title: Transcription of the Trypanosoma brucei spliced leader RNA gene is dependent only on the presence of upstream regulatory elements.
abstract: The spliced leader (SL) RNA plays a key role in mRNA maturation in trypanosomatid protozoa by providing the SL sequence, which is joined to the 5' end of every mRNA. As a first step towards a better understanding of the biogenesis and function of the SL RNA, we expressed a tagged SL RNA gene in a cell-free system of procyclic Trypanosoma brucei cells. Transcription initiates at + 1 can be detected as early as 1 min after addition of extract. Transcription of the SL RNA gene in vitro, as well as in permeable cells, is mediated by an alpha-amanitin/tagetitoxin resistant complex, suggesting a promoter that is intermediate between a classical RNA polymerase II and RNA polymerase III promoter. An analysis of the promoter architecture of the SL RNA gene revealed that regulatory elements are located upstream of the coding region and that the SL sequence, in contrast to the nematode SL sequence, is not required for T. brucei SL RNA gene transcription.
authors.affiliation: Department of Internal Medicine, Yale University School of Medicine, New Haven, CT 06520-8022, USA.
authors.forename: A
authors.initials: A
authors.lastname: Günzl
authors.forename: E
authors.initials: E
authors.lastname: Ullu
authors.forename: M
authors.initials: M
authors.lastname: Dörner
authors.forename: S P
authors.initials: SP
authors.lastname: Fragoso
authors.forename: K F
authors.initials: KF
authors.lastname: Hoffmann
authors.forename: J D
authors.initials: JD
authors.lastname: Milner
authors.forename: Y
authors.initials: Y
authors.lastname: Morita
authors.forename: E K
authors.initials: EK
authors.lastname: Nguu
authors.forename: S
authors.initials: S
authors.lastname: Vanacova
authors.forename: S
authors.initials: S
authors.lastname: Wünsch
authors.forename: A O
authors.initials: AO
authors.lastname: Dare
authors.forename: H
authors.initials: H
authors.lastname: Kwon
authors.forename: C
authors.initials: C
authors.lastname: Tschudi
mesh_terms: D000546:Amanitins / Q000494:pharmacology; D000818:Animals; D001483:Base Sequence; D003998:Dicarboxylic Acids / Q000494:pharmacology; D017125:Genes, Protozoan; D008969:Molecular Sequence Data; D009154:Mutation; D019384:Nucleic Acid Synthesis Inhibitors / Q000494:pharmacology; D009943:Organophosphorus Compounds / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D012326:RNA Splicing; D012333:RNA, Messenger / Q000096:biosynthesis / Q000235:genetics*; D016053:RNA, Protozoan / Q000096:biosynthesis / Q000235:genetics*; D014158:Transcription, Genetic; D014346:Trypanosoma brucei brucei / Q000235:genetics*
chemical_list: D000546:Amanitins; D003998:Dicarboxylic Acids; D019384:Nucleic Acid Synthesis Inhibitors; D009943:Organophosphorus Compounds; D012333:RNA, Messenger; D016053:RNA, Protozoan; C062221:tagetitoxin