Carbon tetrachloride suppresses ER‐Golgi transport by inhibiting COPII vesicle formation on the ER membrane in the RLC‐16 hepatocyte cell line

2020 ◽  
Author(s):  
Hiroshi Nakagawa ◽  
Masayuki Komori ◽  
Kazuhiko Nishimura
Keyword(s):  
Carbon Tetrachloride ◽  
Cell Line ◽  
Vesicle Formation ◽  
Hepatocyte Cell Line ◽  
Golgi Transport ◽  
Copii Vesicle ◽  
Er Membrane

scholarly journals Insights into structural and regulatory roles of Sec16 in COPII vesicle formation at ER exit sites

2012 ◽  
Vol 23 (15) ◽  
pp. 2930-2942 ◽  
Author(s):  
Tomohiro Yorimitsu ◽  
Ken Sato
Keyword(s):  
Lipid Membrane ◽  
Vesicle Formation ◽  
Gtpase Activity ◽  
Essential Factor ◽  
Present Evidence ◽  
Planar Lipid Membrane ◽  
Golgi Transport ◽  
Copii Vesicle ◽  
Er Exit Sites

COPII-coated buds are formed at endoplasmic reticulum exit sites (ERES) to mediate ER-to-Golgi transport. Sec16 is an essential factor in ERES formation, as well as in COPII-mediated traffic in vivo. Sec16 interacts with multiple COPII proteins, although the functional significance of these interactions remains unknown. Here we present evidence that full-length Sec16 plays an important role in regulating Sar1 GTPase activity at the late steps of COPII vesicle formation. We show that Sec16 interacts with Sec23 and Sar1 through its C-terminal conserved region and hinders the ability of Sec31 to stimulate Sec23 GAP activity toward Sar1. We also find that purified Sec16 alone can self-assemble into homo-oligomeric complexes on a planar lipid membrane. These features ensure prolonged COPII coat association within a preformed Sec16 cluster, which may lead to the formation of ERES. Our results indicate a mechanistic relationship between COPII coat assembly and ERES formation.

scholarly journals Genes that control the fidelity of endoplasmic reticulum to Golgi transport identified as suppressors of vesicle budding mutations.

1996 ◽  
Vol 7 (7) ◽  
pp. 1043-1058 ◽  
Author(s):  
M J Elrod-Erickson ◽  
C A Kaiser
Keyword(s):  
Endoplasmic Reticulum ◽  
Membrane Proteins ◽  
Integral Membrane Proteins ◽  
Secretory Proteins ◽  
Vesicle Formation ◽  
Gene Products ◽  
Vesicle Budding ◽  
Golgi Transport ◽  
Transport Vesicles ◽  
Copii Vesicle

Although convergent evidence suggests that proteins destined for export from the endoplasmic reticulum (ER) are separated from resident ER proteins and are concentrated into transport vesicles, the proteins that regulate this process have remained largely unknown. In a screen for suppressors of mutations in the essential COPII gene SEC13, we identified three genes (BST1, BST2/EMP24, and BST3) that negatively regulate COPII vesicle formation, preventing the production of vesicles with defective or missing subunits. Mutations in these genes slow the secretion of some secretory proteins and cause the resident ER proteins Kar2p and Pdi1p to leak more rapidly from the ER, indicating that these genes are also required for proper discrimination between resident ER proteins and Golgi-bound cargo molecules. The BST1 and BST2/EMP24 genes code for integral membrane proteins that reside predominantly in the ER. Our data suggest that the BST gene products represent a novel class of ER proteins that link the regulation of vesicle coat assembly to cargo sorting.

scholarly journals SED4 encodes a yeast endoplasmic reticulum protein that binds Sec16p and participates in vesicle formation.

