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Avidity within the N‐terminal anchor drives α‐synuclein membrane interaction and insertion
Author(s) -
Cholak Ersoy,
Bugge Katrine,
Khondker Adree,
Gauger Kimmie,
PedrazCuesta Elena,
Pedersen Morten Enghave,
Bucciarelli Saskia,
Vestergaard Bente,
Pedersen Stine F.,
Rheinstädter Maikel C.,
Langkilde Annette Eva,
Kragelund Birthe B.
Publication year - 2020
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fj.202000107r
Subject(s) - membrane , avidity , biophysics , chemistry , membrane protein , microbiology and biotechnology , lipid bilayer , plasma protein binding , lipid bilayer fusion , biochemistry , biology , antigen , genetics
In the brain, α‐synuclein (aSN) partitions between free unbound cytosolic and membrane bound forms modulating both its physiological and pathological role and complicating its study due to structural heterogeneity. Here, we use an interdisciplinary, synergistic approach to characterize the properties of aSN:lipid mixtures, isolated aSN:lipid co‐structures, and aSN in mammalian cells. Enabled by the isolation of the membrane‐bound state, we show that within the previously described N‐terminal membrane anchor, membrane interaction relies both on an N‐terminal tail (NTT) head group layer insertion of 14 residues and a folded‐upon‐binding helix at the membrane surface. Both binding events must be present; if, for example, the NTT insertion is lost, the membrane affinity of aSN is severely compromised and formation of aSN:lipid co‐structures hampered. In mammalian cells, compromised cooperativity results in lowered membrane association. Thus, avidity within the N‐terminal anchor couples N‐terminal insertion and helical surface binding, which is crucial for aSN membrane interaction and cellular localization, and may affect membrane fusion.