Zsíros J, Jebbink M F, Lukashov V V, Voûte P A, Berkhout B
Department of Pediatric Oncology, Academic Medical Center, University of Amsterdam, The Netherlands.
J Gen Virol. 1998 Jan;79 ( Pt 1):61-70. doi: 10.1099/0022-1317-79-1-61.
The prototype endogenous retrovirus HERV-K10 was identified in the human genome by its homology to the exogenous mouse mammary tumour virus. By analysis of a short 244 bp segment of the reverse transcriptase (RT) gene of other HERV-K10-like sequences, it has become clear that these elements represent an extended family consisting of multiple groups (the HML-1 to HML-6 subgroups). Some of these elements are transcriptionally active and contain an intact open reading frame for the RT protein, raising the possibility that this family is still expanding through retrotransposition. To better define the relationship of these endogenous retroviruses, we identified ten new members of the HML-2 subgroup. PCR was used to amplify reverse-transcribed RNA of a 595 bp region of the RT gene in a variety of human cell samples, including normal and leukaemic bone marrow and peripheral blood, placenta cells and a transformed T cell line. We provide an extensive phylogenetic analysis of the relationships for this cluster of HERV-K-related endogenous retroviral elements. Nucleotide diversity values for nonsynonymous versus synonymous codon positions indicate that moderately strong selection is or was operating on these retroviral RT gene segments. The evolution of this class of endogenous retroelements is discussed.
通过与外源性小鼠乳腺肿瘤病毒的同源性，在人类基因组中鉴定出了内源性逆转录病毒原型HERV-K10。通过分析其他HERV-K10样序列逆转录酶（RT）基因的一段短的244bp片段，已清楚这些元件代表一个由多个组（HML-1至HML-6亚组）组成的扩展家族。其中一些元件具有转录活性，并包含RT蛋白的完整开放阅读框，这增加了该家族仍通过逆转座进行扩展的可能性。为了更好地定义这些内源性逆转录病毒之间的关系，我们鉴定了HML-2亚组的十个新成员。使用PCR在多种人类细胞样本中扩增RT基因595bp区域的逆转录RNA，这些样本包括正常和白血病骨髓及外周血、胎盘细胞和一个转化的T细胞系。我们对这一组与HERV-K相关的内源性逆转录病毒元件之间的关系进行了广泛的系统发育分析。非同义与同义密码子位置的核苷酸多样性值表明，中等强度的选择正在或曾经作用于这些逆转录病毒RT基因片段。讨论了这类内源性逆转元件的进化。
