Genomic regions targeted by DNA topoisomerase IIβ frequently interact with a nuclear scaffold/matrix protein hnRNP U/SAF-A/SP120.

ABSTRACT: Type II DNA topoisomerases (topo II) play critical roles in some cellular events through repeated cleavage/rejoining of nuclear DNA. The β isoform (topo IIβ) is essential for the transcriptional induction of neuronal genes in terminal differentiation. Genomic sites targeted by the enzyme are nonrandom. Although previous studies have claimed that topo II cleavage sites are close to the nuclear scaffold/matrix attachment region (S/MAR), it is still unclear whether this view can be generalized. We report here that a library of cloned genomic DNA fragments targeted by topo IIβ in vivo frequently contains S/MAR and binding sites for hnRNP U/SAF-A/SP120. Binding assays in vitro showed that a large proportion of the target DNAs bound to SP120 but their affinity to the nuclear scaffold/matrix vari

SUBMITTER: Miyaji M 

PROVIDER: S-EPMC5024068 | biostudies-literature | 2015 Apr

REPOSITORIES: biostudies-literature