Protein: Ubiquitin conjugation factor E4 ufd-2 (EC 2.3.2.27) (E4 ubiquitin-protein ligase ufd-2) (RING-type E3 ubiquitin transferase E4) (Ubiquitin fusion degradation protein 2) (Q09349)
Organism: Caenorhabditis elegans
Function: 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.
Subcellular location: Cytoplasm {ECO:0000269|PubMed:27669035}. Nucleus membrane {ECO:0000269|PubMed:27669035}; Peripheral membrane protein {ECO:0000269|PubMed:27669035}; Cytoplasmic side {ECO:0000269|PubMed:27669035}. Nucleus, nucleolus {ECO:0000269|PubMed:27669035}. Note=Localizes to germline syncytium. In the late pachytene, accumulates at the nuclear periphery forming a ring. Following ionizing radiation-mediated DNA damage, localizes to foci within nucleoli where it colocalizes with cdc-48.1 and/or cdc-48.2, atx-3, proteasome alpha subunit and ubiquitinated proteins. Localization to foci is ubiquitin-dependent and regulated by E3 ligase hecd-1 and deubiquitinating enzyme atx-3. ufd-2 foci are formed following the initiation of homologous recombination (HR) and persist until HR is completed. ufd-2 foci are also formed upon cep-1 activation. {ECO:0000269|PubMed:27669035}.
Interaction partners:
- UV excision repair protein RAD23
- Ubiquitin fusion degradation protein 1 homolog
- Transitional endoplasmic reticulum ATPase homolog 1
- UNC-45
- Ubiquitin fusion degradation protein 3 homolog
- UBA domain-containing protein
- UBX domain-containing protein 2
- Ubiquilin
- E3 ubiquitin-protein ligase CHIP
- Transitional endoplasmic reticulum ATPase homolog 2
Sequence:
MIEDEKAGLQPMDISDASVFFFQADVESKDFLTSLFDCEGKSDDRMLRYADAIIDVQNLNFDVSPQCLQSNIAEIITKFVLLSQDGSRRGLSRSFNFIDPDIIAGCREEDAIEFLLINFVRCHHELGKSGTSNCYKKTLESTRKAVFSVFVMIQRGYLESQLRSQHASLVFTKRLLEDTVSNVFLRTLVEYLASTDECDEDAITETFNPIFGILRSGIICQRFEDNKDEIVRQILRVMNLLLSIRLPSNGPRPLSNLLVNREDFLPTPSEKIQGREFGLMSFLGPFFSYGLESSARRPNHRVFVDCEEDARKYDGSVNTEQKLYFQRMDPIRTMLHQLMLPLASDQGSRNKTLRWIATIISTNDIRTRSHYDPSDVLCDHYMTNFLSVMYMFSEKIDLSKIIVDYPFLPSSLINISKETRLKMDESGAVAFASQFADRPDEYHFSTVCFFLTIAAQRLVIPPLMNQISEYSRHLKELKHKINALKEKLNTVSGFERAEVEKKLNYETEHWKLMSRHLLCVKTQAQDPALMASSMDFVDKQMKFILNLLCDNLDLLGDDSQLPTEVSQMFCALPEYFLEDALDFYIFAISNGMKLLMERNADWISRLTVLFTQYHYIKSPFLVSKLVRVLSSIQPPLWFNVVRLRMAQENLLMCMIKFYSDFEDNGDFYEKFNVRGNIQYMLEKMEEDMFYKGKFMDMARECGAEFIRFVNMVINDATWCIDESLSGLKSIHDVEKKMANKVEWDNTDQEIRNQDLGVYEEAKRKVKGWLGTAKSNLKLLLSITVNSPEPFRTPVLGERLAAMLNHNLSQLIGSKASELKVKDPRSYGWEPREFVSLLISIYLKLNMPAFVKYIAYDERTYSPEFFHNAIECMRKNSIVGFSQLESFEHLAEDVKKEYEAKAELEEEYDDVPEEFKDPIMDAIMVDPVKLPSGHVMDRAVIERHLLSTPNNPFNRAPLSHNELSPDSELKAKIQEWICQKRNSKK