Evolution’s Fast Lane - The Monster at Our Door: The Global Threat of Avian Flu - page 3

Figure 1 The Influenza Virus
After HA turns the lock, the influenza virus enters the host cell clothed in some of the host's own
plasma membrane. The M2 channel protein then pumps ions into the interior of this capsule ( endosome ).
The increased acidity dissolves the membrane and releases influenza's genome segments (the RNPs) into
the host cell. The RNPs then flock to the nucleus, where viral RNA replication takes place. Like all vir-
uses, influenza hijacks the host's biosynthetic machinery to produce several hundred copies of itself; in
human influenza, the virus also issues instructions to stop making the proteins that the host cell requires
for its own survival.