Fig. 3

Apoptotic cleavage of DFS70/LEDGF. a Early during apoptosis caspases-3 and -7 cleave DFS70/LEDGF at specific aspartic acids (D30 and D486) to generate fragments p72 (truncated PWWP) and p68 (deletion of extreme C-terminal region). These fragments are subsequently cleaved to generate p65, which lacks a portion of the PWWP domain. b Caspase-mediated cleavage of DFS70/LEDGF influenced its ability to transactivate the Hsp27 gene promoter (Hsp27pr). U2OS cells were transiently transfected with luciferase (luc) reporter plasmids empty pGL3 vector control, pGL3-Hsp27pr-luc, empty pcDNA3.1 + vector control (Vec), or effector plasmids encoding p75, p65, p72, p68, or irrelevant transcription factors AP-2 and AP-2 mutant as negative controls. At 48 h post-transfection, luciferase activity was measured and fold activation of promoter activity was calculated. The highest fold activation was produced by p72, which has a deletion of the N-terminal residues 1–30, consistent with autorepression activity residing in the PWWP domain. The lowest activation was produced by p68, which has deletions in both the N- and C-terminal regions, including complete removal of the PWWP domain. Results are representative from 3 independent experiments performed in triplicates