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Sun H, Zhang H. Lysine Methylation-Dependent Proteolysis by the Malignant Brain Tumor (MBT) Domain Proteins. Int J Mol Sci 2024; 25:2248. [PMID: 38396925 PMCID: PMC10889763 DOI: 10.3390/ijms25042248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2023] [Revised: 02/07/2024] [Accepted: 02/08/2024] [Indexed: 02/25/2024] Open
Abstract
Lysine methylation is a major post-translational protein modification that occurs in both histones and non-histone proteins. Emerging studies show that the methylated lysine residues in non-histone proteins provide a proteolytic signal for ubiquitin-dependent proteolysis. The SET7 (SETD7) methyltransferase specifically transfers a methyl group from S-Adenosyl methionine to a specific lysine residue located in a methylation degron motif of a protein substrate to mark the methylated protein for ubiquitin-dependent proteolysis. LSD1 (Kdm1a) serves as a demethylase to dynamically remove the methyl group from the modified protein. The methylated lysine residue is specifically recognized by L3MBTL3, a methyl-lysine reader that contains the malignant brain tumor domain, to target the methylated proteins for proteolysis by the CRL4DCAF5 ubiquitin ligase complex. The methylated lysine residues are also recognized by PHF20L1 to protect the methylated proteins from proteolysis. The lysine methylation-mediated proteolysis regulates embryonic development, maintains pluripotency and self-renewal of embryonic stem cells and other stem cells such as neural stem cells and hematopoietic stem cells, and controls other biological processes. Dysregulation of the lysine methylation-dependent proteolysis is associated with various diseases, including cancers. Characterization of lysine methylation should reveal novel insights into how development and related diseases are regulated.
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Affiliation(s)
| | - Hui Zhang
- Department of Chemistry and Biochemistry, Nevada Institute of Personalized Medicine, University of Nevada, Las Vegas, 4505 South Maryland Parkway, P.O. Box 454003, Las Vegas, NV 89154-4003, USA;
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Guo P, Lim RC, Rajawasam K, Trinh T, Sun H, Zhang H. A methylation-phosphorylation switch controls EZH2 stability and hematopoiesis. eLife 2024; 13:e86168. [PMID: 38346162 PMCID: PMC10901513 DOI: 10.7554/elife.86168] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2023] [Accepted: 02/11/2024] [Indexed: 02/29/2024] Open
Abstract
The Polycomb Repressive Complex 2 (PRC2) methylates H3K27 to regulate development and cell fate by transcriptional silencing. Alteration of PRC2 is associated with various cancers. Here, we show that mouse Kdm1a deletion causes a dramatic reduction of PRC2 proteins, whereas mouse null mutation of L3mbtl3 or Dcaf5 results in PRC2 accumulation and increased H3K27 trimethylation. The catalytic subunit of PRC2, EZH2, is methylated at lysine 20 (K20), promoting EZH2 proteolysis by L3MBTL3 and the CLR4DCAF5 ubiquitin ligase. KDM1A (LSD1) demethylates the methylated K20 to stabilize EZH2. K20 methylation is inhibited by AKT-mediated phosphorylation of serine 21 in EZH2. Mouse Ezh2K20R/K20R mutants develop hepatosplenomegaly associated with high GFI1B expression, and Ezh2K20R/K20R mutant bone marrows expand hematopoietic stem cells and downstream hematopoietic populations. Our studies reveal that EZH2 is regulated by methylation-dependent proteolysis, which is negatively controlled by AKT-mediated S21 phosphorylation to establish a methylation-phosphorylation switch to regulate the PRC2 activity and hematopoiesis.
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Affiliation(s)
- Pengfei Guo
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, United States
| | - Rebecca C Lim
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, United States
| | - Keshari Rajawasam
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, United States
| | - Tiffany Trinh
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, United States
| | - Hong Sun
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, United States
| | - Hui Zhang
- Department of Chemistry and Biochemistry, University of Nevada, Las Vegas, Las Vegas, United States
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3
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Zemke NR, Hsu E, Barshop WD, Sha J, Wohlschlegel JA, Berk AJ. Adenovirus E1A binding to DCAF10 targets proteasomal degradation of RUVBL1/2 AAA+ ATPases required for quaternary assembly of multiprotein machines, innate immunity, and responses to metabolic stress. J Virol 2023; 97:e0099323. [PMID: 37962355 PMCID: PMC10734532 DOI: 10.1128/jvi.00993-23] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Accepted: 10/16/2023] [Indexed: 11/15/2023] Open
Abstract
IMPORTANCE Inactivation of EP300/CREBB paralogous cellular lysine acetyltransferases (KATs) during the early phase of infection is a consistent feature of DNA viruses. The cell responds by stabilizing transcription factor IRF3 which activates transcription of scores of interferon-stimulated genes (ISGs), inhibiting viral replication. Human respiratory adenoviruses counter this by assembling a CUL4-based ubiquitin ligase complex that polyubiquitinylates RUVBL1 and 2 inducing their proteasomal degradation. This inhibits accumulation of active IRF3 and the expression of anti-viral ISGs, allowing replication of the respiratory HAdVs in the face of inhibition of EP300/CBEBBP KAT activity by the N-terminal region of E1A.
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Affiliation(s)
- Nathan R. Zemke
- Molecular Biology Institute, University of California, Los Angeles, California, USA
- Department of Cellular and Molecular Medicine, UCSD School of Medicine, La Jolla, California, USA
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California, USA
| | - Emily Hsu
- Molecular Biology Institute, University of California, Los Angeles, California, USA
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California, USA
- Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - William D. Barshop
- Thermo Fisher Scientific, San Jose, California, USA
- Department of Biochemistry and Molecular Medicine and the Norris Comprehensive Cancer Center, Keck School of Medicine, USC, Los Angeles, California, USA
| | - Jihui Sha
- Thermo Fisher Scientific, San Jose, California, USA
| | - James A. Wohlschlegel
- Molecular Biology Institute, University of California, Los Angeles, California, USA
- Thermo Fisher Scientific, San Jose, California, USA
| | - Arnold J. Berk
- Molecular Biology Institute, University of California, Los Angeles, California, USA
- Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California, USA
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Nakagawa T, Morohoshi A, Nagasawa Y, Nakagawa M, Hosogane M, Noda Y, Hosoi T, Nakayama K. SPT16 ubiquitylation by DCAF14- CRL4 regulates FACT binding to histones. Cell Rep 2022; 38:110541. [PMID: 35320725 DOI: 10.1016/j.celrep.2022.110541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2021] [Revised: 12/23/2021] [Accepted: 02/28/2022] [Indexed: 12/27/2022] Open
Abstract
The histone chaperone complex FACT comprises SPT16 and SSRP1 and contributes to DNA replication, transcription, and repair, but how it plays such various roles is unclear. Here, we show that human SPT16 is ubiquitylated at lysine-674 (K674) by the DCAF14-CRL4 ubiquitin ligase. K674 is located in the middle domain of SPT16, and the corresponding residue of the yeast ortholog is critical for binding to histone H3.1-H4. We show that the middle domain of human SPT16 binds to histone H3.1-H4 and that this binding is inhibited by K674 ubiquitylation. Cells with heterozygous knockin of a K674R mutant of SPT16 manifest reduction of both SPT16 ubiquitylation and H3.1 in chromatin, a reduced population in mid S phase, impaired proliferation, and increased susceptibility to S phase stress. Our data thus indicate that SPT16 ubiquitylation by DCAF14-CRL4 regulates FACT binding to histones and may thereby control DNA replication-coupled histone incorporation into chromatin.
