Has a role in growth of the perineurial glial layer of the larval peripheral nerve (PubMed:27552662). May have a role in male fertility and eye development or function (PubMed:27552662). Involved in the negative regulation of the Ras/MAPK signaling pathway in the wing by acting with the E2 enzyme Unc6 and the putative E3 ligases Kcmf1 and Ufd4 to mediate the ubiquitination and proteasomal degradation of rl/MAPK (PubMed:27552662). May bind calmodulin (PubMed:9813038). Interacts with Kcmf1 (PubMed:27552662). Expressed in embryonic central nervous system and adult testes. Flies increase the growth of the perineurial glial layer of the larval peripheral nerve and exhibit male sterility due to the inhibition of sperm individualization. Belongs to the UBR4 family. Wrong choice of frame.