Regulation of α-synuclein by chaperones in mammalian cells

Abstract

Neurodegeneration in Parkinson's disease is correlated with the occurrence of Lewy bodies, intracellular inclusions containing aggregates of the intrinsically disordered protein (IDP) α-Synuclein 1 . The aggregation propensity of α-Synuclein in cells is modulated by specific factors including posttranslational modifications 2,3 , Abelson-kinase-mediated phosphorylation 4,5 and interactions with intracellular machineries such as molecular chaperones, although the underlying mechanisms are unclear [6][7][8] . Here, we systematically characterize the interaction of molecular chaperones with α-Synuclein in vitro as well as in cells at the atomic level. We find that six vastly different molecular chaperones commonly recognize a canonical motif in α-Synuclein, consisting Users may view, print, copy, and download text and data-mine the content in such documents, for the purposes of academic research, subject always to the full Conditions of use:http://www.nature.com/authors/editorial_policies/license.html#terms *

NMR unveils an N-terminal interaction interface on acetylated-α-synuclein monomers for recruitment to fibrils

“…The N-terminus of αS has been recognized as an interaction hotspot that may contribute to induction or inhibition of amyloid formation. N-terminal interactions of αS monomers with chaperones (45) and nanoparticles (46) have been shown to inhibit amyloid formation, and recently a canonical motif for transient interactions of αS with chaperones was determined (45), which shares the 11 N-terminal amino acids identified here. In this work, the shared monomer binding site for off-pathway oligomers and fibrils suggests that the oligomers can delay fibril formation through competitive interactions with monomers.…”

Megadalton-sized dityrosine aggregates of α-synuclein retain high degrees of structural disorder and internal dynamics

“…apoptosis (12). Recent findings substantiate this notion by revealing direct interactions between aSyn and mitochondrial membranes and lipids (13,14), aSyn-induced organelle toxicity (15, 16,Mahul-Mellier, 2020 #93), stress-related re-localization of aSyn to mitochondria (17,18) and pathological colocalization with mitochondria (and other non-proteinaceous structures) in brain-derived LB inclusions (5) and cellular models of LB formation and maturation (4). In addition, the functions of many other Parkinson's disease proteins converge on mitochondria and are directly linked to mitochondrial biology (19).…”

“…Next, we asked whether cyt c/H2O2 HMWAs of aSyn formed in the presence of competing interactions with other macromolecules in crowded environments. We initially employed bovine serum albumin (BSA), which has been shown to transiently interact with Nterminal aSyn residues and to bind to Y39 via weak hydrophobic contacts (18,38), and reconstituted cyt c/H2O2 aggregation reactions with 15 N isotope-labeled aSyn and increasing amounts of unlabeled BSA ( Figure 3A). SDS-PAGE analysis revealed that stacking gelretained HMWAs specifically formed in solutions of up to 10 mg/mL of BSA, which was the highest concentration we used to avoid overloading the gel.…”

When Small becomes Too Big: Expanding the Use of In‐Cell Solid‐State NMR Spectroscopy

“…The protein of interest needs to be relatively inert in cells for detection by solution‐NMR studies . Examples of proteins that adhere to such criteria are SOD (mentioned above) or the protein alpha‐synuclein (α‐syn) which can exist in a multitude of states, ranging from disordered monomers to a membrane associated state or forming an aggregated fibril . Next to structural insights as well as experiments that examine transient interactions, such in‐cell NMR studies have also provided novel and unexpected insights into largely unexplored chemical impact of the cellular environment including the occurrence of post‐translational modifications (PTMs).…”