Calpain-2 participates in the process of calpain-1 inactivation.
Calpain-2 participates in the process of calpain-1 inactivation.
复制标题
Calpain-2参与Calpain-1灭活过程。
DOI：
10.1042/bsr20200552
复制
发表时间：
2020-11-27
影响因子：
4
通讯作者：
Ono Y
中科院分区：
文献类型：
--
作者：
Shinkai-Ouchi F;Shindo M;Doi N;Hata S;Ono Y
Calpain-1 和 calpain-2 是结构高度相似的 calpain 亚型。钙蛋白酶是细胞内半胱氨酸蛋白酶家族，在特定位点切割其底物，从而改变其特性，例如功能或活性。长期以来，这些亚型一直被认为以冗余或互补的方式发挥作用，因为它们都以 Ca2+ 依赖性方式普遍表达和激活。然而，使用异构体特异性敲除和敲低策略的研究表明，每种钙蛋白酶物种在体内执行特定的功能。为了了解区分 calpain-1 和 calpain-2 的机制，我们重点研究了每种 calpain 物种在激活后的效率和寿命。利用肌钙蛋白 T 的体外蛋白水解测定与质谱分析相结合，我们揭示了每种亚型的独特方面。 calpain-1 介导的蛋白水解作用更持久，可持续长达数小时，而 calpain-2 介导的蛋白水解作用很快减弱。 Calpain-1 和 calpain-2 的自溶模式也各不相同。 Calpain-2 的 PC1 结构域中的特异性自溶位点不会被 calpain-1 切割，但 calpain-2 在相应位置切割 calpain-1。此外，至少在体外，calpain-1和calpain-2不以协同方式进行底物蛋白水解。相反，在存在 calpain-2 的情况下，calpain-1 活性受到抑制，可能是因为它被后者蛋白质裂解。这些结果表明 calpain-2 起到下调 calpain-1 的作用，这种机制也可能适用于其他 calpain 物种。
Calpain-1 and calpain-2 are highly structurally similar isoforms of calpain. The calpains, a family of intracellular cysteine proteases, cleave their substrates at specific sites, thus modifying their properties such as function or activity. These isoforms have long been considered to function in a redundant or complementary manner, as they are both ubiquitously expressed and activated in a Ca2+- dependent manner. However, studies using isoform-specific knockout and knockdown strategies revealed that each calpain species carries out specific functions in vivo. To understand the mechanisms that differentiate calpain-1 and calpain-2, we focused on the efficiency and longevity of each calpain species after activation. Using an in vitro proteolysis assay of troponin T in combination with mass spectrometry, we revealed distinctive aspects of each isoform. Proteolysis mediated by calpain-1 was more sustained, lasting as long as several hours, whereas proteolysis mediated by calpain-2 was quickly blunted. Calpain-1 and calpain-2 also differed from each other in their patterns of autolysis. Calpain-2–specific autolysis sites in its PC1 domain are not cleaved by calpain-1, but calpain-2 cuts calpain-1 at the corresponding position. Moreover, at least in vitro, calpain-1 and calpain-2 do not perform substrate proteolysis in a synergistic manner. On the contrary, calpain-1 activity is suppressed in the presence of calpain-2, possibly because it is cleaved by the latter protein. These results suggest that calpain-2 functions as a down-regulation of calpain-1, a mechanism that may be applicable to other calpain species as well.
Calpain-2抑制剂治疗优先降低表达该酶最高水平的人类结肠癌细胞的肿瘤进展。
影响因子：
4
作者：
Marciel MP;Rose AH;Martinez V;Horio DT;Hashimoto AS;Hoffmann FW;Bertino P;Hoffmann PR
通讯作者：
Hoffmann PR