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Affiliation(s)
- Tadashi Nakagawa
- Division of Cell Proliferation, ART, Graduate School of Medicine, Tohoku University, Sendai, Miyagi 980-8575, Japan; Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, Sanyo-Onoda, Yamaguchi 756-0884, Japan
| | - Akane Morohoshi
- Division of Cell Proliferation, ART, Graduate School of Medicine, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Yuko Nagasawa
- Division of Cell Proliferation, ART, Graduate School of Medicine, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Makiko Nakagawa
- Division of Cell Proliferation, ART, Graduate School of Medicine, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Masaki Hosogane
- Division of Cell Proliferation, ART, Graduate School of Medicine, Tohoku University, Sendai, Miyagi 980-8575, Japan
| | - Yasuhiro Noda
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, Sanyo-Onoda, Yamaguchi 756-0884, Japan
| | - Toru Hosoi
- Department of Clinical Pharmacology, Faculty of Pharmaceutical Sciences, Sanyo-Onoda City University, Sanyo-Onoda, Yamaguchi 756-0884, Japan
| | - Keiko Nakayama
- Division of Cell Proliferation, ART, Graduate School of Medicine, Tohoku University, Sendai, Miyagi 980-8575, Japan.
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5
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Shan BQ, Wang XM, Zheng L, Han Y, Gao J, Lv MD, Zhang Y, Liu YX, Zhang H, Chen HS, Ao L, Zhang YL, Lu X, Wu ZJ, Xu Y, Che X, Heger M, Cheng SQ, Pan WW, Zhang X. DCAF13 promotes breast cancer cell proliferation by ubiquitin inhibiting PERP expression. Cancer Sci 2022; 113:1587-1600. [PMID: 35178836 PMCID: PMC9128170 DOI: 10.1111/cas.15300] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Revised: 02/07/2022] [Accepted: 02/09/2022] [Indexed: 11/29/2022] Open
Abstract
Evolutionarily conserved DDB1-and CUL4-associated factor 13 (DCAF13) is a recently discovered substrate receptor for the cullin RING-finger ubiquitin ligase 4 (CRL4) E3 ubiquitin ligase that regulates cell cycle progression. DCAF13 is overexpressed in many cancers, although its role in breast cancer is currently elusive. In this study we demonstrate that DCAF13 is overexpressed in human breast cancer and that its overexpression closely correlates with poor prognosis, suggesting that DCAF13 may serve as a diagnostic marker and therapeutic target. We knocked down DCAF13 in breast cancer cell lines using CRISPR/Cas9 and found that DCAF13 deletion markedly reduced breast cancer cell proliferation, clone formation, and migration both in vitro and in vivo. In addition, DCAF13 deletion promoted breast cancer cell apoptosis and senescence, and induced cell cycle arrest in the G1/S phase. Genome-wide RNAseq analysis and western blotting revealed that loss of DCAF13 resulted in both mRNA and protein accumulation of p53 apoptosis effector related to PMP22 (PERP). Knockdown of PERP partially reversed the hampered cell proliferation induced by DCAF13 knockdown. Co-immunoprecipitation assays revealed that DCAF13 and DNA damage-binding protein 1 (DDB1) directly interact with PERP. Overexpression of DDB1 significantly increased PERP polyubiquitination, suggesting that CRL4DCAF13 E3 ligase targets PERP for ubiquitination and proteasomal degradation. In conclusion, DCAF13 and the downstream effector PERP occupy key roles in breast cancer proliferation and potentially serve as prognostics and therapeutic targets.
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Affiliation(s)
- Bao-Qian Shan
- College of Forest and Biotechnology, Zhejiang A & F University, Hangzhou, 311300, China
| | - Xiao-Min Wang
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Li Zheng
- The Key Laboratory, The Second Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang, 314000, China
| | - Yao Han
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Jie Gao
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Meng-Dan Lv
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Yi Zhang
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Yi-Xuan Liu
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Han Zhang
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Hao-Sa Chen
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Lei Ao
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Yin-Li Zhang
- Department of Obstetrics and Gynecology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, 310016, China
| | - Xiang Lu
- Department of Cardiothoracic Surgery, Affiliated Hospital of Jiaxing University, Jiaxing, 314001, China
| | - Zhong-Jie Wu
- Department of Cardiothoracic Surgery, Affiliated Hospital of Jiaxing University, Jiaxing, 314001, China
| | - Ying Xu
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China
| | - Xuan Che
- Department of Anesthesiology, Jiaxing Maternity and Child Health Care Hospital, affiliated with Women and Children Hospital, Jiaxing University, Zhejiang Province, Jiaxing, 314001, China
| | - Michal Heger
- Department of Pharmaceutics, Jiaxing Key Laboratory for Photonanomedicine and Experimental Therapeutics, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China.,Department of Pharmaceutics, Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Utrecht, the Netherlands
| | - Shu-Qun Cheng
- Department of Hepatic Surgery VI, Eastern Hepatobiliary Surgery Hospital, Second Military Medical University, 225 Changhai Road, Shanghai, 200438, China.,G60 STI Valley Industry & Innovation Institute, Jiaxing University
| | - Wei-Wei Pan
- Department of Cell Biology, College of Medicine, Jiaxing University, 118 Jiahang Road, Jiaxing, 314001, China.,G60 STI Valley Industry & Innovation Institute, Jiaxing University
| | - Xin Zhang
- College of Forest and Biotechnology, Zhejiang A & F University, Hangzhou, 311300, China
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Kim DK, Redon CE, Aladjem MI, Kim HK, Jang SM. Molecular double clips within RepID WD40 domain control chromatin binding and CRL4-substrate assembly. Biochem Biophys Res Commun 2021; 567:208-214. [PMID: 34171797 PMCID: PMC9969741 DOI: 10.1016/j.bbrc.2021.06.047] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 06/11/2021] [Accepted: 06/13/2021] [Indexed: 01/07/2023]
Abstract
The cell cycle is modulated by ubiquitin ligases, including CRL4, which facilitate degradation of the chromatin-bound substrates involved in DNA replication and chromosome segregation. One of the members of the CRL4 complex, RepID (DCAF14/PHIP), recognizes kinetochore-localizing BUB3, known as the CRL4 substrate, and recruits CRL4 to the chromatin/chromosome using the WD40 domain. Here, we show that the RepID WD40 domain provides different platforms to CRL4 and BUB3. Deletion of the H-box or exon 8 located in the RepID WD40 domain compromises the interaction between RepID and CRL4, whereas BUB3 interacts with the exon 1-2 region. Moreover, deletion mutants of other exons in the WD40 domain lost chromatin binding affinity. Structure prediction revealed that the RepID WD40 domain has two beta-propeller folds, linked by loops, which are possibly crucial for chromatin binding. These findings provide mechanistic insights into the space occupancy of the RepID WD40 domain to form a complex with CRL4, BUB3, or chromatin.
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Affiliation(s)
- Dong-Kyu Kim
- Department of Biochemistry, Chungbuk National University, Cheongju, 28644, Republic of Korea
| | - Christophe E. Redon
- Developmental Therapeutics Branch, Center for Cancer Research, NCI, NIH, Bethesda, MD, 20892-4255, USA
| | - Mirit I. Aladjem
- Developmental Therapeutics Branch, Center for Cancer Research, NCI, NIH, Bethesda, MD, 20892-4255, USA
| | - Hyong Kyu Kim
- Department of Medicine and Microbiology, College of Medicine, Chungbuk National University, Cheongju, 361-763, Republic of Korea
| | - Sang-Min Jang
- Department of Biochemistry, Chungbuk National University, Cheongju, 28644, Republic of Korea; Developmental Therapeutics Branch, Center for Cancer Research, NCI, NIH, Bethesda, MD, 20892-4255, USA.
