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.
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
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.
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.