Figure 2.

p300 acetyltransferase acetylates SRY in vitro. (A) Purified human SRY (wt) and GST-SRY fusion proteins (box, Cter, Nter) were in vitro acetylated after incubation of SRY proteins (500 μg) with ¹⁴C-acetylCoenzymeA in the absence of p300 (−) and presence of 50 ng of recombinant p300 (+) or HAT-inactive p300 (Δ). Reaction products were separated by SDS–PAGE and visualised by autoradiography. Autoacetylated p300 and acetylated SRY are indicated. (B) The synthetic peptide P35 corresponding to SRY (amino acids 107–139) was in vitro acetylated using p300 and submitted to mass spectra. The unmodified peptide (long arrow) has an Mr of 4712, and the peak of Mr 4754 corresponds to a monoacetylated peptide (short arrow). Other peaks correspond to oxidative forms of acetylated and unacetylated peptides.