Wang Duo, Chen Xi, Feng Joshua, Jing Xueyuan A, Tang Jiaqi, Chadarevian Jean Paul, Park Haeyoung, Lee Matthew, Feng Fan, 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.
Stem Cell Reports. 2025 Jul 8;20(7):102512. doi: 10.1016/j.stemcr.2025.102512. Epub 2025 Jun 5.
Glycogen synthase kinase 3 (GSK3) is a crucial regulator of cellular processes, including stem cell maintenance and differentiation. Although the roles of the two GSK3 isozymes, GSK3α and GSK3β, are well documented, their specific interactions remain less understood. In this study, we explored the regulatory interplay between GSK3α and GSK3β in mouse embryonic stem cells (mESCs). Using genetic manipulation, small-molecule inhibitors, and biochemical analysis, we found that inhibition of GSK3α kinase activity increases GSK3β protein levels and activity, whereas overexpression of GSK3α reduces GSK3β protein levels and activity. Domain-swapping experiments between the two isozymes identified the glycine-rich region at the N terminus of GSK3α as the key sequence responsible for downregulating GSK3β protein levels. Our findings reveal a novel interaction between GSK3 isozymes, with GSK3α modulating GSK3β activity to maintain the balance between stem cell pluripotency and neural differentiation. This insight may open new pathways for understanding stem cell fate mechanisms and developing GSK3-targeted therapeutic strategies in regenerative medicine.
糖原合酶激酶3（GSK3）是细胞过程的关键调节因子，包括干细胞维持和分化。尽管两种GSK3同工酶GSK3α和GSK3β的作用已有充分记载，但其具体相互作用仍了解较少。在本研究中，我们探讨了小鼠胚胎干细胞（mESCs）中GSK3α和GSK3β之间的调节相互作用。通过基因操作、小分子抑制剂和生化分析，我们发现抑制GSK3α激酶活性会增加GSK3β蛋白水平和活性，而GSK3α的过表达会降低GSK3β蛋白水平和活性。两种同工酶之间的结构域交换实验确定了GSK3α N端富含甘氨酸的区域是负责下调GSK3β蛋白水平的关键序列。我们的研究结果揭示了GSK3同工酶之间的一种新相互作用，即GSK3α调节GSK3β活性以维持干细胞多能性和神经分化之间的平衡。这一见解可能为理解干细胞命运机制和开发再生医学中靶向GSK3的治疗策略开辟新途径。
