Plays a role in DNA damage repair as component of the ASCC complex. Recruits ASCC3 and ALKBH3 to sites of DNA damage by binding to polyubiquitinated proteins that have 'Lys-63'-linked polyubiquitin chains. Part of the ASC-1 complex that enhances NF-kappa-B, SRF and AP1 transactivation. Involved in activation of the ribosome quality control (RQC pathway, a pathway that degrades nascent peptide chains during problematic translation. As part of the ribosome quality control trigger (RQT complex, recognizes ZNF598-dependent ubiquitination of stalled ribosomes (By similarity.,ASCC2,ASC1p100,p100,Signal Transduction,ASCC2