Zhao Shuang, Zhang Chuanyu, Xu Jia, Liu Siying, Yu Lu, Chen Shang, Wen Hang, Li Zongjin, Liu Na
School of Medicine, Nankai University, 94# Weijin Road, Tianjin, 300071, China.
Key Laboratory of Bioactive Materials, Ministry of Education, College of Life Sciences, Nankai University, Tianjin, 300071, China.
Stem Cell Res Ther. 2022 Apr 27;13(1):169. doi: 10.1186/s13287-022-02846-8.
Developmental pluripotency-associated 3 (Dppa3, also called Stella or PGC7) is a principal maternal protein specially expressed in pre-implantation embryos, embryonic stem cells (ES cells) and primordial germ cells (PGCs). It plays critical role in the regulating of DNA methylation in zygotes and oocytes. However, the effect of Dppa3 in ES cells on the stability of proteins is still unclear.
In this study, we first identified the potential interacting proteins with Dppa3 using immunoprecipitation-mass spectrometry (IP-MS). After GO analysis, we further constructed Dppa3-silenced ES cells and ES cell lines overexpressing with different lengths of Dppa3 to explore the mechanisms of Dppa3 on protein stability.
IP-MS results showed that Dppa3 interacted with quite a few subunits of 26S proteasome. Full length of Dppa3 stabilized Uhrf1 and Nanog by inhibiting its degradation. Silencing Dppa3 promoted degradation of Nanog protein.
Our results indicated that Dppa3 safeguard the stability of Uhrf1 and Nanog by inhibiting proteasome-associated degradation in ES cells. These findings shed light on new function of Dppa3 in maintaining stability of proteins and provides a valuable resource for understanding the roles of Dppa3 in embryonic stem cells.
发育多能性相关蛋白3（Dppa3，也称为Stella或PGC7）是一种主要的母体蛋白，特别在植入前胚胎、胚胎干细胞（ES细胞）和原始生殖细胞（PGCs）中表达。它在调节受精卵和卵母细胞中的DNA甲基化方面发挥着关键作用。然而，Dppa3在ES细胞中对蛋白质稳定性的影响仍不清楚。
在本研究中，我们首先使用免疫沉淀-质谱（IP-MS）鉴定了与Dppa3潜在相互作用的蛋白质。经过基因本体（GO）分析后，我们进一步构建了Dppa3沉默的ES细胞和过表达不同长度Dppa3的ES细胞系，以探索Dppa3对蛋白质稳定性的作用机制。
IP-MS结果表明，Dppa3与26S蛋白酶体的相当一部分亚基相互作用。全长Dppa3通过抑制Uhrf1和Nanog的降解来使其稳定。沉默Dppa3会促进Nanog蛋白的降解。
我们的结果表明，Dppa3通过抑制ES细胞中蛋白酶体相关的降解来保障Uhrf1和Nanog的稳定性。这些发现揭示了Dppa3在维持蛋白质稳定性方面的新功能，并为理解Dppa3在胚胎干细胞中的作用提供了有价值的资源。
