与LDL受体相关的蛋白质,多功能ApoE受体,结合分泌的β-粉样蛋白前体蛋白并调解其降解
M Z Kounnas1, R D Moir, G W Rebeck
1Department of Biochemistry, Holland Laboratories, American Red Cross, Rockville, Maryland 20855, USA.
Cell
|July 28, 1995
概括
低密度脂蛋白 (LDL) 受体相关蛋白 (LRP) 中介于分泌的β-粉样蛋白前体蛋白 (APP) 的细胞吸收和降解. 这一发现将LRP和APP代谢与阿尔茨海默病 (AD) 风险因素联系起来.
科学领域:
- 神经科学是一个神经科学.
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
背景情况:
- 含有Kunitz蛋白酶抑制剂 (KPI) 域的分泌β-粉样蛋白前体蛋白 (APP),也称为蛋白酶nexin II,被细胞内化和降解.
- 阿尔茨海默病 (AD) 是一种神经退行性疾病,与粉样β (Aβ) 积累有关.
研究的目的:
- 为了确定负责分泌APP的内分细胞分裂的细胞受体.
- 研究低密度脂蛋白 (LDL) 受体相关蛋白 (LRP) 在 APP代谢中的作用.
- 探索LRP,APP和阿尔茨海默病 (AD) 病理生理学的联系.
主要方法:
- 在细胞培养中研究了分泌的APP (APPs770) 的内细胞分裂.
- 使用受体相关蛋白 (RAP) 作为LRP对手.
- 使用LRP抗体来阻止受体功能.
- 在LRP遗传缺陷的纤维细胞中检查了APP降解.
- 评估了不同APP异型 (APPs770与APPs695) 与LRP的结合.
主要成果:
- 低密度脂蛋白 (LDL) 受体相关蛋白 (LRP) 被确定为主要受体,介导分泌APP的内细胞化.
- APPs770的降解被LRP抗体 (RAP,LRP抗体) 和LRP缺乏细胞显著抑制.
- APPs695缺少KPI域,显示与LRP的结合较差.
- 此外,LRP还与阿波利波蛋白E (apoE) 丰富的脂蛋白结合.
结论:
- LRP是细胞吸收和降解含有KPI域的分泌APP的关键受体.
- 这些发现表明,LRP介导的APP代谢与阿波利波蛋白E (apoE) 西隆4等位基之间存在直接联系,这是一种已知的阿尔茨海默病 (AD) 风险因素.
- 这项研究涉及一个单一的代谢途径,涉及LRP和APP在AD的病理生理学.
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