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Query: UMLS:C0019693 (HIV)
 170,526 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

During human immunodeficiency virus type 1 (HIV-1) assembly, tRNA(Lys) isoacceptors are selectively incorporated into virions and tRNA(Lys)3 is used as the primer for reverse transcription. We show herein that the tRNA(Lys)-binding protein, lysyl-tRNA synthetase (LysRS), is also selectively packaged into HIV-1. The viral precursor protein Pr55gag alone will package LysRS into Pr55gag particles, independently of tRNA(Lys). With the additional presence of the viral precursor protein Pr160gag-pol, tRNA(Lys) and LysRS are both packaged into the particle. While the predominant cytoplasmic LysRS has an apparent M(r) of 70,000, viral LysRS associated with tRNA(Lys) packaging is shorter, with an apparent M(r) of 63,000. The truncation occurs independently of viral protease and might be required to facilitate interactions involved in the selective packaging and genomic placement of primer tRNA.
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PMID:Incorporation of lysyl-tRNA synthetase into human immunodeficiency virus type 1. 1133 84

During human immunodeficiency virus type 1 (HIV-1) assembly, tRNA(Lys) is selectively packaged into the virus, where tRNA(Lys3) serves as the primer for reverse transcription. Lysyl-tRNA synthetase is also selectively incorporated into HIV-1 and is therefore a strong candidate for being the signal by which viral proteins interact with tRNA(Lys) isoacceptors. Previously, mutations in the tRNA(Lys3) anticodon have been shown to strongly inhibit the charging of tRNA(Lys3) by lysyl-tRNA synthetase in vitro, and we show here that in vivo aminoacylation is also inhibited by anticodon changes. The order of decreasing in vivo aminoacylation for tRNA(Lys3) anticodon mutants is: wild-type SUU (where S = mcm(5)S(2)U) 100%) --> SGU (49%) --> CGU (40%) --> SGA (0%) and CGA (0%). We found that the ability of these tRNA(Lys3) anticodon variants to be aminoacylated in vivo is directly correlated with their ability to be packaged into HIV-1. These data showed that the anticodon is a major determinant for tRNA(Lys3) packaging and support the conclusion that its productive interaction with lysyl-tRNA synthetase is important for tRNA(Lys3) incorporation into HIV-1.
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PMID:Correlation between tRNALys3 aminoacylation and its incorporation into HIV-1. 1188 98

During the assembly of HIV-1, tRNA(Lys) isoacceptors are selectively packaged into the virion, and one of these, tRNA(Lys3), is annealed to the viral RNA genome where it acts to prime the reverse transcriptase (RT)-catalyzed synthesis of viral DNA. We review herein what is known about the selective packaging and annealing of primer tRNA(Lys3). Current evidence suggests that a complex of two major precursor viral proteins, Pr55gag and Pr160(gag-pol), interact with a tRNA(Lys)/lysyl-tRNA synthetase (LysRS) complex during viral assembly, with Pr55gag interacting with both LysRS and Pr160(gag-pol), and RT sequences within Pr160(gag-pol) binding to tRNA(Lys). LysRS appears to target the tRNA(Lys) isoacceptors for incorporation into HIV-1. In the virion, the 3' terminal 18 nucleotides of tRNA(Lys3) anneals to an 18-nucleotide sequence at the 5' terminal region of viral RNA termed the primer binding site (PBS). Evidence is presented that other regions on the tRNA(Lys3) also anneal with other regions in viral RNA upstream of the PBS, resulting in a destabilized tRNA(Lys3) structure. Both viral and tRNA(Lys3) regions need to be denatured to establish annealing, and the roles of both viral and cellular proteins in this process are discussed.
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PMID:tRNA(Lys3): the primer tRNA for reverse transcription in HIV-1. 1204 92

