Dr. Veprintsev Dmitry
November 5, 2013. Time slot: 13.00 – 14.30
Skolkovo School of Management: Beijing – 1 Auditorium
SEMINAR ABSTRACT
Intracellular signaling is activated by external or internal trigger and regulated by dynamic processes. The tumor suppressor p53is a transcription factor activated in response to carcinogenic stress. Using systematic substitutions in the p53 response element, we quantified the ability of p53 to recognize DNA and found that it is not sufficient to explain the observed specificity of its action. We speculated that a cooperative interaction with another transcription factor. We identified KLF4 as an example of such factor, and showed that it increases the affinity of p53 for DNA via direct protein – protein interactions, and that this increase is modulated by phosphorylation state of p53.
G protein coupled receptors (GPCRs) are membrane proteins that sense extracellular signals and activate a number of intracellular signaling pathways. Over 30% of the drugs used in medicine today modulate the activity of GPCRs. To study conformational dynamics of GPCRs and G proteins during the signal transduction cycle we are developing a novel biophysical and protein engineering technique, conformational phi-value analysis. It is based on the ideas originated in the protein folding field and is using alanine mutations as a probe for the changes of a local structure, as reflected by a change in stability of various states of a protein. By comparing stability of the mutants with those for the wild type, we can study the ligand-induced structural changes at a single-residue level. We have created a library of single alanine mutants of a G protein covering all 354 amino acids, and are now measuring the phi values for all mutants. We are planning to integrate the phi-values with NMR, crystallographic, functional and biophysical data using hybrid computational methods for structure and dynamics characterisation.
SPEAKER INTRODUCTION:
Dr. Dmitry Veprintsev graduated in biophysics from the Department of Biology, Moscow State University, in 1991. He did his PhD work at the Institute of Theoretical and Experimental Biophysics, Puschino, and the Department of Chemistry at the Ohio State University, Columbus, USA, under the supervision of Prof. Eugene A. Permyakov. In his PhD he studied the effects of metal ions on stability and folding of metal-binding proteins. In 1999 he joined the MRC Centre for Protein Engineering in Cambridge, UK, directed by Prof Sir. Alan Fersht, as a Human Frontier postdoctoral fellow, and later as a staff scientist. His work was focussed on structural and biophysical characterisation of the tumour suppressor p53 and its recognition of DNA using NMR spectroscopy and variety of biophysical methods. In 2007 he joined the MRC Laboratory of Molecular Biology, Cambridge, UK, as a staff scientist and continued his work on recognition of DNA by p53 and other cancer associated transcription factors. In 2010 Dmitry changed his research direction and moved to the Laboratory for Biomolecular Research at the Paul Scherrer Institut in Switzerland, as a group leader. He is applying x-ray crystallography, NMR and biophysical approaches to study conformational dynamics of G protein coupled receptors during their signalling cycle.
