Immunological analyses of selected eukaryotic RNA polymerases II

1985 ◽  
Vol 63 (12) ◽  
pp. 1217-1230 ◽  
Author(s):  
Michael F. Bettiol ◽  
Randall T. Irvin ◽  
Paul A. Horgen

Polyclonal antibodies to native RNA polymerase II of Achlya ambisexualis and Agaricus bisporus were produced in rabbits and in mice. Monoclonal antibodies were produced against the α-amanitin resistant RNA polymerase II of the mushroom A. bisporus. These antibodies were used in comparative cross-reactivity studies with five purified RNA polymerases II (A. bisporus, A. ambisexualis, Saccharomyces cerevisiae, wheat germ, and calf thymus). A method for quantitatively comparing cross-reactivity was developed utilizing an enzyme-linked immunosorbant assay (ELISA). ELIS A comparisons indicated that the two filamentous fungi cross-reacted effectively with one another and depending upon the preparation reacted less effectively with yeast and wheat germ RNA polymerases II. Cross-reactivity measurements were also made by immunoblotting sodium dodecyl sulfate – polyacrylamide separated RNA polymerases II. The mouse anti-A. bisporus RNA polymerase II immunoglobulin G (IgG) and the monoclonal antibody preparations did not react with high molecular subunits of A. bisporus RNA polymerase II. The sera did, however, cross-react with high molecular weight subunits of A. ambisexualis. Similarily, rabbit anti-A. ambisexualis RNA polymerase II IgG reacted only with low molecular weight subunits of A. bisporus RNA polymerase II, but reacted with high molecular weight subunits of A. ambisexualis and wheat germ. Our results indicate differences in the cross-reactivity of native and denatured RNA polymerases II and suggest differences in the tertiary and quaternary organization of the enzymes examined.

2004 ◽  
Vol 166 (1) ◽  
pp. 27-36 ◽  
Author(s):  
Vincent van den Boom ◽  
Elisabetta Citterio ◽  
Deborah Hoogstraten ◽  
Angelika Zotter ◽  
Jean-Marc Egly ◽  
...  

The Cockayne syndrome B (CSB) protein is essential for transcription-coupled DNA repair (TCR), which is dependent on RNA polymerase II elongation. TCR is required to quickly remove the cytotoxic transcription-blocking DNA lesions. Functional GFP-tagged CSB, expressed at physiological levels, was homogeneously dispersed throughout the nucleoplasm in addition to bright nuclear foci and nucleolar accumulation. Photobleaching studies showed that GFP-CSB, as part of a high molecular weight complex, transiently interacts with the transcription machinery. Upon (DNA damage-induced) transcription arrest CSB binding these interactions are prolonged, most likely reflecting actual engagement of CSB in TCR. These findings are consistent with a model in which CSB monitors progression of transcription by regularly probing elongation complexes and becomes more tightly associated to these complexes when TCR is active.


1990 ◽  
Vol 55 (11) ◽  
pp. 2769-2780
Author(s):  
Aleš Cvekl ◽  
Květa Horská

A comparison was drawn between the action of Cibacron Blue F3GA on the enzymic activity of DNA-dependent RNA polymerases from different sources, e.g. Escherichia coli, calf thymus and wheat germ (polymerase II). Sensitivity towards this inhibitor was determined for polymer formation and primed abortive synthesis of trinucleotide UpApU. In case of E. coli polymerase and wheat germ polymerase II the dye inhibits both polymer formation and abortive synthesis. Calf thymus polymerase II is inhibited only in the polymerisation step. The primed initiation reaction was found to be resistant towards the dye. In case of E. coli polymerase and wheat germ polymerase II the sensitive step is the formation of internucleotide bond whereas in case of calf thymus polymerase II the translocation of the enzyme is influenced. An analysis of kinetic data indicates more than one binding site for the dye on RNA polymerase II from calf thymus and wheat germ. Cibacron blue does not inhibit specific transcription catalyzed by RNA polymerase III from human HeLa cells and mouse leukemia L1210 cells.


1986 ◽  
Vol 28 (6) ◽  
pp. 1076-1087 ◽  
Author(s):  
Chris L. Baszczynski

Polyclonal antibodies to 18-kilodalton (kDa) heat-shock proteins (HSPs) and to the high molecular weight (73 000 – 89 000) HSPs from 5- day-old maize plumules have been produced in rabbits. The antisera to high molecular weight HSPs show minor cross-reactivity to proteins of similar molecular mass in not heat-shocked tissues, while antisera to 18-kDa HSPs react only with this 18-kDa HSP class. HSPs of similar molecular mass and isoelectric points in maize plumules, mesocotyls, radicles, and young leaves also have similar antigenic determinants based on positive reactions with antisera to plumule HSPs. Among 13 maize inbreds and genetic stocks tested, differences were noted in the amount of immunoprecipitable 18-kDa HSPs. Antisera to maize plumule HSPs also showed cross-reactivity with similar-sized HSPs from pea epicotyls and soybean hypocotyls but not with HSPs from several animal tissues.Key words: polyclonal antibodies, maize, heat-shock.


