Neuraminidase enzymatic release from sialic acid

Stable Identifier
R-HSA-168870
Type
Reaction [transition]
Species
Homo sapiens
Related Species
Influenza A virus
Compartment
extracellular region, plasma membrane
ReviewStatus
5/5
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Neuraminidase enzymatic release from sialic acid
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The release of influenza virus particles after seperation of the virus and infected cell membrane is an active process. During the budding process, HA on the surface of the newly budding virion binds to cell surface molecules containing sialic acid residues as seen during attachment. The NA glycoproteins neuraminidase activity is essential to cleave the link between the HA and sialic acid on the surface of the host cell from which the budding virus is emeging from. Thus the NA mediated cleavage of sialic acid residues terminally linked to glycoproteins and glycolipids is the final step in releasing the virus particle from the host cell. This essential role of NA in release of virus particle has been demonstrated with the use of NA inhibitors (Palese, 1976; Luo, 1999; Garman, 2004), ts NA mutant viruses (Palese, 1974) and with viruses lacking NA activity (Liu, 1995). In all cases, viruses remain bound to the cell surface in clumps in the absence of NA enzymatic activity, resulting in loss of infectivity. Addition of exogenous sialidase results in virus release and recovery of infectivity. The sialidase activity of the NA is also important for removing sialic acid from the HA on virus particles, if this is not removed, virus particles aggregate.
Literature References
Participants
Input
Output
Participates
as an event of
Event Information
Go Biological Process
viral release from host cell (0019076)
Catalyst Activity

exo-alpha-sialidase activity of NA [extracellular region]

Physical Entity
NA [extracellular region] (Influenza A virus)
Activity
exo-alpha-sialidase activity (GO:0004308)
Disease
Name Identifier Synonyms
influenza DOID:8469 Influenza with other manifestations (disorder), Influenza with other manifestations NOS (disorder), flu, Influenza with other manifestations, Influenza with non-respiratory manifestation (disorder), influenza with non-respiratory manifestation
Authored
Marsh, G  (2007-05-01)
Reviewed
Squires, B  (2007-05-01)
Rush, MG  (2007-05-01)
Created
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