Figure 5.

CTSL participated in the degradation of 53BP1 that occurs in response to CPT. A, A549 parental cells were treated with 500 nm CPT or vehicle in the presence or absence of 10 μm MG132 or 100 nm CTSLi for 8 h, and expression of the indicated proteins was examined. Protein quantitation was performed as in Fig. 1A. B, HEK293T cells were transfected with FLAG-53BP1 WT or S28A for 48 h and treated with 500 nm CPT in the presence of absence of 100 nm CTSLi for 8 h, and expression of the indicated proteins was examined. Protein quantitation was performed as in Fig. 1A.