Clic4, a novel protein that sensitizes β-cells to apoptosis.
Clic4, a novel protein that sensitizes β-cells to apoptosis.
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Clic4，一种新型蛋白质，可将β细胞敏感到细胞凋亡。
DOI：
10.1016/j.molmet.2015.01.003
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发表时间：
2015-04
影响因子：
8.1
通讯作者：
Thorens B
中科院分区：
文献类型：
--
作者：
Patel D;Ythier D;Brozzi F;Eizirik DL;Thorens B
氯离子胞内通道蛋白4（Clic 4）是一种广泛表达的蛋白质，其参与多种细胞过程，包括细胞周期控制、细胞分化和凋亡。在此，我们研究了Clic 4在胰腺β细胞凋亡中的作用。我们使用来自β细胞特异性Clic 4敲除小鼠（β Clic 4KO）的βTC-tet细胞和胰岛，并评估了奎宁诱导的细胞凋亡、Bcl 2家族蛋白表达和稳定性，并通过免疫共沉淀和质谱分析鉴定了Clic 4相互作用蛋白。我们发现，细胞因子增加βTC-tet细胞和小鼠胰岛中Clic 4的表达，siRNA介导的βTC-tet细胞中Clic 4表达沉默或胰岛β细胞中Clic 4基因失活，减少了甘氨酸诱导的细胞凋亡。这与Bcl-2的表达增加以及Bad的表达和磷酸化增加有关。βTC-tet细胞中Bcl-2和Bad半衰期的测量表明，Clic 4沉默增加了这些蛋白的稳定性。在原代胰岛β细胞中，Clic 4表达的缺乏增加Bcl-2和Bcl-xL表达以及Bad的表达和磷酸化。对来自βTC-tet细胞的与Clic 4免疫共沉淀的蛋白质的质谱分析显示Clic 4与Bcl-2家族蛋白没有关联。然而，Clic 4与来自蛋白酶体的蛋白质共纯化，表明Clic 4在调节蛋白质降解中可能起作用。总的来说，我们的数据表明Clic 4是一种奎宁诱导的基因，其通过降低Bcl-2、Bad和磷酸化Bad的稳态水平使β细胞对凋亡敏感。
Chloride intracellular channel protein 4 (Clic4) is a ubiquitously expressed protein involved in multiple cellular processes including cell-cycle control, cell differentiation, and apoptosis. Here, we investigated the role of Clic4 in pancreatic β-cell apoptosis. We used βTC-tet cells and islets from β-cell specific Clic4 knockout mice (βClic4KO) and assessed cytokine-induced apoptosis, Bcl2 family protein expression and stability, and identified Clic4-interacting proteins by co-immunoprecipitation and mass spectrometry analysis. We show that cytokines increased Clic4 expression in βTC-tet cells and in mouse islets and siRNA-mediated silencing of Clic4 expression in βTC-tet cells or its genetic inactivation in islets β-cells, reduced cytokine-induced apoptosis. This was associated with increased expression of Bcl-2 and increased expression and phosphorylation of Bad. Measurement of Bcl-2 and Bad half-lives in βTC-tet cells showed that Clic4 silencing increased the stability of these proteins. In primary islets β-cells, absence of Clic4 expression increased Bcl-2 and Bcl-xL expression as well as expression and phosphorylation of Bad. Mass-spectrometry analysis of proteins co-immunoprecipitated with Clic4 from βTC-tet cells showed no association of Clic4 with Bcl-2 family proteins. However, Clic4 co-purified with proteins from the proteasome suggesting a possible role for Clic4 in regulating protein degradation. Collectively, our data show that Clic4 is a cytokine-induced gene that sensitizes β-cells to apoptosis by reducing the steady state levels of Bcl-2, Bad and phosphorylated Bad.
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影响因子：
5.1
作者：
Dupraz, P;Rinsch, C;Thorens, B
通讯作者：
Thorens, B
影响因子：
7.7
作者：
Donath, MY;Gross, DJ;Kaiser, N
通讯作者：
Kaiser, N
影响因子：
7.7
作者：
Butler, AE;Janson, J;Butler, PC
通讯作者：
Butler, PC
影响因子：
4.8
作者：
Gremlich, S;Bonny, C;Thorens, B
通讯作者：
Thorens, B
影响因子：
40.5
作者：
Eizirik, Decio L.;Colli, Maikel L.;Ortis, Fernanda
通讯作者：
Ortis, Fernanda