Modifications induced by HIV-1 Tat protein in cellular splicing mechanisms

Intracellular Tat101 deregulated the expression of spliceosome core components, such as SF3B2, SF3A1, SFPQ, PCBP1, SYNCRIP, YBX1 and HSP8A/HSP7C, and thus likely the splicing pathway. Viral splicing experiments showed that Tat101 favored the expression of viral unspliced RNA, which are used at the late steps of the viral cycle, rather than spliced RNAs allowing the progression of HIV-1 replication. CD4+ T cell line stably transfected with TetOff and pTRE2hyg-Tat72 vectors (Tat72 is the first exon of HIV-1 Tat protein regulator) CD4+ T cell line stably transfected with TetOff and pTRE2hyg-Tat101 vectors (Tat101 contains the first and second exons of HIV-1 Tat protein regulator) CD4+ T cell line stably transfected with TetOff and pTRE2hyg-Tat101C22G vectors (Tat101 contains the first and second exons of HIV-1 Tat protein regulator with the change C22G)

胞内Tat101可失调剪接体（spliceosome）核心组分的表达，例如SF3B2、SF3A1、SFPQ、PCBP1、SYNCRIP、YBX1及HSP8A/HSP7C，进而可能影响剪接通路。病毒剪接实验结果显示，Tat101更倾向于促进病毒未剪接RNA的表达，这类RNA在病毒周期的晚期阶段发挥功能，而非促进可助力HIV-1复制进程的剪接型RNA的表达。稳定转染了TetOff与pTRE2hyg-Tat72载体的CD4+ T细胞系（Tat72为HIV-1 Tat调控蛋白的第一外显子）；稳定转染了TetOff与pTRE2hyg-Tat101载体的CD4+ T细胞系（Tat101包含HIV-1 Tat调控蛋白的第一与第二外显子）；稳定转染了TetOff与pTRE2hyg-Tat101C22G载体的CD4+ T细胞系（Tat101C22G为携带C22G突变的、包含HIV-1 Tat调控蛋白第一与第二外显子的Tat101变体）