A transcriptionally active form of TFIIIC is modified in poliovirus-infected HeLa cells

1990 ◽  
Vol 10 (10) ◽  
pp. 5106-5113
Author(s):  
M E Clark ◽  
A Dasgupta
Keyword(s):  
Infected Cell ◽  
Hela Cells ◽  
Complex I ◽  
Transcriptional Activity ◽  
Limited Proteolysis ◽  
Complex Iii ◽  
Complex Ii ◽  
Cell Extracts ◽  
Infected Cells ◽  
Pol Iii

In HeLa cells, RNA polymerase III (pol III)-mediated transcription is severely inhibited by poliovirus infection. This inhibition is due primarily to the reduction in transcriptional activity of the pol III transcription factor TFIIIC in poliovirus-infected cells. However, the specific binding of TFIIIC to the VAI gene B-box sequence, as assayed by DNase I footprinting, is not altered by poliovirus infection. We have used gel retardation analysis to analyze TFIIIC-DNA complexes formed in nuclear extracts prepared from mock- and poliovirus-infected cells. In mock-infected cell extracts, two closely migrating TFIIIC-containing complexes, complexes I and II, were detected in the gel retardation assay. The slower migrating complex, complex I, was absent in poliovirus-infected cell extracts, and an increase occurred in the intensity of the faster-migrating complex (complex II). Also, in poliovirus-infected cell extracts, a new, rapidly migrating complex, complex III, was formed. Complex III may have been the result of limited proteolysis of complex I or II. These changes in TFIIIC-containing complexes in poliovirus-infected cell extracts correlated kinetically with the decrease in TFIIIC transcriptional activity. Complexes I, II, and III were chromatographically separated; only complex I was transcriptionally active and specifically restored pol III transcription when added to poliovirus-infected cell extracts. Acid phosphatase treatment partially converted complex I to complex II but did not affect the binding of complex II or III. Dephosphorylation and limited proteolysis of TFIIIC are discussed as possible mechanisms for the inhibition of pol III-mediated transcription by poliovirus.

scholarly journals A transcriptionally active form of TFIIIC is modified in poliovirus-infected HeLa cells.

1990 ◽  
Vol 10 (10) ◽  
pp. 5106-5113 ◽  
Author(s):  
M E Clark ◽  
A Dasgupta
Keyword(s):  
Infected Cell ◽  
Hela Cells ◽  
Complex I ◽  
Transcriptional Activity ◽  
Limited Proteolysis ◽  
Complex Iii ◽  
Complex Ii ◽  
Cell Extracts ◽  
Infected Cells ◽  
Pol Iii

In HeLa cells, RNA polymerase III (pol III)-mediated transcription is severely inhibited by poliovirus infection. This inhibition is due primarily to the reduction in transcriptional activity of the pol III transcription factor TFIIIC in poliovirus-infected cells. However, the specific binding of TFIIIC to the VAI gene B-box sequence, as assayed by DNase I footprinting, is not altered by poliovirus infection. We have used gel retardation analysis to analyze TFIIIC-DNA complexes formed in nuclear extracts prepared from mock- and poliovirus-infected cells. In mock-infected cell extracts, two closely migrating TFIIIC-containing complexes, complexes I and II, were detected in the gel retardation assay. The slower migrating complex, complex I, was absent in poliovirus-infected cell extracts, and an increase occurred in the intensity of the faster-migrating complex (complex II). Also, in poliovirus-infected cell extracts, a new, rapidly migrating complex, complex III, was formed. Complex III may have been the result of limited proteolysis of complex I or II. These changes in TFIIIC-containing complexes in poliovirus-infected cell extracts correlated kinetically with the decrease in TFIIIC transcriptional activity. Complexes I, II, and III were chromatographically separated; only complex I was transcriptionally active and specifically restored pol III transcription when added to poliovirus-infected cell extracts. Acid phosphatase treatment partially converted complex I to complex II but did not affect the binding of complex II or III. Dephosphorylation and limited proteolysis of TFIIIC are discussed as possible mechanisms for the inhibition of pol III-mediated transcription by poliovirus.

