#chk1

2,3,5–tris-(Glutathion-S-yl)hydroquinone (TGHQ) is a reactive oxygen species (ROS) generating metabolite of the nephotoxicant, hydroquinone. In renal proximal tubule epithelial cells (LLC-PK1), TGHQ catalyzes the formation of single strand breaks in DNA, followed by growth arrest and oncotic/necrotic death during the cell cycle. Treatment of synchronized LLC-PK1 cells with TGHQ causes an initial decrease in the expression of the DNA damage inducible protein kinase chk1. The degradation of chk1 in highly synchronized LLC-PK1 cells might induce mitotic catastrophe, a potential mechanism of cell death in this model.