Poster abstracts
Poster number 90 submitted by Natalie McAdams
RNA trafficking during trypanosome RNA editing
Natalie M. McAdams (Department of Microbiology and Immunology, University at Buffalo School of Medicine), Laurie K. Read (Department of Microbiology and Immunology, University at Buffalo School of Medicine)
Abstract:
Kinetoplastid parasites, including Trypanosoma brucei, T. cruzi, and Leishmania spp., are the causative agents of African sleeping sickness, Chagas disease, and leishmaniasis in humans leading to hundreds of thousands of deaths per year worldwide. Mitochondrial mRNAs in kinetoplastid parasites require extensive remodeling by a unique process termed uridine insertion/deletion RNA editing. For the majority of transcripts, RNA editing is required to create translatable open reading frames, and thus editing is essential for proliferation of both human and insect vector stages of the kinetoplastid, Trypanosoma brucei. Small trans-acting guide RNAs (gRNAs), encoded in the minicircle component of the mitochondrial genome, direct proper U insertion or deletion. The enzymes that catalyze endonucleolytic cleavage of pre-mRNA, U addition, U removal, and resealing by ligation are present in a stable multiprotein structure termed the RNA editing core complex (RECC) or 20S editosome. While RECC structure and enzymology has been probed, the mechanisms by which RECC interacts with mRNAs and gRNAs are almost completely unknown. Recently, we have identified a dynamic multiprotein complex termed the MRB1 complex (mitochondrial RNA binding complex) as a key component of the editing machinery, possibly as the RNA binding component of the editing holoenzyme. Our hypothesis is that the MRB1 complex plays a critical role in RNA trafficking to RECC. Here we look to define the role of two MRB1 subcomplexes in the recruitment of gRNA and pre-mRNA to RECC using UV cross-linking/RNA-immunoprecipitation (CLIP) in cells depleted of specific MRB1 proteins.
Keywords: RNA editing, trypanosome