NA Functional Roles in Replication
What is the role of N neuraminidase proteins of influenza viruses?
An important function of the NA protein is to remove sialic acid from glycoproteins. Sialic acid is present on many cell surface proteins as well as on the viral glycoproteins; it is the cell receptor to which influenza virus attaches via the HA protein.
What is the role of the NA neuraminidase protein in influenza infection quizlet?
The main function of the Neuraminidase (NA) might be to remove receptors for influenza virus from newly formed virus particles so allowing these to be released and spread the infection.
Viral neuraminidase cleaves terminal sialic acid residues from glycan structures on the surface of the infected cell. This promotes the release of progeny viruses and the spread of the virus from the host cell to uninfected surrounding cells.
What does the N neuraminidase designation indicate?
The designation “H1N1” indicates unique traits, which exhibit characteristics that identify the virus to the immune system and allows for attachment and replication of the virus. The “H” (hemagglutinin) and the “N” (neuraminidases) are both proteins that are found on the outer shell or envelope of the virus.
Which one is not useful in the treatment of virus?
Antibiotics cannot kill viruses because bacteria and viruses have different mechanisms and machinery to survive and replicate. The antibiotic has no “target” to attack in a virus. However, antiviral medications and vaccines are specific for viruses.
What is the role of hemagglutinin in influenza infections?
The hemagglutinin glycoprotein of influenza virus has important functions in the initiation of infection: it mediates adsorption of the virus particles to cell surface receptors and is responsible for the subsequent uncoating of the virus by a process of fusion between viral and host membranes.
What is the role of neuraminidase during infection of the host?
Neuraminidase cleaves the sialic acid molecule, thereby freeing the virus to infect other cells in the host organism. Antibodies against neuraminidase that are generated by the host’s immune system following infection bind to a portion of the neuraminidase antigen known as an epitope.
Which of the following are symptoms of influenza infection?
- Aching muscles.
- Chills and sweats.
- Dry, persistent cough.
- Shortness of breath.
- Tiredness and weakness.
- Runny or stuffy nose.
Antigenic drift: A subtle change in the surface glycoprotein (either hemagglutinin or neuraminidase) caused by a point mutation or deletion in the viral gene. This results in a new strain that requires yearly reformulation of the seasonal influenza vaccine.
Is neuraminidase a fusion protein?
These two functions, binding and fusion, are mediated by one or multiple envelope glycoproteins. … In contrast, paramyxoviruses have two glycoproteins that mediate these functions: hemagglutinin-neuraminidase (HN) or hemagglutinin is responsible for binding, and the fusion (F) protein induces fusion (16).
What do neuraminidase inhibitors do?
Neuraminidase inhibitors are a new class of antiviral drugs that inhibit influenza A and B viruses. Zanamivir is approved for treatment of uncomplicated acute illness caused by influenza virus in persons aged greater than or equal to 12 years who have been symptomatic for no more than 2 days.