Department of Biochemistry and Molecular Biophysics, Columbia University Medical Center, New York, NY, USA.
Department of Microbiology and Immunology, Columbia University Medical Center, New York, NY, USA.
Nat Commun. 2022 Mar 18;13(1):1474. doi: 10.1038/s41467-022-29097-8.
Retroviruses utilize the viral integrase (IN) protein to integrate a DNA copy of their genome into host chromosomal DNA. HIV-1 integration sites are highly biased towards actively transcribed genes, likely mediated by binding of the IN protein to specific host factors, particularly LEDGF, located at these gene regions. We here report a substantial redirection of integration site distribution induced by a single point mutation in HIV-1 IN. Viruses carrying the K258R IN mutation exhibit a high frequency of integrations into centromeric alpha satellite repeat sequences, as assessed by deep sequencing, a more than 10-fold increase over wild-type. Quantitative PCR and in situ immunofluorescence assays confirm this bias of the K258R mutant virus for integration into centromeric DNA. Immunoprecipitation studies identify host factors binding to IN that may account for the observed bias for integration into centromeres. Centromeric integration events are known to be enriched in the latent reservoir of infected memory T cells, as well as in elite controllers who limit viral replication without intervention. The K258R point mutation in HIV-1 IN is also present in databases of latent proviruses found in patients, and may reflect an unappreciated aspect of the establishment of viral latency.
逆转录病毒利用病毒整合酶（IN）蛋白将其基因组的 DNA 拷贝整合到宿主染色体 DNA 中。HIV-1 的整合位点高度偏向于活跃转录的基因，这可能是由 IN 蛋白与特定宿主因子（特别是位于这些基因区域的 LEDGF）的结合介导的。我们在这里报告了 HIV-1 IN 中的单点突变引起的整合位点分布的大量重定向。通过深度测序评估，携带 K258R IN 突变的病毒表现出高频整合到着丝粒α卫星重复序列中，比野生型增加了 10 多倍。定量 PCR 和原位免疫荧光检测证实了 K258R 突变病毒对整合到着丝粒 DNA 的这种偏向。免疫沉淀研究鉴定了与 IN 结合的宿主因子，这些因子可能解释了观察到的偏向整合到着丝粒的原因。已知着丝粒整合事件在受感染记忆 T 细胞的潜伏储库中以及在无需干预即可限制病毒复制的精英控制器中富集。HIV-1 IN 中的 K258R 点突变也存在于患者潜伏前病毒数据库中，这可能反映了病毒潜伏建立的一个未被认识的方面。
