National Institutes of Health/National Heart, Lung, and Blood Institute (NIH/NHLBI)
1R01HL168178
米国
引用
ジャーナル: Nat Commun / 年: 2025 タイトル: Impact of anionic lipids on the energy landscape of conformational transition in anion exchanger 1 (AE1). 著者: Tianle Chen / Francesca Vallese / Eva Gil-Iturbe / Kookjoo Kim / Tito Calì / Matthias Quick / Oliver B Clarke / Emad Tajkhorshid / 要旨: Anion Exchanger 1 (AE1) is an elevator-type transporter that plays a key role in acid-base homeostasis of erythrocytes. Here, we report three high-resolution cryo-electron microscopy (cryo-EM) ...Anion Exchanger 1 (AE1) is an elevator-type transporter that plays a key role in acid-base homeostasis of erythrocytes. Here, we report three high-resolution cryo-electron microscopy (cryo-EM) structures of distinct states of AE1: two inward-facing (IF1 and IF2) and one outward-facing (OF). Uptake assay revealed the modulatory effect of phosphatidylinositol 4,5-bisphosphate (PIP) lipids on AE1. Molecular dynamics simulations are conducted on these structures to determine the anion binding sites in AE1. We then use advanced enhanced sampling to study the OF⇌IF transition in AE1 in three systems: apo, HCO-bound, and an AE1 system in which cryo-EM-determined PIP lipids had been removed. The transition pathways were then used to calculate the free energy of the OF⇌IF transition in AE1 under different conditions. The results show how substrate reduces the transition barrier against transport. Furthermore, they capture the inhibitory effect of PIP lipids and provide a molecular mechanism for this inhibitory effect.