Skip to main content
. 2004 Mar;24(5):1884–1896. doi: 10.1128/MCB.24.5.1884-1896.2004

FIG. 1.

FIG. 1.

Tip60 and Tip60b are associated with homologs of yeast NuA4 complex subunits. (A) Amino acid sequence alignment between the yeast Esa1, human Tip60, and Tip60b/PLIP histone acetyltransferases. The chromodomain and MYST HAT family homology regions are indicated. (B) Nuclear extracts from mock, FLAG-Tip60, and FLAG-Tip60b-transduced MCF7 cells were immunoprecipitated with α-FLAG resin, eluted with FLAG peptide, and analyzed by Western blotting with antibodies against protein homologous to yeast NuA4 subunits. Native FLAG eluates were also tested in HAT assays on free histones and chromatin substrates. Specific association of actin with Tip60(b) cannot be concluded from this experiment since it is also detected in the control lane. Proteins previously shown to be associated with Tip60 are marked with an asterisk (26). (C) Tip60b is part of a large HAT protein complex. The Tip60b FLAG eluate from panel B was purified over a calibrated Superose 6HR gel filtration column, and fractions were analyzed by Western blotting and HAT assay. Tip60b, EPC1, and H4/H2A HAT activity coelute as a single high-molecular-mass complex of ∼1.8 MDa. Molecular mass standards eluted as follows: void volume, fraction 19; 670 kDa, fraction 28; 158 kDa, fraction 32; 44 kDa, fraction 35; and 17 kDa, fraction 37.