NMR structure of the (1–51) N‐terminal domain of the HIV‐1 regulatory protein Vpr

Abstract

The human immunodeficiency virus type 1 (HIV-1) genome encodes a highly conserved 16 kDa regulatory gene product, Vpr (viral protein of regulation, 96 amino acid residues), which is incorporated into virions, in quantities equivalent to those of the viral Gag proteins. In the infected cells, Vpr is believed to function in the early phase of HIV-1 replication, including nuclear migration of preintegration complex, transcription of the provirus genome and viral multiplication by blocking cells in the G2 phase. Vpr has a critical role in long-term AIDS disease by inducing infection in nondividing cells such as monocytes and macrophages. Mutations have suggested that the N-terminal domain of Vpr encompassing the first 40 residues could be required for nuclear localization, packaging into virions and binding of transcription factor (TFIIB, Sp1), viral proteins (p6) and cellular proteins (RIP1, UNG, karyopherins). To gain insight into the structure±function relationship of Vpr, (1±51)Vpr was synthesized and its structure analyzed by circular dichroism and two-dimensional 1 H NMR in aqueous trifluoroethanol (30%) solution and refined by restrained molecular dynamics. The structure is characterized by three turns around the first three prolines, Pro5, Pro10, Pro14, followed by a long amphipathic a helix-turna helix (Asp17±Ile46) motif ended by a turn extending from Tyr47 to Thr49. The a helix-turn-a helix motif and the amphipathic helix are well known for being implicated in protein±protein or protein±nucleic acid interaction. Therefore structural characteristics of the (1±51) N-terminal fragment of Vpr could explain why this region of Vpr plays a role in several biological functions of this protein.

Molecular mimicry in inducing DNA damage between HIV-1 Vpr and the anticancer agent, cisplatin

“…It has been shown that residues (15-34) and (54-78) within the full-length Vpr adopt and a-helix structure in the (1-51) Vpr and (52-96) Vpr domains, respectively (Schuler et al, 1999;Wecker and Roques, 1999). We consider it likely that these residues will adopt the same conformation in .…”

Functional and Structural Characterization of Synthetic HIV-1 Vpr That Transduces Cells, Localizes to the Nucleus, and Induces G2 Cell Cycle Arrest

“…. A, primary sequence of sVpr derived from the isolate HIV-1 NL4 -3 is shown below the model of secondary structures identified in Vpr fragments (36,39). Positively or negatively charged residues at the termini, helical structures, and a leucine-rich (LR) zipper-like motif that is presumably involved in the oligomerization of Vpr are indicated.…”

“…Recent structural studies on a 51-residue N-terminal fragment of Vpr revealed no consequences of pH variation on secondary structure (39). These findings implied that the struc- tural motif contributing to the pH-dependent folding of sVpr (Fig.…”

Synthetic Vpr Protein Activates Activator Protein-1, c-Jun N-terminal Kinase, and NF-κB and Stimulates HIV-1 Transcription in Promonocytic Cells and Primary Macrophages

“…Reagents-Synthetic HIV-1 Vpr, Vpr-(1-51), and Vpr-(52-96) proteins (kindly provided by Dr. Bernard P. Roques, U266 INSERM UMR8600 CNRS, Paris France) were used to treat U937 cells, U1 cells, and primary M⌽ (39,68). Anti-HIV-1 Vpr antibody was provided by Dr. Josephine Sire (INSERM U372, Marseille, France).…”