The tRNAs used to prime reverse transcription in human immunodeficiency virus type 1 (HIV-1), Rous sarcoma virus (RSV), and Moloney murine leukemia virus (Mo-MuLV) are, tRNA(Trp), and tRNA(Pro), respectively. Using antibodies to the three cognate human aminoacyl-tRNA synthetases, we found that only lysyl-tRNA synthetase (LysRS) is present in HIV-1, only tryptophanyl-tRNA synthetase (TrpRS) is present in RSV, and neither these two synthetases nor prolyl-tRNA synthetase (ProRS) is present in Mo-MuLV. LysRS and TrpRS are present in HIV-1 and RSV at approximately 25 and 12 molecules/virion, respectively. These results support the hypothesis that, in HIV-1 and RSV, the cognate aminoacyl-tRNA synthetase may be used as the signal for targeting the selective packaging of primer tRNAs into retroviruses. The absence of ProRS in Mo-MuLV is consistent with reports that selective packaging of tRNA(Pro) in this virus is less important for achieving optimum annealing of the primer to Mo-MuLV genomic RNA.
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PMID:Retrovirus-specific packaging of aminoacyl-tRNA synthetases with cognate primer tRNAs. 1243 42

Human lysyl-tRNA synthetase (LysRS) is a tRNA-binding protein that is selectively packaged into HIV-1 along with its cognate tRNALys isoacceptors. Evidence exists that Gag alone is sufficient for the incorporation of LysRS into virions. Herein, using both in vitro and in vivo methods, we begin to map regions in Gag and LysRS that are required for this interaction. In vitro reactions between wild-type and truncated HIV-1 Gag and human LysRS were monitored using GST-tagged molecules and glutathione-agarose chromatography. Gag/LysRS interaction in vivo was detected in 293FT cells cotransfected with plasmids coding for wild-type or mutant HIV-1 Gag and LysRS, either by monitoring Gag.LysRS complexes immunoprecipitated from cell lysate with anti-LysRS or by measuring the ability of LysRS to be packaged into budded Gag viral-like particles. Based on these studies, we conclude that the Gag/LysRS interaction depends upon Gag sequences within the C-terminal domain of capsid (the last 54 amino acids) and amino acids 208-259 of LysRS. The latter domain includes the class II aminoacyl-tRNA synthetase consensus sequence known as motif 1. Both regions have been implicated in homodimerization of capsid and LysRS, respectively. Sequences falling outside these amino acid stretches can be deleted from either molecule without affecting the Gag/LysRS interaction, further supporting the observation that LysRS is incorporated into Gag viral-like particles independent of its ability to bind tRNALys.
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PMID:The interaction between HIV-1 Gag and human lysyl-tRNA synthetase during viral assembly. 1275 46

HIV-1 utilizes cellular tRNA(3)(Lys) to prime the initiation of reverse transcription. The selective incorporation of cytoplasmic tRNA(3)(Lys) into HIV-1 particles was recently shown to involve the lysyl-tRNA synthetase, and hence, the encapsidated tRNA(3)(Lys) is likely to be aminoacylated. Here, we tested the effect of aminoacylation on the initiation of reverse transcription. We show that HIV-1 reverse transcriptase is unable to extend lysyl-tRNA(3)(Lys). In addition, the viral polymerase does not significantly enhance the rate of tRNA deacylation, in contrast with previous studies on avian retroviruses. Thus, aminoacylation of the primer tRNA might prevent the initiation of HIV-1 reverse transcription from taking place before viral budding and maturation.
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PMID:Effects of tRNA 3 Lys aminoacylation on the initiation of HIV-1 reverse transcription. 1276 11

In HIV-1, tRNA(Lys3) serves as the primer for reverse transcriptase, and during viral assembly, the tRNA(Lys) isoacceptors, tRNA(Lys1,2) and tRNA(Lys3), are selectively packaged into the virion. In this review, we shall first discuss the evidence for the formation of a tRNA(Lys) packaging complex, whose components include Gag, GagPol, genomic RNA, lysyl-tRNA synthetase (LysRS), and tRNA(Lys). Evidence suggests that the formation of this complex involves a Gag/GagPol/viral genomic RNA complex interacting with a tRNA(Lys)/ LysRS complex, with Gag interacting with both GagPol and LysRS, and GagPol interacting with the tRNA(Lys). The interaction of Gag with LysRS is quite specific, does not require the presence of tRNA(Lys), and LysRS is believed to be the target that allows the specific packaging of tRNA(Lys) into the virion. The parameters influencing these interactions, and the molecular sites of interaction, will be discussed. The selective packaging of tRNA(Lys3) into HIV-1 facilitates annealing of tRNA(Lys) to the 5' region of viral RNA genome. This region contains a series of stem loops, and there exists several regions in both the viral RNA and the tRNA(Lys) that are believed to be important for tRNA(Lys) annealing. The annealing is facilitated by viral proteins such as unprocessed Gag, nucleocapsid, and reverse transcriptase.
Curr HIV Res 2004 Apr
PMID:The selective packaging and annealing of primer tRNALys3 in HIV-1. 1507 80

