Ubiquitin carboxyl-terminal hydrolase 14 (USP14)

Proteasome-associated deubiquitinase which releases ubiquitin from the proteasome targeted ubiquitinated proteins. Ensures the regeneration of ubiquitin in the proteasome.

Is a reversibly associated subunit of the proteasome and a large fraction of proteasome-free protein exists within the cell. Required for the degradation of the chemokine receptor CXCR4 that's vital for CXCL12-induced cell chemotaxis.