An RNA polymerase II transcription factor inactivated in poliovirus-infected cells copurifies with transcription factor TFIID

1988 ◽  
Vol 8 (8) ◽  
pp. 3175-3182
Author(s):  
S Kliewer ◽  
A Dasgupta
Keyword(s):  
Transcription Factor ◽  
Infected Cell ◽  
Rna Polymerase ◽  
Host Cell ◽  
Rna Polymerase Ii ◽  
Heat Inactivation ◽  
Early Event ◽  
Cell Extracts ◽  
Infected Cells ◽  
Rna Polymerase Ii Transcription

Inhibition of host cell RNA polymerase II-mediated transcription by poliovirus infection was studied in vitro. Whole-cell extracts prepared from poliovirus-infected HeLa cells at 3 h postinfection were shown to be deficient in a factor required for specific transcription from the adenovirus major late promoter. Three lines of evidence suggest that transcription factor TFIID is deficient in poliovirus-infected cells. First, the activity required to specifically restore transcription in poliovirus-infected cell extracts was shown to copurify with TFIID through three chromatographic steps. Second, transcription reactions reconstituted with phosphocellulose-derived chromatographic fractions revealed a fourfold decrease in the specific activity of the TFIID-containing fraction prepared from poliovirus-infected cells compared with that of the same fraction prepared from mock-infected cells. Finally, TFIID and the activity required to specifically restore transcription in virus-infected cell extracts were shown to have the same kinetics of heat inactivation. Together, these results suggest that inactivation of TFIID is an early event in the inhibition of host cell RNA polymerase II transcription by poliovirus.

scholarly journals A Role for Single-Stranded Templates in Cell-Free Adeno-Associated Virus DNA Replication

2000 ◽  
Vol 74 (2) ◽  
pp. 744-754 ◽  
Author(s):  
Peter Ward ◽  
R. Michael Linden
Keyword(s):  
Dna Replication ◽  
Infected Cell ◽  
Dna Binding Protein ◽  
Strand Displacement ◽  
Dna Templates ◽  
Single Stranded Dna ◽  
Adeno Associated Virus ◽  
Rep Protein ◽  
Cell Extracts ◽  
Infected Cells

ABSTRACT Assays have been described in which duplex adeno-associated virus (AAV) DNA can be replicated in HeLa cell extracts with exogenous AAV Rep protein. These assays appear to mimic the AAV DNA replication that occurs in the cell, including the ability of extracts from adenovirus (Ad)-infected cells to replicate duplex AAV DNA templates more efficiently than extracts from uninfected cells can. We showed previously that the Ad-infected extract was able to support a more processive replication than the uninfected extract. When the Ad single-stranded DNA binding protein (Ad-DBP) was added to an uninfected extract, DNA replication became processive. Based on a strand displacement replication model, we hypothesized that the Ad-DBP was stabilizing the displaced single-stranded DNA during strand displacement replication. In this report, we show that in Ad-infected extracts most of the newly replicated duplex DNA is converted into a single-stranded form shortly after synthesis. Using the results of assays for the replication of single-stranded AAV DNA, we show that these single-stranded molecules serve as templates for additional replication. In addition, we identify a class of molecules which are likely to be intermediates of replication on single-stranded templates. We discuss a possible role for replication of single-stranded molecules in the infected cell.

scholarly journals Interleukin-1 (IL-1) Receptor-Associated Kinase-Dependent IL-1-Induced Signaling Complexes Phosphorylate TAK1 and TAB2 at the Plasma Membrane and Activate TAK1 in the Cytosol

2002 ◽  
Vol 22 (20) ◽  
pp. 7158-7167 ◽  
Author(s):  
Zhengfan Jiang ◽  
Jun Ninomiya-Tsuji ◽  
Youcun Qian ◽  
Kunihiro Matsumoto ◽  
Xiaoxia Li
Keyword(s):  
Plasma Membrane ◽  
Complex I ◽  
Interleukin 1 ◽  
Critical Role ◽  
Complex Iii ◽  
Receptor Complex ◽  
Complex Ii ◽  
Jnk Activation ◽  
Cytosolic Factors ◽  
Sequential Formation

ABSTRACT Interleukin-1 (IL-1) receptor-associated kinase (IRAK) plays an important role in the sequential formation and activation of IL-1-induced signaling complexes. Previous studies showed that IRAK is recruited to the IL-1-receptor complex, where it is hyperphosphorylated. We now find that the phosphorylated IRAK in turn recruits TRAF6 to the receptor complex (complex I), which differs from the previous concept that IRAK interacts with TRAF6 after it leaves the receptor. IRAK then brings TRAF6 to TAK1, TAB1, and TAB2, which are preassociated on the membrane before stimulation to form the membrane-associated complex II. The formation of complex II leads to the phosphorylation of TAK1 and TAB2 on the membrane by an unknown kinase, followed by the dissociation of TRAF6-TAK1-TAB1-TAB2 (complex III) from IRAK and consequent translocation of complex III to the cytosol. The formation of complex III and its interaction with additional cytosolic factors lead to the activation of TAK1, resulting in NF-κB and JNK activation. Phosphorylated IRAK remains on the membrane and eventually is ubiquitinated and degraded. Taken together, the new data reveal that IRAK plays a critical role in mediating the association and dissociation of IL-1-induced signaling complexes, functioning as an organizer and transporter in IL-1-dependent signaling.

