PROJECT SUMMARY/ABSTRACT The recent wave of cryo-electron microscopy (cryo-EM) studies on amyloid fibrils has highlighted the complexity of protein deposition amongst patients of amyloid diseases. A convincing example is found in tau, a microtubule binding protein whose pathological aggregation causes tauopathies. Each of these tauopathies seems to be associated with a particular structural assembly, suggesting causality. Similar to tauopathies, other amyloid diseases manifest differential prognosis, onset, and symptomatology. This is the case of TDP-43, α-synuclein, β-amyloid, or transthyretin (TTR), to name a few. We hypothesize that these phenotypical differences are driven by the formation of various structural assemblies, similar to what is found in tau. As a consequence, the detection of these disease-specific assemblies in a timely manner could ensure proper diagnosis and treatment. We aim to map the structural spectrum of amyloid fibrils in an amyloid disease model using cryo-EM and a co- culture system to be developed in our laboratory. Using the obtained structural information, our laboratory will design structure-specific peptides for the detection and inhibition of amyloid fibrils in cells, mice, and patient- derived samples. If successful, our study will serve as a launching platform for the development of personalized structure-based diagnostics and therapeutics for amyloid diseases.

PROJECT NARRATIVE The resolution revolution of cryo-electron microscopy has revealed that a given amyloid precursor can form structurally different assemblies, or polymorphs, that seem to associate with distinct disease. However, the association of these specific assemblies with the biology and pathology of an amyloid disease is still unclear. I aim to establish a multidisciplinary high-risk program to obtain atomic information about amyloid fibrils using cryo-electron microscopy, to analyze their pathological role in a co-culture cell system to be developed in my laboratory, and to design structure-specific tools to use in the clinic.