Effect of 2',3'-dideoxythymidine-5'-triphosphate on HeLa cell in vitro DNA synthesis: evidence that DNA polymerase alpha is the only polymerase required for cellular DNA replication.
Effect of 2',3'-dideoxythymidine-5'-triphosphate on HeLa cell in vitro DNA synthesis: evidence that DNA polymerase alpha is the only polymerase required for cellular DNA replication.
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2,3-二脱氧胸苷-5-三磷酸对 HeLa 细胞体外 DNA 合成的影响：DNA 聚合酶 α 是细胞 DNA 复制所需的唯一聚合酶的证据。
DOI：
10.1093/nar/5.6.1933
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发表时间：
1978
影响因子：
14.9
通讯作者：
J. Huberman
中科院分区：
文献类型：
--
作者：
M. Waqar;M. J. Evans;J. Huberman
我们研究了核苷酸类似物2‘，3’-二脱氧胸苷-5‘-三磷酸(DdTTP)对HeLa细胞裂解产物复制DNA合成的影响。如前所述(1)，这种裂解物在体外以类似于体内DNA复制的速度和方式进行广泛的DNA合成。我们在这里报道，当dTTP浓度保持在10微米时，这种裂解产物中DNA合成的所有方面(总dNTP掺入、连续新生链条的伸长以及Okazaki片段的起始、延伸和连接)仅被高达100-500微米的ddTTP浓度轻微抑制。这一发现与Edenberg、Anderson和DePamPhilis的报告(2)一致，即体外复制的猿猴病毒40DNA合成的所有方面也对ddTTP具有耐药性。我们还发现，与Edenberg，Anderson和DePamPhilis(2)一致，DNA聚合酶β或伽马催化的DNA合成很容易被ddTTP抑制，而DNA聚合酶α催化的合成非常抵抗。这些观察表明，DNA聚合酶α可能是细胞DNA合成的所有方面所需的唯一DNA聚合酶。
We have studied the effects of the nucleotide analogue, 2',3'-dideoxythymidine-5'-triphosphate (ddTTP) on replicative DNA synthesis in HeLa cell lysates. As previously demonstrated (1), such lysates carry out extensive DNA synthesis in vitro, at rates and in a fashion similar to in vivo DNA replication. We report here that all aspects of DNA synthesis in such lysates (total dNTP incorporation, elongation of continuous nascent strands, and the initiation, elongation, and joining of Okazaki pieces) are only slightly inhibited by concentrations of ddTTP as high as 100-500 micrometer when the dTTP concentration is maintained at 10 micrometer. This finding is consistent with the report by Edenberg, Anderson, and DePamphilis (2) that all aspects of replicative in vitro simian virus 40 DNA synthesis are also resistant to ddTTP. We also find, in agreement with Edenberg, Anderson, and DePamphilis (2), that DNA synthesis catalyzed by DNA polymerases beta or gamma is easily inhibited by ddTTP, while synthesis catalyzed by DNA polymerase alpha is very resistant. These observations suggest that DNA polymerase alpha may be the only DNA polymerase required for all aspects of cellular DNA synthesis.