ubiquitin conjugation factor E4 B; ubiquitin fusion degradation protein 2; homozygously deleted in neuroblastoma 1 (UBE4B, HDNB1, KIAA0684, UFD2)

Function

• binds to the ubiquitin moieties of preformed conjugates & catalyzes ubiquitin chain assembly in conjunction with E1, E2, & E3 (putative)
• proteolytically cleaved by caspases during apoptosis
• cleaved efficiently at Asp-123 by caspase-6 & granzyme B
• cleaved with ~ 10-fold less efficiency at Asp-109 by caspase-3 & caspase-7
• interacts with VCP (putative)

Structure

• belongs to the ubiquitin conjugation factor E4 family
• contains 1 U-box domain

Compartment

cytoplasm (putative)

Alternative splicing

named isoforms=3

Expression

• highest expression in ovary, testis, heart & skeletal muscle
• expression is low in colon, thymus & peripheral blood leukocytes
• expression is almost undetectable in lung & spleen

More general terms

• ubiquitin conjugation factor e4
• phosphoprotein

Database

• Entrez gene: http://www.ncbi.nlm.nih.gov/sites/entrez?db=gene&cmd=Retrieve&dopt=Graphics&list_uids=10277
• Kegg: http://www.genome.jp/dbget-bin/www_bget?hsa:10277
• UniProt: http://www.uniprot.org/uniprot/O95155.html