Order and disorder in the physiological membrane binding of α-synuclein

Fusco, Giuliana; Sanz-Hernández, Máximo; Simone, Alfonso De

doi:10.1016/j.sbi.2017.09.004

Cited by 66 publications

(81 citation statements)

References 91 publications

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“…Trypsin cleaves peptide bonds C‐terminal of lysine and arginine residues, of which αSyn contains 15 and none, respectively. αSyn lysines feature prominently in the six imperfect KTK‐E/Q‐GV repeats that span residues 1–80 of the protein where they contribute to membrane binding (Figure S1B, Supporting Information) . Given the large number of protease substrate sites, Trypsin cleavage produced multiple αSyn fragments (Figure S1C, Supporting Information).…”

Section: Resultsmentioning

confidence: 99%

Time‐Resolved NMR Analysis of Proteolytic α‐Synuclein Processing in vitro and in cellulo

et al. 2018

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Targeted proteolysis of the disordered Parkinson's disease protein alpha-synuclein (αSyn) constitutes an important event under physiological and pathological cell conditions. In this work, site-specific αSyn cleavage by different endopeptidases in vitro and by endogenous proteases in extracts of challenged and unchallenged cells was studied by time-resolved NMR spectroscopy. Specifically, proteolytic processing was monitored under neutral and low pH conditions and in response to Rotenone-induced oxidative stress. Further, time-dependent degradation of electroporation-delivered αSyn in intact SH-SY5Y and A2780 cells was analyzed. Results presented here delineate a general framework for NMR-based proteolysis studies in vitro and in cellulo, and confirm earlier reports pertaining to the exceptional proteolytic stability of αSyn under physiological cell conditions. However, experimental findings also reveal altered protease susceptibilities in selected mammalian cell lines and upon induced cell stress.

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Section: Resultsmentioning

confidence: 99%

Time‐Resolved NMR Analysis of Proteolytic α‐Synuclein Processing in vitro and in cellulo

et al. 2018

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“…aSyn is expressed throughout the brain and abundantly found in presynaptic terminals of dopaminergic neurons, where it is involved in synaptic vesicle clustering and trafficking 2 . Whereas isolated aSyn is disordered in solution, residues 1-100 adopt extended or kinked helical conformations upon binding to membranes containing negatively charged phospholipids 3 . Complementary electrostatic interactions between lysine residues within aSyn's N-terminal KTKEGV-repeats and acidic phospholipid headgroups align these a-helices on respective membrane surfaces 4 .…”

Section: Introductionmentioning

confidence: 99%

“…Phosphatidylinositol 3,4,5-trisphosphate, PI (3,4,5)P3, or PIP3 hereafter, harbors an additional phosphate group, which renders it even more acidic (net charge -5 at pH 7) 21 . The steady-state abundance of PIP3 at the PM is low 16 but local levels increase dynamically in response to cell signaling, especially following phosphatidylinositol-3 kinase (PI3K) activation 24 .…”

Section: Introductionmentioning

confidence: 99%

α-Synuclein plasma membrane localization correlates with cellular phosphatidylinositol polyphosphate levels

Jacob

Dema

Mercadante

et al. 2020

Preprint

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The Parkinson′s disease protein α-synuclein (αSyn) promotes membrane fusion and fission by interacting with various negatively charged phospholipids. Despite postulated roles in endocytosis and exocytosis, plasma membrane (PM) interactions of αSyn are poorly understood. Here, we show that phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphatidylinositol 3,4,5-trisphosphate (PIP3), two highly acidic components of inner PM leaflets, mediate plasma membrane localization of endogenous pools of αSyn in A2780, HeLa, SH-SY5Y and SK-MEL-2 cells. We demonstrate that αSyn binds reconstituted PIP2-membranes in a helical conformation in vitro and that PIP2 kinases and phosphatases reversibly redistribute αSyn in cells. We further delineate that αSyn-PM targeting follows phosphoinositide-3 kinase (PI3K)-dependent changes of cellular PIP2 and PIP3 levels, which collectively suggests that phosphatidylinositol polyphosphates contribute to αSyn′s cellular function(s) at the plasma membrane.

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“…Instead, β-synuclein has been shown to inhibit the aggregation of α-synuclein both in vitro and in vivo [5,16]. Mutations in β-synuclein have been linked to case of dementia with Lewy bodies [17,18].…”

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confidence: 99%

“…All members of the synuclein family interact robustly with lipid membranes, and appear to be important for the physiological functions of proteins while in uencing the pathological aggregation of α-synuclein. Many in vitro experiments have demonstrated the a nity of synucleins towards membranes containing negatively charged lipids, esteri ed with oleic acid and polyunsaturated fatty acids, suggesting that it may speci cally recognize the membrane microdomains that differs in uidity and charging [8,16,32]. α-Synuclein also associates with the membranes composed of zwitterionic phospholipids with varied reports of strong or weak binding [36,37,38].…”

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confidence: 99%

Triple-knockout, synuclein-free mice display compromised lipid pattern

Guschina

Ninkina

Roman

et al. 2020

Preprint

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Background: Recent studies have implicated synucleins in several reactions during the biosynthesis of lipids and fatty acids in addition to their recognised role in membrane lipid binding and synaptic functions. All members of the synuclein family interact robustly with lipid membranes, and appear to be important for the physiological functions of proteins while influencing the pathological aggregation of α-synuclein. Methods: The following tissues were used for lipid and fatty acid analysis: plasma, liver and two brain areas (cortex and midbrain). Lipid classes were separated using thin-layer chromatography. Fatty acids were analysed using gas chromatography. Results: We describe the importance of long-chain polyunsaturated fatty acids (LCPUFA) and palmitic acid in liver and plasma, reduced triacylglycerol (TAG) accumulation in liver and circulated plasma non-esterified fatty acids in synuclein free mice. In midbrain, observed changes in the relative concentrations of phosphatidylcholine (PC) and cerebrosides (CER) were counterbalanced. In midbrain, we recorded a notable reduction in ethanolamine plasmalogens in synuclein free mice and consider this an important finding considering the abnormal ether lipid metabolism usually associated with neurological disorders.Conclusions: In summary, our data demonstrate that synuclein deficiency can result in alterations of PUFA synthesis, storage lipid accumulation in liver, and reduction of plasmalogens and CER, those polar lipids which are principal compounds of lipid rafts in many tissues. An ablation of all three synuclein family members resulted in more pronounced lipid modifications then previously showed by us γ-synuclein deficiency. Possible mechanisms by which synuclein deficiency may govern the reported modifications of lipid metabolism in TKO mice are proposed and discussed.

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Order and disorder in the physiological membrane binding of α-synuclein

Cited by 66 publications

References 91 publications

Time‐Resolved NMR Analysis of Proteolytic α‐Synuclein Processing in vitro and in cellulo

Time‐Resolved NMR Analysis of Proteolytic α‐Synuclein Processing in vitro and in cellulo

α-Synuclein plasma membrane localization correlates with cellular phosphatidylinositol polyphosphate levels

Triple-knockout, synuclein-free mice display compromised lipid pattern

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