RESUMO
Human immunodeficiency virus type 1 (HIV-1) has been classified into three main groups and 11 distinct subtypes. Moreover, several circulating recombinant forms (CRFs) of HIV-1 have been recently documented to have spread widely causing extensive HIV-1 epidemics. A subtype, initially designated I (CRF04_cpx), was documented in Cyprus and Greece and was found to comprise regions of sequence derived from subtypes A and G as well as regions of unclassified sequence. Re-analysis of the three full-length CRF04_cpx sequences that were available revealed a mosaic genomic organization of unique complexity comprising regions of sequence from at least five distinct subtypes, A, G, H, K and unclassified regions. These strains account for approximately 2% of the total HIV-1-infected population in Greece, thus providing evidence of the great capability of HIV-1 to recombine and produce highly divergent strains which can be spread successfully through different infection routes.
Assuntos
Proteínas do Capsídeo , HIV-1/genética , Proteínas Virais , Capsídeo/classificação , Capsídeo/genética , Chipre , Produtos do Gene gag/classificação , Produtos do Gene gag/genética , Produtos do Gene pol/classificação , Produtos do Gene pol/genética , Produtos do Gene vif/classificação , Produtos do Gene vif/genética , Grécia , Antígenos HIV/classificação , Antígenos HIV/genética , Proteína do Núcleo p24 do HIV/classificação , Proteína do Núcleo p24 do HIV/genética , Proteína gp120 do Envelope de HIV/classificação , Proteína gp120 do Envelope de HIV/genética , Proteína gp41 do Envelope de HIV/classificação , Proteína gp41 do Envelope de HIV/genética , HIV-1/classificação , HIV-1/isolamento & purificação , Humanos , Filogenia , Recombinação Genética , Produtos do Gene gag do Vírus da Imunodeficiência Humana , Produtos do Gene vif do Vírus da Imunodeficiência HumanaRESUMO
Little sequence information is available for human immunodeficiency virus type 1 (HIV-1) vif genes of African origin. Here we describe 37 new complete vif genes of 18 AIDS patients from Uganda and show that vif has a high in vivo genetic variability. vif proviral DNA sequences of peripheral blood cells were determined by direct sequencing of PCR products. Only 52% of the deduced Vif amino acids were absolutely conserved; when Vif sequences previously analysed were considered, only 32% of the Vif consensus sequence comprised conserved and as such possibly functionally important motifs. The high inter-individual vif variability was in contrast to a very low intra-individual variability. One patient carried a vif gene with a stable C-terminal deletion, but N-terminal truncations were not found in patients' predominant vif sequences. The vif genes analysed comprised subtypes A, D and an A/D mosaic. Phylogenetic analyses additionally showed that HIV- 1 in Uganda has spread across the boundaries of ethnic groups.
Assuntos
Síndrome da Imunodeficiência Adquirida/virologia , Produtos do Gene vif/genética , Variação Genética , HIV-1/genética , Adulto , Sequência de Aminoácidos , Sequência Consenso , Feminino , Produtos do Gene vif/classificação , HIV-1/classificação , Humanos , Masculino , Dados de Sequência Molecular , Filogenia , Uganda , Produtos do Gene vif do Vírus da Imunodeficiência HumanaRESUMO
The nonstructural/regulatory genes of human immunodeficiency virus type 1 (HIV-1) and other lentiviruses are believed to play an important role in the replication and pathogenesis of these viruses. In HIV-1 and other lentiviruses, the vif (viral infectivity factor) open reading frame (ORF) (also termed sor or Q in some lentivirus genomes) is located in the central region, overlapping the 3' end of the pol ORF, but in a different reading frame. Among the lentiviruses, only equine infectious anemia virus lacks a vif ORF. The predicted Vif protein sequences from 38 lentiviruses were analyzed for the presence of global and local sequence similarity. The Vif proteins of closely related lentiviruses are highly conserved (HIV-1HXB2:HIV-1mn = 91% identity), while those of more distantly related lentirviruses have diverged significantly (HIV-1HXB2:simian immunodeficiency virusmax = 30% identity). A search for local sequence similarity revealed that a unifying feature of predicted lentivirus Vif proteins is the presence of at least one of two short, highly conserved sequence motifs, SL(I/V)X4YX9Y and SLQXLA. SLQXLA was present in 34 of 38 lentiviruses examined, while the remaining four lentiviruses had one (three viruses) or two (one virus) substitutions in this motif (of five total substitutions, three were conservative changes). The SL(I/V)X4YX9Y motif was found only in primate lentiviruses and in bovine immunodeficiency-like virus. Based on these findings, we suggest that the locus designation vif be used to denote all lentivirus ORFs previously called vif, Q, or sor.
