NUCLEASE S-1 SENSITIVE SITES IN PARENTAL DEOXYRIBONUCLEIC-ACID OF COLD-SENSITIVE AND TEMPERATURE-SENSITIVE MAMMALIAN-CELLS
NUCLEASE S-1 SENSITIVE SITES IN PARENTAL DEOXYRIBONUCLEIC-ACID OF COLD-SENSITIVE AND TEMPERATURE-SENSITIVE MAMMALIAN-CELLS
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DOI：
10.1021/bi00257a026
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发表时间：
1982-01-01
期刊：
影响因子：
2.9
通讯作者：
CHU, AK
中科院分区：
文献类型：
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作者：
COLLINS, JM;GLOCK, MS;CHU, AK
[小鼠成纤维细胞]3T3细胞（H6-15）的温度敏感突变体在33℃时表达转化的表型。C和正常表型在39度。C.中国仓鼠卵巢细胞冷敏感突变体cs4-D3在39度表达转化表型。C和正常表型，以及G1块，在33度。C.当任一细胞类型处于正常状态和G0状态时，纯化DNA中仅在亲本链上标记的s1敏感位点的数量为零。当10%的血清刺激正常细胞时，每105个碱基对的S1位点数量略有增加，cs4-D3为0.7个，H6-15为1.1个。在允许表达转化表型但不允许增殖的条件下，每105个碱基对中cs4-D3最多有5个S1位点，H6-15最多有44个。当静止转化细胞被10%的血清刺激时，每105个碱基对中S1位点的数量在cs4-D3中增加到6个，在H6-15中增加到43个。此外，来自受刺激的转化H6-15细胞的DNA包含的S1位点至少是断裂总数（缺口加间隙）的两倍，这增加了细胞在受刺激时获得稳定的环状或十字形结构的可能性。
Temperature-sensitive mutants of [mouse fibroblast] 3T3 cells (H6-15) express the transformed phenotype at 33.degree. C and the normal phenotype at 39.degree. C. Cold-sensitive mutants of Chinese hamster ovary cells (cs4-D3) express the transformed phenotype at 39.degree. C and the normal phenotype, along with a G1 block, at 33.degree. C. When either cell type is under conditions such that it is normal and in a G0 state, the number of S1-sensitive sites in purified DNA, labeled in parental chains only, is zero. When the normal cells are stimulated by 10% serum, the number of S1 sites per 105 base pairs increases slightly, to 0.7 in cs4-D3 and 1.1 in H6-15. Under conditions permitting the expression of the transformed phenotype, but not proliferation, the maximum number of S1 sites per 105 base pairs is 5 in cs4-D3 and 44 in H6-15. When the stationary transformed cells are stimulated by 10% serum, the number of S1 sites per 105 base pairs increases to 6 in cs4-D3 and 43 in H6-15. Furthermore, the DNA from the stimulated transformed H6-15 cells contains at least twice as many S1 sites as the total number of breaks (nicks plus gaps), raising the possibility of the acquisition of stable looped or cruciform structures as the cells are stimulated.