired Golgi acidification and methods for measuring Golgi pH.
Topics: Acids; Animals; Cell Culture Techniques; Genes, Reporter; Genetic Techniques; Glycosylation; Golgi Apparatus; Humans; Hydrogen-Ion Concentration; Models, Biological; Mutagenesis; Protein Processing, Post-Translational; Protein Transport; Proteins; Staining and Labeling
PubMed: 20816224
DOI: 10.1016/S0076-6879(10)80022-9 -
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 -
Biochemical Society Transactions Jun 2006The unique lipid composition of the Golgi membranes is critical for maintaining their structural and functional identity, and is regulated by local lipid metabolism, a... (Review)
Review
The unique lipid composition of the Golgi membranes is critical for maintaining their structural and functional identity, and is regulated by local lipid metabolism, a variety of lipid-binding, -modifying, -sensing and -transfer proteins, and by selective lipid sorting mechanisms. A growing body of evidence suggests that certain lipids, such as phosphoinositides and diacylglycerol, regulate Golgi-mediated transport events. However, their exact role in this process, and the underlying mechanisms that maintain their critical levels in specific membrane domains of the Golgi apparatus, remain poorly understood. Nevertheless, recent advances have revealed key regulators of lipid homoeostasis in the Golgi complex and have demonstrated their role in Golgi secretory function.
Topics: Animals; Golgi Apparatus; Homeostasis; Humans; Lipid Metabolism; Lipids
PubMed: 16709162
DOI: 10.1042/BST0340363