COP9 signalosome complex subunit 7b

COPS7B encodes COP9 signalosome complex subunit 7b (SGN7b), a structural component of the COP9 signalosome (CSN), a multi-subunit complex that regulates ubiquitin-dependent protein degradation (UniProt: Q9H9Q2). The CSN mediates deneddylation of cullin subunits in SCF-type E3 ligase complexes, thereby modulating their catalytic activity. The complex also phosphorylates key signaling proteins including p53, c-Jun, and NF-κB components, likely through associations with kinases such as CK2 and PKD.

CSN subunits are broadly involved in cellular homeostasis and developmental processes through coordination of protein turnover and signal transduction pathways. No primary disease associations are documented in UniProt curated annotations for COPS7B.

In Alzheimer's disease, COPS7B is upregulated in post-mortem AD brain tissue relative to age-matched controls (Chaparral AD proteomics). The protein showed a mean log₂ fold-change of +0.636 in human post-mortem AD brain versus control tissue, based on TMT-labeled proteomics across four subcellular fractions. This elevation suggests altered CSN-mediated protein degradation or signaling activity may contribute to AD pathophysiology.