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7
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Tang WS, Weng L, Wang X, Liu CQ, Hu GS, Yin ST, Tao Y, Hong NN, Guo H, Liu W, Wang HR, Zhao TJ. The Mediator subunit MED20 organizes the early adipogenic complex to promote development of adipose tissues and diet-induced obesity. Cell Rep 2021; 36:109314. [PMID: 34233190 DOI: 10.1016/j.celrep.2021.109314] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 04/17/2021] [Accepted: 06/06/2021] [Indexed: 02/07/2023] Open
Abstract
MED20 is a non-essential subunit of the transcriptional coactivator Mediator complex, but its physiological function remains largely unknown. Here, we identify MED20 as a substrate of the anti-obesity CRL4-WDTC1 E3 ubiquitin ligase complex through affinity purification and candidate screening. Overexpression of WDTC1 leads to degradation of MED20, whereas depletion of WDTC1 or CUL4A/B causes accumulation of MED20. Depleting MED20 inhibits adipogenesis, and a non-degradable MED20 mutant restores adipogenesis in WDTC1-overexpressing cells. Furthermore, knockout of Med20 in preadipocytes abolishes development of brown adipose tissues. Removing one allele of Med20 in preadipocytes protects mice from diet-induced obesity and reverses weight gain in Cul4a- or Cul4b-depleted mice. Chromatin immunoprecipitation sequencing (ChIP-seq) analysis reveals that MED20 organizes the early adipogenic complex by bridging C/EBPβ and RNA polymerase II to promote transcription of the central adipogenic factor, PPARγ. Our findings have thus uncovered a critical role of MED20 in promoting adipogenesis, development of adipose tissue and diet-induced obesity.
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Affiliation(s)
- Wen-Shuai Tang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Li Weng
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Xu Wang
- Shanghai Key Laboratory of Metabolic Remodeling and Disease, Zhongshan Hospital, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China; Shanghai Qi Zhi Institute, Shanghai, China
| | - Chang-Qin Liu
- Department of Endocrinology and Diabetes, the First Affiliated Hospital, Xiamen University, Xiamen, Fujian, China
| | - Guo-Sheng Hu
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Xiamen, Fujian, China
| | - Shu-Ting Yin
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Ying Tao
- Shanghai Key Laboratory of Metabolic Remodeling and Disease, Zhongshan Hospital, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China
| | - Ni-Na Hong
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Huiling Guo
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Wen Liu
- School of Pharmaceutical Sciences, Fujian Provincial Key Laboratory of Innovative Drug Target Research, Xiamen University, Xiamen, Fujian, China
| | - Hong-Rui Wang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, China
| | - Tong-Jin Zhao
- Shanghai Key Laboratory of Metabolic Remodeling and Disease, Zhongshan Hospital, Institute of Metabolism and Integrative Biology, Fudan University, Shanghai, China; Shanghai Qi Zhi Institute, Shanghai, China.
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8
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Coego A, Julian J, Lozano-Juste J, Pizzio GA, Alrefaei AF, Rodriguez PL. Ubiquitylation of ABA Receptors and Protein Phosphatase 2C Coreceptors to Modulate ABA Signaling and Stress Response. Int J Mol Sci 2021; 22:7103. [PMID: 34281157 DOI: 10.3390/ijms22137103] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2021] [Revised: 06/25/2021] [Accepted: 06/26/2021] [Indexed: 12/12/2022] Open
Abstract
Post-translational modifications play a fundamental role in regulating protein function and stability. In particular, protein ubiquitylation is a multifaceted modification involved in numerous aspects of plant biology. Landmark studies connected the ATP-dependent ubiquitylation of substrates to their degradation by the 26S proteasome; however, nonproteolytic functions of the ubiquitin (Ub) code are also crucial to regulate protein interactions, activity, and localization. Regarding proteolytic functions of Ub, Lys-48-linked branched chains are the most common chain type for proteasomal degradation, whereas promotion of endocytosis and vacuolar degradation is triggered through monoubiquitylation or Lys63-linked chains introduced in integral or peripheral plasma membrane proteins. Hormone signaling relies on regulated protein turnover, and specifically the half-life of ABA signaling components is regulated both through the ubiquitin-26S proteasome system and the endocytic/vacuolar degradation pathway. E3 Ub ligases have been reported that target different ABA signaling core components, i.e., ABA receptors, PP2Cs, SnRK2s, and ABFs/ABI5 transcription factors. In this review, we focused specifically on the ubiquitylation of ABA receptors and PP2C coreceptors, as well as other post-translational modifications of ABA receptors (nitration and phosphorylation) that result in their ubiquitination and degradation.
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White SM, Bhoj E, Nellåker C, Lachmeijer AM, Marshall AE, Boycott KM, Li D, Smith W, Hartley T, McBride A, Ernst ME, May AS, Wieczorek D, Abou Jamra R, Koch-Hogrebe M, Õunap K, Pajusalu S, van Gassen K, Sadedin S, Ellingwood S, Tan TY, Christodoulou J, Barea J, Lockhart PJ, Nezarati MM, Kernohan KD, Kernohan KD. A DNA repair disorder caused by de novo monoallelic DDB1 variants is associated with a neurodevelopmental syndrome. Am J Hum Genet 2021; 108:749-756. [PMID: 33743206 DOI: 10.1016/j.ajhg.2021.03.007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2020] [Accepted: 03/02/2021] [Indexed: 12/27/2022] Open
Abstract
The DNA damage-binding protein 1 (DDB1) is part of the CUL4-DDB1 ubiquitin E3 ligase complex (CRL4), which is essential for DNA repair, chromatin remodeling, DNA replication, and signal transduction. Loss-of-function variants in genes encoding the complex components CUL4 and PHIP have been reported to cause syndromic intellectual disability with hypotonia and obesity, but no phenotype has been reported in association with DDB1 variants. Here, we report eight unrelated individuals, identified through Matchmaker Exchange, with de novo monoallelic variants in DDB1, including one recurrent variant in four individuals. The affected individuals have a consistent phenotype of hypotonia, mild to moderate intellectual disability, and similar facies, including horizontal or slightly bowed eyebrows, deep-set eyes, full cheeks, a short nose, and large, fleshy and forward-facing earlobes, demonstrated in the composite face generated from the cohort. Digital anomalies, including brachydactyly and syndactyly, were common. Three older individuals have obesity. We show that cells derived from affected individuals have altered DDB1 function resulting in abnormal DNA damage signatures and histone methylation following UV-induced DNA damage. Overall, our study adds to the growing family of neurodevelopmental phenotypes mediated by disruption of the CRL4 ubiquitin ligase pathway and begins to delineate the phenotypic and molecular effects of DDB1 misregulation.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Kristin D Kernohan
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON K1H 8L1, Canada; Newborn Screening Ontario, Ottawa, ON K1H 8L1, Canada
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10
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Zhou X, Monnie C, DeLucia M, Ahn J. HIV-1 Vpr activates host CRL4-DCAF1 E3 ligase to degrade histone deacetylase SIRT7. Virol J 2021; 18:48. [PMID: 33648539 PMCID: PMC7923639 DOI: 10.1186/s12985-021-01514-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 02/12/2021] [Indexed: 12/05/2022] Open
Abstract
Background Vpr is a virion-associated protein that is encoded by lentiviruses and serves to counteract intrinsic immunity factors that restrict infection. HIV-1 Vpr mediates proteasome-dependent degradation of several DNA repair/modification proteins. Mechanistically, Vpr directly recruits cellular targets onto DCAF1, a substrate receptor of Cullin 4 RING E3 ubiquitin ligase (CRL4) for poly-ubiquitination. Further, Vpr can mediate poly-ubiquitination of DCAF1-interacting proteins by the CRL4. Because Vpr-mediated degradation of its known targets can not explain the primary cell-cycle arrest phenotype that Vpr expression induces, we surveyed the literature for DNA-repair-associated proteins that interact with the CRL4-DCAF1. One such protein is SIRT7, a deacetylase of histone 3 that belongs to the Sirtuin family and regulates a wide range of cellular processes. We wondered whether Vpr can mediate degradation of SIRT7 via the CRL4-DCAF1. Methods HEK293T cells were transfected with cocktails of plasmids expressing DCAF1, DDB1, SIRT7 and Vpr. Ectopic and endogeneous levels of SIRT7 were monitered by immunoblotting and protein–protein interactions were assessed by immunoprecipitation. For in vitro reconstitution assays, recombinant CRL4-DCAF1-Vpr complexes and SIRT7 were prepared and poly-ubiqutination of SIRT7 was monitored with immunoblotting. Results We demonstrate SIRT7 polyubiquitination and degradation upon Vpr expression. Specifically, SIRT7 is shown to interact with the CRL4-DCAF1 complex, and expression of Vpr in HEK293T cells results in SIRT7 degradation, which is partially rescued by CRL inhibitor MNL4924 and proteasome inhibitor MG132. Further, in vitro reconstitution assays show that Vpr induces poly-ubiquitination of SIRT7 by the CRL4-DCAF1. Importantly, we find that Vpr from several different HIV-1 strains, but not HIV-2 strains, mediates SIRT7 poly-ubiquitination in the reconstitution assay and degradation in cells. Finally, we show that SIRT7 degradation by Vpr is independent of the known, distinctive phenotype of Vpr-induced cell cycle arrest at the G2 phase, Conclusions Targeting histone deacetylase SIRT7 for degradation is a conserved feature of HIV-1 Vpr. Altogether, our findings reveal that HIV-1 Vpr mediates down-regulation of SIRT7 by a mechanism that does not involve novel target recruitment to the CRL4-DCAF1 but instead involves regulation of the E3 ligase activity.
