Functional similarity of HIV-I rev and HTLV-I rex proteins: identification of a new nucleolar-targeting signal in rev protein.
We have tested the functional compatibility between rev protein of human immunodeficiency virus type I (HIV-I) and rex protein of human T-cell lymphotropic virus type I (HTLV-I). Each protein recognized the other's cis-acting sequence, albeit at reduced levels. Both proteins localize predominantly in the nucleolus. We have identified a new nucleolar-targeting signal in rev protein, which was homologous to that of rex protein. The sequence [35-RQARRNRRRRWRERQR-50] in rev protein, when fused to the amino-terminus of beta-galactosidase, directed the hybrid protein to the cell nucleolus. A deletion mutant which lacks several amino acid residues within the signal failed to function in the CAT assay system. These results demonstrate that the nucleolar targeting signals are essential for the functions of Rev and Rex.
Kubota
S
S
Institute for Virus Research, Kyoto University, Japan.
Siomi
H
H
Satoh
T
T
Endo
S
S
Maki
M
M
Hatanaka
M
M
D000595:Amino Acid Sequence; D001483:Base Sequence; D002451:Cell Compartmentation; D002466:Cell Nucleolus; D004252:DNA Mutational Analysis; D004274:DNA, Recombinant; D005786:Gene Expression Regulation; D015694:Gene Products, rev; D005814:Genes, Viral; D006678:HIV / Q000502:physiology*; D015486:HTLV-I Antigens / Q000502:physiology*; D015368:Human T-lymphotropic virus 1 / Q000502:physiology*; D008969:Molecular Sequence Data; D010957:Plasmids; D012045:Regulatory Sequences, Nucleic Acid; D012191:Retroviridae Proteins / Q000502:physiology*; D013329:Structure-Activity Relationship; D015534:Trans-Activators; D014157:Transcription Factors / Q000502:physiology*; D014764:Viral Proteins / Q000502:physiology*; D054321:rev Gene Products, Human Immunodeficiency Virus
D004274:DNA, Recombinant; D015694:Gene Products, rev; D015486:HTLV-I Antigens; D012191:Retroviridae Proteins; D015534:Trans-Activators; D014157:Transcription Factors; D014764:Viral Proteins; D054321:rev Gene Products, Human Immunodeficiency Virus