She Zhen-Yu, Yang Wan-Xi
The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou 310058, China.
Oncotarget. 2017 Jul 18;8(29):46955-46968. doi: 10.18632/oncotarget.15134.
The nucleocytoplasmic shuttling of SOX transcription factors play a crucial role in the regulation of SOX protein functions during development. In this study, we have demonstrated two nuclear localization signals in the HMG box of Eriocheir sinensis SOX14A and SOX14B. These two conserved nuclear localization signals mediate nuclear transport. The N-termini nuclear localization signal mediates the calmodulin-dependent pathway and the C-termini nuclear localization signal interacts with the importin-β pathway. The targeted deletion of nuclear localization signals of SOX14A/B dramatically inhibits the nuclear accumulation. We have first time revealed a non-classic nuclear export signal in the HMG box of E. sinensis SOX14A/B proteins is responds to leptomycin B. E. sinensis SOX14A/B is transported from the nucleus to the cytoplasm via a CRM1-dependent nuclear export pathway. And E. sinensis SOX14A/B are not belong to the subgroup E SOX proteins. Furthermore, these findings could shed a light on the mechanisms involved in the nuclear export of SOX proteins. The imperfect nuclear export signal on other SOX proteins, rather than just those of the SOXE group, may also be functional for nuclear export.
SOX转录因子的核质穿梭在发育过程中SOX蛋白功能的调控中起着关键作用。在本研究中，我们在中华绒螯蟹SOX14A和SOX14B的HMG框中发现了两个核定位信号。这两个保守的核定位信号介导核转运。N端核定位信号介导钙调蛋白依赖性途径，C端核定位信号与输入蛋白-β途径相互作用。靶向缺失SOX14A/B的核定位信号会显著抑制核积累。我们首次在中华绒螯蟹SOX14A/B蛋白的HMG框中发现一个非经典核输出信号，该信号对雷帕霉素敏感。中华绒螯蟹SOX14A/B通过CRM1依赖性核输出途径从细胞核转运到细胞质。并且中华绒螯蟹SOX14A/B不属于E亚组SOX蛋白。此外，这些发现可能有助于揭示SOX蛋白核输出的机制。其他SOX蛋白上不完美的核输出信号，而不仅仅是SOXE组的信号，可能也对核输出起作用。
