Ancestry of a human endogenous retrovirus family

Mariani–Costantini, Renato; Horn, Toby M.; Callahan, Robert

doi:10.1128/jvi.63.11.4982-4985.1989

Cited by 54 publications

(8 citation statements)

References 16 publications

(8 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…3). These features are consistent with the crosshybridization of the probe to the human HERVII family of endogenous retrovirus elements (Mariani-Costantini et al, 1989). The lack of hybridization to placental DNA under conditions of high stringency indicates that the SMRV-H insertions reported here represent the insertion of exogenous viral sequences.…”

Section: Southem-blot Analysis Of Namalwa Cell Linessupporting

confidence: 85%

Insertion of SMRV‐H viral DNA at the c‐myc gene locus of a BL cell line and presence in established cell lines

Middleton¹,

Miller²,

Ross

et al. 1992

Intl Journal of Cancer

View full text Add to dashboard Cite

Mutation of the c-myc gene locus has occurred during in vitro culture of the Burkitt lymphoma cell line Namalwa. Gene cloning and sequencing of this c-myc gene locus has revealed the insertion of incomplete copies of the Squirrel Monkey Retrovirus-Human (SMRV-H) proviral genome. Insertions of the SMRV-H genome were seen in all Namalwa cell lines tested, with multiple insertions being seen in some sublines. Viral particles with the morphology of type-D retrovirus, budding from these cells, were seen by transmission EM. New insertions of the genome were produced spontaneously in these cells. The origins of the type-D retrovirus and its implications for workers in the field are discussed.

show abstract

Section: Southem-blot Analysis Of Namalwa Cell Linessupporting

confidence: 85%

Insertion of SMRV‐H viral DNA at the c‐myc gene locus of a BL cell line and presence in established cell lines

Middleton¹,

Miller²,

Ross

et al. 1992

Intl Journal of Cancer

View full text Add to dashboard Cite

show abstract

“…More recently, six subgroups (HML-1 to HML-6) were described with a nucleotide sequence dissimilarity of approximately 25% for a 244-bp fragment of the RT gene (33), and this phylogeny could be confirmed for a larger RT fragment (55). Although the HERV-K element was first introduced into the human germ line more than 25 million years ago, as judged from its distribution in different primates (28,32), several members contain a complete genome with long terminal repeats and open reading frames encoding Gag, Pol, and Env proteins (25) and three chromosomes are candidates for harboring a completely intact HERV-K locus (30,31). The idea that this virus group may still be biologically active is further supported by the finding that several HERV-K elements are transcriptionally active (1,34).…”

Section: Of the Numerous Endogenous Retroviral Elements That Are Presmentioning

confidence: 95%

Identification of an Active Reverse Transcriptase Enzyme Encoded by a Human Endogenous HERV-K Retrovirus

Berkhout¹,

Jebbink²,

Zsíros

1999

J Virol

View full text Add to dashboard Cite

Of the numerous endogenous retroviral elements that are present in the human genome, the abundant HERV-K family is distinct because several members are transcriptionally active and coding for biologically active proteins. A detailed phylogeny of the HERV-K family based on the partial sequence of the reverse transcriptase (RT) gene revealed a high incidence of an intact RT open reading frame within the HML-2 subgroup of HERV-K elements. In this study, we report the cloning of six full-length HML-2 RT genes, of which five contain an uninterrupted open reading frame. The RT enzymes were expressed as glutathione S-transferase fusion proteins inEscherichia coli, and several HERV-K RT enzymes demonstrated polymerase as well as RNase H activity. Several biochemical properties of the RT polymerase were analyzed, including the template requirements and optimal reaction conditions (temperature, type of divalent cation). Inspection of the nucleotide sequence of the HERV-K RT genes demonstrated a mosaic structure, suggesting that a high level of genetic recombination has occurred in this virus family, which is a hallmark of replication by means of reverse transcription. The selective pressure to maintain the RT coding potential is illustrated by the sequence of a particular HERV-K isolate that contains three 1-nucleotide deletions within a small RT segment, thus maintaining the open reading frame. These combined results may suggest that these endogenous RT enzymes still have a biological function. It is possible that the RT activity was involved in the spread of this major class of retroelements by retrotransposition, and in fact it cannot be excluded that this retrovirus group is still mobile. The endogenous RT activity may also have been involved in the shaping of the human genome, e.g., by formation of pseudogenes.

show abstract

“…Unlike most HERV families, they have been shown to encode functional enzymatic proteins (14,22), viral particles (6), and autoimmune antigens (7), indicating that some HERV-K elements have retained retroviral functions. Previous evolutionary analyses suggested that most HERV-K elements found in humans integrated prior to the divergence of hominoids from the Old World monkey lineages (20,27). Indeed, no retroviral integrations specific to humans have been reported to date.…”

mentioning

confidence: 99%

Human-Specific Integrations of the HERV-K Endogenous Retrovirus Family

Medstrand

Mager

1998

J Virol

212

View full text Add to dashboard Cite

Several distinct families of endogenous retrovirus-like sequences (HERVs) exist in the genomes of humans and other primates. One of these families, the HERV-K group, contains members that encode functional proteins and that have been implicated in the etiology of insulin-dependent diabetes mellitus (IDDM). Because of potential functional and disease relevance, it is important to determine if there are HERV-K-associated genetic differences between individuals. In this study, we have investigated the divergence and evolutionary age of HERV-K long terminal repeats (LTRs). Thirty-seven LTRs, taken primarily from random human clones in GenBank, were aligned and grouped into nine clusters with decreasing sequence divergence. Cluster 1 sequences are 8.6% divergent, on average, whereas cluster 9 LTRs, represented by the LTRs of the fully sequenced HERV-K10 clone, show an average of only 1.1% divergence from each other. The evolutionary age of 18 LTRs from different clusters was then investigated by genomic PCR to determine presence or absence of the retroviral element in different primate species. LTRs from clusters of higher divergence were detected in monkeys and apes, whereas LTRs in clusters with lower divergence were acquired later in evolution. Notably, LTRs of cluster 9 were found only in humans at all nine loci examined. Genomic Southern analysis with an oligonucleotide probe specific for cluster 9 LTRs suggests that HERV-K elements with this type of LTR expanded independently in the genomes of humans and the great apes. This is the first report of endogenous retroviral integrations that are specific to humans and indicates that some HERVs have amplified much later than previously thought. These elements may still be actively transposing and may therefore represent a source of genetic variation linked to disease development.

show abstract

Ancestry of a human endogenous retrovirus family

Cited by 54 publications

References 16 publications

Insertion of SMRV‐H viral DNA at the c‐myc gene locus of a BL cell line and presence in established cell lines

Insertion of SMRV‐H viral DNA at the c‐myc gene locus of a BL cell line and presence in established cell lines

Identification of an Active Reverse Transcriptase Enzyme Encoded by a Human Endogenous HERV-K Retrovirus

Human-Specific Integrations of the HERV-K Endogenous Retrovirus Family

Contact Info

Product

Resources

About