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Affiliation(s)
- Xiaohong Zhou
- Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, RM 1055, 3501 Fifth Ave., Pittsburgh, PA, 15260, USA
| | - Christina Monnie
- Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, RM 1055, 3501 Fifth Ave., Pittsburgh, PA, 15260, USA
| | - Maria DeLucia
- Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, RM 1055, 3501 Fifth Ave., Pittsburgh, PA, 15260, USA
| | - Jinwoo Ahn
- Department of Structural Biology and Pittsburgh Center for HIV Protein Interactions, University of Pittsburgh School of Medicine, Biomedical Science Tower 3, RM 1055, 3501 Fifth Ave., Pittsburgh, PA, 15260, USA.
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11
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Townsend A, Lora G, Engel J, Tirado-Class N, Dungrawala H. DCAF14 promotes stalled fork stability to maintain genome integrity. Cell Rep 2021; 34:108669. [PMID: 33503431 DOI: 10.1016/j.celrep.2020.108669] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2020] [Revised: 11/24/2020] [Accepted: 12/29/2020] [Indexed: 12/15/2022] Open
Abstract
Replication stress response ensures impediments to DNA replication do not compromise replication fork stability and genome integrity. In a process termed replication fork protection, newly synthesized DNA at stalled replication forks is stabilized and protected from nuclease-mediated degradation. We report the identification of DDB1- and CUL4-associated factor 14 (DCAF14), a substrate receptor for Cullin4-RING E3 ligase (CRL4) complex, integral in stabilizing stalled replication forks. DCAF14 localizes rapidly to stalled forks and promotes genome integrity by preventing fork collapse into double-strand breaks (DSBs). Importantly, CRL4DCAF14 mediates stalled fork protection in a RAD51-dependent manner to protect nascent DNA from MRE11 and DNA2 nucleases. Thus, our study shows replication stress response functions of DCAF14 in genome maintenance. Townsend et al. find that DDB1- and CUL4-associated factor DCAF14 is recruited to stalled replication forks. DCAF14 prevents replication fork collapse in a CRL4-dependent manner to promote genome stability and cell survival. DCAF14 depletion triggers nascent strand degradation that is reversible by enhancing RAD51 levels at forks.
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12
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Ting TC, Goralski M, Klein K, Wang B, Kim J, Xie Y, Nijhawan D. Aryl Sulfonamides Degrade RBM39 and RBM23 by Recruitment to CRL4-DCAF15. Cell Rep 2020; 29:1499-1510.e6. [PMID: 31693891 DOI: 10.1016/j.celrep.2019.09.079] [Citation(s) in RCA: 64] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2019] [Revised: 09/09/2019] [Accepted: 09/26/2019] [Indexed: 12/12/2022] Open
Abstract
Indisulam and related sulfonamides recruit the splicing factor RBM39 to the CRL4-DCAF15 E3 ubiquitin ligase, resulting in RBM39 ubiquitination and degradation. Here, we used a combination of domain mapping and random mutagenesis to identify domains or residues that are necessary for indisulam-dependent RBM39 ubiquitination. DCAF15 mutations at Q232 or D475 prevent RBM39 recruitment by indisulam. RBM39 is recruited to DCAF15 by its RRM2 (RNA recognition motif 2) and is ubiquitinated on its N terminus. RBM23, which is an RBM39 paralog, is also recruited to the CRL4-DCAF15 ligase through its RRM2 domain and undergoes sulfonamide-dependent degradation. Indisulam alters the expression of more than 3,000 genes and causes widespread intron retention and exon skipping. All of these changes can be attributed to RBM39, and none are the consequence of RBM23 degradation. Our findings demonstrate that indisulam selectively degrades RBM23 and RBM39, the latter of which is critically important for splicing and gene expression.
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Affiliation(s)
- Tabitha C Ting
- Medical Scientist Training Program, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Maria Goralski
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Katherine Klein
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Baiyun Wang
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Jiwoong Kim
- Quantitative Biomedical Research Center, Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Yang Xie
- Quantitative Biomedical Research Center, Department of Clinical Sciences, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA
| | - Deepak Nijhawan
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Harold C. Simmons Comprehensive Cancer Center, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA; Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas, TX 75390, USA.
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13
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Abstract
This Outlook discusses Cho et al.’s finding showing that CDK7 directly phosphorylates YAP/TAZ/Yki in the nucleus, protecting them from ubiquitination and degradation, in a manner independent of the Hippo cascade and from CDK7 basal transcriptional effects. Inhibition of CDK7 is a promising strategy for cancer therapy. CDK7 so far has been understood mainly in the context of Pol II-driven transcription. However, how are the roles of CDK7 in the “basal” transcriptional machinery reconciled with the function of CDK7 as inducer of specific transcriptional programs in tumor cells? In this issue of Genes & Development, Cho and colleagues (pp. 53–71) advance in this direction, demonstrating that attenuation of CDK7 fosters the oncogenic activity of the YAP/TAZ/Yki coactivators. CDK7 directly phosphorylates YAP/TAZ/Yki in the nucleus, protecting them from ubiquitination and degradation, in a manner independent from the Hippo cascade and independent from CDK7 basal transcriptional functions.
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Affiliation(s)
- Stefano Piccolo
- Department of Molecular Medicine, University of Padua School of Medicine, 35121 Padua, Italy; IFOM, The FIRC Institute of Molecular Oncology, 35121 Padua, Italy
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14
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Reichermeier KM, Straube R, Reitsma JM, Sweredoski MJ, Rose CM, Moradian A, den Besten W, Hinkle T, Verschueren E, Petzold G, Thomä NH, Wertz IE, Deshaies RJ, Kirkpatrick DS. PIKES Analysis Reveals Response to Degraders and Key Regulatory Mechanisms of the CRL4 Network. Mol Cell 2020; 77:1092-1106.e9. [PMID: 31973889 DOI: 10.1016/j.molcel.2019.12.013] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2019] [Revised: 11/18/2019] [Accepted: 12/13/2019] [Indexed: 12/11/2022]
Abstract
Co-opting Cullin4 RING ubiquitin ligases (CRL4s) to inducibly degrade pathogenic proteins is emerging as a promising therapeutic strategy. Despite intense efforts to rationally design degrader molecules that co-opt CRL4s, much about the organization and regulation of these ligases remains elusive. Here, we establish protein interaction kinetics and estimation of stoichiometries (PIKES) analysis, a systematic proteomic profiling platform that integrates cellular engineering, affinity purification, chemical stabilization, and quantitative mass spectrometry to investigate the dynamics of interchangeable multiprotein complexes. Using PIKES, we show that ligase assemblies of Cullin4 with individual substrate receptors differ in abundance by up to 200-fold and that Cand1/2 act as substrate receptor exchange factors. Furthermore, degrader molecules can induce the assembly of their cognate CRL4, and higher expression of the associated substrate receptor enhances degrader potency. Beyond the CRL4 network, we show how PIKES can reveal systems level biochemistry for cellular protein networks important to drug development.
