Activation of automethylated PRC2 by dimerization on chromatin.

Polycomb Repressive Complex 2 (PRC2) is an epigenetic regulator that trimethylates lysine 27 of histone 3 (H3K27me3) and is essential for embryonic development and cellular differentiation. H3K27me3 is associated with transcriptionally repressed chromatin and is established when PRC2 is allosterically activated upon methyl-lysine binding by the regulatory subunit EED. Automethylation of the catalytic subunit EZH2 stimulates its activity by an unknown mechanism.

Measuring Intracellular H O in Intact Human Cells Using the Genetically Encoded Fluorescent Sensor HyPer7.

Depending on its local concentration, hydrogen peroxide (HO) can serve as a cellular signaling molecule but can also cause damage to biomolecules. The levels of H O are influenced by the activity of its generator sites, local antioxidative systems, and the metabolic state of the cell. To study and understand the role of HO in cellular signaling, it is crucial to assess its dynamics with high spatiotemporal resolution.

Spatial and temporal control of mitochondrial H O release in intact human cells.

Hydrogen peroxide (H O ) has key signaling roles at physiological levels, while causing molecular damage at elevated concentrations. H O production by mitochondria is implicated in regulating processes inside and outside these organelles. However, it remains unclear whether and how mitochondria in intact cells release H O .

Hyperoxidation of mitochondrial peroxiredoxin limits H O -induced cell death in yeast.

Hydrogen peroxide (H O ) plays important roles in cellular signaling, yet nonetheless is toxic at higher concentrations. Surprisingly, the mechanism(s) of cellular H O toxicity remain poorly understood. Here, we reveal an important role for mitochondrial 1-Cys peroxiredoxin from budding yeast, Prx1, in regulating H O -induced cell death.

Vectorial Import via a Metastable Disulfide-Linked Complex Allows for a Quality Control Step and Import by the Mitochondrial Disulfide Relay.

Disulfide formation in the mitochondrial intermembrane space (IMS) is an essential process. It is catalyzed by the disulfide relay machinery, which couples substrate import and oxidation. The machinery relies on the oxidoreductase and chaperone CHCHD4-Mia40.