TABLE 2.
Effects of tyrosine substitutions on the fusiogenic capacity of HIV-1, SIV, and HTLV-1 envelope glycoproteins
| Mutant | Syncytium formationa
|
||
|---|---|---|---|
| COS-M6/HeLa-P4 cocultivationb | COS-M6/sMAGI cocultivationc | CosLTRLacZ/HeLa Tat cocultivationd | |
| pCMV-HIV1 | 100 | ND | ND |
| pCMV-HIV1-Y712A | 167 | ND | ND |
| pSRS | ND | 100 | ND |
| pSRS-Y721A | ND | 145 | ND |
| pCMV-ENV-HTLV | ND | ND | 100 |
| pCMV-ENV-HTLV-Y476S | ND | ND | 182 |
| pCMV-ENV-HTLV-Y479S | ND | ND | 474 |
a
Average of two independent experiments performed in triplicate. ND, not determined.
b
Number of syncytia obtained as a percentage of the number obtained with wild-type pCMV-HIV1 (724 ± 104 syncytia/well).
c
Number of syncytia obtained as a percentage of the number obtained with wild-type pSRS (856 ± 65 syncytia/well).
d
β-Galactosidase activity obtained as a percentage of the activity obtained with wild-type pCMV-ENV-HTLV (500 to 1,000 syncytia/3 × 105 transfected cells).