Gliotransmission: focus on exocytotic release of L-glutamate and D-serine from astrocytes

2013 ◽  
Vol 41 (6) ◽  
pp. 1557-1561 ◽  
Author(s):  
Magalie Martineau
Keyword(s):  
Amino Acids ◽  
Plasma Membrane ◽  
Synaptic Plasticity ◽  
Membrane Proteins ◽  
Cognitive Functions ◽  
Neurological Disorders ◽  
Excitatory Amino Acids ◽  
Neuroendocrine Cells ◽  
Present Review ◽  
Regulated Exocytosis

The release of neuromodulators, called gliotransmitters, by astrocytes is proposed to modulate neurotransmission and synaptic plasticity, and thereby cognitive functions; but they are also proposed to have a role in diverse neurological disorders. Two main routes have been proposed to ensure gliotransmitter release: non-exocytotic release from cytosolic pools through plasma membrane proteins, and Ca2+-regulated exocytosis through the fusion of gliotransmitter-storing secretory organelles. Regulated Ca2+-dependent glial exocytosis has received much attention and is appealing since its existence endows astrocytes with some of the basic properties thought to be exclusive to neurons and neuroendocrine cells. The present review summarizes recent findings regarding the exocytotic mechanisms underlying the release of two excitatory amino acids, L-glutamate and D-serine.

scholarly journals Regulated Exocytosis in Neuroendocrine Cells: A Role for Subplasmalemmal Cdc42/N-WASP-induced Actin Filaments

2004 ◽  
Vol 15 (2) ◽  
pp. 520-531 ◽  
Author(s):  
Stéphane Gasman ◽  
Sylvette Chasserot-Golaz ◽  
Magali Malacombe ◽  
Michael Way ◽  
Marie-France Bader
Keyword(s):  
Plasma Membrane ◽  
Membrane Trafficking ◽  
Actin Polymerization ◽  
Cell Activation ◽  
Secretory Granules ◽  
Small Gtpases ◽  
Neuroendocrine Cells ◽  
Actin Dynamics ◽  
Cell Periphery ◽  
Regulated Exocytosis

In neuroendocrine cells, actin reorganization is a prerequisite for regulated exocytosis. Small GTPases, Rho proteins, represent potential candidates coupling actin dynamics to membrane trafficking events. We previously reported that Cdc42 plays an active role in regulated exocytosis in chromaffin cells. The aim of the present work was to dissect the molecular effector pathway integrating Cdc42 to the actin architecture required for the secretory reaction in neuroendocrine cells. Using PC12 cells as a secretory model, we show that Cdc42 is activated at the plasma membrane during exocytosis. Expression of the constitutively active Cdc42L61 mutant increases the secretory response, recruits neural Wiskott-Aldrich syndrome protein (N-WASP), and enhances actin polymerization in the subplasmalemmal region. Moreover, expression of N-WASP stimulates secretion by a mechanism dependent on its ability to induce actin polymerization at the cell periphery. Finally, we observed that actin-related protein-2/3 (Arp2/3) is associated with secretory granules and that it accompanies granules to the docking sites at the plasma membrane upon cell activation. Our results demonstrate for the first time that secretagogue-evoked stimulation induces the sequential ordering of Cdc42, N-WASP, and Arp2/3 at the interface between granules and the plasma membrane, thereby providing an actin structure that makes the exocytotic machinery more efficient.

scholarly journals Synaptic Plasticity and Neurological Disorders in Neurotropic Viral Infections

2015 ◽  
Vol 2015 ◽  
pp. 1-14 ◽  
Author(s):  
Venkata Subba Rao Atluri ◽  
Melissa Hidalgo ◽  
Thangavel Samikkannu ◽  
Kesava Rao Venkata Kurapati ◽  
Madhavan Nair
Keyword(s):  
Nervous System ◽  
Synaptic Plasticity ◽  
Cognitive Functions ◽  
Neurological Disorders ◽  
Nervous Tissue ◽  
Viral Infections ◽  
Neurotropic Viruses ◽  
Aids Pandemic

Based on the type of cells or tissues they tend to harbor or attack, many of the viruses are characterized. But, in case of neurotropic viruses, it is not possible to classify them based on their tropism because many of them are not primarily neurotropic. While rabies and poliovirus are considered as strictly neurotropic, other neurotropic viruses involve nervous tissue only secondarily. Since the AIDS pandemic, the interest in neurotropic viral infections has become essential for all clinical neurologists. Although these neurotropic viruses are able to be harbored in or infect the nervous system, not all the neurotropic viruses have been reported to cause disrupted synaptic plasticity and impaired cognitive functions. In this review, we have discussed the neurotropic viruses, which play a major role in altered synaptic plasticity and neurological disorders.

scholarly journals Membrane proteins synthesized by rabbit reticulocytes.

