The energetics and ion coupling of cholesterol transport through Patched1.
The energetics and ion coupling of cholesterol transport through Patched1.
复制标题
DOI：
10.1126/sciadv.adh1609
复制
发表时间：
2023-08-25
期刊：
影响因子：
13.6
通讯作者：
Sansom, Mark S. P.
中科院分区：
文献类型：
--
作者：
Ansell, T. Bertie;Corey, Robin A.;Viti, Lucrezia Vittoria;Kinnebrew, Maia;Rohatgi, Rajat;Siebold, Christian;Sansom, Mark S. P.
Patched1 (PTCH1) 是哺乳动物 Hedgehog (HH) 信号通路的肿瘤抑制蛋白，与胚胎发生和组织稳态有关。 PTCH1 通过一种有争议的机制（涉及调节纤毛胆固醇可及性）抑制 G 蛋白偶联受体 Smoothened（SMO）。使用广泛的分子动力学模拟和自由能计算来评估通过 PTCH1 的胆固醇转运，我们发现胆固醇输出的能量屏障为每摩尔约 15 至 20 千焦耳。将计算机数据与 PTCH1 突变体的体内生化测定相结合，以探测阳离子结合位点、跨膜运动和 PTCH1 活性之间的耦合。使用 Dispatched1 的互补模拟，我们发现“向内开放”和溶剂“闭塞”状态之间的转变伴随着 Na+ 诱导的细胞内螺旋段的收缩。因此，我们的研究结果阐明了 PTCH1 转运机制的能量学和离子耦合化学计量，其中一到三个 Na+ 或两到三个 K+ 与胆固醇输出偶联，并提供了不同转运状态之间转变的第一个分子描述。模拟揭示了通过 Patched1 运输胆固醇的机制。
Patched1 (PTCH1) is a tumor suppressor protein of the mammalian Hedgehog (HH) signaling pathway, implicated in embryogenesis and tissue homeostasis. PTCH1 inhibits the G protein–coupled receptor Smoothened (SMO) via a debated mechanism involving modulating ciliary cholesterol accessibility. Using extensive molecular dynamics simulations and free energy calculations to evaluate cholesterol transport through PTCH1, we find an energetic barrier of ~15 to 20 kilojoule per mole for cholesterol export. In silico data are coupled to in vivo biochemical assays of PTCH1 mutants to probe coupling between cation binding sites, transmembrane motions, and PTCH1 activity. Using complementary simulations of Dispatched1, we find that transition between “inward-open” and solvent “occluded” states is accompanied by Na+-induced pinching of intracellular helical segments. Thus, our findings illuminate the energetics and ion coupling stoichiometries of PTCH1 transport mechanisms, whereby one to three Na+ or two to three K+ couple to cholesterol export, and provide the first molecular description of transitions between distinct transport states. Simulations reveal a mechanism of cholesterol transport through Patched1.
登录
查看更多内容
影响因子：
64.8
作者：
通讯作者：
--
DOI：
10.1007/978-1-4939-7756-7_11
发表时间：
2018-01-01
期刊：
COMPUTATIONAL DRUG DISCOVERY AND DESIGN
影响因子：
--
作者：
Aldeghi, Matteo;Bluck, Joseph P.;Biggin, Philip C.
通讯作者：
Biggin, Philip C.
影响因子：
5.5
作者：
de Jong, Djurre H.;Singh, Gurpreet;Marrink, Siewert J.
通讯作者：
Marrink, Siewert J.
影响因子：
16.2
作者：
Hollingsworth SA;Dror RO
通讯作者：
Dror RO
影响因子：
3.4
作者：
Gumbart, James;Khalili-Araghi, Fatemeh;Sotomayor, Marcos;Roux, Benoit
通讯作者：
Roux, Benoit