USP19A gene on chromosome 3p21.31 that encodes a deubiquitinating enzyme which regulates the proteasomal degradation of RNF123. Degradation of CDKN1B drives ubiquitin-dependent protein degradation, thus playing a role in cell proliferation. USP19 downregulates protein synthesis in atrophying skeletal muscle, reducing the
transcription of major myofibrillar proteins, and represses myogenesis. It is also involved in turnover of endoplasmic-reticulum-associated degradation (ERAD) substrates and is required for cells to mount an appropriate response to hypoxia; it rescues HIF1A from degradation.