caa a22 4500 465820719 CHVBK 20180323112135.0 cr unu---uuuuu 170327e19900901xx s 000 0 eng 10.1007/BF01233194 doi (NATIONALLICENCE)springer-10.1007/BF01233194 High level of aphidicolin resistance with multiple mutations in mouse FM3A cell mutants [Elektronische Daten] [Michihiko Ito, Michio Matsuhashi, Takeshi Seno, Dai Ayusawa] Spontaneous mutants of mouse FM3A cells (AC1, AC2, and AC3), highly resistant to aphidicolin (3000-, 2500-, and 300-fold increase in resistance, respectively), were isolated by multistep selection. The DNA synthesizing activity in permeabilized cells of all three mutants was substantially resistant to aphidiolin, like that in intact cells. The DNA polymerase activity in nuclear extracts in AC1 and AC3, but not AC2, was resistant to aphidicolin. Partially purified DNA polymerase α from AC3, but not from AC1 or AC2, showed resistance to aphidicolin. The apparentK i value for aphidicolin of AC3 polymerase α was three to four times that of the enzyme from the parent cells, but the apparentK m values of the enzyme for dCTP and dTTP were normal. All the mutants showed cross-resistance to both arabinofuranosyladenine and arabinofuranosylcytosine. The AC3 mutant had expanded deoxyribonucleoside triphosphate pools. On two-dimensional polyacrylamide gel electrophoresis, AC1 gave a new protein (mol wt 40 kDa). The aphidicolin-resistance trait was reversible in AC2, unlike in AC1 and AC3. These results show that in mammalian cells there are at least two mechanisms of aphidicolin-resistance that involve an altered DNA polymerase α that is resistant to aphidicolin and simultaneous expansion of the four DNA-precursor pools. Plenum Publishing Corporation, 1990 Ito Michihiko Institute of Applied Microbiology, The University of Tokyo, Bunkyo-ku, 113, Tokyo, Japan aut Matsuhashi Michio Institute of Applied Microbiology, The University of Tokyo, Bunkyo-ku, 113, Tokyo, Japan aut Seno Takeshi Department of Molecular Genetics, National Institute of Genetics, Mishima, 411, Shizuoka-ken, Japan aut Ayusawa Dai Institute of Applied Microbiology, The University of Tokyo, Bunkyo-ku, 113, Tokyo, Japan aut Somatic Cell and Molecular Genetics Kluwer Academic Publishers-Plenum Publishers 16/5(1990-09-01), 443-450 0740-7750 16:5<443 1990 16 11188 https://doi.org/10.1007/BF01233194 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/BF01233194 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Ito Michihiko Institute of Applied Microbiology, The University of Tokyo, Bunkyo-ku, 113, Tokyo, Japan aut NATIONALLICENCE 700 1- Matsuhashi Michio Institute of Applied Microbiology, The University of Tokyo, Bunkyo-ku, 113, Tokyo, Japan aut NATIONALLICENCE 700 1- Seno Takeshi Department of Molecular Genetics, National Institute of Genetics, Mishima, 411, Shizuoka-ken, Japan aut NATIONALLICENCE 700 1- Ayusawa Dai Institute of Applied Microbiology, The University of Tokyo, Bunkyo-ku, 113, Tokyo, Japan aut NATIONALLICENCE 773 0- Somatic Cell and Molecular Genetics Kluwer Academic Publishers-Plenum Publishers 16/5(1990-09-01), 443-450 0740-7750 16:5<443 1990 16 11188 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer