Zhang Z, Hartmann H, Do V M, Abramowski D, Sturchler-Pierrat C, Staufenbiel M, Sommer B, van de Wetering M, Clevers H, Saftig P, De Strooper B, He X, Yankner B A
Department of Neurology, Harvard Medical School, The Children's Hospital, Boston, Massachusetts 02115, USA.
Nature. 1998 Oct 15;395(6703):698-702. doi: 10.1038/27208.
Mutations of the presenilin-1 gene are a major cause of familial early-onset Alzheimer's disease. Presenilin-1 can associate with members of the catenin family of signalling proteins, but the significance of this association is unknown. Here we show that presenilin-1 forms a complex with beta-catenin in vivo that increases beta-catenin stability. Pathogenic mutations in the presenilin-1 gene reduce the ability of presenilin-1 to stabilize beta-catenin, and lead to increased degradation of beta-catenin in the brains of transgenic mice. Moreover, beta-catenin levels are markedly reduced in the brains of Alzheimer's disease patients with presenilin-1 mutations. Loss of beta-catenin signalling increases neuronal vulnerability to apoptosis induced by amyloid-beta protein. Thus, mutations in presenilin-1 may increase neuronal apoptosis by altering the stability of beta-catenin, predisposing individuals to early-onset Alzheimer's disease.
早老素-1基因的突变是家族性早发型阿尔茨海默病的主要病因。早老素-1可与信号蛋白连环蛋白家族的成员相结合，但其结合的意义尚不清楚。在此我们表明，早老素-1在体内与β-连环蛋白形成复合物，增加β-连环蛋白的稳定性。早老素-1基因中的致病性突变降低了早老素-1稳定β-连环蛋白的能力，并导致转基因小鼠大脑中β-连环蛋白的降解增加。此外，早老素-1突变的阿尔茨海默病患者大脑中β-连环蛋白水平明显降低。β-连环蛋白信号缺失增加了神经元对淀粉样β蛋白诱导的细胞凋亡的易感性。因此，早老素-1中的突变可能通过改变β-连环蛋白的稳定性增加神经元凋亡，使个体易患早发型阿尔茨海默病。
