Isolation of a cDNA clone for human threonyl-tRNA synthetase: amplification of the structural gene in borrelidin-resistant cell lines

1989 ◽  
Vol 9 (5) ◽  
pp. 1832-1838
Author(s):  
K J Kontis ◽  
S M Arfin
Keyword(s):  
Cdna Clone ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Mrna Translation ◽  
Resistant Cell ◽  
Trna Synthetase ◽  
Expression Library ◽  
Hybridization Probe ◽  
Ovary Cells

A cDNA for threonyl-tRNA synthetase was isolated from a human placental cDNA lambda gt11 expression library by immunological screening, and its identity was confirmed by hybrid-selected mRNA translation. With this cDNA used as a hybridization probe, borrelidin-resistant Chinese hamster ovary cells that overproduced threonyl-tRNA synthetase were shown to have increased levels of threonyl-tRNA synthetase mRNA and gene sequences. Amplification of the gene did not appear to have been accompanied by any major structural reorganizations.

scholarly journals Isolation of a cDNA clone for human threonyl-tRNA synthetase: amplification of the structural gene in borrelidin-resistant cell lines.

1989 ◽  
Vol 9 (5) ◽  
pp. 1832-1838 ◽  
Author(s):  
K J Kontis ◽  
S M Arfin
Keyword(s):  
Cdna Clone ◽  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Mrna Translation ◽  
Resistant Cell ◽  
Trna Synthetase ◽  
Expression Library ◽  
Hybridization Probe ◽  
Ovary Cells

A cDNA for threonyl-tRNA synthetase was isolated from a human placental cDNA lambda gt11 expression library by immunological screening, and its identity was confirmed by hybrid-selected mRNA translation. With this cDNA used as a hybridization probe, borrelidin-resistant Chinese hamster ovary cells that overproduced threonyl-tRNA synthetase were shown to have increased levels of threonyl-tRNA synthetase mRNA and gene sequences. Amplification of the gene did not appear to have been accompanied by any major structural reorganizations.

Amplification of the gene for histidyl-tRNA synthetase in histidinol-resistant Chinese hamster ovary cells

1985 ◽  
Vol 5 (9) ◽  
pp. 2381-2388
Author(s):  
F W Tsui ◽  
I L Andrulis ◽  
H Murialdo ◽  
L Siminovitch
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Fold Increase ◽  
Resistant Cell ◽  
Trna Synthetase ◽  
Synthetase Activity ◽  
Wild Type ◽  
Ovary Cells ◽  
Resistant Cells

Histidinol-resistant (HisOHR) mutants with up to a 30-fold increase in histidyl-tRNA synthetase activity have been isolated by stepwise adaptation of wild-type Chinese hamster ovary (CHO) cells to increasing amounts of histidinol in the medium. Immunoprecipitation of [35S]methionine-labeled cell lysates with antibodies to histidyl-tRNA synthetase showed increased synthesis of the enzyme in histidinol-resistant cells. The histidinol-resistant cell lines had an increase in translatable polyadenylated mRNA for histidyl-tRNA synthetase. A cDNA for CHO histidyl-tRNA synthetase has been cloned, using these histidyl-tRNA synthetase-overproducing mutants as the source of mRNA. Southern blot analysis of wild-type and histidinol-resistant cells with this cDNA showed that the histidyl-tRNA synthetase DNA bands were amplified in the resistant cells. These HisOHR cells owed their resistance to histidinol to amplification of the gene for histidyl-tRNA synthetase.

scholarly journals Amplification of the gene for histidyl-tRNA synthetase in histidinol-resistant Chinese hamster ovary cells.

