Sqstm1-GFP knock-in mice reveal dynamic actions of Sqstm1 during autophagy and under stress conditions in living cells.
Sqstm1-GFP knock-in mice reveal dynamic actions of Sqstm1 during autophagy and under stress conditions in living cells.
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DOI：
10.1242/jcs.180174
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发表时间：
2015-12-01
影响因子：
4
通讯作者：
Komatsu M
中科院分区：
文献类型：
--
作者：
Eino A;Kageyama S;Uemura T;Annoh H;Saito T;Narita I;Waguri S;Komatsu M
sqstm 1是选择性自噬的信号中枢和受体。因此，Sqstm 1的失调导致信号通路的失衡并破坏蛋白质稳态，从而促进人类疾病的发展。环境胁迫通过改变其表达和/或自噬降解来影响Sqstm 1的水平，并且还改变了Sqstm 1的定位，使得难以阐明该蛋白的作用和角色。在这项研究中，我们开发了基因敲入小鼠表达融合GFP的Sqstm 1（Sqstm 1-GFPKI/+）。使用这些Sqstm 1-GFPKI/+小鼠，我们首次揭示了活细胞中内源性Sqstm 1的动力学。Sqstm 1-GFP被易位到LC 3阳性结构的限制区域，其主要对应于自噬体的内部，然后被降解。此外，暴露于亚砷酸诱导表达的Sqstm 1-GFP，随后通过自噬降解的大聚集体中的融合蛋白的积累。此外，在Sqstm 1-GFPKI/+小鼠肝脏中抑制自噬引起Sqstm 1-GFP的积累和GFP阳性聚集体结构的形成，导致严重的肝衰竭。这些结果表明，Sqstm 1-GFPKI/+小鼠是分析活细胞和完整动物中Sqstm 1的有用工具。突出显示的文章：我们已经开发了Sqstm 1-GFP基因敲入小鼠，这对于阐明细胞事件的分子机制是有用的，包括自噬，以及Sqstm 1发挥作用的各种疾病。
Sqstm1 serves as a signaling hub and receptor for selective autophagy. Consequently, dysregulation of Sqstm1 causes imbalances in signaling pathways and disrupts proteostasis, thereby contributing to the development of human diseases. Environmental stresses influence the level of Sqstm1 by altering its expression and/or autophagic degradation, and also changes the localization of Sqstm1, making it difficult to elucidate the actions and roles of this protein. In this study, we developed knock-in mice expressing Sqstm1 fused to GFP (Sqstm1-GFPKI/+). Using these Sqstm1-GFPKI/+ mice, we revealed for the first time the dynamics of endogenous Sqstm1 in living cells. Sqstm1–GFP was translocated to a restricted area of LC3-positive structures, which primarily correspond to the inside of autophagosomes, and then degraded. Moreover, exposure to arsenite induced expression of Sqstm1–GFP, followed by accumulation of the fusion protein in large aggregates that were degraded by autophagy. Furthermore, suppression of autophagy in Sqstm1-GFPKI/+ mouse livers caused accumulation of Sqstm1–GFP and formation of GFP-positive aggregate structures, leading to severe hepatic failure. These results indicate that Sqstm1-GFPKI/+ mice are a useful tool for analyzing Sqstm1 in living cells and intact animals. Highlighted Article: We have developed Sqstm1-GFP knock-in mice, which are useful for elucidating the molecular mechanisms of cellular events, including autophagy, and various diseases in which Sqstm1 plays a role.