title: Elucidating the role of C-terminal post-translational modifications using protein semisynthesis strategies: α-synuclein phosphorylation at tyrosine 125.
abstract: Despite increasing evidence that supports the role of different post-translational modifications (PTMs) in modulating α-synuclein (α-syn) aggregation and toxicity, relatively little is known about the functional consequences of each modification and whether or not these modifications are regulated by each other. This lack of knowledge arises primarily from the current lack of tools and methodologies for the site-specific introduction of PTMs in α-syn. More specifically, the kinases that mediate selective and efficient phosphorylation of C-terminal tyrosine residues of α-syn remain to be identified. Unlike phospho-serine and phospho-threonine residues, which in some cases can be mimicked by serine/threonine → glutamate or aspartate substitutions, there are no natural amino acids that can mimic phospho-tyrosine. To address these challenges, we developed a general and efficient semisynthetic strategy that enables the site-specific introduction of single or multiple PTMs and the preparation of homogeneously C-terminal modified forms of α-syn in milligram quantities. These advances have allowed us to investigate, for the first time, the effects of selective phosphorylation at Y125 on the structure, aggregation, membrane binding, and subcellular localization of α-syn. The development of semisynthetic methods for the site-specific introduction of single or PTMs represents an important advance toward determining the roles of such modifications in α-syn structure, aggregation, and functions in heath and disease.
authors.affiliation: Laboratory of Molecular and Chemical Biology of Neurodegeneration, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne (EPFL), CH-1015 Lausanne, Switzerland.
authors.forename: Mirva
authors.initials: M
authors.lastname: Hejjaoui
authors.forename: Sara
authors.initials: S
authors.lastname: Butterfield
authors.forename: Bruno
authors.initials: B
authors.lastname: Fauvet
authors.forename: Filip
authors.initials: F
authors.lastname: Vercruysse
authors.forename: Jia
authors.initials: J
authors.lastname: Cui
authors.forename: Igor
authors.initials: I
authors.lastname: Dikiy
authors.forename: Michel
authors.initials: M
authors.lastname: Prudent
authors.forename: Diana
authors.initials: D
authors.lastname: Olschewski
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhang
authors.forename: David
authors.initials: D
authors.lastname: Eliezer
authors.forename: Hilal A
authors.initials: HA
authors.lastname: Lashuel
mesh_terms: D000595:Amino Acid Sequence; D002478:Cells, Cultured; D057809:HEK293 Cells; D006367:HeLa Cells; D006801:Humans; D010766:Phosphorylation; D011499:Protein Processing, Post-Translational; D016415:Sequence Alignment; D014443:Tyrosine / Q000737:chemistry / Q000378:metabolism*; D051844:alpha-Synuclein / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism
chemical_list: D051844:alpha-Synuclein; D014443:Tyrosine