Figure 3.

Poly‐ubiquitination of estrogen receptor α (ERα) by Hbo1 is dependent on the histone acetyltransferase (HAT) activity of Hbo1 and linked through lysine 48 of the ubiquitin. (a) Hbo1 wild‐type (Hbo1 WT) and the catalytically‐deficient mutant, Hbo1 (G485A) (Hbo1 mut), were transfected into 293T cells with the other Hbo1 complex components, and ERα and HA‐ubiquitin, and analyzed similarly to Figure 2(a). Ten percent of the input was loaded. (b) The ING4‐containing components of Hbo1 protein complex, and ERα were transfected with the empty vector, wild‐type ubiquitin, K48R mutant, or K0 mutant tagged with the HA epitope. The transfectants were handled in a similar fashion to Figure 2(a). *Immunoglobulin heavy chain.