Alpha-amanitin resistant transcription of protein coding genes in insect and bloodstream form Trypanosoma brucei.
AUTOR(ES)
Rudenko, G
RESUMO
The variant cell surface glycoprotein (VSG) gene expression sites of the protozoan Trypanosoma brucei are transcribed by an unusual alpha-amanitin resistant RNA polymerase. All other protein coding genes of T.brucei examined to date are transcribed by an alpha-amanitin sensitive RNA polymerase, presumably RNA polymerase II. We now show that transcription of protein coding genes by alpha-amanitin resistant RNA polymerases is not unique to the bloodstream form expressed VSG gene expression sites, but also occurs in insect form trypanosomes, which do not express VSG genes. In insect form trypanosomes transcription of the procyclin or PARP genes is resistant to alpha-amanitin to a degree comparable with that of VSG and ribosomal RNA (rRNA) genes. Comparison of the alpha-amanitin resistantly transcribed PARP and VSG gene families shows that they both produce one of the most abundant mRNAs [1-3% of poly(A)+] and they both encode the major cell surface proteins of their respective life cycle stages. Transcription of a subset of functionally comparable protein coding genes is thus mediated by an RNA polymerase which differs from the regular RNA polymerase II.
ACESSO AO ARTIGO
http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=401628Documentos Relacionados
- Alpha-amanitin insensitive transcription of the human epsilon-globin gene.
- Influence of the DNA/protein ratio on the alpha-amanitin sensitivity of in vitro transcription.
- DNA-mediated transformation of bloodstream-form Trypanosoma brucei.
- Procyclic acidic repetitive protein (PARP) genes located in an unusually small alpha-amanitin-resistant transcription unit: PARP promoter activity assayed by transient DNA transfection of Trypanosoma brucei.
- Localization of kinetoplast DNA maxicircle transcripts in bloodstream and procyclic form Trypanosoma brucei.
