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Kuo CY, Li X, Kong XQ, Luo C, Chang CC, Chung Y, Shih HM, Li KK, Ann DK. An arginine-rich motif of ring finger protein 4 (RNF4) oversees the recruitment and degradation of the phosphorylated and SUMOylated Krüppel-associated box domain-associated protein 1 (KAP1)/TRIM28 protein during genotoxic stress. J Biol Chem 2014; 289:20757-72. [PMID: 24907272 DOI: 10.1074/jbc.m114.555672] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Krüppel-associated box domain-associated protein 1 (KAP1) is a universal transcriptional corepressor that undergoes multiple posttranslational modifications (PTMs), including SUMOylation and Ser-824 phosphorylation. However, the functional interplay of KAP1 PTMs in regulating KAP1 turnover during DNA damage response remains unclear. To decipher the role and cross-talk of multiple KAP1 PTMs, we show here that DNA double strand break-induced KAP1 Ser-824 phosphorylation promoted the recruitment of small ubiquitin-like modifier (SUMO)-targeted ubiquitin E3 ligase, ring finger protein 4 (RNF4), and subsequent RNF4-mediated, SUMO-dependent degradation. Besides the SUMO interacting motif (SIM), a previously unrecognized, but evolutionarily conserved, arginine-rich motif (ARM) in RNF4 acts as a novel recognition motif for selective target recruitment. Results from combined mutagenesis and computational modeling studies suggest that RNF4 utilizes concerted bimodular recognition, namely SIM for Lys-676 SUMOylation and ARM for Ser(P)-824 of simultaneously phosphorylated and SUMOylated KAP1 (Ser(P)-824-SUMO-KAP1). Furthermore, we proved that arginines 73 and 74 within the ARM of RNF4 are required for efficient recruitment to KAP1 or accelerated degradation of promyelocytic leukemia protein (PML) under stress. In parallel, results of bimolecular fluorescence complementation assays validated the role of the ARM in recognizing Ser(P)-824 in living cells. Taken together, we establish that the ARM is required for RNF4 to efficiently target Ser(P)-824-SUMO-KAP1, conferring ubiquitin Lys-48-mediated proteasomal degradation in the context of double strand breaks. The conservation of such a motif may possibly explain the requirement for timely substrate selectivity determination among a myriad of SUMOylated proteins under stress conditions. Thus, the ARM dynamically regulates the SIM-dependent recruitment of targets to RNF4, which could be critical to dynamically fine-tune the abundance of Ser(P)-824-SUMO-KAP1 and, potentially, other SUMOylated proteins during DNA damage response.
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Affiliation(s)
- Ching-Ying Kuo
- From the Department of Molecular Pharmacology and Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute, City of Hope, Duarte, California 91010
| | - Xu Li
- From the Department of Molecular Pharmacology and
| | - Xiang-Qian Kong
- the Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Cheng Luo
- the Drug Discovery and Design Center, State Key Laboratory of Drug Research, Shanghai Institute of Materia Medica, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
| | - Che-Chang Chang
- the Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan, and
| | - Yiyin Chung
- From the Department of Molecular Pharmacology and
| | - Hsiu-Ming Shih
- the Institute of Biomedical Sciences, Academia Sinica, Taipei 11529, Taiwan, and
| | - Keqin Kathy Li
- the State Key Laboratory of Medical Genomics, Shanghai Institute of Hematology, Rui Jin Hospital Affiliated with Shanghai Jiao Tong University School of Medicine, 197 Ruijin II Road, Shanghai 200025, China
| | - David K Ann
- From the Department of Molecular Pharmacology and Irell and Manella Graduate School of Biological Sciences, Beckman Research Institute, City of Hope, Duarte, California 91010,
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