Characterization of a SR protein from Trypanosoma brucei with homology to RNA-binding cis-splicing proteins.
The protozoan parasite Trypanosoma brucei relies on trans-splicing to process its mRNAs. A novel nuclear serine/arginine (SR)-rich trypanosomal protein (TSR1) was characterized which contains two RNA recognition motifs. The TSR1 protein appears to be homologous to RNA-binding SR proteins of the cis-splicing machinery from higher eukaryotes. Moreover, in the yeast two-hybrid system, TSR1 is able to interact with the human splicing factors involved in the recognition of the 3' splicing site (U2AF35/U2AF65). In both procyclic and bloodstream forms of T. brucei, TSR1 was found to localize in the nucleus. In the bloodstream stage TSR1 showed the speckles pattern characteristic of SR proteins involved in cis-splicing. Moreover, TSR1 was able to specifically bind the spliced leader (SL) RNA involved in trans-splicing in trypanosomes by the yeast three-hybrid system. These and other observations suggest that TSR1 may be involved in trans-splicing in T. brucei.
Ismaïli
N
N
Department of Molecular Biology, Free University of Brussels, Rhode St Genèse, Belgium.
Pérez-Morga
D
D
Walsh
P
P
Mayeda
A
A
Pays
A
A
Tebabi
P
P
Krainer
A R
AR
Pays
E
E
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D016054:DNA, Protozoan / Q000032:analysis; D005455:Fluorescent Antibody Technique; D005656:Fungal Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D006801:Humans; D051379:Mice; D008969:Molecular Sequence Data; D009687:Nuclear Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism; D016053:RNA, Protozoan / Q000378:metabolism; D020038:RNA, Spliced Leader / Q000235:genetics; D016601:RNA-Binding Proteins / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D020040:Trans-Splicing / Q000235:genetics*; D014158:Transcription, Genetic; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000378:metabolism*
D016054:DNA, Protozoan; D005656:Fungal Proteins; D009687:Nuclear Proteins; D016053:RNA, Protozoan; D020038:RNA, Spliced Leader; D016601:RNA-Binding Proteins; C118745:TSR1 protein, Yarrowia lipolytica