Our group is inquired with structural biology (the relationship between the structure and function of certain groups of proteins), particularly we focus on the proteins which participates in the signal transmission in the cell.

PROBLEMATICS:

The study of structure and function of 14-3-3 proteins and their complexes.

Our research team has been studying the 14-3-3 proteins which are highly conserved regulatory molecules found in all eukaryotes. First they have been isolated from the bovine brain and their unusual name “14-3-3”, originates from their elution and migration pattern on two-dimensional DEAE-cellulose

chromatography and starch gel electrophoresis. 14-3-3 proteins have the ability of binding the functionally different signal proteins, including kinases, fosfatases and transmembrane receptors by changing their function. Through the functional modulation of a wide range of binding partners, 14-3-3 proteins are involved in many processes, including cell cycle regulation, metabolism control, apoptosis, and control of gene transcription.More than 300 proteins have been described as binding partners till now. Main goal of these projects is mechanistic understanding of the 14-3-3 protein function in the regulation of selected 14-3-3 binding partners: for example the interaction of 14-3-3 protein with forkhead transcription factor FOXO4, with the regulatory domain of the tyrosine hydroxylase, interaction with ASK1 kinase, with the regulator of G-protein signaling RGS3 and phosducin. Recently, we have been studying two yeast isoforms of 14-3-3 protein (BMH1 and BMH2) and the interaction of BMH with neutral trehalase in yeast.

The study of the cytoplasmatic domains of TRP channels.

Transient receptor potential (TRP) channels are a wide family of non-selective ion channels responsible for monovalent and divalent cation influx into the cells. Members of this family are involved in many sensory processes such as invertebrate vision and hearing, mammalian temperature-, mechano- and chemo-sensation. The TRP channels discovered so far can be divided into seven subfamilies according to their primary structure: TRPV, TRPC, TRPA, TRPM, TRPP, TRPML and TRPN. All are predicted to have six transmembrane helices (S1–S6) and a pore-forming loop between S5 and S6, with varying sizes of intracellular amino and carboxy termini, and are thought to form tetrameric assemblies. Both the N- and C-terminal intracellular domains are comprised of many different domains that are responsible for binding different compounds that can regulate the channels. Our goal is to provide the structural insight into the interactions of TRP channels with ATP, calmodulin and PIP.

METHODS

•      Biochemical approach (recombinant protein expression, site-directed mutagenesis, enzyme  kinetics)

•      Biophysical approach (fluorescence spectroscopy, X-ray crystallography, analytical ultracentrifugation, mass spectrometry, protein structure modeling, molecular dynamics simulations).

•      Crystallography of selected complexes

     →   These methods enable us to better understand the details how is regulated the activity and function of protein-protein complexes.

SOLVED STRUCTURES

DNA-bindind domain of forkhead transcription factor

FOXO4 bound to the DNA

RGS domain of RGS3 (regulator of G-protein signaling)