Influenza B virus neuraminidase (Yamagata lineage) (NA)

Influenza B virus neuraminidase (NA) is a tetrameric type II transmembrane glycoprotein that functions as a sialidase, essential for the release of progeny virions from infected host cells (UniProt: P03474). By cleaving terminal sialic acid residues from cellular receptors and viral hemagglutinin, NA prevents the aggregation of viruses and facilitates their movement through the respiratory mucus (PubMed: PMC4810771). The Yamagata lineage is one of two antigenically distinct lineages of Influenza B that have circulated globally, though it has not been detected in the wild since March 2020 (CDC: Influenza Virus Genome). NA is the primary target for neuraminidase inhibitors (NAIs) such as oseltamivir, zanamivir, and peramivir, which bind to the highly conserved active site to block enzymatic activity (DrugBank: DB00198). Resistance to these drugs can emerge through specific amino acid substitutions in the NA protein, such as H273Y, which reduce the binding affinity of the inhibitor (PubMed: 25605361). The enzyme's structure consists of a cytoplasmic tail, a transmembrane domain, a stalk, and a globular head containing the catalytic site (PubMed: PMC7120342). Effective inhibition of NA results in the trapping of new virions on the surface of the infected cell, effectively halting the progression of the infection (StatPearls: NBK539909). Monitoring for mutations in the NA gene is crucial for public health surveillance to ensure the continued efficacy of available antiviral treatments (WHO: Influenza Laboratory Surveillance).

Other names

NeuraminidaseSialidaseB/Yamagata NAExo-alpha-sialidaseNA

Neuraminidase inhibition; prevents the cleavage of terminal sialic acid residues, thereby inhibiting the release of progeny virions from infected host cells and preventing further viral spread.