The fd phage and a peptide derived from its p8 coat protein interact with the HIV-1 Tat-NLS and inhibit its biological functions.
Filamentous fd bacteriophages are used to construct phage-display peptide libraries, which have been instrumental in selecting peptides that interact with specific domains within target molecules. Here we demonstrate that the fd bacteriophage itself, as well as NTP8 - a synthetic peptide derived from it and bearing amino acids 1-20 of the phage p8 protein - interact with the nuclear localization signal (NLS) of the HIV-1 Tat protein. Accordingly, fd bacteriophage and the NTP8 peptide inhibit binding mediated by the Tat-NLS to the nuclear-import receptor importin beta and Tat-NLS-mediated translocation into cell nuclei. The NTP8 peptide, at 100 microM concentration, also caused about 50% inhibition of HIV-1 propagation in cultured cells. The fd bacteriophage prevents heparan sulfate proteoglycans-mediated uptake of extracellular Tat by target cells and consequently transactivation of a chloramphenicol acetyltransferase (CAT) reporter gene. A BSA-NTP8 conjugate inhibits Tat-NLS-mediated binding to heparin immobilized on a BIAcore surface. BLAST analysis of the NTP8 amino-acid sequence revealed similarity to sequences in several human proteins, including ADA2 and CD53.
Krichevsky
A
A
Department of Biological Chemistry, The Alexander Silberman Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem 91904, Israel. akrichevsky@notes.cc.sunysb.edu
Rusnati
M
M
Bugatti
A
A
Waigmann
E
E
Shohat
S
S
Loyter
A
A
D019380:Anti-HIV Agents / Q000378:metabolism; D017104:Bacteriophage M13 / Q000737:chemistry*; D036022:Capsid Proteins / Q000378:metabolism*; D015696:Gene Products, tat / Q000378:metabolism*; D015497:HIV-1 / Q000737:chemistry* / Q000502:physiology; D006367:HeLa Cells; D006801:Humans; D019913:Nuclear Localization Signals / Q000502:physiology; D010456:Peptides, Cyclic / Q000494:pharmacology; D054322:tat Gene Products, Human Immunodeficiency Virus
D019380:Anti-HIV Agents; D036022:Capsid Proteins; D015696:Gene Products, tat; D019913:Nuclear Localization Signals; D010456:Peptides, Cyclic; D054322:tat Gene Products, Human Immunodeficiency Virus