Calpain is required for macroautophagy in mammalian cells.
Calpain is required for macroautophagy in mammalian cells.
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DOI：
10.1083/jcb.200601024
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发表时间：
2006-11-20
影响因子：
7.8
通讯作者：
Schneider, Claudio
中科院分区：
文献类型：
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作者：
Demarchi, Francesca;Bertoli, Cosetta;Copetti, Tamara;Tanida, Isei;Brancolini, Claudio;Eskelinen, Eeva-Liisa;Schneider, Claudio
无处不在表达的微痛和毫痛都需要钙蛋白酶小1 （CAPNS1）调节亚基发挥作用，在许多生物学和病理现象中起着重要作用。我们之前已经证明GAS2的产物，一种在生长停止时特异性诱导的基因，是微痛的抑制剂，并且其过表达以p53依赖的方式使细胞对凋亡敏感（Benetti， R.， G. Del Sal， M. Monte， G. Paroni， C. Brancolini和C. Schneider. 2001）。Embo [j] . 20:2702-2714)。最近，我们发现在神经酰胺的作用下，钙蛋白酶也参与了核因子κB的激活及其相对的促存活功能，其中钙蛋白酶缺乏增强了神经酰胺的促凋亡作用（Demarchi， F.， C. Bertoli， P.A. Greer, and C. Schneider. 2005）。细胞死亡差异。12:52 - 522)。在这里，我们进一步探讨了calpain在凋亡开关中的作用，发现在calpain缺乏的细胞中，自噬受损，导致凋亡细胞死亡的急剧增加。内源性自噬体标志物LC3的免疫染色和电镜实验表明，capns1缺陷细胞的自噬功能受损。因此，通常在饥饿时发生的溶酶体活性增强和长期蛋白质降解也减少了。在capns1缺失的细胞中，异位LC3在早期内体样囊泡中积累，这可能是自噬缺陷时蛋白质降解的补救途径。
Ubiquitously expressed micro- and millicalpain, which both require the calpain small 1 (CAPNS1) regulatory subunit for function, play important roles in numerous biological and pathological phenomena. We have previously shown that the product of GAS2, a gene specifically induced at growth arrest, is an inhibitor of millicalpain and that its overexpression sensitizes cells to apoptosis in a p53-dependent manner (Benetti, R., G. Del Sal, M. Monte, G. Paroni, C. Brancolini, and C. Schneider. 2001. EMBO J. 20:2702–2714). More recently, we have shown that calpain is also involved in nuclear factor κB activation and its relative prosurvival function in response to ceramide, in which calpain deficiency strengthens the proapoptotic effect of ceramide (Demarchi, F., C. Bertoli, P.A. Greer, and C. Schneider. 2005. Cell Death Differ. 12:512–522). Here, we further explore the involvement of calpain in the apoptotic switch and find that in calpain-deficient cells, autophagy is impaired with a resulting dramatic increase in apoptotic cell death. Immunostaining of the endogenous autophagosome marker LC3 and electron microscopy experiments demonstrate that autophagy is impaired in CAPNS1-deficient cells. Accordingly, the enhancement of lysosomal activity and long-lived protein degradation, which normally occur upon starvation, is also reduced. In CAPNS1-depleted cells, ectopic LC3 accumulates in early endosome-like vesicles that may represent a salvage pathway for protein degradation when autophagy is defective.