The COP9 complex, a novel multisubunit nuclear regulator involved in light control of a plant developmental switch

Cell. 1996 Jul 12;86(1):115-21. doi: 10.1016/s0092-8674(00)80082-3.


Arabidopsis COP9 is a component of a large protein complex that is essential for the light control of a developmental switch and whose conformation or size is modulated by light. The complex is acidic, binds heparin, and is localized within the nucleus. Biochemical purification of the complex to near homogeneity revealed that it contains 12 distinct subunits. One of the other subunits is COP11, mutations in which result in a phenotype identical to cop9 mutants. The COP9 complex may act to regulate the nuclear abundance of COP1, an established repressor of photomorphogenic development. During the biogenesis of the COP9 complex, a certain degree of prior subunit association is a prerequisite for proper nuclear translocation. Since both COP9 and COP11 have closely related human counterparts, the COP9 complex probably represents a conserved developmental regulator in higher eukaryotes.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Arabidopsis / embryology*
  • Arabidopsis Proteins*
  • COP9 Signalosome Complex
  • Carrier Proteins / metabolism
  • Cell Nucleus / chemistry
  • Cell Nucleus / metabolism
  • Darkness
  • Gene Expression Regulation, Developmental / physiology
  • Gene Expression Regulation, Plant / physiology
  • Genes, Plant / physiology
  • Multiprotein Complexes
  • Peptide Hydrolases
  • Plant Proteins / genetics*
  • Plant Proteins / isolation & purification
  • Plant Proteins / metabolism
  • Plant Proteins / ultrastructure
  • Proteins*
  • Repressor Proteins / metabolism
  • Ubiquitin-Protein Ligases*


  • Arabidopsis Proteins
  • Carrier Proteins
  • Multiprotein Complexes
  • Plant Proteins
  • Proteins
  • Repressor Proteins
  • AT2G32950 protein, Arabidopsis
  • Ubiquitin-Protein Ligases
  • Peptide Hydrolases
  • COP9 Signalosome Complex