Differential ligand‐dependent interactions between the AF‐2 activating domain of nuclear receptors and the putative transcriptional intermediary factors mSUG1 and TIF1.

摘要: Using a yeast two-hybrid system we report the isolation of novel mouse protein, mSUG1, that interacts with retinoic acid receptor alpha (RAR alpha) both in cells and vitro ligand- AF-2 activating domain (AF-2 AD)-dependent manner show it is structural functional homologue essential protein SUG1. mSUG1 also efficiently other nuclear receptors, including oestrogen (ER), thyroid hormone (TR), Vitamin D3 (VDR) retinoid X (RXR) receptors. By comparing interaction properties these receptors TIF1, demonstrate that: (i) RXR but not whereas TR much more than RAR alpha, VDR ER interact TIF1; (ii) amphipathic alpha-helix core AD differentially involved interactions (iii) cores are similarly their mSUG1. Thus, interfaces between different either or TIF1 may vary depending on nature putative mediator its function. We discuss possibility mediate transcriptional activity through mechanisms.