NUB1 promotes cytoplasmic localization of p53 through cooperation of the NEDD8 and ubiquitin pathways

Abstract

Non-covalent recognition of ubiquitin (Ub) and ubiquitinlike molecules (Ubls) by interacting proteins has an important role in the regulation of protein function and initiation of signalling events. In addition, growing evidence suggests that regulation of p53 subcellular localization contributes to the biological outcome of the p53 response. Cytoplasmic p53 is shown to promote apoptosis and inhibit the induction of autophagy. In this study we show that NEDD8 ultimate buster 1 (NUB1), a non-covalent interactor of the Ubl NEDD8 (neural precursor cell expressed, developmentally downregulated 8), controls the localization of p53. Expression of NUB1 leads to decreased modification of p53 with NEDD8 and stimulation of p53 ubiquitination. The biological outcome is the cytoplasmic localization and inhibition of the transcriptional activity of p53. Although the effects of NUB1 on p53 depend on NEDDylation and the murine double minute 2 (Mdm2) E3-ligase, the cooperation of NEDD8 with ubiquitin is required. The data identify a role for NEDD8 in controlling p53 localization and suggest that NEDD8 can control protein function through its non-covalent recognition by interacting proteins.

Protein neddylation: beyond cullin–RING ligases

“…The histone acetyl transferase TIP60 can inhibit MDM2-mediated neddylation of TP53, whereas the cyclin-dependent kinase inhibitor p14 ARF inhibits MDM2-mediated ubiquitylation 126 . The balance between neddylation and ubiquitylation of TP53 is further regulated by NUB1, which decreases the former and promotes the latter 127 . Neddylation, ubiquitylation and NUB1 cooperate in the cytoplasmic translocation and inactivation of TP53 in a manner that is not fully understood but is mutually dependent 127 .…”

The NEDD8 inhibitor MLN4924 increases the size of the nucleolus and activates p53 through the ribosomal-Mdm2 pathway

“…Details are included in supplementary information. For immunostaining in U2OS cells, samples were prepared and methods were used as described in 67 . All primary antibodies were used at 1:100 dilution.…”

Regulation of cancer-related pathways by protein NEDDylation and strategies for the use of NEDD8 inhibitors in the clinic

“…NUB1 was identified as a NEDD8 interacting protein and contains two UBA domains . Expression of NUB1 decreases p53 NEDDylation and promotes p53 mono-ubiquitination, which creates a nuclear export signal and cytoplasmic localisation of p53 (Liu & Xirodimas 2010). TIP60 expression causes a preferential decrease in p53 NEDDylation but not ubiquitination (Dohmesen et al 2008).…”