THE EFFECT OF MOLECULAR TOXINS ON PROTEIN PHOSPHATASE 1 TARGETING

这个子项目是众多研究子项目之一

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Molecular toxins are natural products that potently inhibit the catalytic activity of protein phosphatase 1 (PP1). These natural inhibitors are created by numerous organisms such as marine sponges and cyanobacteria and include okadaic acid, calyculin A, microcystins, nodularins, tautomycin and fostriecin. We want to comprehensively understand the structural and dynamical mechanisms of the tight binding of these molecular toxins to PP1. This will enable us to characterize the subtle molecular differences of the PP1 active site induced by targeting and inhibitory proteins versus small molecule molecular toxins. These 3-dimensional molecular models will enable us to fully understand the details of the PP1 active site structure. To understand the PP1 active site dynamics, and its subtle interplay of targeting protein and inhibitory ligand (molecular toxin) interactions in molecular detail, we will use a large portfolio of biochemical and biophysical techniques, especially NMR spectroscopy and X-ray crystallography, to elucidate the structures of numerous targeting proteins and molecular toxins by themselves and as PP1:targeting and PP1:molecular toxin complexes. PSP targeting proteins, such as the neuronal scaffolding protein spinophilin, target PP1 to its point of action. No structural models for these interactions exist, nor is it known how they are affected by interactions with molecular toxins. Thus, we will use the differences and similarities between the multiple PP1:toxin and PP1:targeting structures and dynamics to determine how PP1, a ubiquitous ser/thr phosphatase, is potently and selectively regulated in the cell so that novel agents, which target a particular population of phosphatases (i.e. phosphatases localized in dopaminergic neurons), can be developed.