1985 ◽  
Vol 5 (9) ◽  
pp. 2381-2388 ◽  
Author(s):  
F W Tsui ◽  
I L Andrulis ◽  
H Murialdo ◽  
L Siminovitch
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Fold Increase ◽  
Resistant Cell ◽  
Trna Synthetase ◽  
Synthetase Activity ◽  
Wild Type ◽  
Ovary Cells ◽  
Resistant Cells

Histidinol-resistant (HisOHR) mutants with up to a 30-fold increase in histidyl-tRNA synthetase activity have been isolated by stepwise adaptation of wild-type Chinese hamster ovary (CHO) cells to increasing amounts of histidinol in the medium. Immunoprecipitation of [35S]methionine-labeled cell lysates with antibodies to histidyl-tRNA synthetase showed increased synthesis of the enzyme in histidinol-resistant cells. The histidinol-resistant cell lines had an increase in translatable polyadenylated mRNA for histidyl-tRNA synthetase. A cDNA for CHO histidyl-tRNA synthetase has been cloned, using these histidyl-tRNA synthetase-overproducing mutants as the source of mRNA. Southern blot analysis of wild-type and histidinol-resistant cells with this cDNA showed that the histidyl-tRNA synthetase DNA bands were amplified in the resistant cells. These HisOHR cells owed their resistance to histidinol to amplification of the gene for histidyl-tRNA synthetase.

scholarly journals Isolation of Chinese hamster ovary cells that overproduce asparaginyl-tRNA synthetase.

1984 ◽  
Vol 4 (9) ◽  
pp. 1939-1941
Author(s):  
R E Cirullo ◽  
J J Wasmuth
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Trna Synthetase ◽  
Temperature Sensitive ◽  
Ovary Cells ◽  
Resistant Phenotype ◽  
Lines Of Evidence

Temperature-resistant revertants, derived from the temperature-sensitive CHO asparaginyl-tRNA synthetase mutant, Asn-5, were isolated and characterized. Several lines of evidence indicate that the temperature-resistant phenotype of the revertants is due to their overproducing the same altered enzyme present in the Asn-5 parent.

scholarly journals Internalization of ricin in Chinese hamster ovary cells.

1981 ◽  
Vol 1 (6) ◽  
pp. 544-551 ◽  
Author(s):  
B Ray ◽  
H C Wu
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Polyacrylamide Gel Electrophoresis ◽  
Combined Treatment ◽  
Sodium Dodecyl ◽  
Chinese Hamster ◽  
Resistant Cell ◽  
Proteolytic Processing ◽  
Ph Optimum ◽  
Ovary Cells

Internalization of ricin into Chinese hamster ovary cells has been investigated. Combined treatment with galactose and pronase at 0 degrees C resulted in a complete release of surface-bound [125I]ricin into the media. Galactose-pronase-resistant cell-bound [125I]ricin represents internalized ricin molecules inside the cells. The internalization process is time, temperature, and concentration dependent. The pH optimum of internalization of ricin is about pH 7. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis has revealed that intact ricin molecules are internalized. Neither reduction nor proteolytic processing of ricin is required for the entry of ricin into Chinese hamster ovary cells.

scholarly journals Identification and characterization of a third complementation group of emetine-resistant Chinese hamster cell mutants.

1981 ◽  
Vol 1 (1) ◽  
pp. 58-65 ◽  
Author(s):  
J J Wasmuth ◽  
J M Hill ◽  
L S Vock
Keyword(s):  
Chinese Hamster Ovary ◽  
Chinese Hamster Ovary Cells ◽  
Chinese Hamster ◽  
Chinese Hamster Cell ◽  
Resistant Cell ◽  
Complementation Group ◽  
Ovary Cells ◽  
Complementation Groups ◽  
Resistant Mutants ◽  
Biosynthetic Machinery

We have isolated emetine-resistant cell lines from Chinese hamster peritoneal fibroblasts and have shown that they represent a third distinct class or complementation group of emetine-resistant mutants, as determined by three different criteria. These mutants, like those belonging to the two other complementation groups we have previously defined, which were isolated from Chinese hamster lung and Chinese hamster ovary cells, have alterations that directly affect the protein biosynthetic machinery. So far, there is absolute cell line specificity with respect to the three complementation groups, in that all the emetine-resistant mutants we have isolated from Chinese hamster lung cells belong to one complementation group, all those we have isolated from Chinese hamster ovary cells belong to a second complementation group, and all those isolated from Chinese hamster peritoneal cells belong to a third complementation group. Thus, in cultured Chinese hamster cells, mutations in at least three different loci, designated emtA, emtB, and emtC, encoding for different components of the protein biosynthetic machinery, can give rise to the emetine-resistant phenotype.

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