Table 3.
Polykaryon formation by cells expressing the WSN HA and various other NAs
| Expressed protein* | Cell treatment
|
|||
|---|---|---|---|---|
| Trypsin (0.5 μg/ml) | FCS (1%) | Bovine plasminogen (50 μg/ml) | Human plasminogen (5 μg/ml) | |
| HA only | + | − | − | − |
| HA/WSN NA | + | + | + | + |
| HA/HK NA | + | − | − | − |
| HA/WSN NA− | + | + | + | + |
| HA/WSN NA K453R | + | − | − | − |
| HA/WSN NA K453L | + | − | − | − |
| HA/WSN NA R146N | + | − | − | − |
| HA/WS NA | + | − | − | − |
| HA/WS NA N146R | + | + | + | + |
Polykaryon formation was assayed as described in the legend to Fig. 2. −, no polykaryon formation; +, 100% polykaryon formation.
*
NA− denotes a mutant with loss of NA enzymatic activity due to a Glu-to-Gln change at position 227. The WSN NA K453R mutant is defined by conversion of the carboxyl-terminal Lys-to-Arg; K453L, by conversion of the carboxyl-terminal Lys to Leu; and R146N, by the presence of a potential glycosylation site at position 146. The WS NA N146R is defined by the loss of a potential glycosylation site at position 146.