Mapping Chromatin Interactions of ZBP1 and ADAR Z-Alpha Domains: A ChIP-Seq Based Comparison

Abstract

The DNA double helix typically exists in the canonical B-form conformation, but this structure often can adopt the unique alternative form known as Z-DNA. In Z-DNA, the DNA helix winds to the left in a zigzag pattern instead of the right-handed B-DNA form. Z-DNA is thought to play a key role in transcription, but it is unclear whether is a positive or negative regulator of RNA polymerase activity. Additionally, several studies have shown how Z-DNA contributes to DNA damage or genome instability. However, the precise role of Z-DNA in the genome remains unclear. To address this question, we mapped Z-DNA using a ChIP-Seq assay with two Z-DNA biosensors: Zaa-Zbp1, comprised of a dimerized Z-alpha Z-DNA binding domains from Z-DNA binding protein 1 (Zbp1), and Zaa-Adar1, comprised of dimerized Z-alpha domains from Adenosine deaminase acting on RNA 1 (Adar1). We found that these Zaa probes possessed similar binding profiles when analyzed with motif analysis, but gene ontology analysis revealed that these Z-alpha domains bound to heterogeneous genes, with Zaa-Zbp1 most strongly binding to genes in the RHOQ-GTPase pathway and Zaa-Adar1 binding to genes involved in the M phase of the cell cycle.