The major human tRNALys isoacceptors, tRNALys1,2 and tRNALys3, are selectively packaged into HIV-1 during assembly, where tRNALys3 acts as the primer for initiating reverse transcription. In this report, we shall review the evidence that supports a model for the formation of a tRNALys packaging complex, whose components include the precursor proteins Gag and Gag-Pol, viral genomic RNA, tRNALys, and lysyl-tRNA synthetase (LysRS). In the model proposed, the tRNALys packaging complex is formed when a Gag/Gag-Pol/viral RNA complex interacts with a tRNALys/LysRS complex, with Gag interacting with LysRS, and Gag-Pol interacting with tRNALys. The incorporation of Gag-Pol into HIV-1 requires its interaction with Gag multimers whose polymerization is promoted by RNA. Reverse transcriptase sequences within Gag-Pol also bind to tRNALys, and this binding is required for tRNALys packaging into viruses. LysRS, the enzyme that aminoacylates tRNALys, is also incorporated into HIV-1, and this protein is a strong candidate for being the signal that specifically targets tRNALys for viral incorporation. Newly-synthesized LysRS is a main source of viral LysRS, and its incorporation into viruses occurs via its interaction with Gag and independently of tRNALys packaging. While tRNALys incorporation into viruses depends upon its interaction with LysRS, tRNALys aminoacylation is not a requirement for viral packaging.
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PMID:The tRNALys packaging complex in HIV-1. 1518 44

The primer tRNA for reverse transcription in HIV-1, tRNALys3, is selectively packaged into the virus during its assembly, and annealed to the viral genomic RNA. The ribonucleoprotein complex that is involved in the packaging and annealing of tRNALys into HIV-1 consists of Gag, GagPol, tRNALys, lysyl-tRNA synthetase (LysRS), and viral genomic RNA. Gag targets tRNALys for viral packaging through Gag's interaction with LysRS, a tRNALys-binding protein, while reverse transcriptase (RT) sequences within GagPol (the thumb domain) bind to tRNALys. The further annealing of tRNALys3 to viral RNA requires nucleocapsid (NC) sequences in Gag, but not the NC sequences GagPol. In this report, we further show that while the RT connection domain in GagPol is not required for tRNALys3 packaging into the virus, it is required for tRNALys3 annealing to the viral RNA genome.
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PMID:The connection domain in reverse transcriptase facilitates the in vivo annealing of tRNALys3 to HIV-1 genomic RNA. 1549 76

Human immunodeficiency virus type 1 (HIV-1) viral assembly is mediated by multiple protein-protein and protein-nucleic acid interactions. Human tRNA(Lys3) is used as the primer for HIV reverse transcription, and HIV Gag and GagPol are required for packaging of the tRNA into virions. Human lysyl-tRNA synthetase (LysRS) is also specifically packaged into HIV, suggesting a role for LysRS in tRNA packaging. Gag alone is sufficient for packaging of LysRS, and these two proteins have been shown to interact in vitro using glutathione S-transferase pull-down assays. In vitro pull-down assays using truncated constructs have also revealed that residues important for homodimerization of Gag and LysRS are critical for the Gag/LysRS interaction. In this work, we report further in vitro characterization of the interaction between HIV Gag and human LysRS using affinity pull-down assays, fluorescence anisotropy measurements and gel chromatography. An equilibrium binding constant of 310 +/- 80 nM was measured for the Gag/LysRS interaction. We also show that capsid alone binds to LysRS with a similar affinity as full-length Gag. Point mutations that disrupt the homodimerization of LysRS and Gag in vitro do not affect their interaction. These results suggest that dimerization of each protein per se is not required for the interaction but that residues involved in forming the homodimer interfaces contribute to heterodimer formation. Gel chromatography studies further support the formation of a Gag/LysRS heterodimer.
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PMID:In vitro characterization of the interaction between HIV-1 Gag and human lysyl-tRNA synthetase. 1670 15


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