STK40 通过介导 COP1 泛素化降解 P57 抑制滋养细胞融合。

STK40 inhibits trophoblast fusion by mediating COP1 ubiquitination to degrade P57.

机构信息

Department of Bioinformatics, School of Basic Medical Sciences, Chongqing Medical University, Chongqing, 400016, China.

The Joint International Research Laboratory of Reproduction and Development, Chongqing Medical University, Box 197, No.1 Yixueyuan Rd, Chongqing, 400016, China.

出版信息

J Transl Med. 2024 Sep 20;22(1):852. doi: 10.1186/s12967-024-05360-y.

DOI:10.1186/s12967-024-05360-y

PMID:39304928

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC11414097/

Abstract

BACKGROUND

The syncytiotrophoblast (SCT) layer in the placenta serves as a crucial physical barrier separating maternal-fetal circulation, facilitating essential signal and substance exchange between the mother and fetus. Any abnormalities in its formation or function can result in various maternal syndromes, such as preeclampsia. The transition of proliferative villous cytotrophoblasts (VCT) from the mitotic cell cycle to the G0 phase is a prerequisite for VCT differentiation and their fusion into SCT. The imprinting gene P57, specifically expressed in intermediate VCT capable of fusion, plays a pivotal role in driving this key event. Moreover, aberrant expression of P57 has been linked to pathological placental conditions and adverse fetal outcomes.

METHODS

Validation of STK40 interaction with P57 using rigid molecular simulation docking and co-immunoprecipitation. STK40 expression was modulated by lentivirus in BeWo cells, and the effect of STK40 on trophoblast fusion was assessed by real-time quantitative PCR, western blot, immunofluorescence, and cell viability and proliferation assays. Co-immunoprecipitation, transcriptome sequencing, and western blot were used to determine the potential mechanisms by which STK40 regulates P57.

RESULTS

In this study, STK40 has been identified as a novel interacting protein with P57, and its expression is down-regulated during the fusion process of trophoblast cells. Overexpressing STK40 inhibited cell fusion in BeWo cells while stimulating mitotic cell cycle activity. Further experiments indicated that this effect is attributed to its specific binding to the CDK-binding and the Cyclin-binding domains of P57, mediating the E3 ubiquitin ligase COP1-mediated ubiquitination and degradation of P57. Moreover, abnormally high expression of STK40 might significantly contribute to the occurrence of preeclampsia.

CONCLUSIONS

This study offers new insights into the role of STK40 in regulating the protein-level homeostasis of P57 during placental development.

摘要

背景

胎盘的合体滋养层（SCT）层作为一种重要的物理屏障，分隔着母胎循环，促进母体和胎儿之间的必要信号和物质交换。其形成或功能的任何异常都可能导致各种母体综合征，如子痫前期。增殖性绒毛滋养细胞（VCT）从有丝分裂细胞周期过渡到 G0 期是 VCT 分化并融合成 SCT 的前提。特异性表达于有融合能力的中间 VCT 的印迹基因 P57 在驱动这一关键事件中发挥关键作用。此外，P57 的异常表达与病理性胎盘状况和不良胎儿结局有关。

方法

使用刚性分子模拟对接和共免疫沉淀验证 STK40 与 P57 的相互作用。通过慢病毒在 BeWo 细胞中调节 STK40 的表达，并通过实时定量 PCR、western blot、免疫荧光和细胞活力和增殖测定评估 STK40 对滋养细胞融合的影响。共免疫沉淀、转录组测序和 western blot 用于确定 STK40 调节 P57 的潜在机制。

结果

本研究鉴定出 STK40 是 P57 的一种新型相互作用蛋白，其表达在滋养细胞融合过程中下调。过表达 STK40 抑制 BeWo 细胞融合，同时刺激有丝分裂细胞周期活性。进一步的实验表明，这种作用归因于其特异性结合 P57 的 CDK 结合和细胞周期蛋白结合域，介导 E3 泛素连接酶 COP1 介导的 P57 的泛素化和降解。此外，STK40 的异常高表达可能显著导致子痫前期的发生。