ULK1 and glioma: In summary, TOPK phosphorylates ULK1 at Ser469, Ser495, and Ser533, promoting ubiquitination degradation of ULK1, reducing its stability, inhibiting the binding of ULK1 to other members of its complex, and inhibiting the activity of ULK1, therefore inhibiting the initiation of autophagy and promoting the resistance of glioma cells to TMZ (Fig. 7e).