Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học 'Respiratory Research cung cấp cho các bạn kiến thức về ngành y đề tài: Multiple sites in the N-terminal half of simian immunodeficiency virus capsid protein contribute to evasion from rhesus monkey TRIM5a-mediated restriction. | Kono et al. Retrovirology 2010 7 72 http content 7 1 72 RETROVIROLOGY RESEARCH Open Access Multiple sites in the N-terminal half of simian immunodeficiency virus capsid protein contribute to evasion from rhesus monkey TRIM5a-mediated restriction 1 1 2 2 1 1 Ken Kono Haihan Song Masaru Yokoyama Hironori Sato Tatsuo Shioda Emi E Nakayama Abstract Background We previously reported that cynomolgus monkey CM TRIM5a could restrict human immunodeficiency virus type 2 HIV-2 strains carrying a proline at the 120th position of the capsid protein CA but it failed to restrict those with a glutamine or an alanine. In contrast rhesus monkey Rh TRIM5a could restrict all HIV-2 strains tested but not simian immunodeficiency virus isolated from macaque SIVmac despite its genetic similarity to HIV-2. Results We attempted to identify the viral determinant of SIVmac evasion from Rh TRIM5a-mediated restriction using chimeric viruses formed between SIVmac239 and HIV-2 GH123 strains. Consistent with a previous study chimeric viruses carrying the loop between a-helices 4 and 5 L4 5 from the 82nd to 99th amino acid residues of HIV-2 CA were efficiently restricted by Rh TRIM5a. However the corresponding loop of SIVmac239 CA alone from the 81st to 97th amino acid residues was not sufficient to evade Rh TRIM5a restriction in the HIV-2 background. A single glutamine-to-proline substitution at the 118th amino acid of SIVmac239 CA corresponding to the 120th amino acid of HIV-2 GH123 also increased susceptibility to Rh TRIM5a indicating that glutamine at the 118th of SIVmac239 CA is necessary to evade Rh TRIM5a. In addition the N-terminal portion from the 5th to 12th amino acid residues and the 107th and 109th amino acid residues in a-helix 6 of SIVmac CA are necessary for complete evasion from Rh TRIM5a-mediated restriction. A three-dimensional model of hexameric GH123 CA showed that these multiple regions are located on the CA surface suggesting their direct interaction .
