Natural Sciences and Engineering Research Council (NSERC, Canada)
RGPIN-2018-03951
カナダ
Natural Sciences and Engineering Research Council (NSERC, Canada)
AWD-007855
カナダ
引用
ジャーナル: J Biol Chem / 年: 2025 タイトル: Development of an inhibitory TTC7B selective nanobody that blocks EFR3 recruitment of PI4KA. 著者: Sushant Suresh / Alexandria L Shaw / Damilola K Akintola / Martine Lunke / Sophia Doerr / Pooja Rohilla / Tamas Balla / Calvin K Yip / Scott D Hansen / Jennifer A Cobb / John E Burke / 要旨: Phosphatidylinositol 4 kinase IIIα (PI4KIIIα/PI4KA) is an essential lipid kinase that plays a critical role in regulating plasma membrane identity. PI4KA is primarily recruited to the plasma ...Phosphatidylinositol 4 kinase IIIα (PI4KIIIα/PI4KA) is an essential lipid kinase that plays a critical role in regulating plasma membrane identity. PI4KA is primarily recruited to the plasma membrane through the targeted recruitment by the proteins, EFR3A and EFR3B, which bind to the PI4KA accessory proteins TTC7 (TTC7A/B) and FAM126 (FAM126A/B). Here we characterised how both EFR3 isoforms interact with all possible TTC7-FAM126 combinations and developed a nanobody that specifically blocked EFR3-mediated PI4KA recruitment in TTC7B containing complexes. Most EFR3-TTC7-FAM126 combinations show similar binding affinities, with the exception of EFR3A-TTC7B-FAM126A, which binds with a ∼10-fold higher affinity. Moreover, we showed that EFR3B phosphorylation markedly decreased binding to TTC7-FAM126. Using a yeast display approach, we isolated a TTC7B selective nanobody that blocked EFR3 binding. Cryo-electron microscopy and hydrogen deuterium exchange mass spectrometry showed an extended interface with both PI4KA and TTC7B that sterically blocks EFR3 binding. The nanobody caused decreased membrane recruitment both on lipid bilayers and in cells, with decreased PM production of PI4P. Collectively, these findings provide new insights into PI4KA regulation and provide a tool for manipulating PI4KA complexes, that may be valuable for therapeutic targeting.
凍結剤: ETHANE / チャンバー内湿度: 100 % / チャンバー内温度: 277.15 K / 装置: FEI VITROBOT MARK IV / 詳細: Blot force -5, blot time 1.5 s..
詳細
Gel filtration buffer, filtered through 0.22um filter and degassed. 0.75mg/ml of PI4KA with 3 fold molar excess F3IN Nanobody, with 0.25 mM BS3 crosslinker.
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電子顕微鏡法
顕微鏡
TFS KRIOS
特殊光学系
エネルギーフィルター - 名称: TFS Selectris
撮影
フィルム・検出器のモデル: FEI FALCON III (4k x 4k) 撮影したグリッド数: 2 / 実像数: 14026 / 平均電子線量: 50.0 e/Å2