title: Analysis of RNA decay factor mediated RNA stability contributions on RNA abundance.
abstract: BACKGROUND
  Histone epigenome data determined by chromatin immunoprecipitation sequencing (ChIP-seq) is used in identifying transcript regions and estimating expression levels. However, this estimation does not always correlate with eventual RNA expression levels measured by RNA sequencing (RNA-seq). Part of the inconsistency may arise from the variance in RNA stability, where the transcripts that are more or less abundant than predicted RNA expression from histone epigenome data are inferred to be more or less stable. However, there is little systematic analysis to validate this assumption. Here, we used stability data of whole transcriptome measured by 5'-bromouridine immunoprecipitation chase sequencing (BRIC-seq), which enabled us to determine the half-lives of whole transcripts including lincRNAs, and we integrated BRIC-seq with ChIP-seq to achieve better estimation of the eventual transcript levels and to understand the importance of post-transcriptional regulation that determine the eventual transcript levels.
  
  
  RESULTS
  We identified discrepancies between the RNA abundance estimated by ChIP-seq and measured RNA expression from RNA-seq; for number of genes and estimated that the expression level of 865 genes was controlled at the level of RNA stability in HeLa cells. ENCODE data analysis supported the idea that RNA stability control aids to determine transcript levels in multiple cell types. We identified UPF1, EXOSC5 and STAU1, well-studied RNA degradation factors, as controlling factors for 8% of cases. Computational simulations reasonably explained the changes of eventual mRNA levels attributable to the changes in the rates of mRNA half-lives. In addition, we propose a feedback circuit that includes the regulated degradation of mRNAs encoding transcription factors to maintain the steady state level of RNA abundance. Intriguingly, these regulatory mechanisms were distinct between mRNAs and lincRNAs.
  
  
  CONCLUSIONS
  Integrative analysis of ChIP-seq, RNA-seq and our BRIC-seq showed that transcriptional regulation and RNA degradation are independently regulated. In addition, RNA stability is an important determinant of eventual transcript levels. RNA binding proteins, such as UPF1, STAU1 and EXOSC5 may play active roles in such controls.
authors: Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan. smaekawa@hgc.jp.
authors: Sho
authors: S
authors: Maekawa
authors: Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan. imamachi@ric.u-tokyo.ac.jp.
authors: Naoto
authors: N
authors: Imamachi
authors: Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan. tirie@hgc.jp.
authors: Takuma
authors: T
authors: Irie
authors: Research Institute for Environmental Management Technology, National Institute of Advanced Industrial Science and Technology (AIST), 16-1 Onogawa, Tsukuba, Ibaraki, 305-8569, Japan. h.tani@aist.go.jp.
authors: Hidenori
authors: H
authors: Tani
authors: Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan. kk086409@mgs.k.u-tokyo.ac.jp.
authors: Kyoko
authors: K
authors: Matsumoto
authors: Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan. rena@ric.u-tokyo.ac.jp.
authors: Rena
authors: R
authors: Mizutani
authors: Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan. k.imamura@ric.u-tokyo.ac.jp.
authors: Katsutoshi
authors: K
authors: Imamura
authors: Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan. 3134mk@gmail.com.
authors: Miho
authors: M
authors: Kakeda
authors: Department of Bioscience and Bioinformatics, Kyushu Institute of Technology, 680-4 Kawazu, Iizuka, Fukuoka, 820-8502, Japan. ytetsu@bio.kyutech.ac.jp.
authors: Tetsushi
authors: T
authors: Yada
authors: Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan. ssugano@k.u-tokyo.ac.jp.
authors: Sumio
authors: S
authors: Sugano
authors: Department of Medical Genome Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8562, Japan. ysuzuki@k.u-tokyo.ac.jp.|Department of Computational Biology, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa, Chiba, 277-8561, Japan. ysuzuki@k.u-tokyo.ac.jp.
authors: Yutaka
authors: Y
authors: Suzuki
authors: Radioisotope Center, The University of Tokyo, 2-11-16 Yayoi, Bunkyo-ku, Tokyo, 113-0032, Japan. akimitsu@ric.u-tokyo.ac.jp.
authors: Nobuyoshi
authors: N
authors: Akimitsu
mesh_terms: D000951:Antigens, Neoplasm / Q000378:metabolism; D047369:Chromatin Immunoprecipitation; D003598:Cytoskeletal Proteins / Q000378:metabolism; D063326:Exosome Multienzyme Ribonuclease Complex / Q000378:metabolism; D005786:Gene Expression Regulation; D006207:Half-Life; D006367:HeLa Cells; D059014:High-Throughput Nucleotide Sequencing; D006657:Histones / Q000378:metabolism; D006801:Humans; D012313:RNA / Q000737:chemistry / Q000378:metabolism*; D020365:RNA Helicases; D020871:RNA Stability; D062085:RNA, Long Noncoding / Q000737:chemistry / Q000378:metabolism; D012333:RNA, Messenger / Q000737:chemistry / Q000378:metabolism; D016601:RNA-Binding Proteins / Q000378:metabolism; D017423:Sequence Analysis, RNA; D015534:Trans-Activators / Q000378:metabolism
chemical_list: D000951:Antigens, Neoplasm; D003598:Cytoskeletal Proteins; C467564:EXOSC5 protein, human; D006657:Histones; D062085:RNA, Long Noncoding; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; C492185:STAU1 protein, human; D015534:Trans-Activators; D012313:RNA; D063326:Exosome Multienzyme Ribonuclease Complex; D020365:RNA Helicases; C101828:UPF1 protein, human