Role of Pr160gag-pol in mediating the selective incorporation of tRNA(Lys) into human immunodeficiency virus type 1 particles.
AUTOR(ES)
Mak, J
RESUMO
COS-7 cells transfected with human immunodeficiency virus type 1 (HIV-1) proviral DNA produce virus in which three tRNA species are most abundant in the viral tRNA population. These tRNAs have been identified through RNA sequencing techniques as tRNA(3Lys) the primer tRNA in HIV-1, and members of the tRNA(1,2Lys) isoacceptor family. These RNAs represent 60% of the low-molecular-weight RNA isolated from virus particles, while they represent only 6% of the low-molecular-weight RNA isolated from the COS cell cytoplasm. Thus, tRNA(Lys) is selectively incorporated into HIV-1 particles. We have measured the ratio of tRNA(3Lys) molecules to copies of genomic RNA in viral RNA samples and have calculated that HIV-1 contains approximately eight molecules of tRNA(3Lys) per two copies of genomic RNA. We have also obtained evidence that the Pr160gag-pol precursor is involved in primer tRNA(3Lys) incorporation into virus. First, selective tRNA(Lys) incorporation and wild-type amounts of tRNA(3Lys) were maintained in a protease-negative virus unable to process Pr55gag and Pr160gag-pol precursors, indicating that precursor processing was not required for primer tRNA incorporation. Second, viral particles containing only unprocessed Pr55gag protein did not selectively incorporate tRNA(Lys), while virions containing both unprocessed Pr55gag and Pr160gag-pol proteins demonstrated select tRNA(3Lys) packaging. Third, studies with a proviral mutant containing a deletion of most of the reverse transcriptase sequences and approximately one-third of the integrase sequence in the Pr160gag-pol precursor resulted in the loss of selective tRNA incorporation and an eightfold decrease in the amount of tRNA(3Lys) per two copies of genomic RNA. We have also confirmed herein finding of a previous study which indicated that the primer binding site is not required for the selective incorporation of tRNA(Lys).
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=236680Documentos Relacionados
- Requirements for incorporation of Pr160gag-pol from human immunodeficiency virus type 1 into virus-like particles.
- Effect of mutations in the nucleocapsid protein (NCp7) upon Pr160(gag-pol) and tRNA(Lys) incorporation into human immunodeficiency virus type 1.
- The nonmyristylated Pr160gag-pol polyprotein of human immunodeficiency virus type 1 interacts with Pr55gag and is incorporated into viruslike particles.
- Coding Sequences Upstream of the Human Immunodeficiency Virus Type 1 Reverse Transcriptase Domain in Gag-Pol Are Not Essential for Incorporation of the Pr160gag-pol into Virus Particles
- Human immunodeficiency virus type 1 Pr55gag and Pr160gag-pol expressed from a simian virus 40 late replacement vector are efficiently processed and assembled into viruslike particles.