Ji Tianyi, Li Xiangying, Li Jiachen, Wang Guan
College of Acupuncture and Tuina, Liaoning University of Traditional Chinese Medicine, Shenyang, China.
Endocrinology Department, Shenyang Fifth People's Hospital, Shenyang, China.
J Cell Mol Med. 2025 Apr;29(7):e70539. doi: 10.1111/jcmm.70539.
Wnt signalling is a highly conserved signalling pathway that plays an important role in a variety of biological processes. Frizzled (Fzd) family proteins are receptors for Wnt ligands. The physiological processes involved in mature trafficking of Fzd proteins remain elusive. Here, we identified asparagine residues 59 and 144 as the N-glycosylation modification sites of Fzd4. Sequence analysis of Fzd4 in different species showed that the two asparagine residues were highly conserved. N-glycosylation modification of Fzd4 is indispensable for its maturation and transport to the plasma membrane. N-glycosylation modification enhances the stability of Fzd4 and is also necessary for Fzd4 activity, which promotes Fzd4 interaction with Wnt ligands and co-receptor Norrin. Knockout of Fzd4 in the non-small cell lung cancer (NSCLC) cell line A549 followed by replenishment of Fzd4 glycosylation site mutants inhibited the growth and migration ability of A549 cells in vitro and in vivo. In summary, we identified N-glycosylation modification sites of Fzd4. N-glycosylation modification of Fzd4 is necessary for its stability and activity. When N-glycosylation modification is absent, Fzd4 cannot mediate the Wnt/β-catenin signalling pathway, which can inhibit the proliferation and migration of NSCLC and provide new targets and strategies for the treatment of NSCLC.
Wnt信号通路是一条高度保守的信号通路，在多种生物学过程中发挥重要作用。卷曲蛋白（Frizzled，Fzd）家族蛋白是Wnt配体的受体。Fzd蛋白成熟运输所涉及的生理过程仍不清楚。在此，我们确定天冬酰胺残基59和144为Fzd4的N-糖基化修饰位点。不同物种中Fzd4的序列分析表明，这两个天冬酰胺残基高度保守。Fzd4的N-糖基化修饰对其成熟和转运至质膜是必不可少的。N-糖基化修饰增强了Fzd4的稳定性，也是Fzd4活性所必需的，其促进Fzd4与Wnt配体及共受体Norrin相互作用。在非小细胞肺癌（NSCLC）细胞系A549中敲除Fzd4，随后补充Fzd4糖基化位点突变体，在体外和体内均抑制了A549细胞的生长和迁移能力。总之，我们确定了Fzd4的N-糖基化修饰位点。Fzd4的N-糖基化修饰对其稳定性和活性是必需的。当不存在N-糖基化修饰时，Fzd4不能介导Wnt/β-连环蛋白信号通路，从而抑制NSCLC的增殖和迁移，并为NSCLC的治疗提供新的靶点和策略。
