FIG. 4.

Mutation of K366 reveals its dual property in AF2 activity. (A) COS-1 cells were transiently transfected with expression vector for wild-type (wt) or mutant receptors (left) or Gal4-chimeric receptors (right), the pJ7-lacZ internal control plasmid, and the luciferase (LUC) reporter plasmid as indicated. Data are presented as described for Fig. 2A. (B) Binding of mutant receptors to GST-SRC1 (aa 570 to 780) was examined under the same conditions as described for Fig. 2B. (C) In vivo interaction of mutant mERα LBDs with SRC1 (aa 570 to 780) in transiently transfected HeLa cells. Data are presented as described for Fig. 3C. nd, not determined.