? Assembly of a transcriptional activation complex occurs through cooperative recruitment of numerous proteins targeted to a specific DNA promoter sequence. Our long term goal is to understand the mechanism of allosterically regulated protein assembly as well as how these macromolecular machines regulate gene expression. As a model system, we are using the human progesterone receptor (PR). A mechanistic understanding of function is confounded by the presence of two functionally distinct isoforms, PR-A and PR- B. The two isoforms are identical except that the B-isoform contains an additional 164 amino acids at the N- terminus. Recent studies suggest that isoform specific differences may be due to differential recruitment of co-activating proteins such as steroid receptor coactivator-1 (SRC-1). We hypothesize that residues unique to the B-receptor allosterically regulate PR:isoform:SRC-1 affinities by modulating receptor structure. We will test this hypothesis by examining the energetics and structure of each isoform:SRC-1 complex on a DNA progesterone response element (PRE). We will use analytical ultracentrifugation, DNase footprinting, limited proteolysis, and CD spectroscopy to examine the interactions. ? ?
| Heneghan, Aaron F; Connaghan-Jones, Keith D; Miura, Michael T et al. (2007) Coactivator assembly at the promoter: efficient recruitment of SRC2 is coupled to cooperative DNA binding by the progesterone receptor. Biochemistry 46:11023-32 |
| Bain, David L; Heneghan, Aaron F; Connaghan-Jones, Keith D et al. (2007) Nuclear receptor structure: implications for function. Annu Rev Physiol 69:201-20 |
| Heneghan, Aaron F; Connaghan-Jones, Keith D; Miura, Michael T et al. (2006) Cooperative DNA binding by the B-isoform of human progesterone receptor: thermodynamic analysis reveals strongly favorable and unfavorable contributions to assembly. Biochemistry 45:3285-96 |
| Connaghan-Jones, Keith D; Heneghan, Aaron F; Miura, Michael T et al. (2006) Hydrodynamic analysis of the human progesterone receptor A-isoform reveals that self-association occurs in the micromolar range. Biochemistry 45:12090-9 |
