IDENTIFICATION AND GENOMIC CHARACTERIZATION OF HERV-K(HML-10) IN HUMAN GENOME GRCh37/hg19 ASSEMBLY

Human endogenous retroviruses (HERVs) have been classified into three different classes I, II, III. Betaretrovirus-like sequences, including HERV-K, belong to the class II and contains ten groups, termed HML1-10. It has been reported that an HML-10 sequence, termed HERV-K(C4), is inserted within the gene coding for the human complement C4 in an antisense orientation (Tassabehij et al. 1994). The expression of the HERV-K(C4) RNA has been hypothesized to possibly modulate C4 expression as well as to act as a possible mechanism of defense against retroviral infections (Schneider et al 2001). Recently, it has been demonstrated that low HERV-K(C4) copy number is associated with type 1 diabetes, raising the possibility that this retroviral element contributes to functional protection against this autoimmune disease (Mason et al. 2014). Given the correlation between lower HERV-K(C4) copy number and expression, it has also been proposed that HERV-K(C4) may influence C4 RNA processing and/or have an impact on othe...