Human ubiquitin-activating enzyme (E1): compensation for heat-labile mouse E1 and its gene localization on the X chromosome.
We have constructed interspecific somatic cell hybrids between a temperature-sensitive (ts) mutant cell line of mouse FM3A cells, ts85, that has a heat-labile ubiquitin-activating enzyme (E1) and a human diploid fibroblast cell line, IMR-90. A hybrid clone that could grow stably at a nonpermissive temperature (39 degrees C) was obtained. Segregation of the hybrid cells at a permissive temperature (33 degrees C) gave rise to temperature-sensitive clones. The electrophoresis of extracted histones and karyotype analysis of the segregants revealed a close correlation of the ability to grow at 39 degrees C, the presence of uH2A (ubiquitin-H2A semihistone) at 39 degrees C, and the presence of the human X chromosome. One of the hybrid clones that could grow at the nonpermissive temperature contained the X chromosome as the only human chromosome. The sodium dodecyl sulfate-polyacrylamide gel electrophoretic pattern of affinity-purified E1 showed that this hybrid clone contained both human and mouse type E1. Thus we conclude that the functional gene for human E1 is located on the X chromosome.
Kudo
M
M
Department of Physiological Chemistry, Faculty of Pharmaceutical Sciences, University of Tokyo, Japan.
Sugasawa
K
K
Hori
T
T
Enomoto
T
T
Hanaoka
F
F
Ui
M
M
D000818:Animals; D002874:Chromosome Mapping; D002999:Clone Cells; D003001:Cloning, Molecular; D005816:Genetic Complementation Test; D006657:Histones / Q000378:metabolism; D006801:Humans; D006822:Hybrid Cells; D007621:Karyotyping; D008025:Ligases / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice; D009154:Mutation; D013696:Temperature; D044764:Ubiquitin-Activating Enzymes; D044767:Ubiquitin-Protein Ligases; D014452:Ubiquitins / Q000378:metabolism; D014960:X Chromosome
D006657:Histones; D014452:Ubiquitins; D044767:Ubiquitin-Protein Ligases; D008025:Ligases; D044764:Ubiquitin-Activating Enzymes