State Key Laboratory of Genetic Engineering and Engineering Research Center of Gene Technology, Ministry of Education, Institute of Genetics, School of Life Sciences, Fudan University, Shanghai, People's Republic of China.
Scientific Research Center, Shanghai Public Health Clinical Center, Fudan University, Shanghai, People's Republic of China.
Emerg Microbes Infect. 2022 Dec;11(1):2785-2799. doi: 10.1080/22221751.2022.2140605.
Acquired immunodeficiency syndrome (AIDS) cannot be completely cured, mainly due to the existence of a latent HIV-1 reservoir. However, our current understanding of the molecular mechanisms underlying the establishment and maintenance of HIV-1 latent reservoir is not comprehensive. Here, using a genome-wide CRISPR-Cas9 activation library screening, we identified E3 ubiquitin ligase F-box protein 34 (FBXO34) and the substrate of FBXO34, heterogeneous nuclear ribonucleoprotein U (hnRNP U) was identified by affinity purification mass spectrometry, as new host factors related to HIV-1 latent maintenance. Overexpression of FBXO34 or knockout of hnRNP U can activate latent HIV-1 in multiple latent cell lines. FBXO34 mainly promotes hnRNP U ubiquitination, which leads to hnRNP U degradation and abolishment of the interaction between hnRNP U and HIV-1 mRNA. In a latently infected cell line, hnRNP U interacts with the ReV region of HIV-1 mRNA through amino acids 1-339 to hinder HIV-1 translation, thereby, promoting HIV-1 latency. Importantly, we confirmed the role of the FBXO34/hnRNP U axis in the primary CD4 T lymphocyte model, and detected differences in hnRNP U expression levels in samples from patients treated with antiretroviral therapy (ART) and healthy people, which further suggests that the FBXO34/hnRNP U axis is a new pathway involved in HIV-1 latency. These results provide mechanistic insights into the critical role of ubiquitination and hnRNP U in HIV-1 latency. This novel FBXO34/hnRNP U axis in HIV transcription may be directly targeted to control HIV reservoirs in patients in the future.
获得性免疫缺陷综合征（AIDS）无法完全治愈，主要是因为存在潜伏的 HIV-1 储库。然而，我们目前对 HIV-1 潜伏储库建立和维持的分子机制的理解还不全面。在这里，我们使用全基因组 CRISPR-Cas9 激活文库筛选，鉴定出 E3 泛素连接酶 F-box 蛋白 34（FBXO34）及其底物异质核核糖核蛋白 U（hnRNP U），通过亲和纯化质谱法鉴定为与 HIV-1 潜伏维持相关的新宿主因子。FBXO34 的过表达或 hnRNP U 的敲除均可激活多种潜伏细胞系中的潜伏 HIV-1。FBXO34 主要促进 hnRNP U 的泛素化，导致 hnRNP U 的降解，并消除 hnRNP U 与 HIV-1 mRNA 的相互作用。在潜伏感染的细胞系中，hnRNP U 通过氨基酸 1-339 与 HIV-1 mRNA 的 ReV 区域相互作用，阻碍 HIV-1 翻译，从而促进 HIV-1 潜伏。重要的是，我们在原代 CD4 T 淋巴细胞模型中证实了 FBXO34/hnRNP U 轴的作用，并检测到接受抗逆转录病毒治疗（ART）和健康人样本中 hnRNP U 表达水平的差异，这进一步表明 FBXO34/hnRNP U 轴是 HIV-1 潜伏的新途径。这些结果为泛素化和 hnRNP U 在 HIV-1 潜伏中的关键作用提供了机制见解。该新型 FBXO34/hnRNP U 轴在 HIV 转录中可能成为未来直接靶向控制患者 HIV 储库的新途径。
