Robust Sequence Determinants of α-Synuclein Toxicity in Yeast Implicate Membrane Binding

• DOI: 10.1021/acschembio.0c00339
• Publication Date: 2020-07-27T16:20:32Z
• Authors: Robert W. Newberry; Taylor Arhar; Jean Costello; George C. Hartoul...; Alison M. Maxwell; Zun Zar Chi Naing; Maureen Pittman; Nishith R. Reddy; Daniel M. C. Schwarz; Douglas R. Wassarman; Taia S. Wu; Daniel Barrero; Christa Caggiano; Adam Catching; Taylor B. Cavazos; Laurel S. Estes; Bryan Faust; Elissa A. Fink; Miriam A. Goldman; Yessica K. Gomez; M. Grace Gordon; Laura M. Gunsalus; Nick Hoppe; Maru Jaime-Garza; Matthew C. Johnson; Matthew G. Jones; Andrew F. Kung; Kyle E. Lopez; Jared Lumpe; Calla Martyn; Elizabeth E. McCa...; Lakshmi E. Miller...; Erik J. Navarro; Aji Palar; Jenna Pellegrino; Wren Saylor; Christina A. Step...; Jack Strickland; Hayarpi Torosyan; Stephanie A. Wank...; Daniel R. Wong; Garrett Wong; Sy Redding; Eric D. Chow; William F. DeGrado; Martin Kampmann
• Keywords: Proteostasis; Chemical genetics; Helix (gastropod)

Protein conformations are shaped by cellular environments, but how environmental changes alter the conformational landscapes of specific proteins in vivo remains largely uncharacterized, part due to challenge probing protein structures living cells. Here, we use deep mutational scanning investigate a toxic conformation α-synuclein, dynamic linked Parkinson's disease, responds perturbations proteostasis. In context course for graduate students UCSF Integrative Program Quantitative Biology, screened comprehensive library α-synuclein missense mutants yeast cells treated with variety small molecules that perturb processes biology and pathobiology. We found previously shown drive toxicity-an extended, membrane-bound helix-is unaffected these chemical perturbations, underscoring importance this state as driver toxicity. On other hand, have significant effect on ability mutations suppress Moreover, find sequence determinants toxicity well described simple structural model helix. This predicts penetrates membrane constant depth across its length affinity decreases toward C terminus, which is consistent orthogonal biophysical measurements. Finally, discuss parallelized genetics experiments can provide robust framework inquiry-based coursework.