scholarly journals Oxidative Phosphorylation System in Gastric Carcinomas and Gastritis

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
René G. Feichtinger ◽  
Daniel Neureiter ◽  
Tom Skaria ◽  
Silja Wessler ◽  
Timothy L. Cover ◽  
...  
Keyword(s):  
Oxidative Phosphorylation ◽  
Complex I ◽  
Aerobic Glycolysis ◽  
Complex Iii ◽  
Complex Ii ◽  
Gastric Carcinomas ◽  
Cellular Energy ◽  
Protein Levels ◽  
Chemically Induced ◽  
Grade 3

Switching of cellular energy production from oxidative phosphorylation (OXPHOS) by mitochondria to aerobic glycolysis occurs in many types of tumors. However, the significance of this switching for the development of gastric carcinoma and what connection it may have toHelicobacter pyloriinfection of the gut, a primary cause of gastric cancer, are poorly understood. Therefore, we investigated the expression of OXPHOS complexes in two types of human gastric carcinomas (“intestinal” and “diffuse”), bacterial gastritis with and without metaplasia, and chemically induced gastritis by using immunohistochemistry. Furthermore, we analyzed the effect of HP infection on several key mitochondrial proteins. Complex I expression was significantly reduced in intestinal type (but not diffuse) gastric carcinomas compared to adjacent control tissue, and the reduction was independent of HP infection. Significantly, higher complex I and complex II expression was present in large tumors. Furthermore, higher complex II and complex III protein levels were also obvious in grade 3 versus grade 2. No differences of OXPHOS complexes and markers of mitochondrial biogenesis were found between bacterially caused and chemically induced gastritis. Thus, intestinal gastric carcinomas, but not precancerous stages, are frequently characterized by loss of complex I, and this pathophysiology occurs independently of HP infection.

DNA binding of a nonstructural reovirus protein

1981 ◽  
Vol 59 (2) ◽  
pp. 122-130 ◽  
Author(s):  
Iris H. Shelton ◽  
George J. Kasupski Jr. ◽  
Colette Oblin ◽  
Roger Hand
Keyword(s):  
Infected Cell ◽  
Electrophoretic Analysis ◽  
Size Class ◽  
Structural Protein ◽  
Cell Extracts ◽  
Nuclear Extracts ◽  
Infected Cells ◽  
Early Inhibition ◽  
Inhibition Of Dna Synthesis ◽  
Slab Gels

The specific early inhibition of DNA synthesis in reovirus-infected cells suggests that the cell nucleus is a target for virus-induced damage. We have now examined the affinity of reovirus proteins for DNA, postulating that such affinity could provide a mechanism for the inhibition. Cytoplasmic and nuclear extracts of cells labeled with [35S]methionine from 6 to 8.5 h after infection at high multiplicity were subjected to chromatography on denatured DNA – cellulose columns. Fractions from both cytoplasm and nucleus eluted with 0.6 M NaCl contained a protein with the same electrophoretic mobility on polyacrylamide slab gels as the nonstructural (NS) reovirus protein of the sigma size class. The protein also exhibited affinity for native DNA – cellulose and denatured DNA – agarose. Electrophoretic analysis in tube gels of cell extracts labeled for 48 h before infection with [14C]leucine and from 6 to 8.5 h after infection with [3H]leucine showed increased 3H label in this protein indicating it is reovirus specific. Small amounts of mu proteins also had DNA affinity. Purified virus did not bind strongly to DNA, suggesting that the binding protein is not a structural protein of the sigma size class on the outer surface of the virus. Our results provide evidence that the sigma NS protein binds to DNA. This affinity could interfere with chromosome function in the infected cell.

scholarly journals An RNA polymerase II transcription factor inactivated in poliovirus-infected cells copurifies with transcription factor TFIID.

