UBR4 (Ubiquitin Ligase E3 Component N-Recognin 4)
p600/UBR4 was initially discovered from a human brain cDNA library that was size fractionated for large cDNAs (Ohara et al. 1997). Subsequent investigations into the structure and function of p600/UBR4 identified it as a large, multifunctional protein that is ubiquitously expressed throughout the body. The name UBR4 refers to its function as an E3 ubiquitin (Ub) ligase in the N-end rule proteolytic pathway, whereas the alternative name of p600 reflects the ∼600 kDa size of this protein. Its role in the N-end rule pathway was revealed in a study that established significant retention of the pathway’s activity in fibroblasts that lacked the two known E3 Ub ligases, UBR1 and UBR2 (Tasaki et al. 2005). Further experiments showed that p600/UBR4 and UBR5 were responsible for the residual N-end rule pathway activity...
- Hong JH, Kaustov L, Coyaud E, Srikumar T, Wan J, Arrowsmith C, et al. KCMF1 (potassium channel modulatory factor 1) Links RAD6 to UBR4 (ubiquitin N-recognin domain-containing E3 ligase 4) and lysosome-mediated degradation. Mol Cell Proteomics. 2015;14(3):674–85.PubMedPubMedCentralCrossRefGoogle Scholar