Miyakawa Kei, Tanaka Kiho, Ino Yoko, Kimura Yayoi, Kameya Taichi, Mizukoshi Fuminori, Nishi Mayuko, Yokoyama Masaru, Nakabayashi Jun, Nomaguchi Masako, Sato Hironori, Kimura Hirokazu, Akari Hirofumi, Miura Tomoyuki, Takaoka Akinori, Hasegawa Hideki, Matano Tetsuro, Minamishima Yoji Andrew, Ryo Akihide
AIDS Research Center, National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, Japan.
Influenza Research Center, National Institute of Infectious Diseases, Japan Institute for Health Security, Tokyo, Japan.
PLoS Pathog. 2025 Jun 16;21(6):e1013241. doi: 10.1371/journal.ppat.1013241. eCollection 2025 Jun.
HIV-2 viral protein X (Vpx) plays a pivotal role in antagonizing the host restriction factors, including SAMHD1 and components of the HUSH complex, to facilitate viral replication. However, the regulatory mechanisms controlling Vpx stability remain unclear. In this study, we identify the von Hippel-Lindau (VHL) tumor suppressor as a novel E3 ubiquitin ligase that specifically targets Vpx for proteasomal degradation. Mechanistically, we demonstrate that VHL-mediated degradation depends on the oxygen-dependent hydroxylation of Vpx at proline residue 41 (Pro41), a modification catalyzed by prolyl hydroxylase domain-containing protein 3 (PHD3). Using an integrated approach combining crosslinking mass spectrometry and molecular modeling analyses, we elucidate the structural architecture of the PHD3-Vpx complex, revealing the spatial orientation of the catalytic domain of PHD3 required for Pro41 hydroxylation. Furthermore, we establish the physiological significance of this pathway in human macrophages, where pharmacological inhibition or genetic ablation of VHL or PHD3 enhances HIV-2 infection by facilitating Vpx-mediated SAMHD1 degradation. Collectively, our findings unveil a previously unrecognized oxygen-sensitive regulatory mechanism influencing HIV-2 infection and suggest novel therapeutic strategies targeting Vpx stability through modulation of its prolyl hydroxylation status.
HIV-2病毒蛋白X（Vpx）在对抗宿主限制因子（包括SAMHD1和HUSH复合物的组分）以促进病毒复制方面发挥着关键作用。然而，控制Vpx稳定性的调节机制仍不清楚。在本研究中，我们鉴定出von Hippel-Lindau（VHL）肿瘤抑制因子是一种新型E3泛素连接酶，它特异性地靶向Vpx进行蛋白酶体降解。从机制上来说，我们证明VHL介导的降解依赖于Vpx脯氨酸残基41（Pro41）处的氧依赖性羟基化，这是一种由含脯氨酰羟化酶结构域蛋白3（PHD3）催化的修饰。通过结合交联质谱和分子模拟分析的综合方法，我们阐明了PHD3-Vpx复合物的结构架构，揭示了Pro41羟基化所需的PHD3催化结构域的空间取向。此外，我们确定了该途径在人类巨噬细胞中的生理意义，其中VHL或PHD3的药理学抑制或基因敲除通过促进Vpx介导的SAMHD1降解增强HIV-2感染。总的来说，我们的研究结果揭示了一种以前未被认识的影响HIV-2感染的氧敏感调节机制，并提出了通过调节其脯氨酰羟基化状态来靶向Vpx稳定性的新治疗策略。
