title: PolyA-specific ribonuclease (PARN-1) function in stage-specific mRNA turnover in Trypanosoma brucei.
abstract: Deadenylation is often the rate-limiting event in regulating the turnover of cellular mRNAs in eukaryotes. Removal of the poly(A) tail initiates mRNA degradation by one of several decay pathways, including deadenylation-dependent decapping, followed by 5' to 3' exonuclease decay or 3' to 5' exosome-mediated decay. In trypanosomatids, mRNA degradation is important in controlling the expression of differentially expressed genes. Genomic annotation studies have revealed several potential deadenylases. Poly(A)-specific RNase (PARN) is a key deadenylase involved in regulating gene expression in mammals, Xenopus oocytes, and higher plants. Trypanosomatids possess three different PARN genes, PARN-1, -2, and -3, each of which is expressed at the mRNA level in two life-cycle stages of the human parasite Trypanosoma brucei. Here we show that T. brucei PARN-1 is an active deadenylase. To determine the role of PARN-1 on mRNA stability in vivo, we overexpressed this protein and analyzed perturbations in mRNA steady-state levels as well as mRNA half-life. Interestingly, a subset of mRNAs was affected, including a family of mRNAs that encode stage-specific coat proteins. These data suggest that PARN-1 functions in stage-specific protein production.
authors: Department of Microbiology and Molecular Genetics, University of Medicine and Dentistry-New Jersey Medical School, Newark, NJ 07103, USA.
authors: Christopher J
authors: CJ
authors: Utter
authors: Stacey A
authors: SA
authors: Garcia
authors: Joseph
authors: J
authors: Milone
authors: Vivian
authors: V
authors: Bellofatto
mesh_terms: D005095:Exoribonucleases / Q000235:genetics* / Q000378:metabolism; D006207:Half-Life; D006801:Humans; D046228:Microarray Analysis; D020871:RNA Stability / Q000235:genetics*; D012333:RNA, Messenger / Q000378:metabolism*; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000302:isolation & purification* / Q000378:metabolism; D014158:Transcription, Genetic; D014346:Trypanosoma brucei brucei / Q000235:genetics* / Q000378:metabolism
chemical_list: D005095:Exoribonucleases; D012333:RNA, Messenger; D011993:Recombinant Fusion Proteins