UNIVERSITY OF MALTA
LIFE SCIENCE RESEARCH SEMINARS
Web: http://www.um.edu.mt/events/scisem/ Email: scisem@um.edu.mt
Abstract form
Title:
Structure-functional analyses of Aryl hydrocarbon receptor interacting protein
(AIP) and mutant derivative associated with pituitary adenomas in Malta.
Presenter:
Marita Vella
Contact address:
Tel:
79270791
Fax:
Email:
N/A
Marita.vella.09@um.edu.mt
Presentation date:
19 th
May 2014
Abstract
In Malta there is a high prevalence of pituitary adenomas (PAs) with around 76 per 100,000 inhabitants being affected. Although in the majority of cases PAs are benign in nature, patients still suffer from a considerable amount of co-morbidities. The aryl hydrocarbon receptor interacting protein (AIP) is a cytoplasmic 37 kDa protein acting as a molecular chaperone. AIP is considered as a tumour suppressor and mutations in its gene have been implicated to predispose pituitary adenomas. Locally, a novel mutation, designated as R9Q, has been identified in an acromegalic patient.
Recently, the crystal structure of the TPR-domain of AIP has been solved. However, no structural data exists on the full length AIP protein. Structural data is essential in understanding the protein’s biological function, especially in elucidating its role as a tumour suppressor. The aim of this study is investigate the AIP protein and its R9Q variant with respect to protein structure and interactions with known binding partners, including heat shock protein 90 (Hsp90), aryl hydrocarbon receptor (AhR) and phosphodiesterase PDE4A5.
Optimal conditions for expression of wild type AIP have been established and the protein successfully purified using standard chromatography techniques. Through the use of site-directed mutagenesis, the R9Q variant has been generated, expressed within BL21 CodonPlus (DE3) and likewise purified. Purification techniques were also carried out on the C-terminal fragment of the heat shock protein 90 (Hsp90). In addition to the purification of phosphodiesterase PDE4A5, work is currently being done to sub-clone and eventually purify AhR. The interactions between
AIP and its binding partners will be investigated through co-immunoprecipitation experiments and isothermal titration calorimetry (ITC), the latter being performed in collaboration with the
University of Leeds. Interaction studies will also be carried out on the R9Q variant.
Crystallisation conditions of the WT AIP protein are currently being investigated.