The Role of the Golgi Apparatus in Mammalian Cell Secretion

1981 ◽  
Vol 39 ◽  
pp. 520-523
Author(s):  
Becca Fleischer
Keyword(s):  
Golgi Apparatus ◽  
Mammalian Cells ◽  
Plasma Membranes ◽  
Sole Source ◽  
Cell Secretion ◽  
Cell Organelles ◽  
Major Function ◽  
Cell Components ◽  
Secretory Products

A major function of the Golgi apparatus of mammalian cells is the transport and modification of secretory products of the cell. These include proteins, glycoproteins, glycolipids, and lipoproteins. Our approach to understanding the role of the Golgi apparatus has been to isolate fractions rich in Golgi apparatus from mammalian tissues and to determine directly what secretory products and enzymic activities are present in these fractions compared to other purified cell components such as plasma membranes, mitochondria, nuclei, and endoplasmic reticulum. In order to accomplish this, we developed methods for this isolation of Golgi apparatus from liver, since methods for the isolation of the other organelles of this tissue were already well developed and liver is the sole source of most of the proteins and glycoproteins secreted into serum. We then applied these techniques with appropriate modification to isolate Golgi apparatus and other purified cell organelles from kidney, which we believe was a better source for study of the biosynthesis of glycolipids.

Role of miRNA-146a in the regulation of the innate immune response and cancer

2008 ◽  
Vol 36 (6) ◽  
pp. 1211-1215 ◽  
Author(s):  
Andrew E. Williams ◽  
Mark M. Perry ◽  
Sterghios A. Moschos ◽  
Hanna M. Larner-Svensson ◽  
Mark A. Lindsay
Keyword(s):  
Immune Response ◽  
Innate Immune Response ◽  
Mammalian Cells ◽  
Mrna Translation ◽  
Nuclear Factor Κb ◽  
Causal Link ◽  
Innate Immune ◽  
Major Function ◽  
Biological Responses

In mammalian cells, miRNAs (microRNAs) are the most abundant family of small non-coding RNAs that regulate mRNA translation through the RNA interference pathway. In general, it appears that the major function of miRNAs is in development, differentiation and homoeostasis, which is indicated by studies showing aberrant miRNA expression during the development of cancer. Interestingly, changes in the expression of miR-146a have been implicated in both the development of multiple cancers and in the negative regulation of inflammation induced via the innate immune response. Furthermore, miR-146a expression is driven by the transcription factor NF-κB (nuclear factor κB), which has been implicated as an important causal link between inflammation and carcinogenesis. In the present article, we review the evidence for a role of miR-146a in innate immunity and cancer and assess whether changes in miR-146a might link these two biological responses.

scholarly journals The centrosome–Golgi apparatus nexus

2014 ◽  
Vol 369 (1650) ◽  
pp. 20130462 ◽  
Author(s):  
Rosa M. Rios
Keyword(s):  
Golgi Apparatus ◽  
Mammalian Cells ◽  
Molecular Mechanisms ◽  
Animal Cells ◽  
Critical Feature ◽  
Differentiated Cells ◽  
Ribbon Structure ◽  
Centrosomal Proteins ◽  
Dependent Processes

A shared feature among all microtubule (MT)-dependent processes is the requirement for MTs to be organized in arrays of defined geometry. At a fundamental level, this is achieved by precisely controlling the timing and localization of the nucleation events that give rise to new MTs. To this end, MT nucleation is restricted to specific subcellular sites called MT-organizing centres. The primary MT-organizing centre in proliferating animal cells is the centrosome. However, the discovery of MT nucleation capacity of the Golgi apparatus (GA) has substantially changed our understanding of MT network organization in interphase cells. Interestingly, MT nucleation at the Golgi apparently relies on multiprotein complexes, similar to those present at the centrosome, that assemble at the cis -face of the organelle. In this process, AKAP450 plays a central role, acting as a scaffold to recruit other centrosomal proteins important for MT generation. MT arrays derived from either the centrosome or the GA differ in their geometry, probably reflecting their different, yet complementary, functions. Here, I review our current understanding of the molecular mechanisms involved in MT nucleation at the GA and how Golgi- and centrosome-based MT arrays work in concert to ensure the formation of a pericentrosomal polarized continuous Golgi ribbon structure, a critical feature for cell polarity in mammalian cells. In addition, I comment on the important role of the Golgi-nucleated MTs in organizing specialized MT arrays that serve specific functions in terminally differentiated cells.

scholarly journals Polyphenols as Modulators of Aquaporin Family in Health and Disease

