The structural basis for light acclimation in phycobilisome light harvesting systems systems in Porphyridium purpureum.

Photosynthetic organisms adapt to changing light conditions by manipulating their light harvesting complexes. Biophysical, biochemical, physiological and genetic aspects of these processes are studied extensively. The structural basis for these studies is lacking.

Large-scale FRET simulations reveal the control parameters of phycobilisome light-harvesting complexes.

Phycobilisomes (PBS) are massive structures that absorb and transfer light energy to photochemical reaction centres. Among the range of light harvesting systems, PBS are considered to be excellent solutions for absorption cross-sections but relatively inefficient energy transferring systems. This is due to the combination of a large number of chromophores with intermediate coupling distances.

Phosphorylation of the WWOX Protein Regulates Its Interaction with p73.

We describe a molecular characterization of the interaction between the cancer-related proteins WWOX and p73. This interaction is mediated by the first of two WW domains (WW1) of WWOX and a PPXY-motif-containing region in p73. While phosphorylation of Tyr33 of WWOX and association with p73 are known to affect apoptotic activity, the quantitative effect of phosphorylation on this specific interaction is determined here for the first time.

FlexPepDock lessons from CAPRI peptide-protein rounds and suggested new criteria for assessment of model quality and utility.

CAPRI rounds 28 and 29 included, for the first time, peptide-receptor targets of three different systems, reflecting increased appreciation of the importance of peptide-protein interactions. The CAPRI rounds allowed us to objectively assess the performance of Rosetta FlexPepDock, one of the first protocols to explicitly include peptide flexibility in docking, accounting for peptide conformational changes upon binding. We discuss here successes and challenges in modeling these targets: we obtain top-performing, high-resolution models of the peptide motif for cases with known binding sites but there is a need for better modeling of flanking regions, as well as better selection criteria, in particular for unknown binding sites.

Pleiotropic Functions of Tumor Suppressor WWOX in Normal and Cancer Cells.

WW domain-containing oxidoreductase (WWOX), originally marked as a likely tumor suppressor gene, has over the years become recognized for its role in a much wider range of cellular activities. Phenotypic effects displayed in animal studies, along with resolution of WWOX's architecture, fold, and binding partners, point to the protein's multifaceted biological functions. Results from a series of complementary experiments seem to indicate WWOX's involvement in metabolic regulation.

Versatile communication strategies among tandem WW domain repeats.

Interactions mediated by short linear motifs in proteins play major roles in regulation of cellular homeostasis since their transient nature allows for easy modulation. We are still far from a full understanding and appreciation of the complex regulation patterns that can be, and are, achieved by this type of interaction. The fact that many linear-motif-binding domains occur in tandem repeats in proteins indicates that their mutual communication is used extensively to obtain complex integration of information toward regulatory decisions.