一种具有偏差信号的激活感应受体变体揭示了Gα11合的关键残留物
Matthew R Benson1, Rachael A Wyatt2,3, Michael A Levine4
1Division of Endocrinology, Diabetes & Metabolism, Nemours Children's Health, Jacksonville, FL 32207, United States.
概括
自体主导性低血症 (ADH) 涉及CASR或GNA11基因中的功能获取变异. 一种新的CASR变异,Leu723Arg,显示了偏差的G11信号,可能解释了ADH患者的矮身.
科学领域:
- 内分泌学 在内分泌学.
- 遗传学 遗传学 是一个
- 分子生物学分子生物学
背景情况:
- 自体主导性低血症 (ADH) 是由于增强的依赖信号的结果.
- 在CASR (ADH1) 或GNA11 (ADH2) 中的功能增益 (GOF) 变异会导致ADH,导致低血症和甲状腺激素 (PTH) 水平的改变.
- 在大约42%的病例中,ADH1与高度有关,而ADH2与矮身有关.
研究的目的:
- 为了研究一种新型CASR变异 (Leu723Arg) 的分子机制,该变异在患有偏偏甲状腺症和矮身的患者中发现.
- 描述 Leu723Arg 变体的信号特性,并将其与已知的 CASR 变体进行比较.
主要方法:
- 基因分析以确定CASR基因中的变异.
- 在HEK293细胞中,野生型 (WT) 和Leu723Arg感受受体 (CaSR) 蛋白的重组表达.
- 生物发光共振能量转移 (BRET) 试验用于评估体外G蛋白激活.
主要成果:
- 在该患者身上发现了CASR中的一个新异构的p.Leu723Arg变体.
- 这种 Leu723Arg 变体表现出正常表达,但对于 G11 的细胞外激活 EC50 显著较低,而不会影响其他 G 蛋白 (Gi,Gq,Gs).
- 之前报告的一种变种,Leu616Val,没有对G蛋白通路产生影响,这表明它是良性的.
结论:
- 这种 Leu723Arg CASR 变体显示出一种新的 GOF 现型,具有 G11 信号的偏向激活.
- 这种偏差信号可能是患者观察到的矮身的基础,类似于GNA11GOF变体引起的ADH2.
- 残留物723似乎对于确定CaSR激活G11的情况至关重要.
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