We generated viral constructs to test the hypothesis that the major substrate on retroviral DNA that is utilized for proviral DNA integration is the palindromic sequence, termed the LTR-LTR junction, normally present in circular molecules formed by joining the two termini of linear proviral DNA. Recombinant viral genomes were built which carried a selectable marker and an extra copy of the LTR-...

BACKGROUND Non-human primates infected with simian immunodeficiency virus (SIV) represent a robust model to evaluate pre-clinical efficacy of HIV-1 preventive strategies and to determine the size of reservoir. METHODS We developed a real-time qPCR assay to specifically quantify episomal 2-LTR circular DNA in peripheral blood mononuclear cells and brain tissues from SIV-infected macaques. RE...

A region of the Reticuloendotheliosis virus (REV) long terminal repeat (LTR) harbouring single or duplicated copies of 46-bp and 26-bp sequence elements is implicated in enhancer activity. Sequences residing upstream from the proviral 3' LTR did not contribute to activity of the intact LTR. Gene expression regulated by a combination of REV enhancer and SV40 early region promoter was 50-fold les...

The role of plant tyrosyl-DNA phosphodiesterase 1α in genome stability is studied using a Medicago truncatula MtTdp1α-depleted line. Lack of MtTdp1α results in a 39% reduction of methylated cytosines as compared to control. RNA-Seq analyses revealed that 11 DNA transposons and 22 retrotransposons were differentially expressed in the Tdp1α-2a line. Among them all, DNA transposons (MuDR, hAT, DNA...

The terminal sequences of long-terminal repeat (LTR) retrotransposons are a source of powerful molecular markers for linkage mapping and biodiversity studies. The major factor limiting the widespread application of LTR retrotransposon-based molecular markers is the availability of new retrotransposon terminal sequences. We describe a PCR-based method for the rapid isolation of LTR sequences of ...

BACKGROUND Apolipoprotein E (ApoE) is the major carrier protein that mediates the transport and delivery of cholesterol and other lipids in the brain. Three isoforms of ApoE (ApoE2, ApoE3, ApoE4) exist in humans, and their relative expression levels impact HIV-1 infection, HIV-1/AIDS disease progression, and cognitive decline associated with HIV-1-associated neurocognitive disorder. Because HIV...

Mouse mammary tumor virus (MMTV) transcription is highest in the lactating mammary gland but is detectable in a variety of other tissues. Previous results have shown that MMTV expression is suppressed in lymphoid and other tissues through the binding of the homeodomain-containing repressor special AT-rich binding protein 1 to a negative regulatory element (NRE) in the MMTV long terminal repeat ...

HIV-1 is transcriptionally active in activated T helper (Th)-cells and inactive in naive or resting memory Th-cells. Ets-2 is a preinduction transcriptional repressor of the IL-2 gene in naive Th-cells and a candidate transcriptional repressor of HIV-1 in the same cells, because the -279 to -250 upstream region of HIV-1-LTR [repressor-activator target sequence (RATS)], that participates in HIV-...

Human Jurkat T cells containing a stably integrated human T cell leukaemia virus type 1 (HTLV-1) long terminal repeat (LTR) reporter gene construct were used to study the role of calcium-dependent cellular activation pathways in LTR trans-activation. Treatment of these cells with the calcium ionophore ionomycin resulted in a reduced basal response of the LTR and reduced responses to 12-O-tetrad...