Characteristics of DNA replication in isolated nuclei initiated by an aprotinin-binding protein.
Characteristics of DNA replication in isolated nuclei initiated by an aprotinin-binding protein.
复制标题
由抑肽酶结合蛋白启动的分离细胞核中 DNA 复制的特征。
DOI：
10.1002/jcb.240510207
复制
发表时间：
1993
影响因子：
4
通讯作者：
Cohen,S
中科院分区：
文献类型：
--
作者：
Coffman,FD;Fresa,KL;Hameed,M;Cohen,S
Isolated cell nuclei were used as the source of template DNA to investigate the role of a cytosolic aprotinin‐binding protein (ADR) in the initiation of eukaryotic DNA replication. Computerized image cytometry demonstrated that the DNA content of individual nuclei increased significantly following incubation with ADR‐containing preparations, and the extent of DNA synthesis is consistent with that allowed by the limiting concentration of dTTP. Thus, dTTP incorporation into isolated nuclei represents DNA synthesis and not parent strand repair. We found that dTTP incorporation into the isolated nuclei is dependent on DNA polymerase α (a principal polymerase in DNA replication) but that DNA polymerase β (a principal polymerase in DNA repair processes) does not play a significant role in this system. Finally, neither aprotinin nor a previously described cytosolic ADR inhibitor can block the replication of nuclease‐treated calf thymus DNA, while both strongly inhibit replication of DNA in isolated nuclei. This result, coupled with the relative ineffectiveness of nuclease‐treated DNA compared with nuclear DNA to serve as a replicative template in this assay, argues against a significant contribution from repair or synthesis which initiates at a site of DNA damage. These data indicate that ADR‐mediated incorporation of3H‐dTTP into isolated nuclei results from DNA replicative processes that are directly relevant to in vivo S phase events. © 1993 Wiley‐Liss, Inc.
