SELECTIVE DEGRADATION OF INTEGRATED MURINE LEUKEMIA PROVIRAL DNA BY DEOXYRIBONUCLEASES
SELECTIVE DEGRADATION OF INTEGRATED MURINE LEUKEMIA PROVIRAL DNA BY DEOXYRIBONUCLEASES
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DOI：
10.1016/0092-8674(77)90304-x
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发表时间：
1977-01-01
期刊：
影响因子：
64.5
通讯作者：
CEDAR, H
中科院分区：
文献类型：
--
作者：
PANET, A;CEDAR, H
研究了感染莫洛尼鼠白血病病毒的瑞士小鼠细胞中整合的前病毒DNA序列对微球菌核酸酶和DNA酶I的敏感性。染色质被分离成微球菌核酸酶敏感和耐药区域，并在这些DNA制剂中的前病毒序列的量进行了估计通过动力学杂交与单链互补DNA的莫洛尼小鼠白血病病毒。至少有2/3的前病毒DNA序列位于染色质开放区，只有1/3的前病毒DNA序列对核酸酶具有抗性。前病毒DNA序列对DNA酶I更加敏感。当用有限量的酶处理完整的细胞核时，只有5%的细胞核DNA被消化，但48%的前病毒DNA被降解。与病毒生产细胞相比，不产生病毒的细胞中的前病毒DNA序列对核酸酶消化的抵抗力更强。因此，当用微球菌核酸酶或胰腺DNA酶I检测时，正常未诱导的瑞士小鼠细胞中的内源性前病毒序列随机分布在染色质的抗性和敏感部分之间。用感染莫洛尼鼠白血病病毒的大鼠细胞研究细胞周期同步化对前病毒序列对胰腺DNA酶I的可及性的影响。对胰腺DNA酶I敏感的前病毒DNA的量在活跃分裂的细胞中高于停滞在Go期的细胞，其仅产生少量病毒。
The sensitivity to micrococcal nuclease and DNase I of the integrated proviral DNA sequences in Swiss mouse cells infected with Moloney murine leukemia virus was studied. Chromatin was separated into micrococcal nuclease-sensitive and -resistant regions, and the amount of proviral sequences in these DNA preparations was estimated by kinetic hybridization with single-stranded complementary DNA of Moloney murine leukemia virus. At least 2/3 of the proviral DNA sequences were found in the open regions of chromatin, and only 1/3 was resistant to nuclease. The proviral DNA sequences are even more sensitive to DNase I. When intact nuclei were treated with limited amounts of enzyme, only 5% of the nuclear DNA was digested, but 48% of the proviral DNA was degraded. The proviral DNA sequences in cells which do not produce virus are more resistant to nuclease digestion, as compared to virus producer cells. Thus the endogenous proviral sequences in normal uninduced Swiss mouse cells are randomly distributed between resistant and sensitive portions of chromatin when tested with micrococcal nuclease or pancreatic DNase I. The effect of cell cycle synchronization on the accessibility of the proviral sequences to pancreatic DNase I was investigated with rat cells infected with Moloney murine leukemia virus. The amount of proviral DNA sensitive to pancreatic DNase I is higher in actively dividing cells than in cells arrested at Go phase, which produce only small amounts of virus.