1994 ◽  
Vol 14 (9) ◽  
pp. 6164-6170
Author(s):  
P P Sadhale ◽  
N A Woychik

We identified a partially sequenced Saccharomyces cerevisiae gene which encodes a protein related to the S. cerevisiae RNA polymerase II subunit, RPB7. Several lines of evidence suggest that this related gene, YKL1, encodes the RNA polymerase III subunit C25. C25, like RPB7, is present in submolar ratios, easily dissociates from the enzyme, is essential for cell growth and viability, but is not required in certain transcription assays in vitro. YKL1 has ABF-1 and PAC upstream sequences often present in RNA polymerase subunit genes. The sodium dodecyl sulfate-polyacrylamide gel electrophoresis mobility of the YKL1 gene product is equivalent to that of the RNA polymerase III subunit C25. Finally, a C25 conditional mutant grown at the nonpermissive temperature synthesizes tRNA at reduced rates relative to 5.8S rRNA, a hallmark of all characterized RNA polymerase III mutants.


1980 ◽  
Vol 189 (1) ◽  
pp. 9-15 ◽  
Author(s):  
Yoav Ben-Yoseph ◽  
Melinda Hungerford ◽  
Henry L. Nadler

Galactocerebrosidase (β-d-galactosyl-N-acylsphingosine galactohydrolase; EC 3.2.1.46) activity of brain and liver preparations from normal individuals and patients with Krabbe disease (globoid-cell leukodystrophy) have been separated by gel filtration into four different molecular-weight forms. The apparent mol.wts. were 760000±34000 and 121000±10000 for the high- and low-molecular-weight forms (peaks I and IV respectively) and 499000±22000 (mean±s.d.) and 256000±12000 for the intermediate forms (peaks II and III respectively). On examination by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis, the high- and low-molecular-weight forms revealed a single protein band with a similar mobility corresponding to a mol.wt. of about 125000. Antigenic identity was demonstrated between the various molecular-weight forms of the normal and the mutant galactocerebrosidases by using antisera against either the high- or the low-molecular-weight enzymes. The high-molecular-weight form of galactocerebrosidase was found to possess higher specific activity toward natural substrates when compared with the low-molecular-weight form. It is suggested that the high-molecular-weight enzyme is the active form in vivo and an aggregation process that proceeds from a monomer (mol.wt. approx. 125000) to a dimer (mol.wt. approx. 250000) and from the dimer to either a tetramer (mol.wt. approx. 500000) or a hexamer (mol.wt. approx. 750000) takes place in normal as well as in Krabbe-disease tissues.


1987 ◽  
Author(s):  
J Ingerslev ◽  
B Sloth Christiansen ◽  
A Bukh ◽  
S Stenbjerg ◽  
T Munck Jørgensen ◽  
...  

Human hepatocytes were isolated by the two-step collagenase technique applied on distal left liver lobe. Homogenous and large cells were isolated revealing hepatocyte characteristics by light-microscopy. Hepatocytes were washed repeatedly in albumine buffer (5%), resuspended in the same buffer and sonicated using a cell density of 0.75 × 106 cells/ml. In some cases cells were separated from non-viable cells by flotation on a linear Percoll gradient. Supernate material after sonication was subjected to ELISA for VIII:Ag using human antibodies and vWf:Ag by polyclonal antibodies. Freshly isolated cells contained at least 0.25 IU/ 0.75 × 106 hepatocytes, whereas the vWf:Ag was below 0.01 IU/ 0.75 × 106 cells. The material obtained from sonication was further studied using fast protein liquid chromatography by Mono-Q HR 5/5 revealing a single peak of VIII: Ag eluting in the same position as the high molecular weight polypeptides of VIII :Ag of high purity FVIII derived from the plasma source. Isolated hepatocytes also were cultivated at 37°C in medium RPMI 1640 supplemented with Ultroser G (4%), glutamine and antibiotics. Cells secreted increasing quantities of albumin, fitrinogpn and protease-inhibitors. The supernatants also contained VIII: Ag in quantities ranging from 0.04 - 0.17 IU/ml after 24 hours, but no further secretion was observed. No vWf: Ag could be detected. Cells harvested and sonicated after 30 hours of culture only contained 0.04 IU/ 0.75 × 106 cells. Our results shows, that VIII :Ag is present in freshly isolated human hepatocytes and that only traces of vWf:Ag is found. A hepatocyte site of production of VIII is speculated. These very preliminary findings do not permit conclusions concerning active synthesis of VIII in hepatocytes. Further studies are underway.


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