Fig. 5.

HDAC1 maintains the HSF1–PARP13–PARP1 complex on gene promoters. a Extracts of HeLa cells untreated (−) or treated (+) with DOX were subjected to HSF1 immunoprecipitation and immunoblotting. b HDAC1 occupancy on the HSE of the GADD34 locus. ChIP-qPCR was performed before and after DOX treatment (n = 3). Mean ± s.d. is shown. Asterisks indicate p < 0.01 by Student’s t-test. c, d Endogenous HDAC1 was substituted with GFP, HA-hHDAC1, HA-hHDAC1-H141A, or HA-hHDAC1-S421/423A. Denatured extracts of cells, untreated or treated with DOX, were subjected to PARP1 immunoprecipitation and immunoblotting using antibodies including anti-acetyl lysine antibody (anti-AcK) (c) and anti-PAR antibody (d). e Extracts of untreated or DOX-treated cells, in which endogenous HDAC1 was substituted with a series of mutants, were subjected to immunoprecipitation of PARP1 (upper) or HSF1 (lower) and to immunoblotting. f PARP1 occupancy on HSE in cells expressing hHDAC1 mutants. ChIP-qPCR was performed (n = 3). Mean ± s.d. is shown. Asterisks indicate P < 0.01 by Student’s t-test. g Expression of GADD34 in cells expressing HDAC1 mutants. Cells, in which endogenous HDAC1 was replaced, were treated or not with DOX for 16 h. GADD34 mRNA level was quantified by RT-qPCR (n = 3). Mean ± s.d. is shown. Asterisks indicate P < 0.01 by Student’s t-test