title: PTK2-mediated degradation of ATG3 impedes cancer cells susceptible to DNA damage treatment.
abstract: ATG3 (autophagy-related 3) is an E2-like enzyme essential for autophagy; however, it is unknown whether it has an autophagy-independent function. Here, we report that ATG3 is a relatively stable protein in unstressed cells, but it is degraded in response to DNA-damaging agents such as etoposide or cisplatin. With mass spectrometry and a mutagenesis assay, phosphorylation of tyrosine 203 of ATG3 was identified to be a critical modification for its degradation, which was further confirmed by manipulating ATG3Y203E(phosphorylation mimic) or ATG3Y203F(phosphorylation-incompetent) in Atg3 knockout MEFs. In addition, by using a generated phospho-specific antibody we showed that phosphorylation of Y203 significantly increased upon etoposide treatment. With a specific inhibitor or siRNA, PTK2 (protein tyrosine kinase 2) was confirmed to catalyze the phosphorylation of ATG3 at Y203. Furthermore, a newly identified function of ATG3 was recognized to be associated with the promotion of DNA damage-induced mitotic catastrophe, in which ATG3 interferes with the function of BAG3, a crucial protein in the mitotic process, by binding. Finally, PTK2 inhibition-induced sustained levels of ATG3 were able to sensitize cancer cells to DNA-damaging agents. Our findings strengthen the notion that targeting PTK2 in combination with DNA-damaging agents is a novel strategy for cancer therapy.
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Ke
authors.initials: K
authors.lastname: Ma
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Wan
authors.initials: W
authors.lastname: Fu
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Ming
authors.initials: M
authors.lastname: Tang
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Chaohua
authors.initials: C
authors.lastname: Zhang
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Tianyun
authors.initials: T
authors.lastname: Hou
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Ran
authors.initials: R
authors.lastname: Li
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Xiaopeng
authors.initials: X
authors.lastname: Lu
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Yanan
authors.initials: Y
authors.lastname: Wang
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Jingyi
authors.initials: J
authors.lastname: Zhou
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Xue
authors.initials: X
authors.lastname: Li
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Luyao
authors.initials: L
authors.lastname: Zhang
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Lina
authors.initials: L
authors.lastname: Wang
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.affiliation: a Key Laboratory of Carcinogenesis and Translational Research (Ministry of Education), State Key Laboratory of Natural and Biomimetic Drugs, Beijing Key Laboratory of Protein Posttranslational Modifications and Cell Function, Department of Biochemistry and Molecular Biology , School of Basic Medical Sciences, Peking University Health Science Center , Beijing , China.|b School of Medicine, Shenzhen University , Shenzhen , China.|c Peking-Tsinghua University Center for Life Science, Peking University , Beijing , China.
authors.forename: Wei-Guo
authors.initials: WG
authors.lastname: Zhu
mesh_terms: D048868:Adaptor Proteins, Signal Transducing / Q000378:metabolism; D000818:Animals; D051017:Apoptosis Regulatory Proteins / Q000378:metabolism; D000071183:Autophagy-Related Proteins / Q000378:metabolism*; D045744:Cell Line, Tumor; D049109:Cell Proliferation / Q000187:drug effects; D004249:DNA Damage; D005047:Etoposide / Q000494:pharmacology; D051417:Focal Adhesion Kinase 1 / Q000378:metabolism*; D051379:Mice; D018345:Mice, Knockout; D008938:Mitosis / Q000187:drug effects; D009369:Neoplasms / Q000378:metabolism* / Q000473:pathology*; D010766:Phosphorylation / Q000187:drug effects; D059748:Proteolysis / Q000187:drug effects; D044763:Ubiquitin-Conjugating Enzymes / Q000378:metabolism*
chemical_list: D048868:Adaptor Proteins, Signal Transducing; D051017:Apoptosis Regulatory Proteins; D000071183:Autophagy-Related Proteins; C414431:BAG3 protein, human; D005047:Etoposide; D044763:Ubiquitin-Conjugating Enzymes; D051417:Focal Adhesion Kinase 1; C496050:PTK2 protein, human; C455621:ATG3 protein, human
keywords: ATG3; PTK2; cancer therapy; mitotic catastrophe; tyrosine phosphorylation