Bidirectional silencing of RNA polymerase I transcription by a strand switch region in Trypanosoma brucei

Bidirectional silencing of RNA polymerase I transcription by a strand switch region in Trypanosoma brucei

The procyclin genes in Trypanosoma brucei are transcribed by RNA polymerase I as part of 5-10 kb long polycistronic transcription units on chromosomes VI and X. Each procyclin locus begins with two procyclin genes followed by at least one procyclin-associated gene (PAG). In procyclic (insect midgut) form trypanosomes, PAG mRNA levels are about 100-fold lower than those of procyclins. We show th...

RNA polymerase II subunit RPB7 is required for RNA polymerase I mediated transcription in Trypanosoma brucei

Active RNA polymerase I of Trypanosoma brucei harbors a novel subunit essential for transcription.

A unique characteristic of the protistan parasite Trypanosoma brucei is a multifunctional RNA polymerase I which, in addition to synthesizing rRNA as in other eukaryotes, transcribes gene units encoding the major cell surface antigens variant surface glycoprotein and procyclin. Thus far, purification of this enzyme has revealed nine orthologues of known subunits but no active enzyme. Here, we h...

Histone H3 Variant Regulates RNA Polymerase II Transcription Termination and Dual Strand Transcription of siRNA Loci in Trypanosoma brucei

Base J, β-D-glucosyl-hydroxymethyluracil, is a chromatin modification of thymine in the nuclear DNA of flagellated protozoa of the order Kinetoplastida. In Trypanosoma brucei, J is enriched, along with histone H3 variant (H3.V), at sites involved in RNA Polymerase (RNAP) II termination and telomeric sites involved in regulating variant surface glycoprotein gene (VSG) transcription by RNAP I. Re...

RNA polymerase I transcription stimulates homologous recombination in T. brucei