Figure 3. Accumulation of TLK1 and 2 is negatively regulated by their kinase activity and dimerization at damaged chromatin.

(A-B) TLK1 and TLK2 recruitment to sites of DNA damage is repressed by dimerization and kinase activity. U2OS cells were transfected with indicated GFP-TLK1 or TLK2 wildtype and mutants. Laser-induced micro-irradiation and live-cell imaging experiments were conducted using a confocal microscope, denoted line between the white arrows. Representative images of each experimental group at 10 mins after damage.

(C) DNA damage kinetics of LC8, TLK1, and TLK2 catalytic inactive mutants using laser-induced micro-irradiation.

(D) Kinase activity negatively regulates TLK chromatin loading. HEK293T cells were transfected with the indicated GFP-TLK1 wildtype and catalytic inactive mutants. Cells were harvested 24 h after transfection and fractionated to obtain soluble and chromatin fractions.