Opposite replication polarity of the germ line c-myc gene in HeLa cells compared with that of two Burkitt lymphoma cell lines.
Opposite replication polarity of the germ line c-myc gene in HeLa cells compared with that of two Burkitt lymphoma cell lines.
复制标题
HeLa 细胞中种系 c-myc 基因的复制极性与两种伯基特淋巴瘤细胞系相反。
DOI：
10.1128/mcb.9.2.586-593.1989
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发表时间：
1989
影响因子：
5.3
通讯作者：
James,CD
中科院分区：
文献类型：
--
作者：
Leffak,M;James,CD
为了研究人类c-mycgenes复制方向的细胞类型特异性以及复制极性与转录活性的关系，我们分析了两种Burkitt淋巴瘤细胞系CA 46和ST 486以及HeLa细胞中c-mycgenes的复制方向。在完整细胞中启动的fork的体外径流复制的基础上，我们发现在HeLa细胞中，在生殖系构型中转录的c-mycgenes是从5′-侧翼DNA的起始处沿转录方向复制的，而CA 46和ST 486细胞中被抑制的、未重排的c-mycgenes是沿反转录方向复制的。相反，CA 46细胞转录的c-mycgenes在转录方向上复制，而ST 486细胞易位的扩增的c-mycgenes没有表现出优先复制极性。这些数据还提供了证据，证明在HeLa c-mycgenes的5′端侧翼DNA中存在对DNA聚合酶的内源性屏障。
To study the cell type specificity of the direction of replication of the human c-mycgenes and the relationship of replication polarity to transcriptional activity, we analyzed the directions of replication of the c-mycgenes in two Burkitt lymphoma cell lines, CA46 and ST486, and in HeLa cells. On the basis of in vitro runoff replication of forks initiated in intact cells, we found that transcribed c-mycgenes in the germ line configuration in HeLa cells were replicated in the direction of transcription from origins in the 5′-flanking DNA, while the repressed, unrearranged c-mycgenes of CA46 and ST486 cells were replicated in the antitranscriptional direction. In contrast, the transcribed c-mycgenes of CA46 cells were replicated in the transcriptional direction, while the translocated, amplified c-mycgenes of ST486 cells showed no preferred polarity of replication. The data also provided evidence for the existence of an endogenous barrier to DNA polymerases in the flanking DNA immediately 5′ to the HeLa c-mycgenes.