Production of amyloid beta protein from normal amyloid beta-protein precursor (beta APP) and the mutated beta APPS linked to familial Alzheimer's disease.
Production of amyloid beta protein from normal amyloid beta-protein precursor (beta APP) and the mutated beta APPS linked to familial Alzheimer's disease.
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从正常的淀粉样β蛋白前体（βAPP）和与家族性阿尔茨海默氏病相关的突变βAPPS中产生淀粉样β蛋白。
DOI：
10.1111/j.1749-6632.1993.tb23036.x
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发表时间：
1993
影响因子：
5.2
通讯作者：
Younkin,SG
中科院分区：
文献类型：
--
作者：
Golde,TE;Cai,XD;Shoji,M;Younkin,SG
淀粉样蛋白4kD(∼4kD，39-43个氨基酸)多聚体(A-βProtein，Aβ)在阿尔茨海默病(AD)中沉积为淀粉样蛋白，是由一组6 95-770个残基的前体蛋白衍生而来的，统称为淀粉样蛋白前体(Amyloidβ-Protein Promor，βAPP)。利用免疫印迹技术、代谢标记和测序技术，我们在以下条件下分析了βAPP衍生物：(1)表达模型βAP羧基末端βAPP衍生物的人单核白血病(K562)细胞；(2)表达全长βAPP的人神经母细胞瘤(M17)细胞；(3)仅表达内源性βAPP的M17细胞。在每种情况下，我们都观察到∼4kDβAPP衍生物的释放与AD淀粉样蛋白中发现的Aβ基本相同。在阿尔茨海默病患者和对照组的脑脊液中都很容易检测到类似的βAPP片段，如果不是相同的话。这些观察表明，Aβ是由β应用程序的正常处理产生和释放的。为了确定在表达与家族性AD相关的突变βAPP的细胞中，Aβ或撕裂β末端的βAPP衍生物的产生是否发生改变，我们比较了表达野生型βAPP的M17细胞和表达突变βAPP的M17细胞(βAPPΔIorβAPPΔNL)。在连续代谢标记8小时后，表达βAPPΔNL突变体的细胞显示∼11.4kD Aβ羧基末端βAPP衍生物的相对含量增加了5倍，并向培养液中释放了6倍以上的4 kD Aβ。这些观察提供了强有力的证据，表明(1)在培养细胞中产生Aβ的途径与AD高度相关，(2)βAPPΔNL突变导致AD，因为它的处理发生了改变，释放了更多的Aβ。
The ∼4 kD (39–43 amino acid) polypepride (amyloid β protein, Aβ) deposited as amyloid in Alzheimer's disease (AD) is derived from a set of 695–770 residue precursor proteins collectively referred to as the amyloid β‐protein precursor (βAPP). Using immunoblotting techniques, metabolic labeling, and sequencing we have analyzed βAPP derivatives in medium conditioned by (1) human mononuclear leukemic (K562) cells expressing a model βAP‐bearing carboxyl‐terminal βAPP derivative (2) human neuroblastoma (Ml7) cells transfected with constructs expressing full length βAPP and (3) M17 cells expressing only endogenous βAPP. In each case, we observed the release of a ∼4 kD βAPP derivative essentially identical to the Aβ found in AD amyloid. A similar, if not identical, βAPP fragment was readily detected in CSF from both Alzheimer's disease patients and controls. These observations indicate that the Aβ is produced and released by normal processing of the βAPP. To determine if the production of Aβ or Aβ‐tearing COOH‐terminal βAPP derivatives is altered in cells expressing the mutant βAPPs linked to familial AD, we have compared M17 cells expressing wild type βAPP with those expressing mutant βAPPs (βAPPΔIor βAPPΔNL). After continuous metabolic labeling for 8 hours, cells expressing the βAPPΔNLmutant showed a 5‐fold increase in the relative amount of an ∼ 11.4 kD Aβ‐bearing carboxyl‐terminal βAPP derivative, and they released 6‐fold more 4 kD Aβ into the medium. These observations provide strong evidence that (1) the pathway producing Aβ in cultured cells is highly relevant to AD and (2) the βAPPΔNLmutant causes AD because its processing is altered in a way that releases increased amounts of Aβ.