National Institutes of Health/National Institute of Diabetes and Digestive and Kidney Disease
DK027044
米国
引用
ジャーナル: Nat Commun / 年: 2019 タイトル: Structural basis for the clamping and Ca activation of SNARE-mediated fusion by synaptotagmin. 著者: Kirill Grushin / Jing Wang / Jeff Coleman / James E Rothman / Charles V Sindelar / Shyam S Krishnakumar / 要旨: Synapotagmin-1 (Syt1) interacts with both SNARE proteins and lipid membranes to synchronize neurotransmitter release to calcium (Ca) influx. Here we report the cryo-electron microscopy structure of ...Synapotagmin-1 (Syt1) interacts with both SNARE proteins and lipid membranes to synchronize neurotransmitter release to calcium (Ca) influx. Here we report the cryo-electron microscopy structure of the Syt1-SNARE complex on anionic-lipid containing membranes. Under resting conditions, the Syt1 C2 domains bind the membrane with a magnesium (Mg)-mediated partial insertion of the aliphatic loops, alongside weak interactions with the anionic lipid headgroups. The C2B domain concurrently interacts the SNARE bundle via the 'primary' interface and is positioned between the SNAREpins and the membrane. In this configuration, Syt1 is projected to sterically delay the complete assembly of the associated SNAREpins and thus, contribute to clamping fusion. This Syt1-SNARE organization is disrupted upon Ca-influx as Syt1 reorients into the membrane, likely displacing the attached SNAREpins and reversing the fusion clamp. We thus conclude that the cation (Mg/Ca) dependent membrane interaction is a key determinant of the dual clamp/activator function of Synaptotagmin-1.
全体 : Synaptotagmin 1 C2AB in a complex with the SNAREpin assembly boun...
全体
名称: Synaptotagmin 1 C2AB in a complex with the SNAREpin assembly bound to the negatively charged phospholipid nanotube in presence of Mg2+.
要素
複合体: Synaptotagmin 1 C2AB in a complex with the SNAREpin assembly bound to the negatively charged phospholipid nanotube in presence of Mg2+.
タンパク質・ペプチド: Synaptotagmin 1
タンパク質・ペプチド: Vesicle-associated membrane protein 2
タンパク質・ペプチド: Syntaxin-1A
タンパク質・ペプチド: Synaptosomal-associated protein 25
タンパク質・ペプチド: Synaptosomal-associated protein 25
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超分子 #1: Synaptotagmin 1 C2AB in a complex with the SNAREpin assembly boun...
超分子
名称: Synaptotagmin 1 C2AB in a complex with the SNAREpin assembly bound to the negatively charged phospholipid nanotube in presence of Mg2+. タイプ: complex / ID: 1 / 親要素: 0 / 含まれる分子: all
モデルのタイプ: INSILICO MODEL / In silico モデル: Featureless hollow cylinder
最終 角度割当
タイプ: NOT APPLICABLE
FSC曲線 (解像度の算出)
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原子モデル構築 1
精密化
プロトコル: RIGID BODY FIT
得られたモデル
PDB-6mti: Synaptotagmin-1 C2A, C2B domains and SNARE-pin proteins (5CCI) individually docked into Cryo-EM map of C2AB-SNARE complexes helically organized on lipid nanotube surface in presence of Mg2+