OBSIL GROUP
Biophysical Chemistry of Protein Complexes
Our research

Our research focuses on molecular mechanisms by which protein function can be regulated. In particular, we are interested in 14-3-3 proteins and their complexes with proteins involved in apoptosis, cancer, G-protein and calcium-triggered signaling pathways. We employ integrated structural and biophysical approaches (fluorescence spectroscopy, analytical ultracentrifugation, SAXS, mass spectrometry, X-ray crystallography, NMR, cryo-EM, protein structure modeling, functional assays etc.) to understand the details of how the activity and function of protein complexes are regulated.

Research projects

Current Projects · Previous Projects · Structures solved by our group

Current Projects

Characterization of the interaction between p53 and FOXO4

Transcription factor p53 protects cells against tumorigenesis when subjected to various cellular stresses. Under these conditions, p53 interacts with transcription factor Forkhead box O (FOXO) 4, thereby inducing cellular senescence by upregulating the transcription of senescence-associated protein p21. Cellular senescence induces permanent cell cycle arrest and the secretion of interleukins, inflammatory cytokines, and growth factors. The resulting adverse effects on the cellular microenvironment contribute to aging and to the onset of age-related diseases such as tumorigenesis. Numerous studies have suggested links between FOXOs and p53, but the  structural details of their interaction remain mostly unclear. In this project we aim to characterize the interaction between p53 and FOXO4 using various biophysical approaches including NMR, chemical cross-linking, analytical ultracentrifugation and molecular modeling.


Structural basis of ASK1 regulation

Protein kinase ASK1, a member of the mitogen-activated protein kinase kinase kinase family, activates JNK and p38 MAP kinase signaling pathways in response to various stress stimuli, including oxidative stress, endoplasmic reticulum stress, and calcium ion influx . ASK1 plays a key role in the pathogenesis of multiple diseases including cancer, neurodegeneration and cardiovascular diseases and is considered as a promising therapeutic target. The activity of ASK1 is regulated by several other proteins including thioredoxin and the 14-3-3 protein that both function as physiological inhibitors of ASK1. Main goal of this project is to elucidate structural basis of ASK1 regulation. 


Structural basis of the 14-3-3-dependent regulation of CaMKK kinases

The Ca2+/calmodulin-dependent protein kinase (CaMK) cascade is involved in the regulation of many physiological and pathophysiological processes. This signaling cascade consists of CaMKI and CaMKIV and their upstream activator CaMK kinase (CaMKK). The activity of CaMKK is inhibited through phosphorylation by PKA in a process involving the binding to the 14-3-3 protein. However, the molecular mechanism of this 14-3-3-mediated inhibition of CaMKK is currently unknown. Anticipated mechanisms include direct inhibition through structural modulation of the catalytic site, blocking of dephosphorylation of inhibitory phosphorylation sites or interference with the binding of Ca2+/calmodulin to CaMKK. Main goal of this project is to elucidate the molecular basis of this regulation.


 

 

Previous Projects

Structures solved by our group

PDB ID: 7A6Y

Structure of 14-3-3 gamma in complex with DAPK2 peptide stabilized by FC-A

Horvath et al. (2021) Commun. Biol.


PDB ID: 7A6R

Structure of 14-3-3 gamma in complex with DAPK2 peptide containing the 14-3-3 binding motif

Horvath et al. (2021) Commun. Biol.


PDB ID: 6Y4K

Crystal structure of human 14-3-3 gamma in complex with CaMKK2 14-3-3 binding motif Ser100 and Fusicoccin A

Lentini Santo et al. (2020) ACS Chem. Biol.


 

PDB ID: 6Y6B

Crystal structure of human 14-3-3 gamma in complex with CaMKK2 14-3-3 binding motif Ser100 and 16-OMe-Fusicoccin H

Lentini Santo et al. (2020) ACS Chem. Biol.


PDB ID: 6SAD

Structure of 14-3-3 gamma in complex with double phosphorylated caspase-2 peptide on Ser139 and Ser164

Kalabova et al. (2020) FEBS J.


PDB ID: 6S9K

Structure of 14-3-3 gamma in complex with caspase-2 peptide containing 14-3-3 binding motif Ser139 and NLS

Kalabova et al. (2020) FEBS J.


PDB ID: 6QK8

Crystal structure of yeast 14-3-3 protein (Bmh1) from Saccharomyces cerevisiae with the Nha1p (yeast Na+/H+ antiporter) 14-3-3 binding motif Ser481

Smidova et al. (2019) Biochim Biophys Acta Mol Cell Res


PDB ID: 6QVW

Solution structure of the free FOXO1 DNA binding domain

Psenakova et al. (2019) Cells


PDB ID: 6GKF and 6GKG

Crystal structures of 14-3-3 gamma in complex with caspase-2 14-3-3 binding motifs Ser139 and Ser164

Smidova et al. (2018) FEBS J.

Interactions between 14-3-3 and the 14-3-3-binding motifs of caspase-2. (A) Crystal structure of the 14-3-3gamma:pepS139 complex. The 2Fo-Fc electron density map is contoured at 1σ. (B) Detailed view of contacts between 14-3-3c and the pepS139 peptide. The caspase-2 residues are labeled in red, and the 14-3-3c residues are labeled in black. (C) Crystal structure of the 14-3-3c:pepS164 complex. The 2Fo-Fc electron density map is contoured at 1σ. (D) Detailed view of contacts between 14-3-3gamma and the pepS164 peptide. The caspase-2 residues re labeled in red, and the 14-3-3c residues are labeled in black.


PDB ID: 6EWW and 6FEL

Crystal structures of 14-3-3 zeta and gamma isoforms in complex with CaMKK2 14-3-3 binding motifs Ser100 and Ser511

Psenakova et al. (2018) Biochim Biophys Acta Gen Subj.

Contacts between 14-3-3 and the 14-3-3 binding motifs of phosphorylated CaMKK2. (A) Crystal structure of the 14-3-3ζ:pepS100 complex. The 2Fo-Fc electron density map is contoured at 1σ. (B) Detailed view of contacts between 14-3-3ζ and the pepS100 peptide. The CaMKK2 residues are labeled in red, and the 14-3-3ζ residues are labeled in black. (C) Crystal structure of the 14-3-3γ:pepS511 complex. The 2Fo-Fc electron density map is contoured at 1σ. (D) Detailed view of contacts between 14-3-3γ and the pepS511 peptide. The CaMKK2 residues are labeled in red, and the 14-3-3γ residues are labeled in black.


PDB ID: 5N6N

Crystal structure of the 14-3-3:neutral trehalase Nth1 complex

Alblova et al. (2017) Proc. Natl. Acad. Sci. U.S.A.


PDB ID: 5JTA

Neutral trehalase Nth1 from Saccharomyces cerevisiae

Alblova et al. (2017) Proc. Natl. Acad. Sci. U.S.A.


PDB ID: 5M4A

Neutral trehalase Nth1 from Saccharomyces cerevisiae in complex with trehalose

Alblova et al. (2017) Proc. Natl. Acad. Sci. U.S.A.

 


PDB ID: 6EJL

Structure of 14-3-3 zeta in complex with ASK1 14-3-3 binding motif


PDB ID: 3L2C

Crystal Structure of the DNA Binding Domain of FOXO4 Bound to DNA

Boura et al. (2010) Acta Crystallogr.,Sect.D


PDB ID: 2OJ4

Crystal structure of RGS3 RGS domain

Rezabkova et al. (2010) J.Struct.Biol. 


 

© 2017 Cenek Albl