Chen Xi, Wang Ruizhe, Liu Xu, Wu Yongming, Zhou Tao, Yang Yujia, Perez Andrew, Chen Ying-Chu, Hu Liang, Chadarevian Jean Paul, Assadieskandar Amir, Zhang Chao, Ying Qi-Long
Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research at USC, Department of Stem Cell Biology and Regenerative Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033, USA.
Loker Hydrocarbon Research Institute & Department of Chemistry, University of Southern California, Los Angeles, CA 90089, USA.
Dev Cell. 2017 Dec 4;43(5):563-576.e4. doi: 10.1016/j.devcel.2017.11.007.
Glycogen synthase kinase 3 (GSK3) plays a central role in diverse cellular processes. GSK3 has two mammalian isozymes, GSK3α and GSK3β, whose functions remain ill-defined because of a lack of inhibitors that can distinguish between the two highly homologous isozymes. Here, we show that GSK3α and GSK3β can be selectively inhibited in mouse embryonic stem cells (ESCs) using a chemical-genetic approach. Selective inhibition of GSK3β is sufficient to maintain mouse ESC self-renewal, whereas GSK3α inhibition promotes mouse ESC differentiation toward neural lineages. Genome-wide transcriptional analysis reveals that GSK3α and GSK3β have distinct sets of downstream targets. Furthermore, selective inhibition of individual GSK3 isozymes yields distinct phenotypes from gene deletion, highlighting the power of the chemical-genetic approach in dissecting kinase catalytic functions from the protein's scaffolding functions. Our study opens new avenues for defining GSK3 isozyme-specific functions in various cellular processes.
糖原合酶激酶3（GSK3）在多种细胞过程中发挥核心作用。GSK3有两种哺乳动物同工酶，即GSK3α和GSK3β，由于缺乏能够区分这两种高度同源同工酶的抑制剂，其功能仍不明确。在此，我们表明，使用化学遗传学方法可在小鼠胚胎干细胞（ESC）中选择性抑制GSK3α和GSK3β。选择性抑制GSK3β足以维持小鼠ESC的自我更新，而抑制GSK3α则促进小鼠ESC向神经谱系分化。全基因组转录分析表明，GSK3α和GSK3β具有不同的下游靶标集。此外，选择性抑制单个GSK3同工酶产生的表型与基因敲除不同，突出了化学遗传学方法在从蛋白质支架功能中剖析激酶催化功能方面的作用。我们的研究为在各种细胞过程中定义GSK3同工酶特异性功能开辟了新途径。
