<p>The development and function of B lymphocytes require the precise integration of signaling, transcriptional networks, and metabolic programs. While interferon (IFN)-inducible proteins can bridge innate and adaptive immunity, their roles in B cells remain poorly defined. Here, we identified RNF213, a giant IFN-inducible RING finger E3 ligase, as a key orchestrator of B-cell biology. Mice lacking <i>Rnf213</i> exhibited defective splenic B-cell development, impaired B-cell receptor (BCR) signaling, and compromised metabolic activity. Mechanistically, RNF213 targeted the transcription factor SPIB for proteasomal degradation via K11-linked ubiquitylation. In <i>Rnf213</i>‑deficient B cells, stabilized SPIB transcriptionally upregulated <i>Pik3c3</i>, thereby increasing phosphatidylinositol 3-phosphate (PI3P) production. Excess PI3P recruited PTEN to early endosomes, where PTEN hydrolyzed phosphatidylinositol-3,4,5-trisphosphate (PIP3) and attenuated AKT-mTOR signaling. Strikingly, both genetic deletion of <i>Spib</i> and pharmacological inhibition of PIK3C3 restored AKT-mTOR activation, metabolic fitness, and B-cell development in <i>Rnf213</i>-null mice. Furthermore, <i>Rnf213</i> deficiency impaired both T-independent and T-dependent antibody responses, highlighting its critical role in humoral immunity. Overall, our work reveals a novel ubiquitin-dependent circuit that links interferon signaling to the transcriptional and metabolic control of B-cell homeostasis. This study also establishes RNF213 as a crucial bridge between innate immune sensing and the dynamic regulation of lymphocyte development.</p>

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Ring finger protein 213 regulates B-cell receptor signaling, metabolism, and development in B lymphocytes

  • Ziyin Zhang,
  • Nanshu Xiang,
  • Qian Liu,
  • Yanfeng Li,
  • Linhua Wang,
  • Xinpu Yang,
  • Ju Liu,
  • Lichen Zhang,
  • Liaoxun Lu,
  • Yinming Liang,
  • Lu Yang,
  • Xiaopeng Qi,
  • Chaohong Liu

摘要

The development and function of B lymphocytes require the precise integration of signaling, transcriptional networks, and metabolic programs. While interferon (IFN)-inducible proteins can bridge innate and adaptive immunity, their roles in B cells remain poorly defined. Here, we identified RNF213, a giant IFN-inducible RING finger E3 ligase, as a key orchestrator of B-cell biology. Mice lacking Rnf213 exhibited defective splenic B-cell development, impaired B-cell receptor (BCR) signaling, and compromised metabolic activity. Mechanistically, RNF213 targeted the transcription factor SPIB for proteasomal degradation via K11-linked ubiquitylation. In Rnf213‑deficient B cells, stabilized SPIB transcriptionally upregulated Pik3c3, thereby increasing phosphatidylinositol 3-phosphate (PI3P) production. Excess PI3P recruited PTEN to early endosomes, where PTEN hydrolyzed phosphatidylinositol-3,4,5-trisphosphate (PIP3) and attenuated AKT-mTOR signaling. Strikingly, both genetic deletion of Spib and pharmacological inhibition of PIK3C3 restored AKT-mTOR activation, metabolic fitness, and B-cell development in Rnf213-null mice. Furthermore, Rnf213 deficiency impaired both T-independent and T-dependent antibody responses, highlighting its critical role in humoral immunity. Overall, our work reveals a novel ubiquitin-dependent circuit that links interferon signaling to the transcriptional and metabolic control of B-cell homeostasis. This study also establishes RNF213 as a crucial bridge between innate immune sensing and the dynamic regulation of lymphocyte development.