Fig. 2

Overexpression of P301L-hTau increases acetylated level of STAT1 by tau acetyltransferase activity. a, b Overexpression of P301L increased the interaction of STAT1 and STAT3 in the cytoplasmic fraction of HEK293 cells measured by CO-IP. c Mass spectrometry analysis of the acetylated peptide of STAT1. The detected MS/MS peptide spectra are listed. d Overexpression of P301L increased the level of STAT1 acetylation in whole-cell extracts and the cytoplasm. Proteins were first immunoprecipitated with STAT1, followed by Western blotting with anti-ace-lysine antibody. e, f The CBP level decreased, and p300 and HDAC2 level remained unchanged while overexpressing P301L in HEK293 cells detected by Western blotting. Two-tailed Student’s t test, [CBP] p = 0.021, n = 3. g The P301L-hTau recombinant protein interacted with STAT1 and increased its acetylation level in the whole extracts of HEK293WT cells. h Tau interacted with STAT1 in HEK293WT cells transfected with P301L-hTau detected by the Co-IP assay. i P301L-K18(−) (P301L tau lacking the repeats) had no effect on acetylated STAT1 level. Data were presented as mean ± SEM