1975 ◽  
Vol 65 (1) ◽  
pp. 51-64 ◽  
Author(s):  
H F Lodish ◽  
B Small
Keyword(s):  
Amino Acids ◽  
Plasma Membrane ◽  
Membrane Proteins ◽  
Cell Plasma Membrane ◽  
Whole Cells ◽  
Predominant Species ◽  
Cytoplasmic Surface ◽  
Cell Plasma ◽  
Intact Rabbit ◽  
Rabbit Reticulocytes

Intact rabbit reticulocyte cells synthesize two predominant species of polypeptides which are components of the cell plasma membrane. Previous work (Lodish, H. F. 1973. Proc. Natl. Acad. Sci. U. S. A. 70:1526-1530.) showed that these proteins were synthesized by polyribosomes not attached to membranes. We show here that both polypeptides are confined to the cytoplasmic surface of the cell membrane. These studies utilized iodination of whole cells and of membranes with lactoperoxidase, and digestion of whole cells and membranes with chymotrypsin, One of these proteins is synthesized as a precursor, and about 20-40 amino acids are removed after it is incorporated into the membrane, We discuss the probable sites of synthesis of these and other classes of membrane proteins.

scholarly journals Speculations on Disease States Induced by Excitatory Amino Acids

1987 ◽  
Vol 14 (2) ◽  
pp. 122-126 ◽  
Author(s):  
John Turnbull
Keyword(s):  
Amino Acids ◽  
Nervous System ◽  
Synaptic Plasticity ◽  
Learning And Memory ◽  
Excitatory Amino Acids ◽  
Degenerative Diseases ◽  
Current Interest ◽  
Disease States ◽  
Cerebral Dysfunction

Abstract:There is much current interest in excitatory amino acids and their receptors because of their postulated involvement in several disorders of the nervous system. They function as neurotransmitters, but can act as neurotoxins in some situations. They have been implicated in the pathogenesis of cerebral hypoxic/ischemic and hypoglycemic damage, in epilepsy, in some degenerative diseases, and in some forms of neurotoxin-induced cerebral dysfunction. These diseases may reflect abnormality in a system which has evolved to provide synaptic plasticity essential for learning and memory. The purpose of this paper is to explore the ramifications of such a hypothesis.

scholarly journals PO133 DIFFERENTIAL EXPRESSION OF PLASMA MEMBRANE PROTEINS IN INFLAMMATORY BREAST CANCER VIA STABLE ISOTOPE LABELED AMINO ACIDS IN CULTURE (SILAC)

The Breast ◽  
2015 ◽  
Vol 24 ◽  
pp. S67
Author(s):  
Michelle M. Martinez-Montemayor ◽  
Ivette J. Suarez-Arroyo ◽  
Yismeilin Feliz-Mosquea ◽  
Juliana Perez-Laspiur ◽  
Rezina Arju ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Amino Acids ◽  
Plasma Membrane ◽  
Stable Isotope ◽  
Membrane Proteins ◽  
Differential Expression ◽  
Inflammatory Breast Cancer ◽  
Plasma Membrane Proteins

Changes Occur in Plasma Membrane Turnover when K562 Leukemia Cells are Induced to Differentiate

1982 ◽  
Vol 40 ◽  
pp. 286-287
Author(s):  
L. M. Marshall
Keyword(s):  
Plasma Membrane ◽  
Membrane Proteins ◽  
Intracellular Transport ◽  
Parent Cell ◽  
Membrane Turnover ◽  
Coated Pits ◽  
Surface Distribution ◽  
Specific Proteins ◽  
Erythroleukemic Cell ◽  
Specific Membrane

A human erythroleukemic cell line, metabolically blocked in a late stage of erythropoiesis, becomes capable of differentiation along the normal pathway when grown in the presence of hemin. This process is characterized by hemoglobin synthesis followed by rearrangement of the plasma membrane proteins and culminates in asymmetrical cytokinesis in the absence of nuclear division. A reticulocyte-like cell buds from the nucleus-containing parent cell after erythrocyte specific membrane proteins have been sequestered into its membrane. In this process the parent cell faces two obstacles. First, to organize its erythrocyte specific proteins at one pole of the cell for inclusion in the reticulocyte; second, to reduce or abolish membrane protein turnover since hemoglobin is virtually the only protein being synthesized at this stage. A means of achieving redistribution and cessation of turnover could involve movement of membrane proteins by a directional lipid flow. Generation of a lipid flow towards one pole and accumulation of erythrocyte-specific membrane proteins could be achieved by clathrin coated pits which are implicated in membrane endocytosis, intracellular transport and turnover. In non-differentiating cells, membrane proteins are turned over and are random in surface distribution. If, however, the erythrocyte specific proteins in differentiating cells were excluded from endocytosing coated pits, not only would their turnover cease, but they would also tend to drift towards and collect at the site of endocytosis. This hypothesis requires that different protein species are endocytosed by the coated vesicles in non-differentiating than by differentiating cells.

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