1995 ◽  
Vol 131 (2) ◽  
pp. 325-338 ◽  
Author(s):  
R E Gimeno ◽  
P Espenshade ◽  
C A Kaiser
Keyword(s):  
Secretory Pathway ◽  
Silent Mutation ◽  
Temperature Sensitive ◽  
Vesicle Formation ◽  
Golgi Transport ◽  
Transport Vesicles ◽  
Endoplasmic Reticulum Protein ◽  
Transport Defect ◽  
Transport Vesicle ◽  
Er Membrane

SEC16 is required for transport vesicle budding from the ER in Saccharomyces cerevisiae, and encodes a large hydrophilic protein found on the ER membrane and as part of the coat of transport vesicles. In a screen to find functionally related genes, we isolated SED4 as a dosage-dependent suppressor of temperature-sensitive SEC16 mutations. Sed4p is an integral ER membrane protein whose cytosolic domain binds to the COOH-terminal domain of Sec16p as shown by two-hybrid assay and coprecipitation. The interaction between Sed4p and Sec16p probably occurs before budding is complete, because Sed4p is not found in budded vesicles. Deletion of SED4 decreases the rate of ER to Golgi transport, and exacerbates mutations defective in vesicle formation, but not those that affect later steps in the secretory pathway. Thus, Sed4p is important, but not necessary, for vesicle formation at the ER. Sec12p, a close homologue of Sed4p, also acts early in the assembly of transport vesicles. However, SEC12 performs a different function than SED4 since Sec12p does not bind Sec16p, and genetic tests show that SEC12 and SED4 are not functionally interchangeable. The importance of Sed4p for vesicle formation is underlined by the isolation of a phenotypically silent mutation, sar1-5, that produces a strong ER to Golgi transport defect when combined with sed4 mutations. Extensive genetic interactions between SAR1, SED4, and SEC16 show close functional links between these proteins and imply that they might function together as a multisubunit complex on the ER membrane.

Downregulation of hepcidin and haemojuvelin expression in the hepatocyte cell-line HepG2 induced by thalassaemic sera

2006 ◽  
Vol 135 (1) ◽  
pp. 129-138 ◽  
Author(s):  
Orly Weizer-Stern ◽  
Konstantin Adamsky ◽  
Ninette Amariglio ◽  
Carina Levin ◽  
Ariel Koren ◽  
...  
Keyword(s):  
Cell Line ◽  
Hepatocyte Cell Line

ESTABLISHMENT OF A HIGHLY DIFFERENTIATED IMMORTALIZED HUMAN HEPATOCYTE CELL LINE WITH TIGHT REGULATION

ASAIO Journal ◽  
2000 ◽  
Vol 46 (2) ◽  
pp. 229
Author(s):  
N. Kobayashi ◽  
H. Noguchi ◽  
T. Fujiwara ◽  
N. Tanaka
Keyword(s):  
Cell Line ◽  
Human Hepatocyte ◽  
Hepatocyte Cell Line

Suppression of albumin enhancer activity by H-ras and AP-1 in hepatocyte cell lines

1994 ◽  
Vol 14 (3) ◽  
pp. 1531-1543
Author(s):  
J Hu ◽  
H C Isom
Keyword(s):  
Dna Binding ◽  
Cell Line ◽  
Cell Lines ◽  
Binding Sites ◽  
Simian Virus 40 ◽  
Site Directed Mutagenesis ◽  
Ras Signaling ◽  
Enhancer Activity ◽  
Hepatocyte Cell Line ◽  
Transformed Cell Lines

We demonstrated, using a transient transfection assay, that the albumin enhancer increased the expression of the albumin promoter in a highly differentiated, simian virus 40 (SV40)-immortalized hepatocyte cell line, CWSV1, but was not functional in two ras-transformed cell lines (NR3 and NR4) derived from CWSV1 by stable transfection with the T24ras oncogene. A transient cotransfection assay showed that T24ras and normal c-Ha-ras were each able to inhibit the activity of the albumin enhancer in an immortal hepatocyte cell line. DNase I footprinting and gel mobility shift assays demonstrated that the DNA binding activities specific to the albumin enhancer were not decreased in the ras-transformed cells. ras also did not diminish the expression of HNF1 alpha, C/EBP alpha, HNF3 alpha, HNF3 beta, or HNF3 gamma but did significantly increase AP-1 binding activity. Three AP-1 binding sites were identified within the albumin enhancer, and DNA binding activities specific to these AP-1 sites were induced in the ras-transformed hepatocytes. Subsequent functional assays showed that overexpression of c-jun and c-fos inhibited the activity of the albumin enhancer. Site-directed mutagenesis of the AP-1 binding sites in the albumin enhancer partially abrogated the suppressing effect of ras and c-jun/c-fos on the enhancer. These functional studies therefore supported the results of the structural studies with AP-1. We conclude that the activity of the albumin enhancer is subject to regulation by ras signaling pathways and that the effect of ras on the albumin enhancer activity may be mediated by AP-1.

