| Primary Identifier | IPR037754 | Type | Family |
| Short Name | CSN4 |
| description | The COP9 signalosome (CSN) is a conserved protein complex that regulates the ubiquitin (Ubl) conjugation pathway by mediating the deneddylation of the cullin subunits of SCF-type E3 ligase complexes [], which leads to a decrease in Ubl ligase activity of SCF-type complexes such as SCF, CSA or DDB2 []. Protein kinases CK2 and D, which phosphorylate proteins such as cJun and p53 resulting in their degradation by the ubiquitin-26S proteasome system, also binds to CSN [, ]. The mammalian CSN typically consistis of eight subunits designated CSN1-CSN8. The fission yeast possesses a smaller version of the CSN, consisting only of six subunits, whereas a more distant CSN-like complex has been described in Saccharomyces cerevisiae [].This entry includes the COP9 signalosome complex (CSN) subunit 4 (CSN4). CSN4 also binds to the AAA+ ATPase torsinA, and CSN4 and torsinA in turn stabilize snapin, which is phosphorylated by protein kinase D, and stonin 2, which is neddylated. A mutation in torsinA leads to DYT1 dystonia, and overexpression of the mutant leads to a reduction of stonin 2 expression, suggesting that the mutant compromises the role of torsinA in protein stabilization and synaptic vesicle recycling []. |
