West Nile virus pre-membrane protein (prM) (prM)

The West Nile virus pre-membrane protein (prM) is a critical structural component of the West Nile virus (WNV) virion, playing a dual role in viral assembly and maturation. During the assembly process in the endoplasmic reticulum, prM acts as a molecular chaperone for the envelope (E) protein, forming a heterodimer that prevents the E protein from undergoing premature, low-pH-induced conformational changes during transport through the acidic secretory pathway (Source: UniProt P06935, PubMed PMID: 11448161). As the immature virion moves through the trans-Golgi network, the host protease furin cleaves prM into the 'pr' peptide and the mature 'M' protein. This cleavage is a prerequisite for the virion to become fully infectious, as it triggers a structural reorganization of the E proteins on the viral surface (Source: PubMed PMID: 18451131). Because of its essential role in the viral life cycle and its exposure on the surface of immature particles, prM is a primary target for the development of recombinant vaccines and diagnostic serological assays. However, antibodies against prM are often non-neutralizing and have been implicated in antibody-dependent enhancement (ADE), a phenomenon where sub-neutralizing antibodies facilitate viral entry into Fc-receptor-bearing cells, potentially complicating vaccine design (Source: PubMed PMID: 20554777).

Other names

prM proteinPre-membrane proteinprM/M proteinSmall envelope protein M

Vaccines targeting prM induce neutralizing and non-neutralizing antibodies that interfere with viral assembly, maturation, or entry into host cells. Experimental inhibitors may target the furin-mediated cleavage of prM to M, which is essential for virion infectivity (Source: PubMed PMID: 12163516, 22438551).