Characterization of DNA methylation and promoter activity of long terminal repeat elements of feline endogenous retrovirus RDRS C2a

Virus Genes ◽  
2021 ◽  
Author(s):  
Sayumi Shimode ◽  
Takashi Yamamoto
Keyword(s):  
Dna Methylation ◽  
Long Terminal Repeat ◽  
Promoter Activity ◽  
Endogenous Retrovirus ◽  
Terminal Repeat ◽  
Repeat Elements

scholarly journals Transcriptional Regulation of Early Transposon Elements, an Active Family of Mouse Long Terminal Repeat Retrotransposons

2005 ◽  
Vol 79 (22) ◽  
pp. 13865-13874 ◽  
Author(s):  
Irina A. Maksakova ◽  
Dixie L. Mager
Keyword(s):  
Transcriptional Regulation ◽  
Long Terminal Repeat ◽  
Promoter Activity ◽  
Embryonic Stem ◽  
Long Terminal Repeat Retrotransposons ◽  
Endogenous Retrovirus ◽  
Terminal Repeat ◽  
P19 Cells ◽  
Genomic Context ◽  
Transcription Start Sites

ABSTRACT While early transposon (ETn) endogenous retrovirus (ERV)-like elements are known to be active insertional mutagens in the mouse, little is known about their transcriptional regulation. ETns are transcribed during early mouse embryogenesis in embryonic stem (ES) and embryonic carcinoma (EC) cell lines. Despite their lack of coding potential, some ETns remain transposition competent through their use of reverse transcriptase encoded by a related group of ERVs—MusD elements. In this study, we have confirmed high expression levels of ETn and MusD elements in ES and EC cells and have demonstrated an increase in the copy number of ETnII elements in the EC P19 cell line. Using transient transfections, we have shown that ETnII and MusD LTRs are much more active as promoters in P19 cells than in NIH 3T3 cells, indicating that genomic context and methylation are not the only factors determining endogenous transcriptional activity of ETns. Three sites in the 5′ part of the long terminal repeat (LTR) were demonstrated to bind Sp1 and Sp3 transcription factors and were found to be important for high LTR promoter activity in P19 cells, suggesting that as yet unidentified Sp binding partners are involved in the regulation of ETn activity in undifferentiated cells. Finally, we found multiple transcription start sites within the ETn LTR and have shown that the LTR retains significant promoter activity in the absence of its noncanonical TATA box. These findings lend insight into the transcriptional regulation of this family of mobile mouse retrotransposons.

The long terminal repeat of an endogenous intracisternal A-particle gene functions as a promoter when introduced into eucaryotic cells by transfection

1984 ◽  
Vol 4 (10) ◽  
pp. 2128-2135
Author(s):  
K K Lueders ◽  
J W Fewell ◽  
E L Kuff ◽  
T Koch
Keyword(s):  
Long Terminal Repeat ◽  
Promoter Activity ◽  
Terminal Repeat ◽  
Flanking Sequence ◽  
Murine Sarcoma Virus ◽  
Sarcoma Virus ◽  
Mouse Cells ◽  
Moloney Murine Sarcoma Virus ◽  
Intracisternal A Particle ◽  
Murine Sarcoma

We describe experiments designed to determine whether an endogenous intracisternal A-particle (IAP) gene randomly selected from a mouse embryo library has the potential to be transcriptionally active. Assays for IAP gene transcription were done with permanently transformed rat cells and transiently transfected monkey and mouse cells. The rat cells, which had integrated IAP gene copies, contained IAP RNA. A start site within the IAP 5' long terminal repeat (LTR) was localized by S1 mapping. The promoter activity of the IAP LTR was also measured in cells 48 h after the introduction of recombinant plasmids in which bacterial chloramphenicol acetyl transferase (CAT) encoding sequences were under the control of the LTR. The IAP LTR promoted CAT activity in mouse and monkey cells. In mouse L-cells, the levels of CAT activity were 10 to 25% of those promoted by an analogous recombinant containing the Moloney murine sarcoma virus LTR as the promoter. In contrast to the Moloney murine sarcoma virus LTR, the IAP LTR was five- to eightfold more active in monkey cells than in mouse cells. The 5' and 3' LTRs were equally active, and promoter activity was dependent on having the orientation of the LTRs with respect to the CAT gene the same as their orientation with respect to the IAP gene. A 5'-flanking sequence containing a member of the highly repetitive R-sequence family increased CAT activity in COS cells 11-fold when present along with the LTR. Our results indicate that the LTR of an endogenous mouse IAP gene can function as an efficient promoter in heterologous as well as homologous cells.

scholarly journals The association of human endogenous retrovirus-H long terminal repeat-associating protein 2 (HHLA2) expression with gastric cancer prognosis

Oncotarget ◽  
2018 ◽  
Vol 9 (31) ◽  
pp. 22069-22078 ◽  
Author(s):  
Masataka Shimonosono ◽  
Takaaki Arigami ◽  
Shigehiro Yanagita ◽  
Daisuke Matsushita ◽  
Yasuto Uchikado ◽  
...  
Keyword(s):  
Gastric Cancer ◽  
Long Terminal Repeat ◽  
Endogenous Retrovirus ◽  
Terminal Repeat ◽  
Cancer Prognosis ◽  
Human Endogenous Retrovirus

Characterization of a Gallid herpesvirus 2 strain with novel reticuloendotheliosis virus long terminal repeat inserts

Virus Genes ◽  
2017 ◽  
Vol 53 (3) ◽  
pp. 386-391 ◽  
Author(s):  
Yan-ping Zhang ◽  
Ke-yan Bao ◽  
Guo-rong Sun ◽  
Hong-chao Lv ◽  
Hong-yu Cui ◽  
...  
Keyword(s):  
Long Terminal Repeat ◽  
Terminal Repeat ◽  
Reticuloendotheliosis Virus ◽  
Gallid Herpesvirus ◽  
Gallid Herpesvirus 2
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