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Affiliation(s)
- Kurt M Reichermeier
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd., Pasadena, CA 91125, USA; Genentech, 1 DNA Way, South San Francisco, 94080 CA, USA.
| | - Ronny Straube
- Max Plank Institute for Dynamics of Complex Technical Systems, Sandtorstr. 1, 39106 Magdeburg, Germany; Bristol-Myers Squibb, 3551 Lawrenceville Princeton Rd, Lawrence Township, NJ 08648, USA
| | - Justin M Reitsma
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd., Pasadena, CA 91125, USA; Abbvie, 1 N Waukegan Rd, North Chicago, IL 60064, USA
| | - Michael J Sweredoski
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd., Pasadena, CA 91125, USA
| | | | - Annie Moradian
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd., Pasadena, CA 91125, USA
| | - Willem den Besten
- Genentech, 1 DNA Way, South San Francisco, 94080 CA, USA; Amgen Research, Amgen, One Amgen Center Drive, 29MB, Thousand Oaks, CA 91320, USA
| | - Trent Hinkle
- Genentech, 1 DNA Way, South San Francisco, 94080 CA, USA
| | | | - Georg Petzold
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Nicolas H Thomä
- Friedrich Miescher Institute for Biomedical Research, Maulbeerstrasse 66, 4058 Basel, Switzerland
| | - Ingrid E Wertz
- Genentech, 1 DNA Way, South San Francisco, 94080 CA, USA
| | - Raymond J Deshaies
- Division of Biology and Biological Engineering, California Institute of Technology, 1200 E California Blvd., Pasadena, CA 91125, USA; Amgen Research, Amgen, One Amgen Center Drive, 29MB, Thousand Oaks, CA 91320, USA
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15
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Abstract
DNA damage occurs in a human cell at an average frequency of 10,000 incidences per day by means of external and internal culprits, damage that triggers sequential cellular responses and stalls the cell cycle while activating specific DNA repair pathways. Failure to remove DNA lesions would compromise genomic integrity, leading to human diseases such as cancer and premature aging. If DNA damage is extensive and cannot be repaired, cells undergo apoptosis. DNA damage response (DDR) often entails posttranslational modifications of key DNA repair and DNA damage checkpoint proteins, including phosphorylation and ubiquitination. Cullin-RING ligase 4 (CRL4) enzyme has been found to target multiple DDR proteins for ubiquitination. In this chapter, we will discuss key repair and checkpoint proteins that are subject to ubiquitin-dependent regulation by members of the CRL4 family during ultraviolet light (UV)-induced DNA damage.
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16
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Cho YS, Li S, Wang X, Zhu J, Zhuo S, Han Y, Yue T, Yang Y, Jiang J. CDK7 regulates organ size and tumor growth by safeguarding the Hippo pathway effector Yki/Yap/Taz in the nucleus. Genes Dev 2019; 34:53-71. [PMID: 31857346 PMCID: PMC6938674 DOI: 10.1101/gad.333146.119] [Citation(s) in RCA: 41] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Accepted: 11/25/2019] [Indexed: 01/09/2023]
Abstract
Hippo signaling controls organ size and tumor progression through a conserved pathway leading to nuclear translocation of the transcriptional effector Yki/Yap/Taz. Most of our understanding of Hippo signaling pertains to its cytoplasmic regulation, but how the pathway is controlled in the nucleus remains poorly understood. Here we uncover an evolutionarily conserved mechanism by which CDK7 promotes Yki/Yap/Taz stabilization in the nucleus to sustain Hippo pathway outputs. We found that a modular E3 ubiquitin ligase complex CRL4DCAF12 binds and targets Yki/Yap/Taz for ubiquitination and degradation, whereas CDK7 phosphorylates Yki/Yap/Taz at S169/S128/S90 to inhibit CRL4DCAF12 recruitment, leading to Yki/Yap/Taz stabilization. As a consequence, inactivation of CDK7 reduced organ size and inhibited tumor growth, which could be reversed by restoring Yki/Yap activity. Our study identifies an unanticipated layer of Hippo pathway regulation, defines a novel mechanism by which CDK7 regulates tissue growth, and implies CDK7 as a drug target for Yap/Taz-driven cancer.
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Affiliation(s)
- Yong Suk Cho
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Shuang Li
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Xiaohui Wang
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02215, USA.,Harvard Stem Cell Institute, Boston, Massachusetts 02215, USA
| | - Jian Zhu
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Shu Zhuo
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Yuhong Han
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Tao Yue
- Center for the Genetics and Host Defense, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
| | - Yingzi Yang
- Department of Developmental Biology, Harvard School of Dental Medicine, Boston, Massachusetts 02215, USA.,Harvard Stem Cell Institute, Boston, Massachusetts 02215, USA
| | - Jin Jiang
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA.,Department of Pharmacology, University of Texas Southwestern Medical Center, Dallas, Texas 75390, USA
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17
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Abstract
Cryptochromes (CRYs) are UVA and blue light photoreceptors present in all major evolutionary lineages ranging from cyanobacteria to plants and animals, including mammals. In plants, blue light activates CRYs to induce photomorphogenesis by inhibiting the CRL4Cop1 E3 ligase complex which regulates the degradation of critical transcription factors involved in plant development and growth. However, in mammals, CRYs do not physically interact with Cop1, and of course mammals are not photomorphogenic, leading to the belief that the CRY-Cop1 axis is not conserved in mammals. This belief was recently overturned by Rizzini et al., who showed that although mammalian CRYs do not inhibit Cop1 activity in a light-dependent manner, they antagonize Cop1 activity by displacing Cop1 from CRL4 E3 ligase complex. Because CRYs oscillate, they act in a circadian manner resulting in daily oscillations in Cop1 substrates and the downstream pathways that they regulate. The conserved antagonism of Cop1 by CRY indicates that the CRY-Cop1 axis has an ancient origin, and was repurposed by evolution to regulate photomorphogenesis in plants and circadian rhythms in mammals.
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Affiliation(s)
- Choogon Lee
- Department of Biomedical Sciences, Program in Neuroscience, College of Medicine, Florida State University, 1115 West Call Street, Tallahassee, FL 32306 USA
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18
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Rizzini L, Levine DC, Perelis M, Bass J, Peek CB, Pagano M. Cryptochromes-Mediated Inhibition of the CRL4Cop1-Complex Assembly Defines an Evolutionary Conserved Signaling Mechanism. Curr Biol 2019; 29:1954-1962.e4. [PMID: 31155351 DOI: 10.1016/j.cub.2019.04.073] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/04/2019] [Accepted: 04/30/2019] [Indexed: 11/24/2022]
Abstract
In plants, cryptochromes are photoreceptors that negatively regulate the ubiquitin ligase CRL4Cop1. In mammals, cryptochromes are core components of the circadian clock and repressors of the glucocorticoid receptor (GR). Moreover, mammalian cryptochromes lost their ability to interact with Cop1, suggesting that they are unable to inhibit CRL4Cop1. Contrary to this assumption, we found that mammalian cryptochromes are also negative regulators of CRL4Cop1, and through this mechanism, they repress the GR transcriptional network both in cultured cells and in the mouse liver. Mechanistically, cryptochromes inactivate Cop1 by interacting with Det1, a subunit of the mammalian CRL4Cop1 complex that is not present in other CRL4s. Through this interaction, the ability of Cop1 to join the CRL4 complex is inhibited; therefore, its substrates accumulate. Thus, the interaction between cryptochromes and Det1 in mammals mirrors the interaction between cryptochromes and Cop1 in planta, pointing to a common ancestor in which the cryptochromes-Cop1 axis originated.
