scholarly journals Vesicle-associated Membrane Protein (VAMP)/Synaptobrevin-2 Is Associated with Dense Core Secretory Granules in PC12 Neuroendocrine Cells

1995 ◽  
Vol 270 (3) ◽  
pp. 1332-1336 ◽  
Author(s):  
Emanuele Papini ◽  
Ornella Rossetto ◽  
Daniel F. Cutler
Keyword(s):  
Membrane Protein ◽  
Secretory Granules ◽  
Neuroendocrine Cells ◽  
Dense Core

scholarly journals Secretagogue-dependent phosphorylation of phogrin, an insulin granule membrane protein tyrosine phosphatase homologue

1999 ◽  
Vol 341 (3) ◽  
pp. 563-569 ◽  
Author(s):  
Christina WASMEIER ◽  
John C. HUTTON
Keyword(s):  
Protein Kinase ◽  
Membrane Protein ◽  
Time Course ◽  
Secretory Granules ◽  
Tyrosine Phosphatase ◽  
Signal Transduction Pathway ◽  
Integral Membrane Protein ◽  
Neuroendocrine Cells ◽  
Calmodulin Antagonist ◽  
Min6 Cells

Phogrin, a 60/64 kDa integral membrane protein localized to dense-core secretory granules of neuroendocrine cells, was found to be reversibly phosphorylated in intact pancreatic β-cells. Phosphorylation occurred in response to a variety of secretory stimuli, including glucose and depolarizing concentrations of K+. In MIN6 cells, the glucose dose-response and time course of phogrin phosphorylation paralleled that of insulin secretion. Like secretion, glucose- or K+-stimulated phosphorylation required the presence of Ca2+. The calmodulin antagonist W-7 and the Ca2+/calmodulin-dependent kinase II inhibitor KN-93 dose-dependently inhibited both phosphorylation and secretion, while the ‘inactive’ analogue KN-92 was effective only at significantly higher concentrations. Phosphorylation of phogrin was also stimulated in cells exposed to forskolin, an effect presumably mediated by protein kinase A (cAMP-dependent protein kinase). Under these conditions, phogrin phosphorylation could be dissociated from the secretory response. In MIN6 cells, as in pancreatic islets, cAMP potentiates rather than initiates insulin release. Thus our observations are consistent with a role for phogrin phosphorylation in the signal-transduction pathway at a site proximal to the exocytic event itself, possibly regulating secretory-granule mobilization and recruitment to the exocytic site.

scholarly journals Protein p38: an integral membrane protein specific for small vesicles of neurons and neuroendocrine cells.

1986 ◽  
Vol 103 (6) ◽  
pp. 2511-2527 ◽  
Author(s):  
F Navone ◽  
R Jahn ◽  
G Di Gioia ◽  
H Stukenbrok ◽  
P Greengard ◽  
...  
Keyword(s):  
Nervous System ◽  
Membrane Protein ◽  
Synaptic Vesicles ◽  
Secretory Granules ◽  
Light And Electron Microscopy ◽  
Immunoblot Analysis ◽  
Integral Membrane Protein ◽  
Neuroendocrine Cells ◽  
Synapsin I ◽  
Large Dense Core Vesicles

An intrinsic membrane protein of brain synaptic vesicles with Mr 38,000 (p38, synaptophysin) has recently been partially characterized (Jahn, R., W. Schiebler, C. Ouimet, and P. Greengard, 1985, Proc. Natl. Acad. Sci. USA, 83:4137-4141; Wiedenmann, B., and W. W. Franke, 1985, Cell, 41:1017-1028). We have now studied the presence of p38 in a variety of tissues by light and electron microscopy immunocytochemistry and by immunochemistry. Our results indicate that, within the nervous system, p38, like the neuron-specific phosphoprotein synapsin I, is present in virtually all nerve terminals and is selectively associated with small synaptic vesicles (SSVs). No p38 was detectable on large dense-core vesicles (LDCVs). p38 and synapsin I were found to be present in similar concentrations throughout the brain. Outside the nervous system, p38 was found in a variety of neuroendocrine cells, but not in any other cell type. In neuroendocrine cells p38 was localized on a pleiomorphic population of small, smooth-surfaced vesicles, which were interspersed among secretory granules and concentrated in the Golgi area, but not on the secretory granules themselves. Immunoblot analysis of endocrine tissues and cell lines revealed a band with a mobility slightly different from that of neuronal p38. This difference was attributable to a difference in glycosylation. The finding that p38, like synapsin I, is a component of SSVs of virtually all neurons, but not of LDCVs, supports the idea that SSVs and LDCVs are organelles of two distinct pathways for regulated neuronal secretion. In addition, our results indicate the presence in a variety of neuroendocrine cells of an endomembrane system, which is related to SSVs of neurons but is distinct from secretory granules.

scholarly journals Dense core secretory vesicles revealed as a dynamic Ca2+store in neuroendocrine cells with a vesicle-associated membrane protein aequorin chimaera

