West Nile virus premembrane protein (prM)

The **West Nile virus premembrane protein (prM)** is a structural protein encoded by the West Nile virus (WNV), a member of the *Flaviviridae* family[1][8]. The prM protein acts as a chaperone for the viral envelope (E) glycoprotein, ensuring correct folding of the E protein and preventing premature fusion of viral and host membranes during viral egress[1][8]. Immature WNV particles are composed of the E and prM proteins arranged as heterodimers; the pr segment of prM covers the fusion loop of E, blocking fusion activity[8]. Viral maturation occurs as prM is cleaved by host cell furin in the trans-Golgi network, a step essential for producing fully infectious virus particles; after cleavage, only a small “M” protein remains associated with the virion, while the "pr" fragment is released[8]. Residues in prM can modulate viral virulence and particle secretion, and mutations have been shown experimentally to alter pathogenesis and virulence in animal models[1]. The prM protein is not a conventional drug target such as an enzyme or receptor, but its essential role in viral maturation makes it a theoretical target for antiviral strategies or vaccine development, e.g., by blocking prM cleavage or interfering with prM-E interactions to prevent formation of infectious virions[1][8]. There are currently no approved drugs that directly target prM, nor are there established premembrane protein-specific biomarkers used in clinical monitoring. While prM is essential for West Nile virus infectivity, targeting viral structural proteins for therapy can be challenging due to viral variability and potential for escape mutations[1].

Other names

prM proteinpremembrane proteinprecursor membrane proteinprM of West Nile virus

Not directly drug-targeted; theoretically, inhibitors could block prM cleavage/maturation or its chaperone function to reduce infectious virus production