Long terminal repeats of human endogenous retrovirus K family (HERV‐K) specifically bind host cell nuclear proteins

Abstract

Solitary long terminal repeats (LTRs) of the human endogenous retroviruses, scattered in several thousand copies throughout the human genome, are potentially capable of affecting the expression of closely located genes. To assess their regulatory potential, the LTR sequences of one of the most abundant HERV families (HERV-K) were screened for the presence of binding sites for the host cell nuclear factors using mobility shift and UV-crosslinking assays. It was shown that the LTR sequences of two subfamilies harbor a specific binding site for a complex consisting of at least three proteins, ERF1, ERF2 and ERF3 of 98, 91 and 88 kDa apparent molecular mass, respectively. This binding site is located in the 5P region of the LTR U3 element. The preservation of the specific protein binding site in different HERV-K LTR sequences suggests their possible role in regulation of nearby located genes.z 1998 Federation of European Biochemical Societies.

CpG Methylation Directly Regulates Transcriptional Activity of the Human Endogenous Retrovirus Family HERV-K(HML-2)

“…An early study noted upregulation of HERV-K(HML-2) expression in T47D cells after treatment of cells with estradiol and progesterone (34). A complex of at least three otherwise-unidentified proteins was reported to bind to the 5Ј portion of the LTR U3 region (2). Furthermore, the transcription factor YY1 and other unidentified proteins were shown to bind to an enhancer region within the proviral LTR U3 region.…”

Isolation and phytogeny of SINE‐R retroposons derived from human endogenous retrovirus HERV‐K family in schizophrenia

“…SINE-R retroposons have a pofypurine tract (PPT) that serves as a primer binding site for plus-strand DNA synthesis from retrovirally mediated reverse transcription (Ono et al, 1987). Akopov et al (1998) noted that such sequences have the capacity to modify the expression of neighboring genes. In addition, a similar retrotransposable element to SINE-R.C2 (human-specific retroposon) has been reported as the cause of Fukuyama type muscular dystrophy, and this appears to be the first association of this class of elements with disease (Kobayashi et al, 1998).…”

Molecular Phylogenetic Analysis of the Human Endogenous Retrovirus E (HERV-E) Family in Human Tissues and Human Cancers

“…So far, more than 200 different HERV and LTR families are mentioned in the widely employed databases of repetitive sequences (Jurka, 2000). A function of the multiple copy families, scattered throughout the genome, has been reported regulatory functions on the gene expression of nearby located genes (Akopov et al, 1998). Although many are defective through the accumulation of mutations, deletions, and termination signals within coding sequences, structural genes from some HERV families are expressed preferentially in human placenta (Kjellman et al, 1999;Mi et al, 2000;Venables et al, 1995) and several cancer cell lines (Lower et al, 1993;Yi et al, 2004).…”