2001 ◽  
Vol 155 (1) ◽  
pp. 41-52 ◽  
Author(s):  
Kathryn J. Mitchell ◽  
Paolo Pinton ◽  
Aniko Varadi ◽  
Carlo Tacchetti ◽  
Edward K. Ainscow ◽  
...  
Keyword(s):  
Membrane Protein ◽  
Neuroendocrine Cells ◽  
Dense Core ◽  
Secretory Vesicles

scholarly journals Secretagogue-triggered Transfer of Membrane Proteins from Neuroendocrine Secretory Granules to Synaptic-like Microvesicles

1999 ◽  
Vol 10 (8) ◽  
pp. 2619-2630 ◽  
Author(s):  
Jane E. Strasser ◽  
Monica Arribas ◽  
Anastasia D. Blagoveshchenskaya ◽  
Daniel F. Cutler
Keyword(s):  
Membrane Proteins ◽  
Membrane Protein ◽  
Pc12 Cells ◽  
Transferrin Receptor ◽  
Fluorescent Protein ◽  
Secretory Granules ◽  
Chimeric Protein ◽  
Neuroendocrine Cells ◽  
Dense Core Granules ◽  
Green Fluorescent

The membrane proteins of all regulated secretory organelles (RSOs) recycle after exocytosis. However, the recycling of those membrane proteins that are targeted to both dense core granules (DCGs) and synaptic-like microvesicles (SLMVs) has not been addressed. Since neuroendocrine cells contain both RSOs, and the recycling routes that lead to either organelle overlap, transfer between the two pools of membrane proteins could occur during recycling. We have previously demonstrated that a chimeric protein containing the cytosolic and transmembrane domains of P-selectin coupled to horseradish peroxidase is targeted to both the DCG and the SLMV in PC12 cells. Using this chimera, we have characterized secretagogue-induced traffic in PC12 cells. After stimulation, this chimeric protein traffics from DCGs to the cell surface, internalizes into transferrin receptor (TFnR)-positive endosomes and thence to a population of secretagogue-responsive SLMVs. We therefore find a secretagogue-dependent rise in levels of HRP within SLMVs. In addition, the levels within SLMVs of the endogenous membrane protein, synaptotagmin, as well as a green fluorescent protein-tagged version of vesicle-associated membrane protein (VAMP)/synaptobrevin, also show a secretagogue-dependent increase.

Synaptic Transmission in the Immune System

e-Neuroforum ◽  
2017 ◽  
Vol 23 (4) ◽  
Author(s):  
Jens Rettig ◽  
David R. Stevens
Keyword(s):  
Nervous System ◽  
Immune System ◽  
Synaptic Transmission ◽  
Molecular Mechanisms ◽  
Secretory Granules ◽  
Neuroendocrine Cells ◽  
Regulated Exocytosis ◽  
Protein Receptor ◽  
Immunological Synapses ◽  
Immunological Diseases

AbstractThe release of neurotransmitters at synapses belongs to the most important processes in the central nervous system. In the last decades much has been learned about the molecular mechanisms which form the basis for this fundamental process. Highly regulated exocytosis, based on the SNARE (soluble N-ethylmaleimide-sensitive attachment protein receptor) complex and its regulatory molecules is the signature specialization of the nervous system and is shared by neurons and neuroendocrine cells. Cells of the immune system use a similar mechanism to release cytotoxic materials from secretory granules at contacts with virally or bacterially infected cells or cancer cells, in order to remove these threats. These contact zones have been termed immunological synapses in reference to the highly specific targeted exocytosis of effector molecules. Recent findings indicate that mutations in SNARE or SNARE-interacting proteins are the basis of a number of devastating immunological diseases. While SNARE complexes are ubiquitous and mediate a wide variety of membrane fusion events it is surprising that in many cases the SNARE proteins involved in immunological synapses are the same molecules which mediate regulated exocytosis of transmitters and hormones in neurons and neuroendocrine cells. These similarities raise the possibility that results obtained at immunological synapses may be applicable, in particular in the area of presynaptic function, to neuronal synapses. Since immunological synapses (IS) are assembled and disassembled in about a half an hour, the use of immune cells isolated from human blood allows not only the study of the molecular mechanisms of synaptic transmission in human cells, but is particularly suited to the examination of the assembly and disassembly of these “synapses” via live imaging. In this overview we discuss areas of similarity between synapses of the nervous and immune systems and in the process will refer to results of our experiments of the last few years.

scholarly journals HID-1 controls formation of large dense core vesicles by influencing cargo sorting and trans-Golgi network acidification

2017 ◽  
Vol 28 (26) ◽  
pp. 3870-3880 ◽  
Author(s):  
Blake H. Hummer ◽  
Noah F. de Leeuw ◽  
Christian Burns ◽  
Lan Chen ◽  
Matthew S. Joens ◽  
...  
Keyword(s):  
Biochemical Properties ◽  
Neuroendocrine Cells ◽  
Dense Core ◽  
Core Formation ◽  
Dense Core Vesicles ◽  
Atpase Subunit ◽  
Trans Golgi Network ◽  
Large Dense Core Vesicles ◽  
Golgi Network ◽  
Cargo Sorting

