The enzymes of the ubiquitylation pathway play a pivotal role in a number of cellular processes including regulated and targeted proteasomal degradation of substrate proteins. Three classes of enzymes are involved in the process of ubiquitylation; activating enzymes (E1s), conjugating enzymes (E2s) and protein ligases (E3s). UBE2D2 is a member of the E2 ubiquitin-conjugating enzyme family and cloning of the human gene was first described by Jensen et al. (1995). UBE2D2 shares 95% and 79% sequence identity with the Drosophila and S. cerevisiae homologues respectively. UBE2D2 can conjugate ubiquitin to targets in an E6AP dependent manner. UBE2D2 forms part of a ubiquitin E3 ligase complex with Cullin1, Skp1, Roc1 and BTRC (Kim et al., 2005). This complex has been shown to mediate activation of NFκB and promote degradation of phosphorylated IκBα. Co-immunoprecipitation has shown that the Shigella flexneri effector protein (OspG) interacts with UBE2D2 (Kim et al., 2005). Glial cell missing homolog 1 (GCM1) is an important transcription factor regulating placental cell fusion and it has been shown that UBE2D2 is required for Skp1-Cullin-F-Box (SCF) E3 ligase mediated ubiquitylation of GCM1 (Chiang et al., 2008). UBE2D2 also supports mdm2 mediated ubiquitylation of p53 (Saville et al., 2004).
Chiang MH, Chen LF, Chen H (2008) Ubiquitin-conjugating enzyme UBE2D2 is responsible for FBXW2 (F-box and WD repeat domain containing 2)-mediated human GCM1 (glial cell missing homolog 1) ubiquitination and degradation. Biol Reprod 79, 914-20.
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Kim DW, Lenzen G, Page AL, Legrain P, Sansonetti PJ, Parsot C (2005) The Shigella flexneri effector OspG interferes with innate immune responses by targeting ubiquitin-conjugating enzymes. Proc Natl Acad Sci USA 102, 14046-51.
Saville MK, Sparks A, Xirodimas DP, Wardrop J, Stevenson LF, Bourdon JC, Woods YL, Lane DP (2004) Regulation of p53 by the ubiquitin-conjugating enzymes UbcH5B/C in vivo. J Biol Chem 279, 42169-81.