scholarly journals Epigenetic Control of Human Endogenous Retrovirus Expression: Focus on Regulation of Long-Terminal Repeats (LTRs)

Viruses ◽  
2017 ◽  
Vol 9 (6) ◽  
pp. 130 ◽  
Author(s):  
Tara Hurst ◽  
Gkikas Magiorkinis
Keyword(s):  
Endogenous Retrovirus ◽  
Human Endogenous Retrovirus ◽  
Long Terminal Repeats ◽  
Epigenetic Control ◽  
Terminal Repeats

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

FEBS Letters ◽  
1998 ◽  
Vol 421 (3) ◽  
pp. 229-233 ◽  
Author(s):  
Sergey B Akopov ◽  
Lev G Nikolaev ◽  
Pavel P Khil ◽  
Yuri B Lebedev ◽  
Eugene D Sverdlov
Keyword(s):  
Host Cell ◽  
Endogenous Retrovirus ◽  
Nuclear Proteins ◽  
Human Endogenous Retrovirus ◽  
Long Terminal Repeats ◽  
Terminal Repeats

scholarly journals Unusually long target site duplications flanking some of the long terminal repeats of human endogenous retrovirus K in the human genome

2004 ◽  
Vol 85 (6) ◽  
pp. 1485-1488 ◽  
Author(s):  
Ilgar Z. Mamedov ◽  
Yuri B. Lebedev ◽  
Eugene D. Sverdlov
Keyword(s):  
Human Genome ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Human Endogenous Retrovirus ◽  
Substantial Part ◽  
Direct Repeats ◽  
Long Terminal Repeats ◽  
Solo Ltrs ◽  
Insertion Mechanism ◽  
Terminal Repeats

Human endogenous retroviruses (HERVs) make up a substantial part of the human genome. HERVs and solitary long terminal repeats (solo LTRs) are usually flanked by 4–6 nt short direct repeats through the well-known mechanism of their integration. A number of solo LTRs flanked by unusually long direct repeats were detected in the human genome. These unusual structures might be a product of an alternative virus insertion mechanism.

Long terminal repeats of dwarf hamster endogenous retrovirus are highly diverged and do not maintain efficient transcription

Virology ◽  
1991 ◽  
Vol 181 (1) ◽  
pp. 367-370 ◽  
Author(s):  
Andrei T. Tikhonenko ◽  
Alla V. Polotskaya ◽  
Nikita S. Vassetzky ◽  
Tanya V. Golovkina ◽  
Andrei V. Gudkov
Keyword(s):  
Endogenous Retrovirus ◽  
Long Terminal Repeats ◽  
Dwarf Hamster ◽  
Terminal Repeats

scholarly journals Human Endogenous Retrovirus HERV-K14 Families: Status, Variants, Evolution, and Mobilization of Other Cellular Sequences

2005 ◽  
Vol 79 (5) ◽  
pp. 2941-2949 ◽  
Author(s):  
Aline Flockerzi ◽  
Stefan Burkhardt ◽  
Werner Schempp ◽  
Eckart Meese ◽  
Jens Mayer
Keyword(s):  
Human Genome ◽  
Germ Line ◽  
Endogenous Retrovirus ◽  
Endogenous Retroviruses ◽  
Human Endogenous Retrovirus ◽  
Long Terminal Repeats ◽  
Essential Information ◽  
Human Endogenous Retroviruses ◽  
Consensus Sequences

ABSTRACT The human genome harbors many distinct families of human endogenous retroviruses (HERVs) that stem from exogenous retroviruses that infected the germ line millions of years ago. Many HERV families remain to be investigated. We report in the present study the detailed characterization of the HERV-K14I and HERV-K14CI families as they are represented in the human genome. Most of the 68 HERV-K14I and 23 HERV-K14CI proviruses are severely mutated, frequently displaying uniform deletions of retroviral genes and long terminal repeats (LTRs). Both HERV families entered the germ line ∼39 million years ago, as evidenced by homologous sequences in hominoids and Old World primates and calculation of evolutionary ages based on a molecular clock. Proviruses of both families were formed during a brief period. A majority of HERV-K14CI proviruses on the Y chromosome mimic a higher evolutionary age, showing that LTR-LTR divergence data can indicate false ages. Fully translatable consensus sequences encoding major retroviral proteins were generated. Most HERV-K14I loci lack an env gene and are structurally reminiscent of LTR retrotransposons. A minority of HERV-K14I variants display an env gene. HERV-K14I proviruses are associated with three distinct LTR families, while HERV-K14CI is associated with a single LTR family. Hybrid proviruses consisting of HERV-K14I and HERV-W sequences that appear to have produced provirus progeny in the genome were detected. Several HERV-K14I proviruses harbor TRPC6 mRNA portions, exemplifying mobilization of cellular transcripts by HERVs. Our analysis contributes essential information on two more HERV families and on the biology of HERV sequences in general.

scholarly journals The Solitary Long Terminal Repeats of ERV-9 Endogenous Retrovirus Are Conserved during Primate Evolution and Possess Enhancer Activities in Embryonic and Hematopoietic Cells

2002 ◽  
Vol 76 (5) ◽  
pp. 2410-2423 ◽  
Author(s):  
Jianhua Ling ◽  
Wenhu Pi ◽  
Roni Bollag ◽  
Shan Zeng ◽  
Meral Keskintepe ◽  
...  
Keyword(s):  
Fluorescent Protein ◽  
Hematopoietic Cells ◽  
K562 Cells ◽  
Endogenous Retrovirus ◽  
Embryonic Cells ◽  
Long Terminal Repeats ◽  
Enhancer Activity ◽  
Boundary Area ◽  
Functional Studies ◽  
Terminal Repeats

ABSTRACT The solitary long terminal repeats (LTRs) of ERV-9 endogenous retrovirus contain the U3, R, and U5 regions but no internal viral genes. They are middle repetitive DNAs present at 2,000 to 4,000 copies in primate genomes. Sequence analyses of the 5" boundary area of the erythroid β-globin locus control region (β-LCR) and the intron of the embryonic axin gene show that a solitary ERV-9 LTR has been stably integrated in the respective loci for at least 15 million years in the higher primates from orangutan to human. Functional studies utilizing the green fluorescent protein (GFP) gene as the reporter in transfection experiments show that the U3 region of the LTRs possesses strong enhancer activity in embryonic cells of widely different tissue origins and in adult cells of blood lineages. In both the genomic LTRs of embryonic placental cells and erythroid K562 cells and transfected LTRs of recombinant GFP plasmids in K562 cells, the U3 enhancer activates synthesis of RNAs that are initiated from a specific site 25 bases downstream of the AATAAA (TATA) motif in the U3 promoter. A second AATAAA motif in the R region does not serve as the TATA box or as the polyadenylation signal. The LTR-initiated RNAs extend through the R and U5 regions into the downstream genomic DNA. The results suggest that the ERV-9 LTR-initiated transcription process may modulate transcription of the associated gene loci in embryonic and hematopoietic cells.

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