Differential Subcellular Distribution and Translocation of Seven 14-3-3 Isoforms in Response to EGF and During the Cell Cycle
Differential Subcellular Distribution and Translocation of Seven 14-3-3 Isoforms in Response to EGF and During the Cell Cycle
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DOI：
10.3390/ijms21010318
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发表时间：
2020-01-01
影响因子：
5.6
通讯作者：
Wang, Zhixiang
中科院分区：
文献类型：
--
作者：
Abdrabou, Abdalla;Brandwein, Daniel;Wang, Zhixiang
14-3-3蛋白的多种亚型存在于不同的生物体中。在哺乳动物细胞中，14-3-3蛋白有7种亚型（α/β、β、eta、γ、sigma、theta/tau和delta/zeta），其中α和delta分别代表β和zeta的磷酸化版本。虽然多种异构体的存在可能代表14-3-3信号传导中的多一个调节水平，但我们关于14-3-3蛋白的异构体特异性功能的知识非常有限。不同14-3-3亚型的亚细胞定位的确定可以给我们提供重要的线索，他们的具体功能。在这项研究中，通过使用间接免疫荧光，亚细胞分离，免疫印迹，我们研究了亚细胞定位的总14-3-3蛋白和每7个14-3-3异构体;它们在整个细胞周期的重新分配;和它们的易位在Cos-7细胞中EGF的反应。我们发现，14-3-3蛋白广泛分布在整个细胞中，并与许多亚细胞结构/细胞器，包括质膜（PM），线粒体，ER，细胞核，微管和肌动蛋白纤维。这种广泛的分布强调了14-3-3蛋白的多种功能。14-3-3蛋白的不同亚型具有不同的亚细胞定位，这表明它们具有不同的细胞功能。最重要的是，14-3-3？在有丝分裂过程中，14-3-3 γ几乎专门定位于线粒体，14 - 3 -3 γ仅定位于细胞核，而14-3-3 σ与中心体强烈且特异地相关。我们还检查了其他细胞中7种14-3-3同种型的亚细胞定位，包括HEK-293、MDA-MB-231和MCF-7细胞，这在很大程度上证实了我们在Cos-7细胞中的发现。
Multiple isoforms of 14-3-3 proteins exist in different organisms. In mammalian cells, 14-3-3 protein has seven isoforms (alpha/beta, epsilon, eta, gamma, sigma, theta/tau, and delta/zeta), with alpha and delta representing the phosphorylated versions of beta and zeta, respectively. While the existence of multiple isoforms may represent one more level of regulation in 14-3-3 signaling, our knowledge regarding the isoform-specific functions of 14-3-3 proteins is very limited. Determination of the subcellular localization of the different 14-3-3 isoforms could give us important clues of their specific functions. In this study, by using indirect immunofluorescence, subcellular fractionation, and immunoblotting, we studied the subcellular localization of the total 14-3-3 protein and each of the seven 14-3-3 isoforms; their redistribution throughout the cell cycle; and their translocation in response to EGF in Cos-7 cells. We showed that 14-3-3 proteins are broadly distributed throughout the cell and associated with many subcellular structures/organelles, including the plasma membrane (PM), mitochondria, ER, nucleus, microtubules, and actin fibers. This broad distribution underlines the multiple functions identified for 14-3-3 proteins. The different isoforms of 14-3-3 proteins have distinctive subcellular localizations, which suggest their distinctive cellular functions. Most notably, 14-3-3? is almost exclusively localized to the mitochondria, 14-3-3 gamma is only localized to the nucleus, and 14-3-3 sigma strongly and specifically associated with the centrosome during mitosis. We also examined the subcellular localization of the seven 14-3-3 isoforms in other cells, including HEK-293, MDA-MB-231, and MCF-7 cells, which largely confirmed our findings with Cos-7 cells.