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Diana Fiorentini ◽  
Laura Zambonin ◽  
Francesco Vieceli Dalla Sega ◽  
Silvana Hrelia
Keyword(s):  
Plasma Membranes ◽  
Skin Diseases ◽  
Water Channel ◽  
Bioactive Molecules ◽  
Food Sources ◽  
Major Function ◽  
Cell Plasma ◽  
Original Analysis ◽  
Health And Disease

Polyphenols are bioactive molecules widely distributed in fruits, vegetables, cereals, and beverages. Polyphenols in food sources are extensively studied for their role in the maintenance of human health and in the protection against development of chronic/degenerative diseases. Polyphenols act mainly as antioxidant molecules, protecting cell constituents against oxidative damage. The enormous number of polyphenolic compounds leads to huge different mechanisms of action not fully understood. Recently, some evidence is emerging about the role of polyphenols, such as curcumin, pinocembrin, resveratrol, and quercetin, in modulating the activity of some aquaporin (AQP) isoforms. AQPs are integral, small hydrophobic water channel proteins, extensively expressed in many organs and tissues, whose major function is to facilitate the transport of water or glycerol over cell plasma membranes. Here we summarize AQP physiological functions and report emerging evidence on the implication of these proteins in a number of pathophysiological processes. In particular, this review offers an overview about the role of AQPs in brain, eye, skin diseases, and metabolic syndrome, focusing on the ability of polyphenols to modulate AQP expression. This original analysis can contribute to elucidating some peculiar effects exerted by polyphenols and can lead to the development of an innovative potential preventive/therapeutic strategy.

Immunolocalization of the intracellular sites of accumulation of mutant influenza hemagglutinins by Electron Microscopy

1989 ◽  
Vol 47 ◽  
pp. 968-969
Author(s):  
K. McCammon ◽  
M. Segal ◽  
J. Sambrook ◽  
M. J. Gething ◽  
A. McDowall
Keyword(s):  
Electron Microscopy ◽  
Golgi Apparatus ◽  
Mammalian Cells ◽  
Intracellular Transport ◽  
Secretory Pathway ◽  
Cysteine Residue ◽  
Homologous Sequence ◽  
Golgi Compartment ◽  
Golgi Network

The hemagglutinin (HA) of influenza virus has been used as a model system to study the biosynthesis and intracellular transport of integral membrane proteins in mammalian cells. To investigate the role of protein structure in facilitating transport along the secretory pathway, we have examined the expression in monkey CV-1 cells of a large number of mutant HA molecules. The majority of the HA mutants do not progress along the secretory pathway and accumulate in the endoplasmic reticulum (ER), and we have shown that assembly of newly-synthesized HA monomers into correctly folded trimeric structures is required for transport of the protein to the Golgi apparatus. By contrast, only one HA mutant has beegn characterized whose transport is blocked at a post-Golgi stage of the pathway and thus little is known about the factors involved in the sorting of the HA molecule from the Golgi apparatus to the plasma membrane (PM). In this study we are using electron microscopy to precisely define the intracellular site of accumulation of two mutant HAs whose transport is blocked at different stages of the secretory pathway. In mutant HAJS67, a cysteine residue (cys67) involved in a key disulfide bond has been substituted by a serine residue. In mutant HA164, the 10 amino acid cytoplasmic tail of the wild-type HA has been replaced by a non-homologous sequence of 16 amino acids. Biochemical and immunof1uoresence analyses have indicated that HAJS67 molecules remain in the ER compartment while HA164 is largely confined to a post-Golgi compartment, possibly the trans Golgi network (TGN).

Studies on the Epidermis of Temnocephala Iv. Observations on the Ultrastructure of the Epidermis of Temnocephala Dendyi, With Notes on the Role of the Golgi Apparatus in Autolysis.

1979 ◽  
Vol 27 (4) ◽  
pp. 483 ◽  
Author(s):  
JB Williams
Keyword(s):  
Golgi Apparatus ◽  
Plasma Membranes ◽  
Close Association ◽  
Phagocytic Cells ◽  
Functional Characteristics ◽  
Cell Processes ◽  
Residual Bodies ◽  
Myelin Figures

The epidermis of Temnocephala dendyi is a patchwork of several syncytial epithelia with different structural and functional characteristics. Adjacent epithelia are limited by lateral plasma membranes and cohere by junctional structures. Cell processes which protrude into the epidermis appear to function in the transport of metabolites. Small vesicles fuse to form the double isolation membranes of autophagosomes: larger, Golgi-derived vesicles, interpreted as primary lysosomes, are enclosed with the sequestered cytoplasm. The formation of autolysosomes from autophagosomes is described. A possible mode of formation of myelin figures in autolysis is suggested. Autolysosomes form linear sequences and may occur in close association with Golgi cisternae. Advanced autolysosomes or residual bodies are transported elsewhere by phagocytic cells of the parenchyma. Starvation evidently induces a greatly enhanced autophagy, with presumed diminution in volume, in the temnocephalid epidermis. [For part III see Hm/A 48, 1332.] [AS]

