Evidence for the persistence of an active endogenous retrovirus (ERVE) in humans

Abstract

Transposable elements (TEs) account for nearly half (44 %) of the human genome. However, their overall activity has been steadily declining over the past 35-50 million years, so that <0.05 % of TEs are presumably still "alive" (potentially transposable) in human populations. All the active elements are retrotransposons, either autonomous (LINE-1 and possibly the endogenous retrovirus ERVK), or non-autonomous (Alu and SVA, whose transposition is dependent on the LINE-1 enzymatic machinery). Here we show that a lineage of the endogenous retrovirus ERVE was recently engaged in ectopic recombination events and may have at least one potentially fully functional representative, initially reported as a novel retrovirus isolated from blood cells of a Chinese patient with chronic myeloid leukemia, which bears signals of positive selection on its envelope region. Altogether, there is strong evidence that ERVE should be included in the short list of potentially active TEs, and we give clues on how to identify human specific insertions of this element that are likely to be segregating in some of our populations.

Restricting retrotransposons: a review

“…However, some intracisternal A-particle (IAP) and Etn/MusD family LTR elements remain insertionally active in mice [ 8 ], and formation of infective virions by recombination or phenotypic mixing of intact proteins from different ERV proviruses has been reported [ 9 – 12 ]. Among the 31 human endogenous retrovirus subfamilies extant in the human genome, no replication-competent HERVs are known, although their existence has not been ruled out [ 13 , 14 ], and recently an unfixed fully intact HERV-K (HML2) provirus was identified in some individuals [ 15 ]. Many HERVs, and their lone LTRs that populate the genome as a consequence of non-homologous recombination, remain capable of expression and may act as transcriptional regulatory elements for genes (reviewed in [ 16 ]).…”

In-depth transcriptome reveals the potential biotechnological application of Bothrops jararaca venom gland

“…We identified with KEGG mapper [ 71 ] one of the largest mapped/annotated pathways of the components of the human retrovirus response. Subsequently, one of the identified components of the Gene Ontology term [ 34 ] identified by Blast2Go in our analysis is the virion part, consisting of sequences coding for several endogenous retrovirus described in snakes such as Python curtus endogenous retrovirus , Python molurus endogenous retrovirus , Endogenous retrovirus group PABLB member 1, Endogenous retrovirus group K members of families 1, 8, 9, 10, 11, 18, 19 and 25, and human endogenous retroviruses (HERVs) such as HCML-ARV already isolated from blood cells of patient with chronic myeloid leukemia [ 72 ].…”

The impact of transposable element activity on therapeutically relevant human stem cells

“…2). Among the 31 human endogenous retrovirus subfamilies covering 8% of the human genome, replication-competent HERVs have not been described to date, although their existence cannot be ruled out [33, 34]. The only TEs that are currently verifiably mobilized in the human genome are members of the group of non-LTR retrotransposons (Fig.…”