Presence of calpain-5 in mitochondria
Presence of calpain-5 in mitochondria
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DOI：
10.1016/j.bbrc.2018.08.144
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发表时间：
2018-10-02
影响因子：
3.1
通讯作者：
Ozaki, Taku
中科院分区：
文献类型：
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作者：
Iwamoto, Takeshi;Ishiyama, Eri;Ozaki, Taku
钙蛋白酶是 Ca2+ 依赖性半胱氨酸蛋白酶，广泛分布于动物组织中并调节多种细胞过程。哺乳动物中钙蛋白酶家族有 15 个成员。在动物细胞中，线粒体中存在三种类型的钙蛋白酶，即钙蛋白酶1、钙蛋白酶2和钙蛋白酶10。三种类型的钙蛋白酶已被证明在病理生理条件下发挥重要作用，包括细胞凋亡和坏死样细胞死亡。常染色体显性遗传性新生血管炎性玻璃体视网膜病是一种严重的视网膜疾病，已知是由 calpain-5 基因突变引起的。然而，calpain-5在视网膜中的分布尚未阐明。因此，在本研究中，我们确定了 calpain-5 在猪视网膜中的定位。我们使用免疫组织化学检测了感光细胞内段的 calpain-5。通过免疫电镜观察，calpain-5 定位于感光细胞的线粒体中。 Western blot 分析显示每个线粒体亚组分中都存在 calpain-5。此外，我们发现线粒体 calpain-5 的分子量略小于胞质中的分子量。我们的结果表明，一种新的线粒体钙蛋白，calpain-5，位于视网膜感光细胞的线粒体中。 (C) 2018 Elsevier Inc. 保留所有权利。
Calpains are Ca2+-dependent cysteine proteases that are widely distributed in animal tissues and modulate a variety of cellular processes. There are 15 members of the calpain family in mammals. In animal cells, there are three types of calpains, viz., calpain-1, calpain-2, and calpain-10 in the mitochondria. The three types of calpains have been shown to play significant roles in pathophysiological conditions, including in apoptosis- and necrosis-like cell death. One of the severe retinal diseases, autosomal dominant neovascular inflammatory vitreoretinopathy, is known to be induced by mutations of the calpain-5 gene. However, the distribution of calpain-5 in the retina has not been elucidated. Therefore, in the present study, we determined the localization of calpain-5 in the porcine retina. We detected calpain-5 in the inner segment of photoreceptor cells using immunohistochemistry. With immunoelectron microscopy, calpain-5 was localized in the mitochondria of photoreceptor cells. Western blot analyses showed that calpain-5 was present in each mitochondrial subfraction. Furthermore, we showed that the molecular weight of mitochondrial calpain-5 was slightly smaller than cytosolic one. Our results demonstrated that a novel mitochondrial calpian, calpain-5, was localized in the mitochondria of retinal photoreceptor cells. (C) 2018 Elsevier Inc. All rights reserved.