In vitro analysis of alpha-amanitin-resistant transcription from the rRNA, procyclic acidic repetitive protein, and variant surface glycoprotein gene promoters in Trypanosoma brucei.

In Vitro Analysis of a-Amanitin-Resistant Transcription from the rRNA, Procyclic Acidic Repetitive Protein, and Variant Surface Glycoprotein Gene Promoters in Trypanosoma brucei

Alpha-amanitin-resistant transcription units in trypanosomes: a comparison of promoter sequences for a VSG gene expression site and for the ribosomal RNA genes.

Transcription of the predominant surface antigen genes in Trypanosoma brucei is unusual in its resistance to the RNA polymerase inhibitor alpha-amanitin, a property typical for rDNA transcription in eukaryotes. Transcription of most other protein-coding genes in trypanosomes is sensitive to alpha-amanitin. To investigate whether RNA polymerase I, the polymerase that transcribes rRNA genes, can ...

Developmental Variation of Glycosylphosphatidylinositol Membrane Anchors in Trypanosoma brucei

The major surface antigen of the mammalian bloodstream form of Trypanosoma brucei, the variant surface glycoprotein (VSG), is attached to the cell membrane by a glycosylphosphatidylinositol (GPI) anchor. The VSG anchor is susceptible to phosphatidylinositolspecific phospholipase C (PI-PLC). Candidate precursor glycolipids, P2 and P3, which are PI-PLC-sensitive and -resistant respectively, have ...

Position-dependent and promoter-specific regulation of gene expression in Trypanosoma brucei.

Trypanosoma brucei evades the mammalian immune response by a process of antigenic variation. This involves mutually exclusive and alternating expression of telomere-proximal variant surface glycoprotein genes (vsgs), which is controlled at the level of transcription. To examine transcription repression in T.brucei we inserted reporter genes, under the control of either rRNA or vsg expression si...

RNA polymerase I transcribes procyclin genes and variant surface glycoprotein gene expression sites in Trypanosoma brucei.

In eukaryotes, RNA polymerase (pol) I exclusively transcribes the large rRNA gene unit (rDNA) and mRNA is synthesized by RNA pol II. The African trypanosome, Trypanosoma brucei, represents an exception to this rule. In this organism, transcription of genes encoding the variant surface glycoprotein (VSG) and the procyclins is resistant to alpha-amanitin, indicating that it is mediated by RNA pol...