An evolutionarily conserved splice generates a secreted env-Bet fusion protein during human foamy virus infection.
Foamy viruses (spumaretroviruses) represent a retroviral genus which exhibits unusual features relating it to pararetroviruses. Previously, we reported the existence of a protein species harboring Env, Bel, and Bet epitopes in human foamy virus (HFV)-infected cells (M. L. Giron, F. Rozain, M. C. Debons-Guillemin, M. Canivet, J. Périès, and R. Emanoil-Ravier, J. Virol. 67:3596-3600, 1993). Here, we identify this protein as a 160-kDa Env-Bet fusion glycoprotein (gp160) translated from an mRNA species harboring a highly conserved splice site which deletes the membrane anchor domain of Env and fuses the env open reading frame with that of bel1/bet. While gp160 and Bet proteins were both secreted into the supernatant, only Bet was taken up by recipient cells. Since Bet plays a key role in the switch from lytic to chronic infection, secretion of Bet and gp160, together with cellular uptake of Bet, could be highly relevant for both immune response and development of HFV infection in vivo.
Giron
M L
ML
CNRS UPR 9051, University of Paris VII, Hôpital Saint-Louis, 75475 Paris Cedex 10, France.
de Thé
H
H
Saïb
A
A
D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D017124:Conserved Sequence; D006224:Cricetinae; D015752:Genes, env; D006801:Humans; D008969:Molecular Sequence Data; D012326:RNA Splicing; D012192:Retroviridae Infections / Q000378:metabolism*; D012191:Retroviridae Proteins / Q000235:genetics* / Q000378:metabolism*; D016092:Spumavirus / Q000235:genetics / Q000378:metabolism*; D014764:Viral Proteins / Q000235:genetics
D012191:Retroviridae Proteins; D014764:Viral Proteins; C080099:bet protein, human foamy virus