Ube2E3 (also known as UbcH9) is an E2 enzyme, which is part of the E1, E2, E3 cascade that is responsible for ubiquitination of protein substrates. It has been found to interact with the E3 enzyme Nedd4-2 in order to regulate ubiquitination of the epithelial Na+ channel (ENaC). Studies have shown that Ube2E3 may be able to associate with the substrate directly, which implies the assistance of an E3 may not be required under all circumstances.