1988 ◽  
Vol 8 (8) ◽  
pp. 3175-3182 ◽  
Author(s):  
S Kliewer ◽  
A Dasgupta
Keyword(s):  
Transcription Factor ◽  
Infected Cell ◽  
Rna Polymerase ◽  
Host Cell ◽  
Rna Polymerase Ii ◽  
Heat Inactivation ◽  
Early Event ◽  
Cell Extracts ◽  
Infected Cells ◽  
Rna Polymerase Ii Transcription

Inhibition of host cell RNA polymerase II-mediated transcription by poliovirus infection was studied in vitro. Whole-cell extracts prepared from poliovirus-infected HeLa cells at 3 h postinfection were shown to be deficient in a factor required for specific transcription from the adenovirus major late promoter. Three lines of evidence suggest that transcription factor TFIID is deficient in poliovirus-infected cells. First, the activity required to specifically restore transcription in poliovirus-infected cell extracts was shown to copurify with TFIID through three chromatographic steps. Second, transcription reactions reconstituted with phosphocellulose-derived chromatographic fractions revealed a fourfold decrease in the specific activity of the TFIID-containing fraction prepared from poliovirus-infected cells compared with that of the same fraction prepared from mock-infected cells. Finally, TFIID and the activity required to specifically restore transcription in virus-infected cell extracts were shown to have the same kinetics of heat inactivation. Together, these results suggest that inactivation of TFIID is an early event in the inhibition of host cell RNA polymerase II transcription by poliovirus.

scholarly journals Lysis of measles virus-infected cells by the purified cytolytic alternative complement pathway and antibody.

1979 ◽  
Vol 150 (3) ◽  
pp. 445-454 ◽  
Author(s):  
J G Patrick Sissons ◽  
R D Schreiber ◽  
L H Perrin ◽  
N R Cooper ◽  
H J Müller-Eberhard ◽  
...  
Keyword(s):  
Infected Cell ◽  
Human Serum ◽  
Serum Protein ◽  
Hela Cells ◽  
Measles Virus ◽  
Alternative Pathway ◽  
Complement Pathway ◽  
Virus Infected Cell ◽  
Alternative Complement ◽  
Infected Cells

The dependence of antibody-and-complement-mediated lysis of virus-infected cells on the alternative pathway was examined utilizing the isolated cytolytic alternative pathway--a system consisting of the six purified proteins of the alternative pathway of activation (C3, factors B and D, beta 1H, C3b inactivator and properdin), and the five proteins of the membrane attack pathway (C5--9) of complement. HeLa cells acutely infected with measles virus were lysed by anti-viral IgG and the isolated cytolytic alternative pathway with an efficiency comparable to whole human serum. IgG and its F(ab')2 fragment were equally effective in inducing lysis by the isolated cytolytic alternative pathway, binding of approximately equal to 5 X 10(7) molecules per cell being required for 50% lysis; in contrast, no lysis occurred when equivalen or greater amounts of Fab' were bound to the virus-infected cell. Properdin was required for lysis. No lysis occurred if properdin was deleted from the isolated cytolytic alternative pathway, and lysis was diminished by 80% in properdin-depleted serum. Uptake of [125I]C3b from the isolated alternative pathway onto measles virus-infected cells occurred in the absence of properdin, but was accelerated in the presence of properdin. The 11 proteins of the isolated cytolytic alternative pathway are thus sufficient for lysis of measles virus-infected cells bearing anti-viral IgG or F(ab')2 without any other serum protein.

Further Observations on the Virus of Epizootic Diarrhea of Infant Mice. An Electron Microscopic Study

1967 ◽  
Vol 25 ◽  
pp. 110-111
Author(s):  
W. G. Banfield ◽  
G. Kasnic ◽  
J. H. Blackwell
Keyword(s):  
Electron Microscope ◽  
Infected Cell ◽  
Microscopic Study ◽  
Intestinal Epithelium ◽  
Ultrastructural Study ◽  
Osmium Tetroxide ◽  
Lead Citrate ◽  
Electron Microscopic ◽  
Virus Particles ◽  
Infected Cells

An ultrastructural study of the intestinal epithelium of mice infected with the agent of epizootic diarrhea of infant mice (EDIM virus) was first performed by Adams and Kraft. We have extended their observations and have found developmental forms of the virus and associated structures not reported by them.Three-day-old NLM strain mice were infected with EDIM virus and killed 48 to 168 hours later. Specimens of bowel were fixed in glutaraldehyde, post fixed in osmium tetroxide and embedded in epon. Sections were stained with uranyl magnesium acetate followed by lead citrate and examined in an updated RCA EMU-3F electron microscope.The cells containing virus particles (infected) are at the tips of the villi and occur throughout the intestine from duodenum through colon. All developmental forms of the virus are present from 48 to 168 hours after infection. Figure 1 is of cells without virus particles and figure 2 is of an infected cell. The nucleus and cytoplasm of the infected cells appear clearer than the cells without virus particles.

Sign in / Sign up

Export Citation Format

Share Document