Table 1.
Role of IAV proteins in IAV pathogenesis and host cell death
| IAV Protein | Primary viral function | Role in cell death |
|---|---|---|
| NP | –Nucleocapsid protein which provides virion structure –Mediates genome replication through RNA binding activity |
–Possibly inhibits anti-apoptotic host proteins such as AP1535 |
| NS1 | –Antagonises host IFN response –Mediates vRNA synthesis, mRNA splicing and translation |
–Prevents the early induction of apoptosis by inhibiting pro-apoptotic proteins such as Scribble26,28 –Induces apoptosis downstream of FasR21 |
| NS2 (NEP) | –Mediates export of viral RNA from the nucleus to the cytoplasm | – |
| PA | –Part of the RNA polymerase complex, required for RNA synthesis | – |
| PB1 | –Part of the RNA polymerase complex, required for RNA synthesis | – |
| PB2 | –Part of the RNA polymerase complex, required for RNA synthesis | – |
| PA-X | –Impairs cellular host gene expression | – |
| PB1-F2 | –Intrinsically induces apoptosis | –Mediates permeabilisation of the mitochondrial membrane through ANT3 and VDAC129 |
| PB1-N40 | –Currently unclear | – |
| NA | –Cleaves sialic acid to release viral progeny | – |
| HA | –Mediates host cell entry by binding membrane receptors | –Some variants may impair IAV-induced necroptosis19 |
| M1 | –Provides structure and stability to the virion | – |
| M2 | –Ion channel which aids viral assembly and budding | –Interacts with autophagy regulators and blocks autophagosome fusion, in turn enhancing apoptosis41 |