The RRM-mediated RNA binding activity in T. brucei RAP1 is essential for VSG monoallelic expression.

Trypanosoma brucei is a protozoan parasite that causes human African trypanosomiasis. Its major surface antigen VSG is expressed from subtelomeric loci in a strictly monoallelic manner. We previously showed that the telomere protein TbRAP1 binds dsDNA through its RKRRR patch to silence VSGs globally.

TbTRF suppresses the TERRA level and regulates the cell cycle-dependent TERRA foci number with a TERRA binding activity in its C-terminal Myb domain.

Telomere repeat-containing RNA (TERRA) has been identified in multiple organisms including Trypanosoma brucei, a protozoan parasite that causes human African trypanosomiasis. T. brucei regularly switches its major surface antigen, VSG, to evade the host immune response.

RAP1 has an unusual duplex DNA binding activity required for its telomere localization and VSG silencing.

Localization of Repressor Activator Protein 1 (RAP1) to the telomere is essential for its telomeric functions. RAP1 homologs either directly bind the duplex telomere DNA or interact with telomere-binding proteins. We find that RAP1 relies on a unique double-stranded DNA (dsDNA) binding activity to achieve this goal.

Cytosine DNA methylation at promoter of non LTR retrotransposon and heat shock protein gene (HSP70) of Entamoeba histolytica and lack of correlation with transcription status.

Non LTR retrotransposons (EhLINEs and EhSINEs) occupy 11% of the Entamoeba histolytica genome. Since promoter DNA methylation at cytosines has been correlated with transcriptional silencing of transposable elements in model organisms we checked whether this was the case in EhLINE1. We located promoter activity in a 841bp fragment at 5'-end of this element by luciferase reporter assay.

Functionally conserved RNA-binding and protein-protein interaction properties of LINE-ORF1p in an ancient clade of non-LTR retrotransposons of Entamoeba histolytica.

Retrotransposons are mobile genetic elements found in most organisms. Their origin and evolution is not very well understood. Retrotransposons that lack long terminal repeats (non-LTR) have been classified based on their reverse transcriptase (RT) and endonuclease sequences into groups, of which R2 is the most ancient.