Rab7 Localizes to Zymogen Granule Membrane in Pancreatic Acinar Cells and Contributes to Maturation of Zymogen Granules but Not to Exocytosis

2017 ◽  
Vol 152 (5) ◽  
pp. S900
Author(s):  
Kenichi Takahashi ◽  
Hirosato Mashima ◽  
Kouichi Miura ◽  
Takahsi Goto ◽  
Hirohide Ohnishi
Keyword(s):  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Zymogen Granule ◽  
Zymogen Granules ◽  
Granule Membrane

scholarly journals SYNTHESIS AND MIGRATION OF PROTEINS IN THE CELLS OF THE EXOCRINE PANCREAS AS REVEALED BY SPECIFIC ACTIVITY DETERMINATION FROM RADIOAUTOGRAPHS

1963 ◽  
Vol 16 (1) ◽  
pp. 1-23 ◽  
Author(s):  
H. Warshawsky ◽  
C. P. Leblond ◽  
B. Droz
Keyword(s):  
Specific Activity ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Zymogen Granule ◽  
Zymogen Granules ◽  
The Mean ◽  
And Migration ◽  
Rats And Mice ◽  
Silver Grains ◽  
Golgi Zone

Radioautographs of pancreatic acinar cells were prepared in rats and mice sacrificed at various times after injection of leucine-, glycine-, or methionine-H3. Measurements of radioactivity concentration (number of silver grains per unit area) and relative protein concentration (by microspectrophotometry of Millon-treated sections) yielded the mean specific activity of proteins in various regions of the acinar cells. The 2 to 5 minute radioautographs as well as the specific activity time curves demonstrate protein synthesis in ergastoplasm. From there, most newly synthesized proteins migrate to and accumulate in the Golgi zone. Then they spread to the whole zymogen region and, finally, enter the excretory ducts. An attempt at estimating turnover times indicated that two classes of proteins are synthesized in the ergastoplasm: "sedentary" with a slow turnover (62.5 hours) and "exportable" with rapid turnover (4.7 minutes). It is estimated that the exportable proteins spend approximately 11.7 minutes in the Golgi zone where they are built up into zymogen granules, and thereafter 36.0 minutes as fully formed zymogen granules, before they are released outside the acinar cell as pancreatic secretion. The mean life span of a zymogen granule in the cell is estimated to be 47.7 minutes.

A novel zymogen granule protein (ZG29p) and the nuclear protein MTA1p are differentially expressed by alternative transcription initiation in pancreatic acinar cells of the rat

1999 ◽  
Vol 112 (15) ◽  
pp. 2539-2548
Author(s):  
R. Kleene ◽  
J. Zdzieblo ◽  
K. Wege ◽  
H.F. Kern
Keyword(s):  
Blot Analysis ◽  
Transcription Initiation ◽  
Northern Blot Analysis ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Zymogen Granule ◽  
Zymogen Granules ◽  
Rt Pcr ◽  
Rat Pancreas ◽  
Alternative Transcription

Using a polyclonal antibody against purified zymogen granule membrane components from rat pancreas a cDNA coding for the 29 kDa protein (ZG29p) was identified by immunoscreening of a hormonally stimulated pancreas cDNA library. Western blot analysis suggests that ZG29p is a pancreas-specific protein and immunofluorescence shows that ZG29p is mainly associated with zymogen granules. Analysis of subcellular fraction applying immunoblotting revealed that ZG29p was localized mainly in the soluble fraction of zymogen granules and in a Golgi- and RER-enriched fraction, but was absent from the cytosol. In isolated zymogen granule content ZG29p was associated with protein complexes containing amylase as main constituent. The cDNA coding for ZG29p is homologous to the C-terminal region of the candidate metastasis-associated gene mta1. Northern blot analysis and RT-PCR showed that no MTA1 mRNA is present in pancreas from fasted rats and in the rat pancreas carcinoma cell line AR4-2J in its protodifferentiated state. Although no ZG29p specific mRNA was seen in the northern blot analysis, RT-PCR showed that ZG29p was expressed under both non-stimulated and stimulated conditions. The expression of MTA1 was up-regulated in the pancreas by endogenous cholecystokinin release and in AR4-2J after induction of cellular differentiation by dexamethasone. Western blotting and immunofluorescense studies indicated that MTA1p is localized in the nucleus in all tissues studied. Using genomic DNA in PCR analysis it was shown that two short introns are present flanking the sequences of the 5′end of ZG29p cDNA. One intron contains consensus elements required for pancreas specific transcription initiation, suggesting that MTA1 and ZG29 are differentially expressed by alternative transcription initiation in the pancreas. The localisation of MTA1p in the nucleus of most cell types could signify a general role in gene regulation, while the cell type specific and exclusive expression of ZG29p in pancreatic acinar cells could indicate a role in granule formation.

