| First Author | Siman R | Year | 2001 |
| Journal | J Biol Chem | Volume | 276 |
| Issue | 48 | Pages | 44736-43 |
| PubMed ID | 11574534 | Mgi Jnum | J:72951 |
| Mgi Id | MGI:2154036 | Doi | 10.1074/jbc.M104092200 |
| Citation | Siman R, et al. (2001) Endoplasmic Reticulum Stress-induced Cysteine Protease Activation in Cortical Neurons. EFFECT OF AN ALZHEIMER'S DISEASE-LINKED PRESENILIN-1 KNOCK-IN MUTATION. J Biol Chem 276(48):44736-43 |
| abstractText | Endoplasmic reticulum (ER) stress elicits protective responses of chaperone induction and translational suppression and, when unimpeded, leads to caspase-mediated apoptosis. Alzheimer's disease-linked mutations in presenilin-1 (PS-1) reportedly impair ER stress-mediated protective responses and enhance vulnerability to degeneration. We used cleavage site-specific antibodies to characterize the cysteine protease activation responses of primary mouse cortical neurons to ER stress and evaluate the influence of a PS-1 knock-in mutation on these and other stress responses. Two different ER stressors lead to processing of the ER-resident protease procaspase-12, activation of calpain, caspase-3, and caspase-6, and degradation of ER and non-ER protein substrates. Immunocytochemical localization of activated caspase-3 and a cleaved substrate of caspase-6 confirms that caspase activation extends into the cytosol and nucleus. ER stress-induced proteolysis is unchanged in cortical neurons derived from the PS-1 P264L knock-in mouse. Furthermore, the PS-1 genotype does not influence stress-induced increases in chaperones Grp78/BiP and Grp94 or apoptotic neurodegeneration. A similar lack of effect of the PS-1 P264L mutation on the activation of caspases and induction of chaperones is observed in fibroblasts. Finally, the PS-1 knock-in mutation does not alter activation of the protein kinase PKR-like ER kinase (PERK), a trigger for stress-induced translational suppression. These data demonstrate that ER stress in cortical neurons leads to activation of several cysteine proteases within diverse neuronal compartments and indicate that Alzheimer's disease-linked PS-1 mutations do not invariably alter the proteolytic, chaperone induction, translational suppression, and apoptotic responses to ER stress. |
