Binding of human prothymosin alpha to the leucine-motif/activation domains of HTLV-I Rex and HIV-1 Rev.
Rex of human T-cell leukemia virus type I (HTLV-I) and Rev of human immunodeficiency virus 1 (HIV-1) are post-transcriptional regulators of viral gene expression. By means of affinity chromatography, we purified an 18-kDa cellular protein that bound to the conserved leucine-motif/activation domain of HTLV-I Rex or HIV-1 Rev. The protein that was purified through a Rev-affinity column was found to bind to Rex immunoprecipitated with anti-Rex IgG from an HTLV-I-producing cell line. We analyzed the purified approximately 18-kDa protein biochemically and identified it as prothymosin alpha. The binding activity of prothymosin alpha to Rev or Rex was completely abolished when the epsilon-amino groups of its lysine residues were chemically modified by N-succinimidyl-3-(4-hydroxy-3,5-diodo- phenyl)propionate. The functional relationship between the nuclear protein prothymosin alpha and Rex-Rev is discussed.
Kubota
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Laboratory of Molecular Virology and Carcinogenesis, NCI-Frederick Cancer Research and Development Center, MD 21702, USA.
Adachi
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Y
Copeland
T D
TD
Oroszlan
S
S
D000595:Amino Acid Sequence; D001665:Binding Sites; D002352:Carrier Proteins / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D002460:Cell Line; D002846:Chromatography, Affinity; D015694:Gene Products, rev / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D016370:Gene Products, rex / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D015497:HIV-1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D015368:Human T-lymphotropic virus 1 / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008969:Molecular Sequence Data; D011233:Precipitin Tests; D011485:Protein Binding; D011498:Protein Precursors / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D017386:Sequence Homology, Amino Acid; D013947:Thymosin / Q000031:analogs & derivatives* / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism; D054321:rev Gene Products, Human Immunodeficiency Virus
D002352:Carrier Proteins; D015694:Gene Products, rev; D016370:Gene Products, rex; D011498:Protein Precursors; C040782:prothymosin alpha; D054321:rev Gene Products, Human Immunodeficiency Virus; D013947:Thymosin