Background
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). UBE2J1 is a member of the E2 conjugating enzyme family and cloning of the human gene was first described by Lester et al. (2000). UBE2J1 is a 318 amino acid single-pass type IV membrane protein, which can be found localised to the membrane of the endoplasmic reticulum (ER) (Lester et al., 2000). UBE2J1 catalyzes the modification of misfolded membrane proteins with ubiquitin which results in their targeting to the proteasome for degradation (Walter et al., 2001). UBE2J1 has been shown to interact with the E3 ligase ICP0 forming polyubiquitin chains in an in vitro polyubiquitylation assay. ICP0 targets substrates such as PML, Sp100, CENP-C, and CENP-A for proteasomal degradation (Everett et al., 1999; Everett et al., 1998; Lomonte et al., 2001; Parkinson and Everett. 2000). Evidence for an association of the UBE2J1 gene locus with Serum creatinine (S CR) levels has been demonstrated. S CR is a biomarker used for the non-invasive assessment of kidney function and it is hoped will provide an insight into the genetic basis of serum creatinine regulatory processes (Pattaro et al., 2010).
References
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