Regulation of NEDD8/Rub1 and its substrates
type: CreativeWork
description: NEDD8 is a small ubiquitin like modifier (UBL) essential for life in almost all known eukaryotes. The primary objective of this work is to determine NEDD8 specific regulatory mechanisms. Like ubiquitin, NEDD8 is first matured and then conjugated via a tripartite conjugation cascade (E1, E2, E3). Although Arg72 in ubiquitin prevents misactivation of ubiquitin by the NEDD8 E1, the ubiquitin E1 is not as selective (Souphron et al., 2008). Under conditions of stress or NEDD8 overexpression, the ubiquitin E1 can be charged with NEDD8 (Hjerpe et al.; Hjerpe et al., 2012b; Leidecker et al., 2012). Most ubiquitin E2s can accept the aberrantly activated NEDD8 which then ultimately becomes conjugated to substrates that are normally ubiquitylated (Hjerpe et al., 2012a). Consequently, maintaining the ratio of NEDD8 to ubiquitin is important for maintaining the integrity of the ubiquitin pathway. The mechanism by which the ubiquitin to NEDD8 ratio is regulated remains unclear. In order to insulate the ubiquitylation pathway from NEDD8, we postulated that the ratio of free NEDD8 to free ubiquitin would be tightly controlled. The rapid turnover reported to exist for NEDD8 (Hipp et al., 2004) could be one means of regulating that ratio. However, we have discovered that in yeast that tagging the NEDD8 homolog, related to ubiquitin 1 (Rub1) results in abnormally fast degradation through the unfolded protein response (UPR). Endogenous Rub1 is actually quite stable. The pathway by which endogenous NEDD8 is degraded remains unknown. Another way of distinguishing the two pathways and uncovering NEDD8 specific regulation is to identify genuine substrates of the neddylation pathway. We were unable to uncover novel substrates in yeast. We used several methods to enrich and identify NEDD8 substrates in mammalian cells including cultured human cancer cells and wild type mouse tissue. Mouse testes have an increased neddylation profile by Western Blot (WB). We therefore attempted to identify NE…
abstract: NEDD8 is a small ubiquitin like modifier (UBL) essential for life in almost all known eukaryotes. The primary objective of this work is to determine NEDD8 specific regulatory mechanisms. Like ubiquitin, NEDD8 is first matured and then conjugated via a tripartite conjugation cascade (E1, E2, E3). Although Arg72 in ubiquitin prevents misactivation of ubiquitin by the NEDD8 E1, the ubiquitin E1 is not as selective (Souphron et al., 2008). Under conditions of stress or NEDD8 overexpression, the ubiquitin E1 can be charged with NEDD8 (Hjerpe et al.; Hjerpe et al., 2012b; Leidecker et al., 2012). Most ubiquitin E2s can accept the aberrantly activated NEDD8 which then ultimately becomes conjugated to substrates that are normally ubiquitylated (Hjerpe et al., 2012a). Consequently, maintaining the ratio of NEDD8 to ubiquitin is important for maintaining the integrity of the ubiquitin pathway. The mechanism by which the ubiquitin to NEDD8 ratio is regulated remains unclear. In order to insulate the ubiquitylation pathway from NEDD8, we postulated that the ratio of free NEDD8 to free ubiquitin would be tightly controlled. The rapid turnover reported to exist for NEDD8 (Hipp et al., 2004) could be one means of regulating that ratio. However, we have discovered that in yeast that tagging the NEDD8 homolog, related to ubiquitin 1 (Rub1) results in abnormally fast degradation through the unfolded protein response (UPR). Endogenous Rub1 is actually quite stable. The pathway by which endogenous NEDD8 is degraded remains unknown. Another way of distinguishing the two pathways and uncovering NEDD8 specific regulation is to identify genuine substrates of the neddylation pathway. We were unable to uncover novel substrates in yeast. We used several methods to enrich and identify NEDD8 substrates in mammalian cells including cultured human cancer cells and wild type mouse tissue. Mouse testes have an increased neddylation profile by Western Blot (WB). We therefore attempted to identify NE…
author: Curran, Siobhan
language: eng
keywords: Nedd8, Ubiquitin, Rub1, Ubi1
date published: 2013
date modified: 2026-07-24T02:07:46Z
provider: University of Dundee
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: University of Dundee