Calpain 6 is involved in microtubule stabilization and cytoskeletal organization
Calpain 6 is involved in microtubule stabilization and cytoskeletal organization
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DOI：
10.1128/mcb.00992-06
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发表时间：
2007-04-01
影响因子：
5.3
通讯作者：
Kurihara, Hiroki
中科院分区：
文献类型：
--
作者：
Tonami, Kazuo;Kurihara, Yukiko;Kurihara, Hiroki
钙蛋白酶是一个家族的Ca2+依赖半胱氨酸蛋白酶涉及各种生物过程。在这个家族中，calpain 6 （Capn6）的独特之处在于它缺乏蛋白酶活性所必需的活性位点半胱氨酸残基。在寻找内皮素I （ET-1）信号在咽弓发育过程中的下游基因时，我们发现了Capn6。我们通过原位杂交证实了在et - i缺失的胚胎中咽弓中Capn6的表达下调，并对其功能进行了研究。在转染capn6的细胞中，细胞分裂被延迟，并且经常流产以产生多核细胞。Capn6的过表达也导致微管束的形成，这些微管束富含乙酰化的α -微管蛋白，并且对诺可达唑的解聚活性具有抗性。绿色荧光蛋白-Capn6过表达、内源性Capn6免疫染色和生化分析表明，Capn6与微管之间存在相互作用，这种相互作用似乎主要由结构域III介导。此外，RNA干扰介导的Capn6失活导致微管不稳定，乙酰化α -微管蛋白丢失，并诱导肌动蛋白重组，导致膜褶皱形成板状基板。综上所述，这些结果表明Capn6是一种在胚胎组织中表达的微管稳定蛋白，可能参与微管动力学和细胞骨架组织的调节。
The calpains are a family of Ca2+-dependent cysteine proteases implicated in various biological processes. In this family, calpain 6 (Capn6) is unique in that it lacks the active-site cysteine residues requisite for protease activity. During the search for genes downstream of the endothelin I (ET-1) signaling in pharyngeal-arch development, we identified Capn6. After confirming that the expression of Capn6 in pharyngeal arches is downregulated in ET-I-null embryos by in situ hybridization, we investigated its function. In Capn6-transfected cells, cytokinesis was retarded and was often aborted to yield multinucleated cells. Capn6 overexpression also caused the formation of microtubule bundles rich in acetylated alpha-tubulin and resistant to the depolymerizing activity of nocodazole. Green fluorescent protein-Capn6 overexpression, immunostaining for endogenous Capn6, and biochemical analysis demonstrated interaction between Capn6 and microtubules, which appeared to be mainly mediated by domain III. Furthermore, RNA interference-mediated Capn6 inactivation caused microtubule instability with a loss of acetylated alpha-tubulin and induced actin reorganization, resulting in lamellipodium formation with membrane ruffling. Taken together, these results indicate that Capn6 is a microtubule-stabilizing protein expressed in embryonic tissues that may be involved in the regulation of microtubule dynamics and cytoskeletal organization.