Vaòáèová, Š., Tachezy, J.,
Ullu, E., Tschudi, C. 2001. Unusual diversity in a-amanitin sensitivity of RNA
polymerases in trichomonads. Molecular and Biochemical Parasitology 115 (2):239-247.
Author Keywords:
Trichomonas vaginalis, Tritrichomonas foetus, permeable cells, gene transcription,
alpha-amanitin, tagetitoxin
PROTEIN-CODING GENES, TRYPANOSOMA-BRUCEI, PHYLOGENETIC-RELATIONSHIPS, RESISTANT
TRANSCRIPTION, LARGEST SUBUNIT, DNA, EXPRESSION, MUTATIONS, DEHYDROGENASE, PARABASALIDS
Abstract:
Previous studies in the parasitic protist Trichomonas vaginalis have revealed
that protein coding genes are transcribed by an alpha -amanitin-resistant RNA
polymerase (RNAP) II. To investigate whether this unusual property is a general
characteristic of trichomonads, we addressed the physiology of RNA synthesis in
lysolecithin-permeabilized cells. Unlike in T. vaginalis. RNAP II in Tritrichomonas
foetus was highly sensitive to the inhibitor alpha -amanitin. On the other hand,
RNAP III, identified by its sensitivity to the specific inhibitor tagetitoxin,
was found to be resistant to alpha -amanitin in Tritrichomonas foetus, but showed
a typical intermediate sensitivity in T. vaginalis. Extension of this study to
an additional seven trichomonad species confirmed this genera specific pattern
of alpha -amanitin sensitivity and highlighted an unusual diversity in RNAPs among
trichomonads, a closely related group of unicellular eukaryotes. (C) 2001 Elsevier
Science B.V. All rights reserved.
ISSN 0166-6851
IF 2,622
NETHERLANDS