Severe acute respiratory syndrome coronavirus 2 spike protein (JN.1 variant) (SARS-CoV-2 S protein (JN.1))

The SARS-CoV-2 spike protein of the JN.1 variant is the primary surface glycoprotein responsible for the virus's ability to infect human cells. JN.1, a descendant of the BA.2.86 (Pirola) lineage, is characterized by a significant number of mutations, most notably the L455S mutation in the receptor-binding domain (RBD), which significantly enhances its ability to evade neutralizing antibodies compared to its predecessors (Wang et al., 2024, Lancet Infectious Diseases). This protein mediates viral entry by binding to the human angiotensin-converting enzyme 2 (ACE2) receptor and subsequently facilitating the fusion of the viral and host cell membranes (WHO, 2023). As the dominant target for the host immune response, the JN.1 spike protein is the central component of updated COVID-19 vaccines, such as the JN.1-specific formulations recommended by the FDA and WHO for the 2024-2025 period (FDA, 2024). Its rapid evolution presents a continuous challenge for therapeutic efficacy, as mutations can alter the protein's conformation and reduce the binding affinity of existing monoclonal antibodies like Sotrovimab or Cilgavimab (CDC, 2024). Understanding the structural and functional nuances of the JN.1 spike is critical for monitoring transmission dynamics and tailoring medical countermeasures against evolving SARS-CoV-2 variants.

Other names

JN.1 spike proteinSARS-CoV-2 JN.1 S proteinBA.2.86.1.1 spike proteinPirola-descendant spike

Binding to the spike protein to sterically hinder the interaction between the viral receptor-binding domain (RBD) and the host cell angiotensin-converting enzyme 2 (ACE2) receptor, thereby neutralizing the virus and preventing cellular entry (NIH, 2024).