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19
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Fonseca S, Rubio V. Arabidopsis CRL4 Complexes: Surveying Chromatin States and Gene Expression. Front Plant Sci 2019; 10:1095. [PMID: 31608079 PMCID: PMC6761389 DOI: 10.3389/fpls.2019.01095] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2019] [Accepted: 08/09/2019] [Indexed: 05/10/2023]
Abstract
CULLIN4 (CUL4) RING ligase (CRL4) complexes contain a CUL4 scaffold protein, associated to RBX1 and to DDB1 proteins and have traditionally been associated to protein degradation events. Through DDB1, these complexes can associate with numerous DCAF proteins, which directly interact with specific targets promoting their ubiquitination and subsequent degradation by the proteasome. A characteristic feature of the majority of DCAF proteins that associate with DDB1 is the presence of the DWD motif. DWD-containing proteins sum up to 85 in the plant model species Arabidopsis. In the last decade, numerous Arabidopsis DWD proteins have been studied and their molecular functions uncovered. Independently of whether their association with CRL4 has been confirmed or not, DWD proteins are often found as components of additional multimeric protein complexes that play key roles in essential nuclear events. For most of them, the significance of their complex partnership is still unexplored. Here, we summarize recent findings involving both confirmed and putative CRL4-associated DCAF proteins in regulating nuclei architecture remodelling, DNA damage repair, histone post-translational modification, mRNA processing and export, and ribosome biogenesis, that definitely have an impact in gene expression and de novo protein synthesis. We hypothesized that, by maintaining accurate levels of regulatory proteins through targeted degradation and transcriptional control, CRL4 complexes help to surveil nuclear processes essential for plant development and survival.
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20
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Li S, Cho YS, Wang B, Li S, Jiang J. Regulation of Smoothened ubiquitylation and cell surface expression through a Cul4-DDB1-Gβ E3 ubiquitin ligase complex. J Cell Sci 2018; 131:jcs.218016. [PMID: 29930086 DOI: 10.1242/jcs.218016] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/15/2018] [Indexed: 12/21/2022] Open
Abstract
Hedgehog (Hh) transduces signals by promoting cell surface accumulation and activation of the G-protein-coupled receptor (GPCR)-family protein Smoothened (Smo) in Drosophila, but the molecular mechanism underlying the regulation of Smo trafficking remains poorly understood. Here, we identified the Cul4-DDB1 E3 ubiquitin ligase complex as being essential for Smo ubiquitylation and cell surface clearance. We found that the C-terminal intracellular domain of Smo recruits Cul4-DDB1 through the β subunit of trimeric G protein (Gβ), and that Cul4-DDB1-Gβ promotes the ubiquitylation of both Smo and its binding partner G-protein-coupled-receptor kinase 2 (Gprk2) and induces the internalization and degradation of Smo. Hh dissociates Cul4-DDB1 from Smo by recruiting the catalytic subunit of protein kinase A (PKA) to phosphorylate DDB1, which disrupts its interaction with Gβ. Inactivation of the Cul4-DDB1 complex resulted in elevated Smo cell surface expression, whereas an excessive amount of Cul4-DDB1 blocked Smo accumulation and attenuated Hh pathway activation. Taken together, our study identifies an E3 ubiquitin ligase complex targeting Smo for ubiquitylation and provides new insight into how Hh signaling regulates Smo trafficking and cell surface expression.
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Affiliation(s)
- Shuang Li
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Yong Suk Cho
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Bing Wang
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Shuangxi Li
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
| | - Jin Jiang
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA .,Department of Pharmacology, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390, USA
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21
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Li G, Ji T, Chen J, Fu Y, Hou L, Feng Y, Zhang T, Song T, Zhao J, Endo Y, Lin H, Cai X, Cang Y. CRL4DCAF8 Ubiquitin Ligase Targets Histone H3K79 and Promotes H3K9 Methylation in the Liver. Cell Rep 2017; 18:1499-1511. [PMID: 28178526 DOI: 10.1016/j.celrep.2017.01.039] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2016] [Revised: 10/04/2016] [Accepted: 01/16/2017] [Indexed: 11/26/2022] Open
Abstract
Transcription from chromosomes is regulated by posttranslational modifications to histones, such as methylation and ubiquitination. Monoubiquitination of histones H2A and H2B influences H3 methylation to reinforce the activation or repression of gene expression. Here, we provide evidence that H3 polyubiquitination represses transcription of fetal and cell-cycle genes in postnatal mouse liver by crosstalk with H3K9 methylation. We found that the CRL4 ubiquitin ligase targets H3 for polyubiquitination at K79 via the DCAF8 substrate receptor in hepatocytes. Genetic inactivation of DCAF8 and overexpression of an H3K79 mutant in cells or inducible deletion of CRL4 in mouse liver abrogates H3 ubiquitination, reactivates the expression of fetal liver and cell-cycle genes by interfering with methylated H3K9 occupancy, and leads to cell senescence. Restoring CRL4DCAF8 expression in cells with decreased H3 ubiquitination reinstates the epigenetic gene silencing. Our results suggest that progressive H3 ubiquitination plays an important role in postnatal liver maturation.
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Affiliation(s)
- Gaofeng Li
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Tong Ji
- Department of General Surgery, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jiang Chen
- Department of General Surgery, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yufei Fu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China; Zhejiang Key Laboratory of Gastro-Intestinal Pathophysiology, Zhejiang Hospital of Traditional Chinese Medicine, Hangzhou, Zhejiang 310058, China
| | - Lidan Hou
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yan Feng
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Tingyue Zhang
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Tianyu Song
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jie Zhao
- Department of General Surgery, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Yoko Endo
- Signal Transduction Program, Sanford-Burnham Medical Research Institute, La Jolla, CA 92121, USA
| | - Hui Lin
- Department of General Surgery, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiujun Cai
- Department of General Surgery, Sir Run Run Shaw Hospital, College of Medicine, Zhejiang University, Hangzhou, Zhejiang 310058, China.
| | - Yong Cang
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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22
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Hinnant TD, Alvarez AA, Ables ET. Temporal remodeling of the cell cycle accompanies differentiation in the Drosophila germline. Dev Biol 2017; 429:118-131. [PMID: 28711427 DOI: 10.1016/j.ydbio.2017.07.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2017] [Revised: 06/15/2017] [Accepted: 07/05/2017] [Indexed: 12/27/2022]
Abstract
Development of multicellular organisms relies upon the coordinated regulation of cellular differentiation and proliferation. Growing evidence suggests that some molecular regulatory pathways associated with the cell cycle machinery also dictate cell fate; however, it remains largely unclear how the cell cycle is remodeled in concert with cell differentiation. During Drosophila oogenesis, mature oocytes are created through a series of precisely controlled division and differentiation steps, originating from a single tissue-specific stem cell. Further, germline stem cells (GSCs) and their differentiating progeny remain in a predominantly linear arrangement as oogenesis proceeds. The ability to visualize the stepwise events of differentiation within the context of a single tissue make the Drosophila ovary an exceptional model for study of cell cycle remodeling. To describe how the cell cycle is remodeled in germ cells as they differentiate in situ, we used the Drosophila Fluorescence Ubiquitin-based Cell Cycle Indicator (Fly-FUCCI) system, in which degradable versions of GFP::E2f1 and RFP::CycB fluorescently label cells in each phase of the cell cycle. We found that the lengths of the G1, S, and G2 phases of the cell cycle change dramatically over the course of differentiation, and identified the 4/8-cell cyst as a key developmental transition state in which cells prepare for specialized cell cycles. Our data suggest that the transcriptional activator E2f1, which controls the transition from G1 to S phase, is a key regulator of mitotic divisions in the early germline. Our data support the model that E2f1 is necessary for proper GSC proliferation, self-renewal, and daughter cell development. In contrast, while E2f1 degradation by the Cullin 4 (Cul4)-containing ubiquitin E3 ligase (CRL4) is essential for developmental transitions in the early germline, our data do not support a role for E2f1 degradation as a mechanism to limit GSC proliferation or self-renewal. Taken together, these findings provide further insight into the regulation of cell proliferation and the acquisition of differentiated cell fate, with broad implications across developing tissues.
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Affiliation(s)
- Taylor D Hinnant
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Arturo A Alvarez
- Department of Biology, East Carolina University, Greenville, NC 27858, USA
| | - Elizabeth T Ables
- Department of Biology, East Carolina University, Greenville, NC 27858, USA.
