Purification and pH-Dependent Secretory Vesicle Membrane Binding of Chromogranin B

Biochemistry ◽  
1995 ◽  
Vol 34 (27) ◽  
pp. 8680-8686 ◽  
Author(s):  
Seung Hyun Yoo
Keyword(s):  
Membrane Binding ◽  
Secretory Vesicle ◽  
Chromogranin B ◽  
Vesicle Membrane ◽  
Ph Dependent

scholarly journals Kiss-and-Coat and Compartment Mixing: Coupling Exocytosis to Signal Generation and Local Actin Assembly

2006 ◽  
Vol 17 (4) ◽  
pp. 1495-1502 ◽  
Author(s):  
Anna M. Sokac ◽  
William M. Bement
Keyword(s):  
Cell Types ◽  
Secretory Vesicle ◽  
Signal Generation ◽  
General Mechanism ◽  
Fusion Pore ◽  
Secretory Vesicles ◽  
Actin Assembly ◽  
Vesicle Membrane ◽  
Regulated Exocytosis ◽  
Broad Variety

Regulated exocytosis is thought to occur either by “full fusion,” where the secretory vesicle fuses with the plasma membrane (PM) via a fusion pore that then dilates until the secretory vesicle collapses into the PM; or by “kiss-and-run,” where the fusion pore does not dilate and instead rapidly reseals such that the secretory vesicle is retrieved almost fully intact. Here, we describe growing evidence for a third form of exocytosis, dubbed “kiss-and-coat,” which is characteristic of a broad variety of cell types that undergo regulated exocytosis. Kiss-and-coat exocytosis entails prolonged maintenance of a dilated fusion pore and assembly of actin filament (F-actin) coats around the exocytosing secretory vesicles followed by direct retrieval of some fraction of the emptied vesicle membrane. We propose that assembly of the actin coats results from the union of the secretory vesicle membrane and PM and that this compartment mixing represents a general mechanism for generating local signals via directed membrane fusion.

scholarly journals Processing of prothyrotropin-releasing hormone (Pro-TRH) by bovine intermediate lobe secretory vesicle membrane PC1 and PC2 enzymes.

Endocrinology ◽  
1995 ◽  
Vol 136 (10) ◽  
pp. 4462-4472 ◽  
Author(s):  
T C Friedman ◽  
Y P Loh ◽  
N X Cawley ◽  
N P Birch ◽  
S S Huang ◽  
...  
Keyword(s):  
Secretory Vesicle ◽  
Intermediate Lobe ◽  
Vesicle Membrane ◽  
Releasing Hormone

scholarly journals Complexin-2 redistributes to the membrane of muscle cells in response to insulin and contributes to GLUT4 translocation

2021 ◽  
Author(s):  
Martin Alejandro Pavarotti ◽  
Victoria Tokarz ◽  
Scott Frendo-Cumbo ◽  
Philip Bilan ◽  
Zhi Liu ◽  
...  
Keyword(s):  
Plasma Membrane ◽  
Insulin Signalling ◽  
Muscle Cells ◽  
Secretory Vesicle ◽  
Vesicle Fusion ◽  
Glut4 Translocation ◽  
Vesicle Membrane ◽  
Actin Fiber ◽  
Complexin 2 ◽  
Intracellular Compartments

Insulin stimulates glucose uptake in muscle cells by rapidly redistributing vesicles containing GLUT4 glucose transporters from intracellular compartments to the plasma membrane. GLUT4 vesicle fusion requires formation of SNARE complexes between vesicular VAMP and plasma membrane syntaxin4 and SNAP23. SNARE accessory proteins usually regulate vesicle fusion processes. Complexins aide in neuro-secretory vesicle-membrane fusion by stabilizing trans-SNARE complexes but their participation in GLUT4 vesicle fusion is unknown. We report that complexin-2 is expressed and homogeneously distributed in L6 rat skeletal muscle cells. Upon insulin stimulation, a cohort of complexin-2 redistributes to the plasma membrane. Complexin-2 knockdown markedly inhibited GLUT4 translocation without affecting proximal insulin signalling of Akt/PKB phosphorylation and actin fiber remodelling. Similarly, complexin-2 overexpression decreased maximal GLUT4 translocation suggesting that the concentration of complexin-2 is finely tuned to vesicle fusion.  These findings reveal an insulin-dependent regulation of GLUT4 insertion into the plasma membrane involving complexin-2.

Morphometric analysis of ultrastructural changes induced by Periconia circinata toxin in the outer root cap of sorghum

1983 ◽  
Vol 61 (5) ◽  
pp. 1506-1509
Author(s):  
Jonathan A. Arias ◽  
Larry D. Dunkle ◽  
Charles E. Bracker
Keyword(s):  
Endoplasmic Reticulum ◽  
Plasma Membrane ◽  
Morphometric Analysis ◽  
Secretory Vesicle ◽  
Root Cap ◽  
Toxic Effects ◽  
Ultrastructural Changes ◽  
Vesicle Membrane ◽  
Periconia Circinata ◽  
Resistant Genotypes

Outer root cap cells of sorghum seedlings treated with the host-specific toxin produced by Periconia circinata were analyzed morphometrically to detect changes in the quantities of cytomembranes and numbers of organelles and thus extend our observations of qualitative cytological responses to the toxin. In seedlings susceptible to the pathogen, brief (0.25 h) treatment with the toxin resulted in a marked and permanent decrease in the amounts of secretory vesicle membrane. By 2 h treatment, only secretory vesicle membrane was decreased, but longer treatments led to an increased amount of endoplasmic reticulum (4 h), which later decreased together with the amount of dictyosome membrane, while the amount of tonoplast increased (8 h). In resistant seedlings treated with the toxin, early but transient increases were detected in the quantities of plasma membrane, secretory vesicle membrane, dictyosome membrane, and endoplasmic reticulum and in the number of dictyosomes. Insensitivity to the toxin may involve the ability of resistant genotypes to recover from the toxic effects.

Molecular Machinery and Mechanism of Cell Secretion

2005 ◽  
Vol 230 (5) ◽  
pp. 307-319 ◽  
Author(s):  
Bhanu P. Jena
Keyword(s):  
Lipid Membrane ◽  
Secretory Vesicle ◽  
Secretory Process ◽  
Secretory Vesicles ◽  
Cell Secretion ◽  
Vesicle Membrane ◽  
Cellular Processes ◽  
Molecular Machinery ◽  
Secretory Products ◽  
First Time

Secretion occurs in all living cells and involves the delivery of intracellular products to the cell exterior. Secretory products are Packaged and stored in membranous sacs or vesicles within the cell. When the cell needs to secrete these products, the secretory vesicles containing them dock and fuse at plasma membrane-associated supramolecular structures, called poro-somes, to release their contents. Specialized cells for neurotransmission, enzyme secretion, or hormone release use a highly regulated secretory process. Similar to other fundamen-tal cellular processes, cell secretion is precisely regulated. During secretion, swelling of secretory vesicles results in a build-up of intravesicular pressure, allowing expulsion of vesicular contents. The extent of vesicle swelling dictates the amount of vesicular contents expelled. The discovery of the Porosome as the universal secretory machinery, its isolation, its structure and dynamics at nanometer resolution and in real time, and its biochemical composition and functional reconstitution into artificial lipid membrane have been determined. The Molecular mechanism of secretory vesicle swelling and the fusion of opposing bilayers, that is, the fusion of secretory vesicle membrane at the base of the porosome membrane, have also been resolved. These findings reveal, for the first time, the universal molecular machinery and mechanism of secretion in cells.

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