scholarly journals Role of Secretory Carrier Membrane Protein SCAMP2 in Granule Exocytosis

2002 ◽  
Vol 13 (12) ◽  
pp. 4266-4278 ◽  
Author(s):  
Lixia Liu ◽  
Zhenheng Guo ◽  
Quyen Tieu ◽  
Anna Castle ◽  
David Castle
Keyword(s):  
Pc12 Cells ◽  
Plasma Membranes ◽  
Point Mutations ◽  
Specific Effect ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Granule Exocytosis ◽  
Structural Selectivity ◽  
Large Dense Core Vesicles ◽  
Dependent Inhibition

In secretory carrier membrane proteins (SCAMPs), the most conserved structural segment is between transmembrane spans 2 and 3, facing the cytosol. A synthetic peptide, CWYRPIYKAFR (E peptide), from this segment of SCAMP2 potently inhibits exocytosis in permeabilized neuroendocrine (PC12) cells. E peptide blocked discharge of35S-labeled secretogranin with the same structural selectivity and potency as observed for hexosaminidase secretion in mast cells. SCAMPs 1 and 2 are concentrated primarily on intracellular membranes in PC12 cells. Both, however, are found on plasma membranes, but neither is present on large dense-core vesicles. Yet, large dense-core vesicles marked by secretogranin attach to plasma membranes at foci containing SCAMP2 along with syntaxin1 and complexin at putative cell-surface docking/fusion sites. Regulated overexpression of SCAMP2 with point mutations in its E peptide but not of normal SCAMP2 caused dose-dependent inhibition of depolarization-induced secretion. The SCAMP2 mutants also inhibited secretion stimulated by elevated calcium. Inhibition was largely overcome by adding lysophosphatidylcholine to the medium at concentrations that do not otherwise affect secretion. Although overexpression of normal or mutant SCAMP2 slightly inhibits endocytosis, this effect does not appear to be related to the specific effect of the mutant SCAMP on stimulated exocytosis. Thus, SCAMP2 not only colocalizes with fusion sites but also appears to have an essential function in granule exocytosis through actions mediated by its E peptide–containing domain.

scholarly journals Preferential localization of a vesicular monoamine transporter to dense core vesicles in PC12 cells.

1994 ◽  
Vol 127 (5) ◽  
pp. 1419-1433 ◽  
Author(s):  
Y Liu ◽  
E S Schweitzer ◽  
M J Nirenberg ◽  
V M Pickel ◽  
C J Evans ◽  
...  
Keyword(s):  
Pc12 Cells ◽  
Gradient Centrifugation ◽  
Secretory Vesicle ◽  
Dense Core ◽  
Gamma Aminobutyric Acid ◽  
Dense Core Vesicles ◽  
Protein Marker ◽  
Preferential Localization ◽  
Large Dense Core Vesicles ◽  
Pheochromocytoma Pc12

Neurons and endocrine cells have two types of secretory vesicle that undergo regulated exocytosis. Large dense core vesicles (LDCVs) store neural peptides whereas small clear synaptic vesicles store classical neurotransmitters such as acetylcholine, gamma-aminobutyric acid (GABA), glycine, and glutamate. However, monoamines differ from other classical transmitters and have been reported to appear in both LDCVs and smaller vesicles. To localize the transporter that packages monoamines into secretory vesicles, we have raised antibodies to a COOH-terminal sequence from the vesicular amine transporter expressed in the adrenal gland (VMAT1). Like synaptic vesicle proteins, the transporter occurs in endosomes of transfected CHO cells, accounting for the observed vesicular transport activity. In rat pheochromocytoma PC12 cells, the transporter occurs principally in LDCVs by both immunofluorescence and density gradient centrifugation. Synaptic-like microvesicles in PC12 cells contain relatively little VMAT1. The results appear to account for the storage of monoamines by LDCVs in the adrenal medulla and indicate that VMAT1 provides a novel membrane protein marker unique to LDCVs.

