Influenza A internal proteins

Influenza A "internal proteins" refers collectively to the set of proteins encoded by segments of the influenza A viral genome that are located inside the virion, distinct from the surface glycoproteins hemagglutinin (HA) and neuraminidase (NA). This includes the polymerase complex—polymerase basic protein 2 (PB2), polymerase basic protein 1 (PB1), and polymerase acidic protein (PA)—responsible for viral RNA transcription and replication; the nucleoprotein (NP), which encapsidates viral RNA; the matrix protein 1 (M1), which forms a structural layer inside the viral envelope; the matrix protein 2 (M2), a proton channel important for viral uncoating; and nonstructural proteins including NS1 (which antagonizes the host interferon response) and NEP/NS2 (involved in viral ribonucleoprotein export). These proteins are essential for the replication, assembly, and pathogenicity of influenza A, and several individual internal proteins are targets for antiviral drug development.

M2 ion channel blockade prevents viral uncoating by stopping acidification required for viral RNP release into host cytoplasm. (Potential, under investigation): Inhibitors of viral polymerase–protein–protein interactions, such as PB1–PB2 complex, but these are not yet clinically approved.