Recombinant Probable ubiquitin conjugation factor E4 (ufd-2)

Acts as an E4 ubiquitin ligase mediating the assembly of polyubiquitin chains on substrates ubiquitinated by another E3 ubiquitin ligase. The elongation of preexisting ubiquitin chains preferentially targets ubiquitin 'Lys-29' and 'Lys-48' residues. Also functions as an E3 ligase in conjunction with specific E1 and E2 ligases. Probably by regulating protein ubiquitination at DNA damage repair sites, coordinates DNA double-strand-break repair and apoptosis in the germline. Required for germline apoptosis in response to DNA damage downstream of cep-1. Involved in the resolution of DNA-repair sites by promoting the release of rad-51 from DNA damage foci. In association with protein-ligase chn-1, acts as an E3/E4 ligase to poly-ubiquitinate lysine residues in the UCS domain of myosin chaperone unc-45. By targeting myosin chaperone unc-45 for proteasomal degradation, regulates myosin assembly in body wall muscles in association with cdc-48.1 and chn-1. However, in a contrasting study, acts as an E3 ligase, independently of chn-1, to poly-ubiquitinate unc-45 without promoting unc-45 proteasomal degradation. Instead, uses unc-45 as an adapter protein to recruit and poly-ubiquitinate unfolded myosin heavy chain B unc-54.