scholarly journals Loss of the Zymogen Granule Protein Syncollin Affects Pancreatic Protein Synthesis and Transport but Not Secretion

2002 ◽  
Vol 22 (5) ◽  
pp. 1545-1554 ◽  
Author(s):  
Wolfram Antonin ◽  
Martin Wagner ◽  
Dietmar Riedel ◽  
Nils Brose ◽  
Reinhard Jahn
Keyword(s):  
Protein Synthesis ◽  
Intracellular Transport ◽  
Release Kinetics ◽  
Pancreatic Acinar Cells ◽  
Secretory Proteins ◽  
Zymogen Granule ◽  
Zymogen Granules ◽  
Granule Membrane ◽  
Deficient Mice ◽  
Shed Light

ABSTRACT Syncollin is a small protein that is abundantly expressed in pancreatic acinar cells and that is tightly associated with the lumenal side of the zymogen granule membrane. To shed light on the hitherto unknown function of syncollin, we have generated syncollin-deficient mice. The mice are viable and show a normal pancreatic morphology as well as normal release kinetics in response to secretagogue stimulation. Although syncollin is highly enriched in zymogen granules, no change was found in the overall protein content and in the levels of chymotrypsin, trypsin, and amylase. However, syncollin-deficient mice reacted to caerulein hyperstimulation with a more severe pancreatitis. Furthermore, the rates of both protein synthesis and intracellular transport of secretory proteins were reduced. We conclude that syncollin plays a role in maturation and/or concentration of zymogens in zymogen granules.

The subapical actin cytoskeleton regulates secretion and membrane retrieval in pancreatic acinar cells

1999 ◽  
Vol 112 (1) ◽  
pp. 81-96 ◽  
Author(s):  
K.M. Valentijn ◽  
F.D. Gumkowski ◽  
J.D. Jamieson
Keyword(s):  
Actin Cytoskeleton ◽  
Apical Membrane ◽  
Acinar Cells ◽  
Coupled Processes ◽  
Pancreatic Acinar Cells ◽  
Apical Plasma Membrane ◽  
Zymogen Granule ◽  
Terminal Web ◽  
Granule Membrane ◽  
Contractile Forces

We examined the effects of disruption of the actin cytoskeleton by cytochalasin D (cytoD) on basal and carbamylcholine-stimulated exocytosis and on compensatory membrane retrieval in pancreatic acinar cells. Although the involvement of actin in exocytosis is reasonably well established, its role in these coupled processes is not understood. Our findings suggested that cytoD inhibited stimulated secretion of amylase. However, morphometry revealed that exocytosis had occurred: the number of zymogen granules decreased, the size of the lumen increased, and large vacuolar structures continuous with the lumen formed into which amylase accumulated. Large amounts of amylase were released to the medium on removal of secretagogue and cytoD, suggesting that the subapical actin network provides contractile forces that expel the lumenal contents. Strikingly, we observed that at the apical pole of the cells where exocytosis occurred, cytoD induced an accumulation of membrane invaginations into a vastly enlarged apical membrane. These pits were often surrounded by a clathrin-like coat. Concomitantly, AP-2-, clathrin-, dynamin- and caveolin-like immunoreactivity concentrated around the enlarged lumina, suggesting that incorporation of zymogen granule membrane into the apical plasma membrane triggered the recruitment of these proteins. After wash out of cytoD and carbamylcholine and reformation of the subapical actin cytoskeleton, the coated invaginations largely disappeared in association with a reduction in lumenal size, and relocation of clathrin, AP-2, dynamin and caveolin into the cell. We suggest that the actin terminal web also controls compensatory membrane retrieval following exocytosis.

scholarly journals Expression of sulfated gp300 and changes in glycosylation during pancreatic development.

