Wani Mashhood M, Cooper Joanna M, Migliorini Mary, Strickland Dudley K
The Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland, USA.
The Center for Vascular and Inflammatory Diseases, University of Maryland School of Medicine, Baltimore, Maryland, USA; Department of Physiology, University of Maryland School of Medicine, Baltimore, Maryland, USA.
J Biol Chem. 2025 May 9;301(6):110227. doi: 10.1016/j.jbc.2025.110227.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent of COVID-19, employs the viral spike (S) protein to associate with host cells. While angiotensin-converting enzyme 2 (ACE2) is a major receptor for the SARS-CoV-2 spike protein, evidence reveals that other cellular receptors may also contribute to viral entry. We interrogated the role of the low-density lipoprotein receptor-related protein 1 (LRP1) in the involvement of SARS-CoV-2 viral entry. Employing surface plasmon resonance studies, we demonstrated high-affinity binding of the trimeric SARS-CoV-2 spike protein to purified LRP1. Further, we observed high-affinity interaction of the SARS-CoV-2 spike protein with other low-density lipoprotein receptor (LDLR) family members as well, including LRP2 and the very low-density lipoprotein receptor (VLDLR). Binding of the SARS-CoV-2 spike protein to LRP1 was mediated by its receptor-binding domain (RBD). Several LRP1 ligands require surface exposed lysine residues for their interaction with LRP1, and chemical modification of lysine residues on the RBD with sulfo-NHS-acetate ablated binding to LRP1. Using cellular model systems, we demonstrated that cells expressing LRP1, but not those lacking LRP1, rapidly internalized purified I-labeled S1 subunit of the SARS-CoV-2 spike protein. LRP1-mediated internalization of the I-labeled S1 subunit was enhanced in cells expressing ACE2. By employing pseudovirion particles containing a murine leukemia virus core and luciferase reporter that express the SARS-CoV-2 spike protein on their surface, we confirmed that LRP1 facilitates ACE2-mediated psuedovirion endocytosis. Together, these data implicate LRP1 and perhaps other LDLR family members as host factors for SARS-CoV-2 infection.
严重急性呼吸综合征冠状病毒2（SARS-CoV-2）是新冠病毒病（COVID-19）的病原体，它利用病毒刺突（S）蛋白与宿主细胞结合。虽然血管紧张素转换酶2（ACE2）是SARS-CoV-2刺突蛋白的主要受体，但有证据表明其他细胞受体也可能参与病毒进入过程。我们研究了低密度脂蛋白受体相关蛋白1（LRP1）在SARS-CoV-2病毒进入过程中的作用。通过表面等离子体共振研究，我们证明了三聚体SARS-CoV-2刺突蛋白与纯化的LRP1具有高亲和力结合。此外，我们还观察到SARS-CoV-2刺突蛋白与其他低密度脂蛋白受体（LDLR）家族成员，包括LRP2和极低密度脂蛋白受体（VLDLR），也存在高亲和力相互作用。SARS-CoV-2刺突蛋白与LRP1的结合是由其受体结合域（RBD）介导的。几种LRP1配体需要表面暴露的赖氨酸残基来与LRP1相互作用，用磺基-NHS-乙酸对RBD上的赖氨酸残基进行化学修饰会消除与LRP1的结合。使用细胞模型系统，我们证明表达LRP1的细胞能快速内化纯化的SARS-CoV-2刺突蛋白的I标记S1亚基，而缺乏LRP1的细胞则不能。在表达ACE2的细胞中，LRP1介导的I标记S1亚基的内化作用增强。通过使用含有鼠白血病病毒核心和荧光素酶报告基因的假病毒颗粒，这些颗粒在其表面表达SARS-CoV-2刺突蛋白，我们证实LRP1促进ACE2介导的假病毒内吞作用。总之，这些数据表明LRP1以及可能的其他LDLR家族成员是SARS-CoV-2感染的宿主因子。