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23
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Gao S, Geng C, Song T, Lin X, Liu J, Cai Z, Cang Y. Activation of c-Abl Kinase Potentiates the Anti-myeloma Drug Lenalidomide by Promoting DDA1 Protein Recruitment to the CRL4 Ubiquitin Ligase. J Biol Chem 2017; 292:3683-3691. [PMID: 28087699 DOI: 10.1074/jbc.m116.761551] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2016] [Revised: 12/30/2016] [Indexed: 12/20/2022] Open
Abstract
Cullin-RING ligase 4 (CRL4), a complex of Cul4 and DDB1, regulates the cell cycle, DNA damage repair, and chromatin replication by targeting a variety of substrates for ubiquitination. CRL4 is also hijacked by viral proteins or thalidomide-derived compounds to degrade host restriction factors. Here we report that the c-Abl non-receptor kinase phosphorylates DDB1 at residue Tyr-316 to recruit a small regulatory protein, DDA1, leading to increased substrate ubiquitination. Pharmacological inhibition or genetic ablation of the Abl-DDB1-DDA1 axis decreases the ubiquitination of CRL4 substrates, including IKZF1 and IKZF3, in lenalidomide-treated multiple myeloma cells. Importantly, panobinostat, a recently approved anti-myeloma drug, and dexamethasone enhance lenalidomide-induced substrate degradation and cytotoxicity by activating c-Abl, therefore providing a mechanism underlying their combination with lenalidomide to treat multiple myeloma.
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Affiliation(s)
- Shaobing Gao
- From the Life Sciences Institute and Innovation Center for Cell Signaling Networks, Zhejiang University, Hangzhou, Zhejiang 310058, China and
| | - Chenlu Geng
- From the Life Sciences Institute and Innovation Center for Cell Signaling Networks, Zhejiang University, Hangzhou, Zhejiang 310058, China and
| | - Tianyu Song
- From the Life Sciences Institute and Innovation Center for Cell Signaling Networks, Zhejiang University, Hangzhou, Zhejiang 310058, China and
| | - Xuanru Lin
- the Bone Marrow Transplantation Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jiye Liu
- From the Life Sciences Institute and Innovation Center for Cell Signaling Networks, Zhejiang University, Hangzhou, Zhejiang 310058, China and
| | - Zhen Cai
- the Bone Marrow Transplantation Center, The First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Yong Cang
- From the Life Sciences Institute and Innovation Center for Cell Signaling Networks, Zhejiang University, Hangzhou, Zhejiang 310058, China and
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24
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Sang Y, Yan F, Ren X. The role and mechanism of CRL4 E3 ubiquitin ligase in cancer and its potential therapy implications. Oncotarget 2016; 6:42590-602. [PMID: 26460955 PMCID: PMC4767455 DOI: 10.18632/oncotarget.6052] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Accepted: 09/23/2015] [Indexed: 12/21/2022] Open
Abstract
CRLs (Cullin-RING E3 ubiquitin ligases) are the largest E3 ligase family in eukaryotes, which ubiquitinate a wide range of substrates involved in cell cycle regulation, signal transduction, transcriptional regulation, DNA damage response, genomic integrity, tumor suppression and embryonic development. CRL4 E3 ubiquitin ligase, as one member of CRLs family, consists of a RING finger domain protein, cullin4 (CUL4) scaffold protein and DDB1–CUL4 associated substrate receptors. The CUL4 subfamily includes two members, CUL4A and CUL4B, which share extensively sequence identity and functional redundancy. Aberrant expression of CUL4 has been found in a majority of tumors. Given the significance of CUL4 in cancer, understanding its detailed aspects of pathogenesis of human malignancy would have significant value for the treatment of cancer. Here, the work provides an overview to address the role of CRL4 E3 ubiquitin ligase in cancer development and progression, and discuss the possible mechanisms of CRL4 ligase involving in many cellular processes associated with tumor. Finally, we discuss its potential value in cancer therapy.
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Affiliation(s)
- Youzhou Sang
- Department of Immunology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China.,National Clinical Research Center of Cancer, Tianjin, China.,Key Laboratory of Cancer Immunology and Biotherapy, Tianjin, China
| | - Fan Yan
- Department of Immunology, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China.,National Clinical Research Center of Cancer, Tianjin, China.,Key Laboratory of Cancer Immunology and Biotherapy, Tianjin, China
| | - Xiubao Ren
- Department of Biotherapy, Tianjin Medical University Cancer Institute and Hospital, Tianjin, China.,National Clinical Research Center of Cancer, Tianjin, China.,Key Laboratory of Cancer Immunology and Biotherapy, Tianjin, China
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25
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Djakbarova U, Marzluff WF, Köseoğlu MM. DDB1 and CUL4 associated factor 11 (DCAF11) mediates degradation of Stem-loop binding protein at the end of S phase. Cell Cycle 2016; 15:1986-96. [PMID: 27254819 DOI: 10.1080/15384101.2016.1191708] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [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: 12/31/2022] Open
Abstract
In eukaryotes, bulk histone expression occurs in the S phase of the cell cycle. This highly conserved system is crucial for genomic stability and proper gene expression. In metazoans, Stem-loop binding protein (SLBP), which binds to 3' ends of canonical histone mRNAs, is a key factor in histone biosynthesis. SLBP is mainly expressed in S phase and this is a major mechanism to limit bulk histone production to the S phase. At the end of S phase, SLBP is rapidly degraded by proteasome, depending on two phosphorylations on Thr 60 and Thr 61. Previously, we showed that SLBP fragment (aa 51-108) fused to GST, is sufficient to mimic the late S phase (S/G2) degradation of SLBP. Here, using this fusion protein as bait, we performed pull-down experiments and found that DCAF11, which is a substrate receptor of CRL4 complexes, binds to the phosphorylated SLBP fragment. We further confirmed the interaction of full-length SLBP with DCAF11 and Cul4A by co-immunoprecipitation experiments. We also showed that DCAF11 cannot bind to the Thr61/Ala mutant SLBP, which is not degraded at the end of S phase. Using ectopic expression and siRNA experiments, we demonstrated that SLBP expression is inversely correlated with DCAF11 levels, consistent with the model that DCAF11 mediates SLBP degradation. Finally, we found that ectopic expression of the S/G2 stable mutant SLBP (Thr61/Ala) is significantly more toxic to the cells, in comparison to wild type SLBP. Overall, we concluded that CRL4-DCAF11 mediates the degradation of SLBP at the end of S phase and this degradation is essential for the viability of cells.
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Affiliation(s)
- Umidahan Djakbarova
- a Department of Genetics and Bioengineering , Fatih University , Istanbul , Turkey.,b Bionanotechnology Center , Fatih University , Istanbul , Turkey
| | - William F Marzluff
- c Department of Biochemistry and Biophysics , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA.,d Program in Molecular Biology and Biotechnology , University of North Carolina at Chapel Hill , Chapel Hill , NC , USA
| | - M Murat Köseoğlu
- a Department of Genetics and Bioengineering , Fatih University , Istanbul , Turkey.,b Bionanotechnology Center , Fatih University , Istanbul , Turkey
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26
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Han C, Wani G, Zhao R, Qian J, Sharma N, He J, Zhu Q, Wang QE, Wani AA. Cdt2-mediated XPG degradation promotes gap-filling DNA synthesis in nucleotide excision repair. Cell Cycle 2015; 14:1103-15. [PMID: 25483071 DOI: 10.4161/15384101.2014.973740] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [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: 01/25/2023] Open
Abstract
Xeroderma pigmentosum group G (XPG) protein is a structure-specific repair endonuclease, which cleaves DNA strands on the 3' side of the DNA damage during nucleotide excision repair (NER). XPG also plays a crucial role in initiating DNA repair synthesis through recruitment of PCNA to the repair sites. However, the fate of XPG protein subsequent to the excision of DNA damage has remained unresolved. Here, we show that XPG, following its action on bulky lesions resulting from exposures to UV irradiation and cisplatin, is subjected to proteasome-mediated proteolytic degradation. Productive NER processing is required for XPG degradation as both UV and cisplatin treatment-induced XPG degradation is compromised in NER-deficient XP-A, XP-B, XP-C, and XP-F cells. In addition, the NER-related XPG degradation requires Cdt2, a component of an E3 ubiquitin ligase, CRL4(Cdt2). Micropore local UV irradiation and in situ Proximity Ligation assays demonstrated that Cdt2 is recruited to the UV-damage sites and interacts with XPG in the presence of PCNA. Importantly, Cdt2-mediated XPG degradation is crucial to the subsequent recruitment of DNA polymerase δ and DNA repair synthesis. Collectively, our data support the idea of PCNA recruitment to damage sites which occurs in conjunction with XPG, recognition of the PCNA-bound XPG by CRL4(Cdt2) for specific ubiquitylation and finally the protein degradation. In essence, XPG elimination from DNA damage sites clears the chromatin space needed for the subsequent recruitment of DNA polymerase δ to the damage site and completion of gap-filling DNA synthesis during the final stage of NER.