scholarly journals CHARACTERIZATION OF A HEPATOCYTE CELL LINE AND PRIMARY RAT HEPATOCYTES CULTURED THREE-DIMENSIONALLY IN A CELLCHIP-CONTAINING BIOREACTOR

ASAIO Journal ◽  
2005 ◽  
Vol 51 (2) ◽  
pp. 1A
Author(s):  
Eric Gottwald ◽  
Caroline Augspurger ◽  
Stefan Giselbrecht ◽  
Alex Welle ◽  
Karl-Friedrich Weibezahn
Keyword(s):  
Cell Line ◽  
Rat Hepatocytes ◽  
Primary Rat Hepatocytes ◽  
Hepatocyte Cell Line

scholarly journals Cytosolic ARFs are required for vesicle formation but not for cell-free intra-Golgi transport: evidence for coated vesicle-independent transport.

1994 ◽  
Vol 5 (2) ◽  
pp. 237-252 ◽  
Author(s):  
T C Taylor ◽  
M Kanstein ◽  
P Weidman ◽  
P Melançon
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster ◽  
Specific Inhibitor ◽  
Coated Vesicles ◽  
Coated Vesicle ◽  
Vesicle Formation ◽  
Golgi Transport ◽  
Independent Mechanism ◽  
Free Transport

We investigated the role of ADP-ribosylation factors (ARFs) in Golgi function using biochemical and morphological cell-free assays. An ARF-free cytosol produced from soluble Chinese hamster ovary (CHO) extracts supports intra-Golgi transport by a mechanism that is biochemically indistinguishable from control transport reactions: ARF-free transport reactions are NSF-dependent, remain sensitive to the donor Golgi-specific inhibitor ilimaquinone, and exhibit kinetics that are identical to that of control reactions containing ARFs. In contrast, ARF-free cytosol does not support the formation of coated vesicles on Golgi cisternae. However, vesicle formation is reconstituted upon the addition of ARF1. These data suggest that neither soluble ARFs nor coated vesicle formation are essential for transport. We conclude that cell-free intra-Golgi transport proceeds via a coated vesicle-independent mechanism regardless of vesicle formation on Golgi cisternae.

scholarly journals Increased Cytotoxicity of Carbon Tetrachloride in a Human Hepatoma Cell Line Overexpressing Cytochrome P450 2E1

2002 ◽  
Vol 30 (4) ◽  
pp. 400-405 ◽  
Author(s):  
S Takahashi ◽  
T Takahashi ◽  
S Mizobuchi ◽  
M Matsumi ◽  
K Morita ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cytochrome P450 ◽  
Carbon Tetrachloride ◽  
Cell Line ◽  
Hepatoma Cell ◽  
Mrna Level ◽  
Hepatoma Cell Line ◽  
Cytochrome P450 2E1 ◽  
Hsp70 Mrna ◽  
Potential Marker

Cytotoxic free radicals generated during the metabolism of carbon tetrachloride by cytochrome P450 2E1 (CYP2E1) are thought to cause hepatotoxicity. Here, the cytotoxic effects of carbon tetrachloride in a liver cell line expressing CYP2E1 (HLE/2E1) are compared with those in the mother cell line (HLE). The effects of carbon tetrachloride on the gene expression of HSP70, a potential marker of oxidative stress, were also examined. The viability of HLE/2E1 cells after exposure to carbon tetrachloride was significantly decreased compared with that of HLE cells. Northern blot analysis revealed that the HSP70 mRNA level was significantly increased after carbon tetrachloride treatment in both cell lines, while the magnitude of its increase was much greater in HLE/2E1 cells than in HLE cells. These results suggest that the oxidative stress induced by CYP2E1 plays an important role in the increase in cytotoxicity of carbon tetrachloride in CYP2E1-overexpressing cells.

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