Uniformly curated signaling pathways reveal tissue-specific cross-talks and support drug target discovery.

Motivation: Signaling pathways control a large variety of cellular processes. However, currently, even within the same database signaling pathways are often curated at different levels of detail. This makes comparative and cross-talk analyses difficult.

The small heat-shock proteins HSPB2 and HSPB3 form well-defined heterooligomers in a unique 3 to 1 subunit ratio.

Various mammalian small heat-shock proteins (sHSPs) can interact with one another to form large polydisperse assemblies. In muscle cells, HSPB2/MKBP (myotonic dystrophy protein kinase-binding protein) and HSPB3 have been shown to form an independent complex. To date, the biochemical properties of this complex have not been thoroughly characterized.

Perturbation waves in proteins and protein networks: applications of percolation and game theories in signaling and drug design.

The network paradigm is increasingly used to describe the dynamics of complex systems. Here we review the current results and propose future development areas in the assessment of perturbation waves, i.e.

How to design multi-target drugs.

Despite improved rational drug design and a remarkable progress in genomic, proteomic and high-throughput screening methods, the number of novel, single-target drugs has fallen far behind expectations during the past decade. Multi-target drugs multiply the number of pharmacologically relevant target molecules by introducing a set of indirect, network-dependent effects. Parallel with this, the low-affinity binding of multi-target drugs eases the constraints of druggability and significantly increases the size of the druggable proteome.

Network analysis of protein dynamics.

The network paradigm is increasingly used to describe the topology and dynamics of complex systems. Here, we review the results of the topological analysis of protein structures as molecular networks describing their small-world character, and the role of hubs and central network elements in governing enzyme activity, allosteric regulation, protein motor function, signal transduction and protein stability. We summarize available data how central network elements are enriched in active centers and ligand binding sites directing the dynamics of the entire protein.

Stress-induced rearrangements of cellular networks: Consequences for protection and drug design.

The complexity of the cells can be described and understood by a number of networks such as protein-protein interaction, cytoskeletal, organelle, signalling, gene transcription and metabolic networks. All these networks are highly dynamic producing continuous rearrangements in their links, hubs, network-skeleton and modules. Here we describe the adaptation of cellular networks after various forms of stress causing perturbations, congestions and network damage.

Temperature effects on alpha-crystallin structure probed by 6-bromomethyl-2-(2-furanyl)-3-hydroxychromone, an environmentally sensitive two-wavelength fluorescent dye covalently attached to the single Cys residue.

The single Cys residue in the C-terminal domain of bovine eye lens alpha-crystallin was covalently labelled with 6-bromomethyl-2-(2-furanyl)-3-hydroxychromone. This novel SH-reactive two-band ratiometric fluorescent dye is characterized by excited state intramolecular proton transfer reaction yielding two highly emissive N* and T* bands separated by more than 100 nm. Their relative intensities are known to be highly sensitive to the H-bonding ability of the environment.

Chaperone-like activity of alpha-crystallin is enhanced by high-pressure treatment.

alpha-Crystallin, an oligomeric protein in vertebrate eye lens, is a member of the small heat-shock protein family. Several papers pointed out that its chaperone-like activity could be enhanced by increasing the temperature. We demonstrate in the present study that structural perturbations by high hydrostatic pressures up to 300 MPa also enhance this activity.