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Affiliation(s)
- Chunhua Han
- a Department of Radiology ; The Ohio State University Wexner Medical Center ; Columbus , OH USA
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27
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Hannah J, Zhou P. Distinct and overlapping functions of the cullin E3 ligase scaffolding proteins CUL4A and CUL4B. Gene 2015; 573:33-45. [PMID: 26344709 DOI: 10.1016/j.gene.2015.08.064] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2015] [Revised: 08/03/2015] [Accepted: 08/27/2015] [Indexed: 01/29/2023]
Abstract
The cullin 4 subfamily of genes includes CUL4A and CUL4B, which share a mostly identical amino acid sequence aside from the elongated N-terminal region in CUL4B. Both act as scaffolding proteins for modular cullin RING ligase 4 (CRL4) complexes which promote the ubiquitination of a variety of substrates. CRL4 function is vital to cells as loss of both genes or their shared substrate adaptor protein DDB1 halts proliferation and eventually leads to cell death. Due to their high structural similarity, CUL4A and CUL4B share a substantial overlap in function. However, in some cases, differences in subcellular localization, spatiotemporal expression patterns and stress-inducibility preclude functional compensation. In this review, we highlight the most essential functions of the CUL4 genes in: DNA repair and replication, chromatin-remodeling, cell cycle regulation, embryogenesis, hematopoiesis and spermatogenesis. CUL4 genes are also clinically relevant as dysregulation can contribute to the onset of cancer and CRL4 complexes are often hijacked by certain viruses to promote viral replication and survival. Also, mutations in CUL4B have been implicated in a subset of patients suffering from syndromic X-linked intellectual disability (AKA mental retardation). Interestingly, the antitumor effects of immunomodulatory drugs are caused by their binding to the CRL4CRBN complex and re-directing the E3 ligase towards the Ikaros transcription factors IKZF1 and IKZF3. Because of their influence over key cellular functions and relevance to human disease, CRL4s are considered promising targets for therapeutic intervention.
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Affiliation(s)
- Jeffrey Hannah
- Department of Pathology, Weill Cornell Medical College, 1300 York Ave. NY, NY 10065, United States.
| | - Pengbo Zhou
- Department of Pathology, Weill Cornell Medical College, 1300 York Ave. NY, NY 10065, United States.
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28
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Kim SH, Lee JH, Seo KI, Ryu B, Sung Y, Chung T, Deng XW, Lee JH. Characterization of a Novel DWD protein that participates in heat stress response in Arabidopsis. Mol Cells 2014; 37:833-40. [PMID: 25358503 PMCID: PMC4255104 DOI: 10.14348/molcells.2014.0224] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/02/2014] [Accepted: 09/03/2014] [Indexed: 11/29/2022] Open
Abstract
Cullin4-RING ubiquitin ligase (CRL4) is a family of multi-subunit E3 ligases. To investigate the possible involvement of CRL4 in heat stress response, we screened T-DNA insertion mutants of putative CRL4 substrate receptors that exhibited altered patterns in response to heat stress. One of the mutants exhibited heat stress tolerance and was named heat stress tolerant DWD1 (htd1). Introduction of HTD1 gene into htd1-1 led to recovery of heat sensitivity to the wild type level, confirming that the decrease of HTD1 transcripts resulted in heat tolerance. Therefore, HTD1 plays a negative role in thermotolerance in Arabidopsis. Additionally, HTD1 directly interacted with DDB1a in yeast two-hybrid assays and associated with DDB1b in vivo, supporting that it could be a part of a CRL4 complex. Various heat-inducible genes such as HSP14.7, HSP21, At2g03020 and WRKY28 were hyper-induced in htd1-1, indicating that HTD1 could function as a negative regulator for the expression of such genes and that these genes might contribute to thermotolerance of htd1-1, at least in part. HTD1 was associated with HSP90-1, a crucial regulator of thermotolerance, in vivo, even though the decrease of HTD1 did not affect the accumulation pattern of HSP90-1 in Arabidopsis. These findings indicate that a negative role of HTD1 in thermotolerance might be achieved through its association with HSP90-1, possibly by disturbing the action of HSP90-1, not by the degradation of HSP90-1. This study will serve as an important step toward understanding of the functional connection between CRL4-mediated processes and plant heat stress signaling.
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Affiliation(s)
- Soon-Hee Kim
- Department of Biology Education, Pusan National University, Busan 609-735,
Korea
| | - Joon-Hyun Lee
- Department of Biology Education, Pusan National University, Busan 609-735,
Korea
| | - Kyoung-In Seo
- Department of Biology Education, Pusan National University, Busan 609-735,
Korea
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104,
USA
| | - Boyeong Ryu
- Department of Biology Education, Pusan National University, Busan 609-735,
Korea
| | - Yongju Sung
- Department of Biology Education, Pusan National University, Busan 609-735,
Korea
| | - Taijoon Chung
- Department of Biological Sciences, Pusan National University, Busan 609-735,
Korea
| | - Xing Wang Deng
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104,
USA
| | - Jae-Hoon Lee
- Department of Biology Education, Pusan National University, Busan 609-735,
Korea
- Department of Molecular, Cellular and Developmental Biology, Yale University, New Haven, Connecticut 06520-8104,
USA
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29
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Casey Klockow L, Sharifi HJ, Wen X, Flagg M, Furuya AKM, Nekorchuk M, de Noronha CMC. The HIV-1 protein Vpr targets the endoribonuclease Dicer for proteasomal degradation to boost macrophage infection. Virology 2013; 444:191-202. [PMID: 23849790 DOI: 10.1016/j.virol.2013.06.010] [Citation(s) in RCA: 40] [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] [Received: 05/31/2013] [Accepted: 06/09/2013] [Indexed: 12/13/2022]
Abstract
The HIV-1 protein Vpr enhances macrophage infection, triggers G2 cell cycle arrest, and targets cells for NK-cell killing. Vpr acts through the CRL4(DCAF1) ubiquitin ligase complex to cause G2 arrest and trigger expression of NK ligands. Corresponding ubiquitination targets have not been identified. UNG2 and SMUG1 are the only known substrates for Vpr-directed depletion through CRL4(DCAF1). Here we identify the endoribonuclease Dicer as a target of HIV-1 Vpr-directed proteasomal degradation through CRL4(DCAF1). We show that HIV-1 Vpr inhibits short hairpin RNA function as expected upon reduction of Dicer levels. Dicer inhibits HIV-1 replication in T cells. We demonstrate that Dicer also restricts HIV-1 replication in human monocyte-derived macrophages (MDM) and that reducing Dicer expression in MDMs enhances HIV-1 infection in a Vpr-dependent manner. Our results support a model in which Vpr complexes with human Dicer to boost its interaction with the CRL4(DCAF1) ubiquitin ligase complex and its subsequent degradation.
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Affiliation(s)
- Laurieann Casey Klockow
- Center for Immunology and Microbial Disease, Albany Medical College, 47 New Scotland Avenue, Albany, NY 12208, USA
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