Journal of cell science
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Journal of cell science · Aug 2018
New ubiquitin-dependent mechanisms regulating the Aurora B-protein phosphatase 1 balance in Saccharomyces cerevisiae.
Protein ubiquitylation regulates many cellular processes, including cell division. We report here a novel mutation altering the Saccharomyces cerevisiae E1 ubiquitin-activating enzyme (uba1-W928R) that suppresses the temperature sensitivity and chromosome loss phenotype of a well-characterized Aurora B mutant (ip1-2). The uba1-W928R mutation increases histone H3-S10 phosphorylation in the ipl1-2 strain, indicating that uba1-W928R acts by increasing Ipl1 activity and/or reducing the opposing protein phosphatase 1 (PP1; Glc7 in S. cerevisiae) phosphatase activity. ⋯ Our new UBA1 allele reveals new roles for ubiquitylation in regulating the Ipl1-Glc7 balance in budding yeast. While ubiquitylation likely regulates Ipl1 protein stability via the canonical proteasomal degradation pathway, a non-canonical ubiquitin-dependent pathway maintains normal Glc7 localization and activity. This article has an associated First Person interview with the first author of the paper.