E3 ubiquitin-protein ligase that mediates ubiquitination of target proteins, including p53/TP53, TP73, HDAC1 and CDKN1B (  , ). Mediates ubiquitination and degradation of p53/TP53; preferentially acts on tetrameric p53/TP53 (, ). Catalyzes monoubiquitinates the translesion DNA polymerase POLH . Involved in the ribosome-associated quality control (RQC) pathway, which mediates the extraction of incompletely synthesized nascent chains from stalled ribosomes: RCHY1 acts downstream of NEMF and recognizes CAT tails associated with stalled nascent chains, leading to their ubiquitination and degradation .
Has no E3 ubiquitin-protein ligase activity.
Subcellular locations: Nucleus, Nucleus speckle, Cytoplasm