The connection between an influenza virus surface protein and a host cell lipid has been discovered by University of Maine and National Institutes of Health researchers. Confirmation of direct interaction between the protein and lipid could lead to new antiviral therapies.

The UMaine-led research team is testing a hypothesis that a certain region within the protein hemagglutinin (HA) — its cytoplasmic tail — could be the site of interaction with the host cell lipid PIP2. Because of the stability of the HA tail, there is potential for a targeted treatment that could continue to work, despite the frequent mutations of other parts of HA, according to the scientists, who reported their discovery in Biophysical Journal.

“Our findings show for the first time a connection between the influenza virus surface protein HA (the H in H1N1) and the host cell lipid PIP2,” says UMaine professor of physics Samuel Hess, the team’s lead scientist. “With further single-molecule microscopy experiments, we are now testing the hypothesis that a certain region within HA could be the site of interaction with PIP2.”

Using confocal and super-resolution microscopy, the latter a patented technology developed by Hess, the researchers imaged HA and PIP2 in several living cell types and observed that they sometimes occupied the same regions in the plasma membrane defining the cell exterior. HA and PIP2 also were observed affecting each other’s motions.