Formation and characterization complex between thyroid hormone receptors and coactivator

Author(s)

Tábata Renée Doratioto

• Document type: Master's Dissertation
• Press: Campinas, SP.
• Institution: Universidade Estadual de Campinas (UNICAMP). Instituto de Biologia
• Defense date: 2016-02-22

Examining board members

Ana Carolina Migliorini Figueira; Sandra Martha Gomes Dias; Fernanda Apareceida Helena Batista

• Advisor: Ana Carolina Migliorini Figueira

Abstract

The thyroid hormone regulates many functions of the endocrine system through the interaction with its receptor (nuclear receptor thyroid hormone - TR). In the presence of its ligand, the receptor undergoes a conformational change that allows the interaction with coactivator proteins, asGRIP. The combination of TR with coactivators assists in opening the chromatin structure via the recruitment of histone acetylases. These results in the activation of transcription of many genes, particularly genes linked to the expression of proteins that regulate the basal metabolism. This project aimed to study the formation and characterization of nuclear receptor with coactivator complex to map possible additional interaction interfaces and to better understand their formation. We performed assays which enabled us to evaluate the stoichiometry of the complex, the affinity between these proteins; and, also, the activity of the ligands of these receptors. We developed protocols for protein purification and formation of complex (as pull down-like and coexpression). Fluorescence anisotropy assays made possible to verify the affinity between TRs and GRIP, and also to study the mechanism of action of RXR ligand (9C) in the complex TR: RXR: GRIP. In addition, other biophysical characterization experiments were made to evaluate the quality of the samples and the stability of the secondary structure of proteins and complexes. The main results gave information of the affinity of the complexes and their stability, which showed that the presence of more complete constructions of these receptors are important in their stabilization. By fluorescence anisotropy we observed that the 9C operates in the complex helping to dissociate correpressores. It is worth to highlight that this research helped to get more detail about TR¿s mechanism of action, which could be useful, for example, for drug design (AU)

• FAPESP's process: 13/26507-4 - Complex between thyroid hormone receptor and coactivator: formation and characterization.
• Grantee: Tábata Renée Doratioto
• Support Opportunities: Scholarships in Brazil - Master