title: KREPA4, an RNA binding protein essential for editosome integrity and survival of Trypanosoma brucei.
abstract: The 20S editosome, a multiprotein complex, catalyzes the editing of most mitochondrial mRNAs in trypanosomatids by uridylate insertion and deletion. RNAi mediated inactivation of expression of KREPA4 (previously TbMP24), a component of the 20S editosome, in procyclic form Trypanosoma brucei resulted in inhibition of cell growth, loss of RNA editing, and disappearance of 20S editosomes. Levels of MRP1 and REAP-1 proteins, which may have roles in editing but are not editosome components, were unaffected. Tagged KREPA4 protein is incorporated into 20S editosomes in vivo with no preference for either insertion or deletion subcomplexes. Consistent with its S1-like motif, recombinant KREPA4 protein binds synthetic gRNA with a preference for the 3' oligo (U) tail. These data suggest that KREPA4 is an RNA binding protein that may be specific for the gRNA Utail and also is important for 20S editosome stability.
authors.affiliation: Seattle Biomedical Research Institute, Washington 98109-5219, USA.
authors.forename: Reza
authors.initials: R
authors.lastname: Salavati
authors.forename: Nancy Lewis
authors.initials: NL
authors.lastname: Ernst
authors.forename: Jeff
authors.initials: J
authors.lastname: O'Rear
authors.forename: Troy
authors.initials: T
authors.lastname: Gilliam
authors.forename: Salvador
authors.initials: S
authors.lastname: Tarun
authors.forename: Kenneth
authors.initials: K
authors.lastname: Stuart
mesh_terms: D020816:Amino Acid Motifs; D000595:Amino Acid Sequence; D000818:Animals; D015153:Blotting, Western; D004591:Electrophoresis, Polyacrylamide Gel; D024202:Electrophoretic Mobility Shift Assay; D004926:Escherichia coli / Q000235:genetics; D006639:Histidine / Q000737:chemistry; D008958:Models, Molecular; D008969:Molecular Sequence Data; D017433:Protein Structure, Secondary; D015800:Protozoan Proteins / Q000737:chemistry / Q000378:metabolism*; D017393:RNA Editing; D034622:RNA Interference; D017394:RNA, Guide, Kinetoplastida / Q000378:metabolism; D016053:RNA, Protozoan / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000235:genetics / Q000302:isolation & purification / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D017386:Sequence Homology, Amino Acid; D014346:Trypanosoma brucei brucei / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: C510680:KREPA4 protein, Trypanosoma brucei; D015800:Protozoan Proteins; D016053:RNA, Protozoan; D016601:RNA-Binding Proteins; D011993:Recombinant Fusion Proteins; D006639:Histidine; D017394:RNA, Guide, Kinetoplastida