(
A) Total lysates of MCF10A cells transfected with
H2AFZ(H46C)V5 or
H2AFZ (untagged) driven by the same tetracycline-inducible promoter were analyzed by immunoblotting using an antibody directed against the C-terminus of human H2A.Z. (
B) The same blot was probed with the anti-V5 antibody. Note that the H2A.Z antibody failed to detect the V5-tagged H2A.Z because the V5 tag at the C-terminus interfered with antibody recognition. In addition, the ubiquitylation sites of H2A.Z overlap the epitope of the anti-H2A.Z antibody. This may explain the disproportionately low H2A.Z-Ub signal in the anti-H2A.Z blot in comparison to the anti-V5 blot. The H2A.Z-Ub recognition bias by the C-terminus H2A.Z antibodies was previously observed (
Sarcinella et al., 2007).