Table 2.

Effects of tyrosine substitutions on the fusiogenic capacity of HIV-1, SIV, and HTLV-1 envelope glycoproteins

MutantSyncytium formationa
COS-M6/HeLa-P4 cocultivationbCOS-M6/sMAGI cocultivationcCosLTRLacZ/HeLa Tat cocultivationd
pCMV-HIV1100NDND
pCMV-HIV1-Y712A167NDND
pSRSND100ND
pSRS-Y721AND145ND
pCMV-ENV-HTLVNDND100
pCMV-ENV-HTLV-Y476SNDND182
pCMV-ENV-HTLV-Y479SNDND474
  • 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).