This proposal builds on extensive literature that implicates aberrant regulation of amyloid precursor protein (APP) processing and Abeta production as a major cause of Alzheimer's disease, and the APP intracellular domain (AICD) as a central player in this process. Recent results from our labs show that the prolyl isomerase Pin1 catalyzes cis/trans isomerization of the phosphorylated (p) T668P motif of APP and regulates APP processing and Abeta production. We propose a set of synergistic experiments to address the structural and dynamic mechanisms by which Pin1 regulates the conformation and processing of APP in vitro and in vivo.
In Aim 1 we will apply NMR dynamics methods to determine the structural, microscopic kinetic and thermodynamic, and NH-bond dynamic parameters that describe Pin1-catalysis of phosphorylated AICD. The overall goal of Aim 1 is to derive NMR-based mechanistic models for functional motions in Pin1, and to predict mutations to test these models.
In Aim 2 we will make these NMR-predicted mutants and evaluate their effects on APP processing and Abeta production in vitro and in vivo. The overall goal of Aim 2 is to validate NMR-derived models for the catalytic mechanism and for functional motions.
In Aim 3 we will randomly mutagenize the Pin1 WW domain and select for mutants with high cis-isomer affinity. The effects of the selected mutants on APP processing and Abeta production will be tested in vitro and in vivo. The overall goal of Aim 3 is to determine the role(s) of isomer-specific recognition of the pT668P AICD motif in APP processing and Abeta production. Overall, we will extend our limited structure-based understanding of Pin1 function, exploring functional motions by comparing measured microscopic and NH- bond specific rates in Pin1. Motional models will be tested in vitro and in vivo using all available technology, including the effects on APP processing and Abeta production. By elucidating the regulation of the cis and trans isomers of pT668-APP and establishing their roles in APP processing and Abeta production, these studies will potentially open new avenues for development of novel Alzheimer's disease therapeutics. In lay language, we have recently identified a new enzyme important for the development of Alzheimer's disease. In this proposal, we will combine NMR dynamics, cellular and molecular biology approaches to study how this enzyme affects Alzheimer's disease processes and hope to eventually identify new therapeutic targets. ? ? ?
|Albayram, Onder; Angeli, Peter; Bernstein, Elizabeth et al. (2018) Targeting Prion-like Cis Phosphorylated Tau Pathology in Neurodegenerative Diseases. J Alzheimers Dis Parkinsonism 8:|
|Albayram, Onder; Kondo, Asami; Mannix, Rebekah et al. (2017) Cis P-tau is induced in clinical and preclinical brain injury and contributes to post-injury sequelae. Nat Commun 8:1000|
|Kondo, Asami; Albayram, Onder; Zhou, Xiao Zhen et al. (2017) Pin1 Knockout Mice: A Model for the Study of Tau Pathology in Alzheimer's Disease. Methods Mol Biol 1523:415-425|
|Albayram, Onder; Herbert, Megan K; Kondo, Asami et al. (2016) Function and regulation of tau conformations in the development and treatment of traumatic brain injury and neurodegeneration. Cell Biosci 6:59|
|Chen, Chun-Hau; Li, Wenzong; Sultana, Rukhsana et al. (2015) Pin1 cysteine-113 oxidation inhibits its catalytic activity and cellular function in Alzheimer's disease. Neurobiol Dis 76:13-23|
|Kondo, Asami; Shahpasand, Koorosh; Mannix, Rebekah et al. (2015) Antibody against early driver of neurodegeneration cis P-tau blocks brain injury and tauopathy. Nature 523:431-436|
|Nakamura, Kazuhiro; Greenwood, Alex; Binder, Lester et al. (2012) Proline isomer-specific antibodies reveal the early pathogenic tau conformation in Alzheimer's disease. Cell 149:232-44|
|Pastorino, Lucia; Ma, Suk Ling; Balastik, Martin et al. (2012) Alzheimer's disease-related loss of Pin1 function influences the intracellular localization and the processing of A?PP. J Alzheimers Dis 30:277-97|
|De, Soumya; Greenwood, Alexander I; Rogals, Monique J et al. (2012) Complete thermodynamic and kinetic characterization of the isomer-specific interaction between Pin1-WW domain and the amyloid precursor protein cytoplasmic tail phosphorylated at Thr668. Biochemistry 51:8583-96|
|Tun-Kyi, Adrian; Finn, Greg; Greenwood, Alex et al. (2011) Essential role for the prolyl isomerase Pin1 in Toll-like receptor signaling and type I interferon-mediated immunity. Nat Immunol 12:733-41|
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