| Function |
Influenza viruses are divided into three types, designated A, B and C. Influenza types A and B are responsible for epidemics of respiratory illness that occur almost every winter and are often associated with increased rates for hospitalization and death. Influenza type A viruses are divided into subtypes based on differences in two viral proteins called hemagglutinin (HA) and neur amini-dase (NA). The influenza virus matrix 1, otherwise known as m1, is a critical protein required for assembly and budding. Hemagglutinin (HA) and neuramini-dase (NA) interact with influenza virus m1; HA associates with m1 via its cytoplasmic tail and transmembrane domain. The m2 and NB proteins are critical in the replication cycle of influenza viruses. The m2 channel protein is an essential component of the viral envelope because of its ability to form a highly selective, pH-regulated, proton-conducting channel. The m2 channel allows protons to enter the interior of the virus, and acidification weakens the interaction of the m1 protein with the ribonuclear core. |
