Possible negative regulator of polyubiquitination (By similarity). May modulate the activity of the p38 MAP kinase pnk-3 (PubMed:20592265). May have a role in axon termination and synaptic transmission at motor and mechanosensory neurons (PubMed:20592265). Plays a role in intraflagellar transport in cilia and cilium length regulation (PubMed:26657059). May interact with pmk-3. Expressed ubiquitously. Belongs to the ubiquitin-conjugating enzyme family. Lacks the active site cysteine required for interaction with ubiquitin.