title: The COP1 E3-ligase interacts with FIP200, a key regulator of mammalian autophagy.
abstract: BACKGROUND
  The ubiquitin ligase COP1, COnstitutively Photomorphogenic 1, functions in many biological responses in mammalian cells, but its downstream pathway remains unclear.
  
  
  RESULTS
  Here, we identified FIP200, a key regulator of mammalian autophagy, as a novel COP1-interacting protein by yeast two-hybrid screening. The interaction was confirmed by a GST-pulldown assay. Split-GFP analysis revealed that interaction between COP1 and FIP200 predominantly occurred in the cytoplasm and was enhanced in cells treated with UV irradiation. Different forms of FIP200 protein were expressed in cultured mammalian cells, and ectopic expression of COP1 reduced one of such forms.
  
  
  CONCLUSIONS
  These data suggest that COP1 modulates FIP200-associated activities, which may contribute to a variety of cellular functions that COP1 is involved in.
authors.affiliation: Graduate School of Biological Sciences, Nara Institute of Science and Technology, Nara, Japan.
authors.forename: Saori
authors.initials: S
authors.lastname: Kobayashi
authors.forename: Noriko
authors.initials: N
authors.lastname: Yoneda-Kato
authors.forename: Nagisa
authors.initials: N
authors.lastname: Itahara
authors.forename: Akihiro
authors.initials: A
authors.lastname: Yoshida
authors.forename: Jun-ya
authors.initials: JY
authors.lastname: Kato
mesh_terms: D000818:Animals; D001343:Autophagy / Q000502:physiology*; D000071183:Autophagy-Related Proteins; D002460:Cell Line; D003593:Cytoplasm / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D041681:NIH 3T3 Cells; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011485:Protein Binding; D015398:Signal Transduction; D020798:Two-Hybrid System Techniques; D044767:Ubiquitin-Protein Ligases / Q000235:genetics / Q000378:metabolism*; D014466:Ultraviolet Rays
chemical_list: D000071183:Autophagy-Related Proteins; D047908:Intracellular Signaling Peptides and Proteins; D009687:Nuclear Proteins; C428743:Rb1cc1 protein, mouse; C471982:COP1 protein, mouse; D044767:Ubiquitin-Protein Ligases