Influenza virus nucleoprotein and matrix protein 2 (NP and M2)

The influenza virus nucleoprotein (NP) and matrix protein 2 (M2) are two distinct, highly conserved viral proteins that play essential roles in the life cycle of the influenza A virus. NP is a multifunctional RNA-binding protein that encapsidates the viral genome into ribonucleoprotein (RNP) complexes, which are critical for viral RNA replication, transcription, and nuclear trafficking. M2 is a proton-selective ion channel, or viroporin, that facilitates the uncoating of the virus by acidifying the virion interior and also participates in viral assembly and budding. While M2 is the target of the adamantane class of drugs (amantadine and rimantadine), widespread resistance, particularly the S31N mutation, has rendered these drugs largely ineffective against circulating strains. NP has emerged as a promising alternative target for small-molecule inhibitors, such as nucleozin, which aim to disrupt viral replication by inducing NP aggregation or blocking its nuclear transport. Both proteins are also key components in the development of universal influenza vaccines due to their high sequence conservation across various influenza strains and subtypes.

Other names

NucleoproteinNPProtein NMatrix protein 2M2 ion channelM2 proton channelViroporin M2

M2 ion channel blockade (inhibition of proton transport); NP aggregation induction; NP nuclear export inhibition; disruption of NP-NP interaction