Objective:To construct the bait expression plasmid pGBKT7-GRα-LBD of glucocorticoid receptor 1igand binding domain in order to lay the foundation for constructing small molecule ligand yeast three-hybrid system.Methods:A fragment of GRα-LBD of human HL-60 cell was amplified by RT-PCR

and then was subcloned into the bait expression vector pGBKT7.After verified by sequencing

the bait vector pGBKT7-GRα-LBD was transfected into AH109 yeast cells.And the expression of the bait protein was analyzed by Western-blotting.Toxicity and self-activation of the bait protein were detected simultaneously.Results:GRα-LBD was amplified and cloned into pGBKT7 successfully.The bait vector was transformed into AH109 yeast cells successfully

and no toxicity and self-activation were found.The expression of the bait protein was confirmed by western blot.Conclusion:The bait expression vector pGBKT7-GRα-LBD was constructed successfully

which lays the foundation for constructing small molecule ligand yeast three-hybrid system.