FIG. 5.
LXXLL-related motifs in Dax-1 interact with LRH-1, ERR2, and fly FTZ-F1. (A) In vitro interaction of MBP-Ad4BP and MBP-LRH-1 with fluorescence-labeled GFP-Dax-1[WT] and GFP-Dax-1[M123]. GFP was used not as a source of fluorescence but as a sequence that allows efficient expression (see Materials and Methods), because for unknown reasons, pCMX-Dax-1[WT] and pCMX-Dax-1[M123] failed to express the proteins in vitro. “10% input” represents one-tenth of the amount of labeled protein in a reaction mixture. (B) Interaction of LXXLL-related motifs in Dax-1 with orphan receptors on their LBDs. CV-1 cells were transfected as described in Materials and Methods with 25 ng of bait plasmids per well and 50 ng of prey plasmids per well as effectors as indicated. Data are mean and SD. (C) Repression by Dax-1 against transcription activated by orphan receptors whose DBDs were replaced by GAL4 DBD. EPC cells were transfected as described in Materials and Methods with 25 ng of pCMX-GAL4-LBD plasmids per well, with or without 50 ng of pCMX-Dax-1[WT] per well as effectors in the presence or absence of β-E2 as indicated. Bars represent fold repression by Dax-1. Relative luciferase activities are expressed numerically. In these experiments, the reporter plasmid was UASG-TK-LUC.