1996 ◽  
Vol 44 (1) ◽  
pp. 57-66 ◽  
Author(s):  
R C De Lisle ◽  
K S Isom
Keyword(s):  
Acinar Cells ◽  
Polyclonal Antiserum ◽  
Zymogen Granule ◽  
Zymogen Granules ◽  
Peanut Agglutinin ◽  
Western Blots ◽  
Ulex Europaeus ◽  
Granule Membrane ◽  
Temporally Correlated ◽  
Binding Lectin

The pancreatic zymogen granule membrane protein gp300 is the major sulfated glycoprotein of the mouse acinar cell and has been proposed to be an important structural component of the zymogen granule membrane. A prediction of this proposed function is that gp300 expression should be coordinately regulated with the digestive enzymes and appearance of zymogen granules during differentiation of acinar cells in fetal development. By Western blots and immunolocalization with a polyclonal antiserum to gp300, we found that gp300 protein expression paralleled expression of amylase and the appearance of zymogen granules in differentiating acinar cells. Lectin blots were performed to assess the glycoconjugate composition of gp300 during development. Using the fucose binding lectin Ulex europaeus I, we found that gp300 acquires this carbohydrate only postnatally, temporally correlated with weaning. In addition, gp300 showed complex changes during postnatal development in reactivity with the galactose binding lectin peanut agglutinin (PNA) and the sialic acid binding lectin Maackia amuresis (MAA). Levels of reactivity of PNA and MAA were reciprocal, suggesting that sialylation of galactose (which can block peanut agglutinin binding) was not constant on gp300 during development.

scholarly journals Double immunocytochemical labeling applying the protein A-gold technique.

1982 ◽  
Vol 30 (1) ◽  
pp. 81-85 ◽  
Author(s):  
M Bendayan
Keyword(s):  
Tissue Section ◽  
Protein A ◽  
Antigenic Site ◽  
Acinar Cells ◽  
Pancreatic Acinar Cells ◽  
Secretory Proteins ◽  
Zymogen Granules ◽  
Double Labeling ◽  
Gold Particles ◽  
Antigenic Sites

In the present study we report the modifications and the different steps of the protein A-gold (pAg) technique that allow the simultaneous demonstration of two antigenic sites on the same tissue section. The labeling is carried out in the following manner: face A of the tissue section is incubated with an antiserum followed by a pAg complex prepared with large gold particles; face B of the same tissue section is then incubated with a second antiserum followed by a pAg complex prepared with small gold particles. Each of the pAg complexes reveals a different antigenic site on opposite faces of the tissue section. The transparency of the section in the electron beam allows the visualization of the gold particles present on both faces. The double labeling pAg technique was applied for the simultaneous demonstration of two secretory proteins in the same Golgi, condensing vacuoles, and zymogen granules of the rat pancreatic acinar cells.

Rab3D localizes to zymogen granules in rat pancreatic acini and other exocrine glands

1996 ◽  
Vol 271 (3) ◽  
pp. G531-G538 ◽  
Author(s):  
H. Ohnishi ◽  
S. A. Ernst ◽  
N. Wys ◽  
M. McNiven ◽  
J. A. Williams
Keyword(s):  
Polyclonal Antiserum ◽  
Secretory Cells ◽  
Apical Region ◽  
Zymogen Granule ◽  
Zymogen Granules ◽  
Base Pairs ◽  
Pancreatic Acini ◽  
Pcr Product ◽  
The Family ◽  
Granule Membrane

Rab3 proteins are members of the family of Ras-like monomeric GTP-binding proteins that have been implicated in secretion in neuronal cells. Although an isoform of Rab3 has been assumed to exist in pancreatic acini, its identity has not yet been established. We now report that Rab3D is present in rat pancreatic acini and is localized to the zymogen granule membrane. Reverse transcription-polymerase chain reaction (PCR) was used with primers based on mouse Rab3D to amplify Rab3D from rat pancreas. The PCR product without primer sites consisted of 580 base pairs and was 94% identical to the mouse Rab3D cDNA sequence previously cloned from adipocytes. Western blotting with a polyclonal antiserum raised against Rab3D-specific carboxyterminal amino acids identified Rab3D in rat pancreatic acini and revealed its concentration on zymogen granule membranes. Immunocytochemistry of pancreatic lobules showed that Rab3D localized to the apical region in a pattern similar to amylase. Confocal fluorescence microscopy of lobules double immunolabeled with antibodies to Rab3D and the granule membrane marker protein glycoprotein-2 (GP-2) revealed a similar localization of these proteins to zymogen granules. Immunocytochemistry also revealed the presence of Rab3D in chief and enterochromaffin-like cells in the stomach, acinar cells in lacrimal and parotid gland, and Paneth cells in the intestine. These results show that Rab3D is expressed in rat pancreatic acini and other exocrine secretory cells. Its location implies it may be involved in regulated exocytosis.

Sign in / Sign up

Export Citation Format

Share Document