title: Effect of Ser-129 phosphorylation on interaction of α-synuclein with synaptic and cellular membranes.
abstract: In the healthy brain, less than 5% of α-synuclein (α-syn) is phosphorylated at serine 129 (Ser(P)-129). However, within Parkinson disease (PD) Lewy bodies, 89% of α-syn is Ser(P)-129. The effects of Ser(P)-129 modification on α-syn distribution and solubility are poorly understood. As α-syn normally exists in both membrane-bound and cytosolic compartments, we examined the binding and dissociation of Ser(P)-129 α-syn and analyzed the effects of manipulating Ser(P)-129 levels on α-syn membrane interactions using synaptosomal membranes and neural precursor cells from α-syn-deficient mice or transgenic mice expressing human α-syn. We first evaluated the recovery of the Ser(P)-129 epitope following either α-syn membrane binding or dissociation. We demonstrate a rapid turnover of Ser(P)-129 during both binding to and dissociation from synaptic membranes. Although the membrane binding of WT α-syn was insensitive to modulation of Ser(P)-129 levels by multiple strategies (the use of phosphomimic S129D and nonphosphorylated S129A α-syn mutants; by enzymatic dephosphorylation of Ser(P)-129 or proteasome inhibitor-induced elevation in Ser(P)-129; or by inhibition or stable overexpression of PLK2), PD mutant Ser(P)-129 α-syn showed a preferential membrane association compared with WT Ser(P)-129 α-syn. Collectively, these data suggest that phosphorylation at Ser-129 is dynamic and that the subcellular distribution of α-syn bearing PD-linked mutations, A30P or A53T, is influenced by the phosphorylation state of Ser-129.
authors.affiliation: Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario M5S 3H2, Canada.
authors.forename: Naomi P
authors.initials: NP
authors.lastname: Visanji
authors.affiliation: GIGA Neurosciences, University of Liege, 1 Avenue de l'Hôpital, 4000 Liège, Belgium.
authors.forename: Sabine
authors.initials: S
authors.lastname: Wislet-Gendebien
authors.affiliation: Brain Research Centre, University of British Columbia, British Columbia V6T 2B5, Canada.
authors.forename: Loren W
authors.initials: LW
authors.lastname: Oschipok
authors.affiliation: Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario M5S 3H2, Canada.
authors.forename: Gang
authors.initials: G
authors.lastname: Zhang
authors.affiliation: Sunnybrook Research Institute and Department of Laboratory Medicine and Pathobiology, University of Toronto, Toronto, Ontario M4N 3M5, Canada.
authors.forename: Isabelle
authors.initials: I
authors.lastname: Aubert
authors.affiliation: Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario M5S 3H2, Canada; Department of Medical Biophysics, University of Toronto, Toronto, Ontario M5S 1A8, Canada.
authors.forename: Paul E
authors.initials: PE
authors.lastname: Fraser
authors.affiliation: Centre for Research in Neurodegenerative Diseases, University of Toronto, Toronto, Ontario M5S 3H2, Canada; Department of Medicine, University of Toronto, Toronto, Ontario M5S 1A8, Canada. Electronic address: a.tandon@utoronto.ca.
authors.forename: Anurag
authors.initials: A
authors.lastname: Tandon
mesh_terms: D019943:Amino Acid Substitution; D000818:Animals; D002460:Cell Line; D000939:Epitopes / Q000235:genetics / Q000378:metabolism; D006801:Humans; D016631:Lewy Bodies / Q000235:genetics / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D020125:Mutation, Missense; D020734:Parkinsonian Disorders / Q000235:genetics / Q000378:metabolism; D011485:Protein Binding / Q000235:genetics; D011494:Protein Kinases / Q000096:biosynthesis / Q000235:genetics; D017346:Protein Serine-Threonine Kinases / Q000096:biosynthesis / Q000235:genetics; D021381:Protein Transport / Q000235:genetics; D013570:Synaptic Membranes / Q000235:genetics / Q000378:metabolism*; D051844:alpha-Synuclein / Q000235:genetics / Q000378:metabolism*
chemical_list: D000939:Epitopes; D051844:alpha-Synuclein; D011494:Protein Kinases; C496126:PLK2 protein, human; D017346:Protein Serine-Threonine Kinases; C444640:serum-inducible kinase