Notes: The authors examined whether HMGB1 and HMGB2 proteins could affect promoter activity of the topoisomerase IIα gene. Portions of the topoisomerase IIα gene promoter were cloned into the pGL3 Basic Vector, and Saos-2 cells were cotransfected with the resulting constructs, an HMGB1- or HMGB2-expressing plasmid and the pRL-tk Vector as a control for normalization. Firefly and Renilla luciferase activities were determined using the Dual-Luciferase Reporter Assay. To determine whether HMGB1 and HMGB2 promoted binding of the transcription factor nuclear factor-Y (NF-Y) to the topoisomerase IIα promoter, the authors used a chromatin immunoprecipitation (ChIP) assay. Two populations of Saos-2 cells, one of which expressed HMGB1 or HMGB2 and one that had expression inhibited, were fixed with formaldehyde, then treated to shear chromatin. Immunoprecipitation was performed using an anti-NF-Y antibody, and the amount of DNA bound to the NF-Y was quantified by semi-quantitative PCR using GoTaq^® Hot Start DNA Polymerase and Green GoTaq^® Flexi Reaction Buffer. (4037)

Notes: The authors used T4 RNA Ligase to circularize highly purified total mitochondrial tRNA prior to RT-PCR. (1083)