ABSTRACT
A platform for specifically modulating kinase-dependent signaling using peptides derived from the catalytic domain of the kinase is presented. This technology, termed KinAce, utilizes the canonical structure of protein kinases. The targeted regions (subdomain V and subdomains IX and X) are analyzed and their sequence, three-dimensional structure, and involvement in protein-protein interaction are highlighted. Short myristoylated peptides were derived from the target regions of the tyrosine kinases c-Kit and Lyn and the serine/threonine kinases 3-phosphoinositide-dependent kinase-1 (PDK1) and Akt/protein kinase B (PKB). For each kinase an active designer peptide is shown to selectively inhibit the signaling of the kinase from which it is derived, and to inhibit cancer cell proliferation in the micromolar range. This technology emerges as an applicable tool for deriving sequence-based selective inhibitors for a broad range of protein kinases as hits that may be further developed into drugs. Moreover, it enables identification of novel kinase targets for selected therapeutic indications as demonstrated in the KinScreen application.
Subject(s)
Drug Design , 3-Phosphoinositide-Dependent Protein Kinases , Amino Acid Sequence , Animals , Aorta/metabolism , Catalytic Domain , Cell Cycle Proteins/metabolism , Cell Division , Cell Line, Tumor , Cell-Free System , Cloning, Molecular , Cyclin-Dependent Kinase Inhibitor p27 , Cytosol/metabolism , DNA Mutational Analysis , Dose-Response Relationship, Drug , Glutathione Transferase/metabolism , Humans , Immunoblotting , Male , Mice , Mice, Inbred BALB C , Models, Molecular , Molecular Sequence Data , Myristic Acids/metabolism , Peptides/chemistry , Phosphorylation , Protein Binding , Protein Serine-Threonine Kinases/metabolism , Protein Structure, Tertiary , Proto-Oncogene Proteins/metabolism , Proto-Oncogene Proteins c-akt , Proto-Oncogene Proteins c-kit/metabolism , Substrate Specificity , Tumor Suppressor Proteins/metabolism , src-Family Kinases/metabolismABSTRACT
Coral morphological variability reflects either genetic differences or environmentally induced phenotypic plasticity. We present two coral species that sense gravity and accordingly alter their morphology, as characterized by their slenderness (height to diameter) ratio (SR). We experimentally altered the direction (and intensity) of the gravitational resultant force acting along or perpendicular to the main body axis of coral polyps. We also manipulated light direction, in order to uncouple gravity and light effects on coral development. In the experiments, vertically growing polyps had significantly higher SR than their horizontal siblings even when grown in a centrifuge (experiencing different resultant gravitational forces in proximal and distal positions). Lowest SR was in horizontal side-illuminated polyps, and highest in vertical top-illuminated polyps. Adult colonies in situ showed the same pattern. Gravitational intensity also affected polyp growth form. However, polyp volume, dry skeleton weight and density in the various centrifuge positions, and in aquaria experiments, did not differ significantly. This reflects the coral's ability to sense altered gravity direction and intensity, and to react by changing the development pattern of their body morphology, but not the amount of skeleton deposited.