Golgi Apparatus Secretion of Vacuolar Substances in Maize Root Cells

1976 ◽  
Vol 34 ◽  
pp. 44-45
Author(s):  
H. H. Mollenhauer ◽  
J. E. Hanson
Keyword(s):  
Cell Wall ◽  
Golgi Apparatus ◽  
Mammalian Cells ◽  
Secretory Vesicle ◽  
General Mechanism ◽  
Secretory Vesicles ◽  
Extracellular Medium ◽  
Root Cells ◽  
Ultrastructural Studies ◽  
Secretory Products

It has long been known that secretory vesicles from the Golgi apparatus discharge their contents through the plasmalemma by a process of membrane fusion called exocytosis (2,3). Ultrastructural studies have shown that the membrane of the secretory vesicle fuses with the plasmalemma, opens up at the site of fusion, and then discharges the vesicle product to the extracellular medium (i.e., to the lumen or cell wall) (2,3). Exocytosis is recognized as a widely occurring, and possibly general, mechanism for the discharge of macromolecular secretory products (2,3). A similar mechanism is also operable for the transfer of Golgi apparatus product into the acrosome (a lysosome) of mammalian cells (4).

scholarly journals GM130-dependent Control of Cdc42 Activity at the Golgi Regulates Centrosome Organization

2009 ◽  
Vol 20 (4) ◽  
pp. 1192-1200 ◽  
Author(s):  
Andrew Kodani ◽  
Irene Kristensen ◽  
Lan Huang ◽  
Christine Sütterlin
Keyword(s):  
Golgi Apparatus ◽  
Mammalian Cells ◽  
Rho Gtpase ◽  
Nucleotide Exchange ◽  
Interacting Protein ◽  
Guanine Nucleotide Exchange ◽  
Nucleotide Exchange Factor ◽  
Golgi Protein ◽  
And Function

The physical proximity of the Golgi apparatus and the centrosome is a unique feature of mammalian cells whose functional significance is only poorly understood. Here, we demonstrate that the previously described regulation of centrosome organization and function by the Golgi protein, GM130, involves a Golgi-associated complex consisting of GM130, the Rho GTPase, Cdc42, and its guanine nucleotide exchange factor, Tuba. We identified Tuba as a novel GM130-interacting protein and showed that this association controls Tuba-mediated activation of Cdc42 at the Golgi apparatus. Blocking either Tuba or Cdc42 activity reproduced the GM130 depletion phenotype of aberrant, nonfunctional centrosomes. Expression of constitutively active Cdc42 bypassed the requirement for GM130 in centrosome regulation, indicating that Cdc42 functions downstream of GM130. Our studies demonstrate that Cdc42 has a novel role in controlling centrosome organization in unstimulated cells in addition to its known function as a regulator of centrosome reorientation in stimulated cells. This first description of a regulatory pathway between the Golgi apparatus and the interphase centrosome that complements the known role of Golgi proteins in controlling spindle formation during mitosis and may provide an explanation for the pericentriolar position of the mammalian Golgi apparatus during interphase.

Ultrastructure of Giant Mitochondria and Their Inclusions in Schwann Cells of Bovine Splenic Nerve

1974 ◽  
Vol 32 ◽  
pp. 194-195
Author(s):  
Å. Thureson-Klein
Keyword(s):  
Schwann Cells ◽  
Cell Organelles ◽  
Giant Mitochondria ◽  
Matrix Density ◽  
Physiological Conditions ◽  
Unmyelinated Axons ◽  
Internal Structures ◽  
Structural Abnormalities ◽  
Cytotoxic Compounds ◽  
Cell Components

Giant mitochondria of various shapes and with different internal structures and matrix density have been observed in a great number of tissues including nerves. In most instances, the presence of giant mitochondria has been associated with a known disease or with abnormal physiological conditions such as anoxia or exposure to cytotoxic compounds. In these cases degenerative changes occurred in other cell organelles and, therefore the giant mitochondria also were believed to be induced structural abnormalities.Schwann cells ensheating unmyelinated axons of bovine splenic nerve regularly contain giant mitochondria in addition to the conventional smaller type (Fig. 1). These nerves come from healthy inspected animals presumed not to have been exposed to noxious agents. As there are no drastic changes in the small mitochondria and because other cell components also appear reasonably well preserved, it is believed that the giant mitochondria are normally present jin vivo and have not formed as a post-mortem artifact.

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