COP1 - from plant photomorphogenesis to mammalian tumorigenesis

Trends Cell Biol. 2005 Nov;15(11):618-25. doi: 10.1016/j.tcb.2005.09.007. Epub 2005 Sep 29.


The COP1 (constitutive photomorphogenic 1) protein, comprising RING finger, coiled-coil and WD40 domains, is conserved in both higher plants and vertebrates. In plants, COP1 acts as an E3 ubiquitin ligase to repress light signaling by targeting photoreceptors and downstream transcription factors for ubiquitylation and degradation. The activity of COP1 in plant cells correlates with its cytoplasmic and nuclear partitioning according to dark or light conditions. In addition, various signaling molecules have been shown to directly interact with COP1 and modulate its activity. Recently, scientists have begun to probe the function and regulation of COP1 in mammalian systems. Initial studies have pointed at possible roles for mammalian COP1 in tumorigenesis and the stress response through regulating the activities of p53 and c-Jun.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Review

MeSH terms

  • Animals
  • Arabidopsis Proteins / physiology*
  • Humans
  • Models, Biological
  • Morphogenesis / physiology
  • Morphogenesis / radiation effects
  • Neoplasms / etiology
  • Nuclear Proteins / physiology*
  • Plant Development
  • Plants / radiation effects
  • Protein Transport / physiology
  • Proto-Oncogene Proteins c-jun / metabolism
  • Tumor Suppressor Protein p53 / metabolism
  • Ubiquitin-Protein Ligases / physiology*


  • Arabidopsis Proteins
  • Nuclear Proteins
  • Proto-Oncogene Proteins c-jun
  • Tumor Suppressor Protein p53
  • AT2G32950 protein, Arabidopsis
  • COP1 protein, human
  • COP1 protein, mouse
  • Ubiquitin-Protein Ligases