86 Structural Elucidation of Hsp90/p23 Client Protein Specificity for the Large Immunophilin Protein FKBP52

Wednesday, November 4, 2009: 10:20 AM
Kohlberg (Camino Real Hotel)
Zacariah L. Hildenbrand , Department of Chemistry, The University of Texas at El Paso, El Paso, TX
Steroid hormones illicit their effects on gene expression through binding to receptor complexes resulting in further interaction with the nuclear membrane.  In order for a hormone/receptor interaction to take place, the receptor must first be stabilized by a chaperone complex which includes the Heat shock 90 protein (Hsp90), the immunophilin FKBP52, and the p23 co-chaperone.  While the composition of the receptor chaperone complex has been well elucidated, the structural architecture of these interactions remains unclear.  In the work presented here, Hsp90, FKBP52 and p23 have been purified to homogeneity and have been used to create an Hsp90/FKBP52/p23 complex in-vitro. Cryo electron microscopy (cryoEM) will be used to identify the interactions of individual proteins with the intact complex. It is anticipated that a three-dimensional reconstruction of the Hsp90/FKBP52/p23 complex will reveal key details of its role in receptor binding.