Fig. 5: PARP14 per se is a target gene of mutant (STAT6^MUT) but not wild type STAT6 (STAT6^WT).

A Cross-linked chromatin immunoprecipitation (ChIP) of 3xFlag-tagged STAT6^WT or STAT6^D419G in OCI-LY8 cells after IL-4 stimulation (10 ng/mL, 24 h) followed by quantitative PCR for the PARP14 promoter region (qChIP). B Schematic of the PARP14 promotor region, indicating predicted / putative STAT6 binding sites and the 641 bp region that was cloned into pGL3. C PARP14 promoter luciferase assay (pGL3) with increasing amounts of co-transfected STAT6^WT or STAT6^D419G in 293 T cells in the presence of IL-4 (24 h after transfection, 10 ng/mL for 6 h). Shown are fold changes (FC) of luciferase activity (relative light unit, RLU) normalized to 1 ng STAT6^WT (N = 6, mean ± SD). D CD23 cell surface expression (by FACS) on OCI-Ly1 and E OCI-Ly8, each expressing either STAT6^WT or STAT6^D419G with shRNA-mediated knock-down of PARP14 (sh4) or a non-targeting (scrambled) control (scr), respectively. Immunoblot of respective cells as indicated below. F CD23 cell surface expression by FACS on OCI-Ly1 and OCI-L8 expressing STAT6^WT or STAT6^D419G with or without IL-4 stimulation (10 mg/mL, 24 h) and treatment with the PARP inhibitor PJ34 (50 µM, 15 min prior to IL-4 stimulation) or vehicle, respectively. (N = 3, mean ± SD). Cell viability of cells as indicated below (N = 3, mean ± SD).