COPS5
Description
The COPS5 (COP9 signalosome subunit 5) is a protein-coding gene located on chromosome 8.
COPS5, also known as Csn5, is a highly conserved gene present from humans to yeast. It encodes a subunit of the COP9 signalosome (CSN), a protein complex crucial for regulating various signaling pathways. The CSN complex resembles the 19S regulatory particle of the 26S proteasome and interacts with SCF-type E3 ubiquitin ligases. COPS5 has been implicated in the degradation of the cyclin-dependent kinase inhibitor CDKN1B/p27Kip1. It also acts as a coactivator, increasing the specificity of JUN/AP1 transcription factors. COPS5 interacts with several proteins, including Macrophage migration inhibitory factor, GFER, BCL3, Ubiquitin carboxy-terminal hydrolase L1, S100A7, and C-jun.
COPS5 is a subunit of the COP9 signalosome (CSN) complex, a key regulator of protein degradation and cellular processes. The CSN complex removes Nedd8 from cullin proteins, inhibiting the activity of SCF-type E3 ubiquitin ligases. COPS5 is crucial for this process, acting as the catalytic center for Nedd8 removal, although it lacks independent metalloprotease activity and requires other CSN subunits. COPS5 also participates in phosphorylation events, potentially through interactions with kinases like CK2 and PKD, affecting the stability of proteins like p53 and c-Jun. Beyond its role in the CSN complex, COPS5 directly interacts with numerous proteins, highlighting its significant regulatory function.
COPS5 is also known as CSN5, JAB1, MOV-34, SGN5.
