Steroid receptors (SRs) are hormone-activated transcription factors controlling tissues-specific gene expression and therapeutically important physiologies. In their inactive states, these receptors are known to form complexes with the chaperone Hsp90 which in turn can be bound by one of four tetratricopeptide repeat (TPR) proteins: FKBP52, FKBP51, Cyp40 and PP5. This fact means that SRs exists in distinct heteromeric complexes defined by TPR protein content. If these distinct complexes exist, they must have distinct functions. Yet we know almost nothing of these differential functions. We now have new evidence to suggest that TPR proteins serve to regulate distinct stages of SR signaling within a cell, as well as tissue specific responses to steroids. We base these conclusions on key observations from our laboratories. We have uncovered a new first step in hormonal activation of the glucocorticoid receptor (GR) that involves a coordinated exchange of FKBP51 for FKBP52 within GR complexes. This TPR exchange is the signal that tells GR complexes to recruit the transport protein dynein and move to the nucleus. We have also determined that FKBP52, PP5 and FKBP51 have hierarchical effects on the hormone-binding function of the GR, and that Cyp40 can regulate both GR protein levels and cause it to become nuclear. Last but not least, we have generated FKBP52 knockout mice that manifest female sterility. Further characterization has revealed the infertility to result from inactivity in the uterus by the PR-A progesterone receptor isoform, leading to a failure of implantation. Interestingly, both the PR-B isoform and the estrogen receptor in uterus tissue were unaffected by loss of FKBP52. Thus, it is now clear that distinct TPRs will have both receptor- and tissue-specific impacts on physiology. With this in mind, the goals of this proposal are to further define the roles of TPR proteins in GR and PR functions under cell-free and tissue culture conditions, followed by testing of mechanisms in select physiological responses using FKBP52 and FKBP51 knockout animals. A better understanding of differential TPR protein effects on both GR and PR could now form the basis for new therapeutic strategies targeting fertility and other physiologies.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
Research Project (R01)
Project #
5R01DK070127-03
Application #
7239515
Study Section
Molecular and Cellular Endocrinology Study Section (MCE)
Program Officer
Margolis, Ronald N
Project Start
2005-08-01
Project End
2010-06-30
Budget Start
2007-07-01
Budget End
2008-06-30
Support Year
3
Fiscal Year
2007
Total Cost
$240,716
Indirect Cost
Name
University of Toledo
Department
Physiology
Type
Schools of Medicine
DUNS #
807418939
City
Toledo
State
OH
Country
United States
Zip Code
43614
Stechschulte, Lance A; Qiu, Bin; Warrier, Manya et al. (2016) FKBP51 Null Mice Are Resistant to Diet-Induced Obesity and the PPAR? Agonist Rosiglitazone. Endocrinology 157:3888-3900
Stechschulte, Lance A; Ge, Chunxi; Hinds Jr, Terry D et al. (2016) Protein Phosphatase PP5 Controls Bone Mass and the Negative Effects of Rosiglitazone on Bone through Reciprocal Regulation of PPAR? (Peroxisome Proliferator-activated Receptor ?) and RUNX2 (Runt-related Transcription Factor 2). J Biol Chem 291:24475-24486
Ramakrishnan, Sadeesh K; Khuder, Saja S; Al-Share, Qusai Y et al. (2016) PPAR? (Peroxisome Proliferator-activated Receptor ?) Activation Reduces Hepatic CEACAM1 Protein Expression to Regulate Fatty Acid Oxidation during Fasting-refeeding Transition. J Biol Chem 291:8121-9
Hinds, Terry D; Stechschulte, Lance A; Elkhairi, Fadel et al. (2014) Analysis of FK506, timcodar (VX-853) and FKBP51 and FKBP52 chaperones in control of glucocorticoid receptor activity and phosphorylation. Pharmacol Res Perspect 2:e00076
Stechschulte, Lance A; Hinds Jr, Terry D; Khuder, Saja S et al. (2014) FKBP51 controls cellular adipogenesis through p38 kinase-mediated phosphorylation of GR? and PPAR?. Mol Endocrinol 28:1265-75
Stechschulte, Lance A; Hinds Jr, Terry D; Ghanem, Simona S et al. (2014) FKBP51 reciprocally regulates GR? and PPAR? activation via the Akt-p38 pathway. Mol Endocrinol 28:1254-64
Marino, Joseph S; Hinds Jr, Terry D; Potter, Rachael A et al. (2013) Suppression of protein kinase C theta contributes to enhanced myogenesis in vitro via IRS1 and ERK1/2 phosphorylation. BMC Cell Biol 14:39
Sanchez, Edwin R (2012) Chaperoning steroidal physiology: lessons from mouse genetic models of Hsp90 and its cochaperones. Biochim Biophys Acta 1823:722-9
Hinds Jr, Terry D; Stechschulte, Lance A; Cash, Harrison A et al. (2011) Protein phosphatase 5 mediates lipid metabolism through reciprocal control of glucocorticoid receptor and peroxisome proliferator-activated receptor-? (PPAR?). J Biol Chem 286:42911-22
Stechschulte, Lance A; Sanchez, Edwin R (2011) FKBP51-a selective modulator of glucocorticoid and androgen sensitivity. Curr Opin Pharmacol 11:332-7

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