Veterinary Research Institute, Lahore 54600, Pakistan.
*Corresponding Author: qclabvri@yahoo.com, Tel. 00923224742353

ABSTRACT
Influenza virus infections are important both epidemically as well as pandemically and have great threat to avian species and humans especially, from last few decades. Certain pandemics of influenza virus have been reported causing severe damages. Once the host infected with influenza virus, it becomes immune-¬compromised and susceptible to secondary bacterial infections. Genome of influenza virus consists of eight segments of RNA, producing eleven types of proteins. Virulence and pathogenecity greatly depend upon its surface glycoproteins such as neuraminidase (NA) and hemagglutinin (HA). Other proteins of influenza virus are nucleoprotein (NP), 2 types of matrix proteins (M1 and M2), 2 non-structural proteins (NS1 and NS2), and polymerase subunit (PA) i.e. PB1, PB1‐F2 and PB2. NP and M proteins are responsible for further classification of Influenza virus into influenza virus A, influenza virus B and influenza virus C. The aim of the review article is to discuss the structural importance of proteins of influenza A viruses.

Key Words: Neuraminidase, Hemagglutinin, Nucleoprotein, Non-structural proteins, Polymerase subunit, PB1, PB1-F2 and PB2