Disordered N-Terminal Domain of Human Uracil DNA Glycosylase (hUNG2) Enhances DNA Translocation.
Gaddiel RodriguezAlexandre EsadzeBrian P WeiserJoseph D SchonhoftPhilip A ColeJames T StiversPublished in: ACS chemical biology (2017)
Nuclear human uracil-DNA glycosylase (hUNG2) initiates base excision repair (BER) of genomic uracils generated through misincorporation of dUMP or through deamination of cytosines. Like many human DNA glycosylases, hUNG2 contains an unstructured N-terminal domain that encodes a nuclear localization signal, protein binding motifs, and sites for post-translational modifications. Although the N-terminal domain has minimal effects on DNA binding and uracil excision kinetics, we report that this domain enhances the ability of hUNG2 to translocate on DNA chains as compared to the catalytic domain alone. The enhancement is most pronounced when physiological ion concentrations and macromolecular crowding agents are used. These data suggest that crowded conditions in the human cell nucleus promote the interaction of the N-terminus with duplex DNA during translocation. The increased contact time with the DNA chain likely contributes to the ability of hUNG2 to locate densely spaced uracils that arise during somatic hypermutation and during fluoropyrimidine chemotherapy.
Keyphrases
- circulating tumor
- cell free
- endothelial cells
- single molecule
- dna binding
- induced pluripotent stem cells
- nucleic acid
- squamous cell carcinoma
- circulating tumor cells
- gene expression
- bone marrow
- dna damage
- mesenchymal stem cells
- genome wide
- binding protein
- single cell
- radiation therapy
- small molecule
- oxidative stress
- chemotherapy induced