Biosynthesis of large dense-core vesicles in PC12 cells: effects of depolarization and second messengers on the mRNA levels of their constituents

1995 ◽  
Vol 31 (1-2) ◽  
pp. 131-140 ◽  
Author(s):  
Claudia Tschernitz ◽  
Andrea Laslop ◽  
Christine Eiter ◽  
Stephan Kroesen ◽  
Hans Winkler
Keyword(s):  
Pc12 Cells ◽  
Second Messengers ◽  
Dense Core ◽  
Mrna Levels ◽  
Dense Core Vesicles ◽  
Large Dense Core Vesicles

The GTPase Rab3a is associated with large dense core vesicles in bovine chromaffin cells and rat PC12 cells

1995 ◽  
Vol 108 (4) ◽  
pp. 1639-1649 ◽  
Author(s):  
F. Darchen ◽  
J. Senyshyn ◽  
W.H. Brondyk ◽  
D.J. Taatjes ◽  
R.W. Holz ◽  
...  
Keyword(s):  
Subcellular Localization ◽  
Pc12 Cells ◽  
Immunoelectron Microscopy ◽  
Chromaffin Cells ◽  
Secretory Granules ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Large Dense Core Vesicles ◽  
Bovine Chromaffin Cells ◽  
Specific Association

Small GTPases of the rab family control intracellular vesicle traffic in eukaryotic cells. Although the molecular mechanisms underlying the activity of the Rab proteins have not been elucidated yet, it is known that the function of these proteins is dependent on their precise subcellular localization. It has been suggested that Rab3a, which is mainly expressed in neural and endocrine cells, might regulate exocytosis. Recently, direct experimental evidence supporting this hypothesis has been obtained. Consistent with such a role for Rab3a in regulated exocytosis was the previously reported specific association of Rab3a with synaptic vesicles and with secretory granules in adrenal chromaffin cells. Since the latter result, based on subcellular fractionation, has been controversial, we have re-investigated the subcellular localization of this GTP-binding protein by using a combination of morphological techniques. Bovine chromaffin cells were labelled with an affinity-purified polyclonal anti-Rab3a antibody and analyzed by confocal microcopy. Rab3a was found to colocalize partially with dopamine beta-hydroxylase, a chromaffin granule marker. In agreement with this observation, immunoelectron microscopy revealed a specific staining of chromaffin granules. In addition to large dense core vesicles, some small vesicles were labelled. To eliminate the possibility that the staining was due to a Rab3a-related protein, we investigated by immunoelectron microscopy the localization of an epitope-tagged Rab3a expressed in rat PC12 cells. Secretory granules were specifically labelled, whereas clear microvesicles were not. These results provide further evidence supporting a specific association of the GTPase Rab3a with large dense core secretory vesicles.

EGFP-Tagged Vasopressin Precursor Protein Sorting Into Large Dense Core Vesicles and Secretion From PC12 Cells

2005 ◽  
Vol 25 (3-4) ◽  
pp. 581-605 ◽  
Author(s):  
Bing-Jun Zhang ◽  
Mitsuo Yamashita ◽  
Ray Fields ◽  
Kiyoshi Kusano ◽  
Harold Gainer
Keyword(s):  
Pc12 Cells ◽  
Protein Sorting ◽  
Precursor Protein ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Large Dense Core Vesicles ◽  
Vasopressin Precursor

Relationship between golgi apparatus and axonal reticulum in sympathetic ganglion cells

1978 ◽  
Vol 36 (2) ◽  
pp. 598-599
Author(s):  
J. Quatacker ◽  
W. De Potter
Keyword(s):  
Golgi Apparatus ◽  
Sympathetic Ganglion ◽  
Phosphotungstic Acid ◽  
Ganglion Cells ◽  
Low Ph ◽  
Dense Core ◽  
Dense Core Vesicles ◽  
Large Dense Core Vesicles ◽  
Cervical Ganglia ◽  
Axoplasmic Reticulum

Mucopolysaccharides have been demonstrated biochemically in catecholamine-containing subcellular particles in different rat, cat and ox tissues. As catecholamine-containing granules seem to arise from the Golgi apparatus and some also from the axoplasmic reticulum we examined wether carbohydrate macromolecules could be detected in the small and large dense core vesicles and in structures related to them. To this purpose superior cervical ganglia and irises from rabbit and cat and coeliac ganglia and their axons from dog were subjected to the chromaffin reaction to show the distribution of catecholamine-containing granules. Some material was also embedded in glycolmethacrylate (GMA) and stained with phosphotungstic acid (PTA) at low pH for the detection of carbohydrate macromolecules.The chromaffin reaction in the perikarya reveals mainly large dense core vesicles, but in the axon hillock, the axons and the terminals, the small dense core vesicles are more prominent. In the axons the small granules are sometimes seen inside a reticular network (fig. 1).

Sign in / Sign up

Export Citation Format

Share Document