Ubiquitin-specific peptidase 29 (USP29, MEROPS identifier C19.040) is a de-ubiquitinating enzyme that releases poly-ubiquitin from conjugates. The USP29 gene is activated by a the far upstream element binding protein (FBP) and JTV1, a subunit of the multi-aminoacyl-tRNA synthetase complex. USP29 is then able to stabilize p53 by removing ubiquitin, and accumulated p53 induces apoptosis []. USP29 is also important in the maintenance of genomic integrity because it de-ubiquitinates claspin. Ubiquitinated claspin is degraded by the proteasome, and upregulation of USP29 promotes claspin survival, whereas downregulation promotes claspin degradation []. USP29 knockdown also leads to impaired phosphorylation of Chk1 following DNA damage and cells show a major defect in S-phase progression []. USP29 is paternally imprinted in the mouse [], and conserved sequence element 1 (CSE-1) within the CpG island that surrounds the genes acts as a repressor for transcription of both the USP29 and PEG3 genes [].
