Related Experiment Video
Updated: Jun 19, 2026

Identification of Protein Interaction Partners in Mammalian Cells Using SILAC-immunoprecipitation Quantitative Proteomics
Published on: July 6, 2014
Mammalian COP9 signalosome
Jun-ya Kato1, Noriko Yoneda-Kato
1Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan. jkata@bs.naist.jp
Abstract:
The COP9 signalosome (CSN) complex is highly conserved from yeast to human. Although the plant CSN was first identified as a negative regulator of photomorphogenesis, the mammalian CSN is linked to different biological responses such as checkpoint control, signal transduction, development and the cell cycle. Frequent over-expression of the CSN subunit in a variety of human cancers suggests its involvement in cell transformation and tumorigenesis. The best-known biochemical function associated with the CSN is the control of protein stability via the ubiquitin-proteasome system through regulation of cullin-RING-E3 ubiquitin ligase activity by deneddylation, by controlling the activity of COP1 E3 ligase, or by counteracting ubiquitin-mediated degradation through a CSN-associated deubiquitinating enzyme. In addition to affecting the stability of transcription factors, the CSN may regulate gene transcription by directly associating with chromatin. This review summarizes recent findings and discusses the physiological role and the cellular function of the mammalian CSN in terms of the regulation of cell proliferation.
Related Concept Videos
Coat Assembly and GTPases
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
Assembly of Signaling Complexes
Interaction domains in cell signaling
Interaction domains recognize exposed features of their binding partners containing post-translationally modified sequences,...
Hedgehog Signaling Pathway
Hedgehog Signaling Pathway
Protein Translocation Machinery on the ER Membrane
Sec61 protein conducting channel
In eukaryotes, the translocon complex comprises a core heterotrimeric translocator channel called the Sec61 complex. This channel includes three transmembrane proteins, Sec61α, Sec61β, and Sec61γ, and is the largest subunit of the translocon complex.
Cotranslational Protein Translocation
Sec61 channel partners for cotranslational translocation
During cotranslational translocation, the Sec61 channel partners with the signal recognition particle (SRP), the signal recognition particle receptor (SR), and the ribosomes to transport the nascent polypeptide chain...

