Feline infectious peritonitis virus membrane protein (M protein) (M protein)

The Feline infectious peritonitis virus (FIPV) membrane protein, historically referred to as the small integral membrane glycoprotein, is the most abundant structural protein of the viral envelope [1, 4]. It is a triple-spanning membrane protein that plays a central role in virion morphogenesis by coordinating the assembly of other structural proteins, including the Spike (S), Envelope (E), and Nucleocapsid (N) proteins [7, 11]. In the pathogenesis of FIP, the M protein is a key immunological target; monoclonal antibodies like FK50-4 have been demonstrated to neutralize the virus and prevent infection in feline macrophages, the primary host cells for FIPV [1]. Unlike the Spike protein, which is often implicated in antibody-dependent enhancement (ADE), the M protein contains conserved epitopes that are candidates for safer vaccine designs and therapeutic antibodies [2, 8]. While research into small-molecule inhibitors for the M protein is ongoing, it remains a critical target for disrupting the viral life cycle and preventing the fatal progression of feline infectious peritonitis [4, 16].

Other names

Small integral membrane glycoproteinMembrane glycoproteinMatrix proteinE1 proteinFeline coronavirus membrane protein

Neutralization of viral entry and replication; interference with virion assembly and budding.