COP9 signalosome complex subunit 3

COP9 signalosome complex subunit 3 is a protein that in humans is encoded by the "COPS3" gene. It encodes a subunit of the COP9 signalosome.
The protein encoded by this gene possesses kinase activity that phosphorylates regulators involved in signal transduction. It phosphorylates I-kappa-B-alpha, p105, and c-Jun. It acts as a docking site for complex-mediated phosphorylation. The gene is located within the Smith-Magenis syndrome region on chromosome 17.