@article{oai:repo.qst.go.jp:00046804,
 author = {菅谷, 公彦 and 石原, よし江 and 井上, 園江 and 辻, 秀雄 and 菅谷 公彦 and 石原 よし江 and 井上 園江 and 辻 秀雄},
 issue = {5},
 journal = {PLOS ONE},
 month = {May},
 note = {Temperature-sensitive (ts) CHO-K1 mutant tsTM3 exhibits chromosomal instability and cell-cycle arrest in the S to G2 phases with decreased DNA synthesis at the nonpermissive temperature, 39°C. Previously, complementation tests with other mutants showed that tsTM3 harbors a genetic defect in the ubiquitin-activating enzyme Uba1. Sequence comparison of the Uba1 gene between wild-type and mutant cells in this study revealed that the mutant phenotype is caused by a G-to-A transition that yields a Met-to-Ile substitution at position 256 in hamster Uba1. The ts defects in tsTM3 were complemented by expression of the wild-type Uba1 tagged with green fluorescent protein. Expression of the Uba1 primarily in the nucleus appeared to rescue tsTM3 cells. Incubation at 39°C resulted in a decrease of nuclear Uba1 in tsTM3 cells, suggesting that loss of Uba1 in the nucleus may lead to the ts defects. Analyses with the fluorescent ubiquitination-based cell cycle indicator revealed that loss of function of Uba1 leads to failure of the ubiquitin system in the nucleus. Incubation at 39°C caused an increase in endogenous geminin in tsTM3 cells. A ts mutation of Uba1 found in tsTM3 cells appears to be a novel mutation reflecting the important roles of Uba1 in nucleus.},
 title = {Characterization of ubiquitin-activating enzyme Uba1 in the nucleus by its mammalian temperature-sensitive mutant},
 volume = {9},
 year = {2014}
}