NEDD8 is a novel 81 amino acid polypeptide which is 60% identical and 80% homologous to ubiquitin. Northern blot analysis showed that the NEDD8 message was developmentally down-regulated. In adult tissues, NEDD8 expression was mostly restricted to the heart and skeletal muscle. Antiserum specific for NEDD8 detected a 6-kDa monomer in SK-N-SH, BJAB, and HL60 cell lysates. A 14-kDa band was also detected in BJAB, HL60, and SK-MEL28 but not in SK-N-SH and K562 cell lysates. An approximately 90-kDa band was detected in all cell lines tested. Thus, NEDD8 is likely to be conjugated to other proteins in a manner analogous to ubiquitination. However, the conjugation pattern of NEDD8 is entirely different from that of ubiquitin in all cell lines tested. To study NEDD8 conjugation in more detail, hemagglutinin-epitope-tagged NEDD8 was expressed in COS cells. Western blot analysis revealed an NEDD8 monomer and a series of higher molecular weight NEDD8-conjugated proteins or NEDD8 multimers. Immunocytochemical analysis showed that NEDD8 expression was highly enriched in the nucleus and was much weaker in the cytosol. In contrast, ubiquitin expression was detectable equally well in the nucleus and cytosol. Mutational analysis showed that the C terminus of NEDD8 was efficiently cleaved and that Gly-76 was required for conjugation of NEDD8 to other proteins. Taken together, NEDD8 provides another substrate for covalent protein modification and may play a unique role during development.
We have not found any resources mentioned in this publication.
SciCrunch is a data sharing and display platform. Anyone can create a custom portal where they can select searchable subsets of hundreds of data sources, brand their web pages and create their community. SciCrunch will push data updates automatically to all portals on a weekly basis. User communities can also add their own data to SciCrunch, however this is not currently a free service.