Figure 2
From: The HPV E6 oncoprotein targets histone methyltransferases for modulating specific gene transcription
In vitro inhibition of HMT activities by E6. E6 inhibits the methyltransferase activities of CRAM1 (a), PRMT1 (b) and SET7 (c). (a, b) The indicated proteins (2 μg of each HMT, 1 or 2 μg of each E6, and 10 μg of core histone proteins) were mixed with SAM. The reaction products were separated by 15% SDS–PAGE. The gels were analyzed by western blotting using Abs against H3 asymmetrically di-methylated at R17 (Asy-H3R17me2) and histone H3 in panel a or H4 asymmetrically di-methylated at R3 (Asy-H4R3me2) and histone H4 in panel b. The molar ratios of histone H3 to CARM1 to E6 are 1:0.2:0.37 (lanes 3, 5 and 7) and 1:0.2:0.72 (lanes 4, 6 and 8) in panel a, and of histone H4 to PRMT1 to E6 are 1:0.21:0.24 (lanes 3, 5 and 7) and 1:0.21:0.48 (lanes 4, 6 and 8) in panel b. (c) The indicated proteins (2 μg of each HMTs, 2 or 5 μg of each E6, and 5 μg of p53) were mixed with [3H]-SAM (S-adenosyl-L-[methyl-3H]-methionine). The reaction products were separated by 15% SDS–PAGE. The gels were stained with Coomassie blue (upper panel) and analyzed by phosphoimaging (lower panel). The molar ratios of p53 to SET7 to E6 are 1:0.44:1.18 (lanes 3, 5 and 7) and 1:0.44:2.94 (lanes 4, 6 and 8).
