在G蛋白β5β-螺旋中引起疾病的突变破坏了其伴介导的折叠轨迹
bioRxiv : the preprint server for biology
|June 12, 2025
概括
在G蛋白β5 (Gβ5) 中的错误突变会破坏其由CCT chaperonin折叠,导致神经系统疾病. 这项研究揭示了这些突变如何将Gβ在非功能状态中捕获,这表明了稳定策略.
科学领域:
- 分子生物学分子生物学
- 神经科学是一个神经科学.
- 结构生物学 结构生物学
背景情况:
- 含有Chaperonin的无尾 polypeptide 1 (CCT或TRiC) 是一个关键的细胞分裂 chaperone,参与折叠许多蛋白质,包括那些具有β螺旋结构的蛋白质.
- G蛋白β5子单元 (Gβ5) 是CCT的β-螺旋基质,在调节神经元信号持续时间的G蛋白信号传导 (RGS) 复合体中发挥作用.
- 在Gβ5中的特定误解突变与由于蛋白质错折导致的神经障碍有关.
研究的目的:
- 为了研究Gβ5中的误解突变如何改变其由CCT chaperonin复合体介导的折叠轨迹.
- 阐明这些突变导致Gβ5不完全折叠的,被困的中间体的分子机制.
- 探索潜在的治疗策略来稳定错误折叠的Gβ和恢复蛋白质功能.
主要方法:
- 使用冷电子显微镜 (cryo-EM) 可视化Gβ5的CCT介导的折叠路径.
- 采用生物化学和冷EM分析疾病相关误解突变对Gβ折叠的影响.
- 追踪了从初始基质相互作用到最终折叠结构的折叠过程.
主要成果:
- 在Gβ5中与疾病相关的误解突变破坏了其在CCT复合体内的正常折叠轨迹.
- 突变Gβ5蛋白与CCT结合,但在折叠时停滞,导致被困的,部分折叠的中间体.
- 这些中间体是非功能性的,这是由于形成封闭的,功能性的β-螺旋结构所必需的侧链相互作用被破坏.
结论:
- 沙佩罗宁介导蛋白质折叠的缺陷有助于神经系统疾病的发病.
- 这项研究揭示了Gβ5在疾病中错误折叠的分子基础,这与CCT辅助折叠过程中的异常相互作用有关.
- 稳定Gβ5正确折叠状态的药理伴侣可能提供一种治疗方法,以恢复受影响个体的功能.
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