Ubc1 turnover contributes to the spindle assembly checkpoint in Saccharomyces cerevisiae.

The spindle assembly checkpoint protects the integrity of the genome by ensuring that chromosomes are properly attached to the mitotic spindle before they are segregated during anaphase. Activation of the spindle checkpoint results in inhibition of the Anaphase-Promoting Complex (APC), an E3 ubiquitin ligase that triggers the metaphase-anaphase transition. Here, we show that levels of Ubc1, an E2 enzyme that functions in complex with the APC, modulate the response to spindle checkpoint activation in Saccharomyces cerevisiae.

Metabolism and the Epigenome: A Dynamic Relationship.

Many chromatin-modifying enzymes require metabolic cofactors to support their catalytic activities, providing a direct path for fluctuations in metabolite availability to regulate the epigenome. Over the past decade, our knowledge of this link has grown significantly. What began with studies showing that cofactor availability drives global abundances of chromatin modifications has transitioned to discoveries highlighting metabolic enzymes as loci-specific regulators of gene expression.

The coordinate actions of calcineurin and Hog1 mediate the stress response through multiple nodes of the cell cycle network.

Upon exposure to environmental stressors, cells transiently arrest the cell cycle while they adapt and restore homeostasis. A challenge for all cells is to distinguish between stress signals and coordinate the appropriate adaptive response with cell cycle arrest. Here we investigate the role of the phosphatase calcineurin (CN) in the stress response and demonstrate that CN activates the Hog1/p38 pathway in both yeast and human cells.