Fig. 2: Multi-omics analysis identifies BCLAF1 as potential downstream effector of nuclear p85β.
From: p85β acts as a transcription cofactor and cooperates with BCLAF1 in the nucleus
A Outline of the analyses to identify potential downstream effectors that mediate the transcriptional changes induced by p85β. B Heatmap showing the 13 transcription factor candidates from transcription factor enrichment analysis and with total and/or phosphorylated protein level changes after PIK3R2 knockdown. Names of the transcription factors are listed on the left of the heatmap and the detected phosphosites are on the right. Phosphosites with antibodies commercially available are marked with asterisks. C Transcription factor candidates with phosphorylation changes determined by mass spectrometry were examined by western blotting with cells transfected with 4 independent sequences of PIK3R2 siRNA for 72 h. ERK2 was loading control. D Total protein lysates of OVCAR8 and SKOV3 cells transfected with PIK3R2 siRNA for 72 h or DOV13 cells stably expressing PIK3R2 (R2-OX) or vector control were subjected to western blotting. E, F Subcellular fractionation was performed with (E) DOV13 stable cells or (F) SKOV3 cells transfected with PIK3R2 siRNA for 72 h prior to western blotting with GAPDH and lamin A/C as markers of the cytoplasm and nucleus respectively. G OVCAR8 cells were transfected with two PIK3R2 siRNA targeting the 5’ UTR for 24 h prior to lentivirus-mediated overexpression of PIK3R2 for another 48 h. H DOV13 or SKOV3 cells stably expressing PIK3R2 (R2-OX) or PIK3R2 with nuclear export signal (NES) at N-terminal (NES-R2-OX) or vector control were subjected to western blotting. I Serous ovarian tumor samples (n = 49) were examined by immunohistochemical staining for p85β and BCLAF1. Left, representative images and their magnified areas are shown. Scale bar, 50 μm. Right, immunostaining scores of BCLAF1 and nuclear p85β or cytoplasmic p85β were analyzed for Pearson’s correlation coefficient r with two-tailed P-value and are depicted in scatter plot. The western blots are representative of n = 3 biological replicates and densitometry values normalized to the loading control are shown (C–H). Source data are provided as a Source Data file.