Large dense core vesicles (LDCVs) mediate the regulated release of neuropeptides and peptide hormones. They form at the trans-Golgi network (TGN), where their soluble content aggregates to form a dense core, but the mechanisms controlling biogenesis are still not completely understood. Recent studies have implicated the peripheral membrane protein HID-1 in neuropeptide sorting and insulin secretion. Using CRISPR/Cas9, we generated HID-1 KO rat neuroendocrine cells, and we show that the absence of HID-1 results in specific defects in peptide hormone and monoamine storage and regulated secretion. Loss of HID-1 causes a reduction in the number of LDCVs and affects their morphology and biochemical properties, due to impaired cargo sorting and dense core formation. HID-1 KO cells also exhibit defects in TGN acidification together with mislocalization of the Golgi-enriched vacuolar H+-ATPase subunit isoform a2. We propose that HID-1 influences early steps in LDCV formation by controlling dense core formation at the TGN.

Synaptotagmin-1: A Multi-Functional Protein that Mediates Vesicle Docking, Priming, and Fusion

2021 ◽  
Vol 22 ◽  
Author(s):  
Najeeb Ullah ◽  
Ezzouhra El Maaiden ◽  
Md. Sahab Uddin ◽  
Ghulam Md Ashraf
Keyword(s):  
Plasma Membrane ◽  
Secretory Granules ◽  
Secretory Vesicle ◽  
Neuroendocrine Cells ◽  
Snare Complex ◽  
Secretory Vesicles ◽  
Functional Protein ◽  
Vesicle Docking ◽  
Synaptotagmin 1

: The fusion of secretory vesicles with the plasma membrane depends on the assembly of v-SNAREs (VAMP2/synaptobrevin2) and t-SNAREs (SNAP25/syntaxin1) into the SNARE complex. Vesicles go through several upstream steps, referred to as docking and priming, to gain fusion competence. The vesicular protein synaptotagmin-1 (Syt-1) is the principal Ca2+ sensor for fusion in several central nervous system neurons and neuroendocrine cells and part of the docking complex for secretory granules. Syt-1 binds to the acceptor complex such as synaxin1, SNAP-25 on the plasma membrane to facilitate secretory vesicle docking, and upon Ca2+-influx promotes vesicle fusion. This review assesses the role of the Syt-1 protein involved in the secretory vesicle docking, priming, and fusion.

scholarly journals Trachynilysin mediates SNARE-dependent release of catecholamines from chromaffin cells via external and stored Ca2+

2000 ◽  
Vol 113 (7) ◽  
pp. 1119-1125 ◽  
Author(s):  
F.A. Meunier ◽  
C. Mattei ◽  
P. Chameau ◽  
G. Lawrence ◽  
C. Colasante ◽  
...  
Keyword(s):  
Chromaffin Cells ◽  
Motor Nerve ◽  
Neuroendocrine Cells ◽  
Dense Core ◽  
Frog Neuromuscular Junction ◽  
Dense Core Vesicles ◽  
Protein Receptor ◽  
Large Dense Core Vesicles ◽  
Quantal Transmitter Release ◽  
Bovine Chromaffin Cells

Trachynilysin, a 159 kDa dimeric protein purified from stonefish (Synanceia trachynis) venom, dramatically increases spontaneous quantal transmitter release at the frog neuromuscular junction, depleting small clear synaptic vesicles, whilst not affecting large dense core vesicles. The basis of this insensitivity of large dense core vesicles exocytosis was examined using a fluorimetric assay to determine whether the toxin could elicit catecholamine release from bovine chromaffin cells. Unlike the case of the motor nerve endings, nanomolar concentrations of trachynilysin evoked sustained Soluble N-ethylmaleimide-sensitive fusion protein Attachment Protein REceptor-dependent exocytosis of large dense core vesicles, but only in the presence of extracellular Ca2+. However, this response to trachynilysin does not rely on Ca2+ influx through voltage-activated Ca2+ channels because the secretion was only slightly affected by blockers of L, N and P/Q types. Instead, trachynilysin elicited a localized increase in intracellular fluorescence monitored with fluo-3/AM, that precisely co-localized with the increase of fluorescence resulting from caffeine-induced release of Ca2+ from intracellular stores. Moreover, depletion of the latter stores inhibited trachynilysin-induced exocytosis. Thus, the observed requirement of external Ca2+ for stimulation of large dense core vesicles exocytosis from chromaffin cells implicates plasma membrane channels that signal efflux of Ca2+ from intracellular stores. This study also suggests that the bases of exocytosis of large dense core vesicles from motor nerve terminals and neuroendocrine cells are distinct.

scholarly journals The Small GTPase RalA Controls Exocytosis of Large Dense Core Secretory Granules by Interacting with ARF6-dependent Phospholipase D1

2005 ◽  
Vol 280 (33) ◽  
pp. 29921-29928 ◽  
Author(s):  
Nicolas Vitale ◽  
Jacques Mawet ◽  
Jacques Camonis ◽  
Romano Regazzi ◽  
Marie-France Bader ◽  
...  
Keyword(s):  
Secretory Granules ◽  
Small Gtpase ◽  
Dense Core ◽  
Phospholipase D1
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