title: Dynamic interactions of the HIV-1 Tat with nucleic acids are critical for Tat activity in reverse transcription.
abstract: The HIV-1 transactivator of transcription (Tat) protein is thought to stimulate reverse transcription (RTion). The Tat protein and, more specifically, its (44-61) domain were recently shown to promote the annealing of complementary DNA sequences representing the HIV-1 transactivation response element TAR, named dTAR and cTAR, that plays a key role in RTion. Moreover, the kinetic mechanism of the basic Tat(44-61) peptide in this annealing further revealed that this peptide constitutes a representative nucleic acid annealer. To further understand the structure-activity relationships of this highly conserved domain, we investigated by electrophoresis and fluorescence approaches the binding and annealing properties of various Tat(44-61) mutants. Our data showed that the Tyr47 and basic residues of the Tat(44-61) domain were instrumental for binding to cTAR through stacking and electrostatic interactions, respectively, and promoting its annealing with dTAR. Furthermore, the annealing efficiency of the mutants clearly correlates with their ability to rapidly associate and dissociate the complementary oligonucleotides and to promote RTion. Thus, transient and dynamic nucleic acid interactions likely constitute a key mechanistic component of annealers and the role of Tat in the late steps of RTion. Finally, our data suggest that Lys50 and Lys51 acetylation regulates Tat activity in RTion.
authors.affiliation: Laboratoire de Biophotonique et Pharmacologie, UMR-CNRS 7213, Faculté de Pharmacie, Université de Strasbourg, Illkirch 67401, France and Laboratoire de Biologie et Pharmacologie Appliquée, UMR-CNRS 8113, Ecole Normale Supérieure de Cachan, Cachan 94235, France.
authors.forename: Christian
authors.initials: C
authors.lastname: Boudier
authors.forename: Nicolas
authors.initials: N
authors.lastname: Humbert
authors.forename: Françoise
authors.initials: F
authors.lastname: Chaminade
authors.forename: Yingying
authors.initials: Y
authors.lastname: Chen
authors.forename: Hugues
authors.initials: H
authors.lastname: de Rocquigny
authors.forename: Julien
authors.initials: J
authors.lastname: Godet
authors.forename: Olivier
authors.initials: O
authors.lastname: Mauffret
authors.forename: Philippe
authors.initials: P
authors.lastname: Fossé
authors.forename: Yves
authors.initials: Y
authors.lastname: Mély
mesh_terms: D000595:Amino Acid Sequence; D001483:Base Sequence; D016325:HIV Long Terminal Repeat; D015497:HIV-1; D008969:Molecular Sequence Data; D009690:Nucleic Acid Conformation; D009841:Oligonucleotides / Q000737:chemistry; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D048348:Reverse Transcription; D054322:tat Gene Products, Human Immunodeficiency Virus / Q000737:chemistry / Q000378:metabolism*
chemical_list: D009841:Oligonucleotides; D010455:Peptides; D054322:tat Gene Products, Human Immunodeficiency Virus