title: Characterization of RNA polymerase II subunits of Trypanosoma brucei.
abstract: The Trypanosoma brucei homolog of the RNA polymerase II (RNA Pol II) subunit RPB9 was cloned and characterized. Contrary to what occurs in Saccharomyces cerevisiae, in T. brucei this protein was found to be essential since the knock down of its expression by RNAi led to lethality in both bloodstream and procyclic forms of the parasite. As expected, TbRPB9 knock down specifically inhibited transcription by RNA Pol II, but not by RNA Pol I and III. TbRPB9 was used as bait to isolate the RNA Pol II core complex by tandem affinity purification. Nine subunits homologous to the other eukaryotic RNA Pol II, namely RPB1, RPB2, RPB3, RPB4, RPB5, RPB6, RPB7, RPB8 and RPB11, were identified in the purified complex. Interestingly, the RPB5 homolog associated with RNA Pol II was different from the one previously found in RNA Pol I. Analysis of the genome database revealed the presence of genes for all purified subunits plus RPB10. As in the case of TbRPB5, two genes coding for different isoforms of TbRPB6 were identified, suggesting the existence of polymerase-specific isoforms for both TbRPB5 and TbRPB6.
authors.affiliation: Laboratory of Molecular Parasitology, Institute for Molecular Biology and Medicine (IBMM), Université Libre de Bruxelles, Gosselies, Belgium.
authors.forename: Sara
authors.initials: S
authors.lastname: Devaux
authors.forename: Laurence
authors.initials: L
authors.lastname: Lecordier
authors.forename: Pierrick
authors.initials: P
authors.lastname: Uzureau
authors.forename: David
authors.initials: D
authors.lastname: Walgraffe
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Dierick
authors.forename: Philippe
authors.initials: P
authors.lastname: Poelvoorde
authors.forename: Etienne
authors.initials: E
authors.lastname: Pays
authors.forename: Luc
authors.initials: L
authors.lastname: Vanhamme
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D003001:Cloning, Molecular; D017125:Genes, Protozoan; D008969:Molecular Sequence Data; D021122:Protein Subunits / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics*; D012319:RNA Polymerase II / Q000235:genetics*; D016415:Sequence Alignment; D014158:Transcription, Genetic; D014346:Trypanosoma brucei brucei / Q000201:enzymology* / Q000235:genetics
chemical_list: D021122:Protein Subunits; D015800:Protozoan Proteins; D012319:RNA Polymerase II