Dataset Information

Ubiquitin S65 proteomics: Targets of ubiquitin phosphorylation

ABSTRACT: Ubiquitylation is an essential post-translational modification that regulates numerous cellular processes, most notably protein degradation. Ubiquitin itself can be post-translationally modified by phosphorylation, with nearly every serine, threonine, and tyrosine residue having the potential to be phosphorylated. However, the effect of this modification on ubiquitin function is largely unknown. Here, we performed in vivo and in vitro characterization of the effects of phosphorylation of yeast ubiquitin at position serine 65. We find ubiquitin S65 phosphorylation to be regulated under oxidative stress, occurring in tandem with the restructuring of the ubiquitin landscape into a highly polymeric state. Phosphomimetic mutation of S65 recapitulates the oxidative stress phenotype, causing a dramatic accumulation of ubiquitylated proteins and a proteome-wide reduction of protein turnover rates. Importantly, this mutation impacts ubiquitin chain disassembly, chain linkage distribution, and substrate targeting. These results demonstrate that phosphorylation represents an additional mode of ubiquitin regulation with broad implications in cellular physiology.

INSTRUMENT(S): LTQ Orbitrap Velos, Q Exactive

ORGANISM(S): Saccharomyces Cerevisiae (baker's Yeast)

SUBMITTER: Danielle Swaney

LAB HEAD: Judit Villen

PROVIDER: PXD002201 | Pride | 2015-07-07

REPOSITORIES: Pride

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Publications

Phosphorylation of ubiquitin at Ser65 affects its polymerization, targets, and proteome-wide turnover.

Swaney Danielle L DL Rodríguez-Mias Ricard A RA Villén Judit J

EMBO reports 20150703 9

Ubiquitylation is an essential post-translational modification that regulates numerous cellular processes, most notably protein degradation. Ubiquitin can itself be phosphorylated at nearly every serine, threonine, and tyrosine residue. However, the effect of this modification on ubiquitin function is largely unknown. Here, we characterized the effects of phosphorylation of yeast ubiquitin at serine 65 in vivo and in vitro. We find this post-translational modification to be regulated under oxida ...[more]

PMID: 26142280

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