Effects of brefeldin A on the expression and transport of influenza A virus haemagglutinin, M1 and M2 proteins within the cell.

Brefeldin A (BFA) decreased the expression of influenza A virus haemagglutinin (HA) and M2 protein on the plasma membrane of virus-infected MDCK cells. It caused a retention of M1 protein in the cell nucleus and a decrease of its expression on the plasma membrane. On the other hand, an increased labelling of the cytoplasmic domain of M2 protein on the plasma membrane in BFA-treated cells was observed in contrast to the labelling in BFA-untreated cells. The effects of BFA on the microtubules and cellular motors are discussed.