Anti-UCHL5 monoclonal antibody, clone 965DU6.6.7

Ubiquitin C-terminal Hydrolase-L5 (UCH-L5/UCH37), a member of the deubiquitinases (DUBs), suppresses protein degeneration via removing ubiquitin from the distal subunit of the polyubiquitin chain. The activity of UCH-L5 is enhanced when UCH-L5 combines with proteasome 19S regulatory subunit by Rpn13/Admr1 receptor and inhibited when UCH-L5 interacts with NFRKB. But the role of UCH-L5 in gliomas remains unknown. In this study, analysis of 19 frozen and 51 paraffin-embedded clinic pathological cases showed that UCH-L5 expression in glioma tissues was lower than normal brain tissues. In vitro, we found that UCH-L5 could inhibit migration and invasion of U87MG and U251 cells. It has been reported that the expression of SNRPN, SNRPF, and CKLF was abnormal in gliomas or other tumors. We also found that SNRPF-siRNA, SNRPN-siRNA and CKLF-siRNA could inhibit migration and invasion of U87MG cells. And knockdown of UCH-L5 expression improved both mRNA expression and protein level of SNRPF. The relationship between UCH-L5 and SNRPF was further confirmed in 293T cells. Our study showed that UCH-L5 could inhibit migration and invasion of glioma cells via down regulating expression of SNRPF. And the above findings suggest that UCH-L5 may inhibit occurrence and metastasis of gliomas.

The proteasome plays an important role in proteostasis by carrying out controlled protein degradation in the cell. Impairments in proteasome function are associated with severe and often age-related diseases. Here, we have characterized a molecular mechanism linking insulin/IGF-1 signaling (IIS) to proteasome activity. We show that decreased IIS, which promotes proteostasis and longevity, increases proteasome activity through the FOXO transcription factor DAF-16 in C. elegans. Furthermore, we reveal that DAF-16 represses expression of the proteasome-associated deubiquitinating enzyme ubh-4, which we suggest functions as a tissue-specific proteasome inhibitor. Finally, we demonstrate that proteasome activation through downregulation of the ubh-4 human ortholog uchl5 increases degradation of proteotoxic proteins in mammalian cells. In conclusion, we have established a mechanism by which the evolutionarily conserved IIS contributes to the regulation of proteasome activity in a multicellular organism.