title: Phospholipid scramblase 1 functionally interacts with angiogenin and regulates angiogenin-enhanced rRNA transcription.
abstract: BACKGROUND
  Angiogenin (ANG) can translocate to the target cell nucleus and accumulate in the nucleolus to enhance rRNA transcription, thus promoting cell proliferation. However, the regulation of ANG-enhanced rRNA transcription remains unknown. Previously we identified phospholipid scramblase 1 (PLSCR1) as a potential ANG-interacting protein in yeast two-hybrid screening.
  
  
  METHODS
  The interaction was re-confirmed in yeast cells and further verified by in vitro pull down, in vivo co-immunoprecipitation (Co-IP), fluorescent resonance energy transfer (FRET) and immunofluorescence analyses. The rRNA transcription level was determined by real-time quantitative PCR and Northern blot.
  
  
  RESULTS
  PLSCR1 was identified as a novel ANG-interacting protein. Notably, PLSCR1 interacted with ANG in the cell nucleus and regulated rRNA transcription. Furthermore, depletion of cellular ANG expression abolished PLSCR1-enhanced rRNA transcription, which could be rescued by exogenous ANG.
  
  
  CONCLUSIONS
  Our data suggest that PLSCR1 positively regulates rRNA transcription through interacting with ANG, thus deepening our understanding on rRNA transcription regulation.
authors.affiliation: Institute of Environmental Medicine, Zhejiang University School of Medicine, Hangzhou, China.
authors.forename: Junqiao
authors.initials: J
authors.lastname: Zhu
authors.forename: Jinghao
authors.initials: J
authors.lastname: Sheng
authors.forename: Haojie
authors.initials: H
authors.lastname: Dong
authors.forename: Lan
authors.initials: L
authors.lastname: Kang
authors.forename: Jian
authors.initials: J
authors.lastname: Ang
authors.forename: Zhengping
authors.initials: Z
authors.lastname: Xu
mesh_terms: D002467:Cell Nucleus / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D047468:Immunoprecipitation; D049294:Phospholipid Transfer Proteins / Q000235:genetics / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D011485:Protein Binding; D034622:RNA Interference; D012335:RNA, Ribosomal / Q000235:genetics / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism; D012259:Ribonuclease, Pancreatic / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D014158:Transcription, Genetic; D020798:Two-Hybrid System Techniques
chemical_list: C493422:PLSCR1 protein, human; D049294:Phospholipid Transfer Proteins; D012335:RNA, Ribosomal; D034741:RNA, Small Interfering; C046366:angiogenin; D012259:Ribonuclease, Pancreatic