additive and transcript-specific effects of kpap1 and tbrnd activities on 3′ non-encoded tail characteristics and mrna stability in trypanosoma brucei添加剂和transcript-specific kpap1和tbrnd活动3u2032non-encoded尾特征和mrna稳定锥虫属brucei.pdfVIP

Additive and Transcript-Specific Effects of KPAP1 and TbRND Activities on 3 9 Non-Encoded Tail Characteristics and mRNA Stability in Trypanosoma brucei Sara L. Zimmer, Sarah M. McEvoy¤a, Sarita Menon¤b, Laurie K. Read* Department of Microbiology and Immunology, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, New York, United States of America Abstract Short, non-encoded oligo(A), oligo(U), or A/U tails can impact mRNA stability in kinetoplastid mitochondria. However, a comprehensive picture of the relative effects of these modifications in RNA stability is lacking. Furthermore, while the U- preferring exoribonuclease TbRND acts on U-tailed gRNAs, its role in decay of uridylated mRNAs has only been cursorily investigated. Here, we analyzed the roles of mRNA 39 tail composition and TbRND in RNA decay using cells harbouring single or double knockdown of TbRND and the KPAP1 poly(A) polymerase. Analysis of mRNA abundance and tail composition reveals dramatic and transcript-specific effects of adenylation and uridylation on mitochondrial RNAs. Oligo(A) and A-rich tails can stabilize a proportion of edited and never-edited RNAs. However, non-tailed RNAs are not inherently unstable, implicating additional stability determinants and/or spatial segregation of sub-populations of a given RNA in regulation of RNA decay. Oligo(U) tails, which have been shown to contribute to decay of some never-edited RNAs, are not universally destabilizing. We also show that RNAs display very different susceptibility to uridylation in the absence of KPAP1, a factor that may contribute to regulation of decay. Finally, 39 tail composition apparently impacts the ability of an RNA to be edited. Citation: Zimmer SL, McEvoy SM, Menon S, Read LK (2012) Additive a