Expression of UCH-L1 is highly specific to neurons and to cells of the diffuse neuroendocrine system and their tumors.

[11] Another potentially protective function of UCH-L1 is its reported ability to stabilize monoubiquitin, an important component of the ubiquitin proteasome system.

[17] Furthermore there is evidence that UCH-L1 might play a role in the pathogenesis of membranous glomerulonephritis as UCH-L1 de novo expression in podocytes was seen in PHN, the rat model of human mGN.

For example, the UCH-L1 dimer has been shown to exhibit the potentially pathogenic ligase activity and may lead to the aforementioned increase in aggregation of α-synuclein.

[12] Ubiquitin carboxy-terminal hydrolase L1 has been shown to interact with COP9 constitutive photomorphogenic homolog subunit 5.