WAVE调节复合物（WRC）通过调节肌动蛋白聚合参与多种细胞过程。WRC成分的失调与癌症发展有关。ABI家族成员3（ABI3）/新分子包括SH3（NESH）是WRC成分之一，据报道ABI3磷酸化会影响WRC功能。虽然已有多个ABI3残基被报道为可能的磷酸化位点，但目前仍不清楚哪些残基对ABI3的功能起重要作用。此外，ABI3的磷酸化形式如何被调节也尚不清楚。在这里，我们证明ABI3与人类白细胞抗原-F相邻的转录物10（FAT10）相互作用可稳定ABI3。使用ABI3磷酸化及模拟突变体，我们发现A BI3的丝氨酸213和216是重要的磷酸化位点。特别是，FAT10对磷酸化形式的ABI3具有比非磷酸化形式更高的亲和力，并通过此差异亲和力更稳定磷酸化形式。 FAT10与ABI3的磷酸化形式之间的相互作用促进了癌细胞迁移。因此，我们的研究结果表明FAT10稳定了ABI3磷酸化形式，这可能导致WRC活化，从而促进癌细胞迁移。©2023作者。Informa UK Limited出版，Taylor＆Francis Group交易。

The WAVE regulatory complex (WRC) is involved in various cellular processes by regulating actin polymerization. The dysregulation of WRC components is associated with cancer development. ABI family member 3 (ABI3)/new molecule including SH3 (NESH) is one of the WRC components and it has been reported that ABI3 phosphorylation can affect WRC function. Although several residues of ABI3 have been reported to be possible phosphorylation sites, it is still unclear which residues are important for the function of ABI3. Furthermore, it is unclear how the phosphorylated form of ABI3 is regulated. Here, we demonstrate that ABI3 is stabilized by its interaction with human leukocyte antigen-F adjacent transcript 10 (FAT10). Using phospho-dead or phospho-mimetic mutants of ABI3, we showed that serine 213 and 216 are important phosphorylation sites of ABI3. In particular, FAT10 has a higher affinity for the phosphorylated form of ABI3 than the non-phosphorylated form, and it stabilizes the phosphorylated form more than the non-phosphorylated form through this differential affinity. The interaction between FAT10 and the phosphorylated form of ABI3 promoted cancer cell migration. Therefore, our results suggest that FAT10 stabilizes the phosphorylated form of ABI3, which may lead to WRC activation, thereby promoting cancer cell migration.© 2023 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.