1
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Kelliher JL, Folkerts ML, Shen KV, Song W, Tengler K, Stiefel CM, Lee SO, Dray E, Zhao W, Koss B, Pannunzio NR, Leung JW. Evolved histone tail regulates 53BP1 recruitment at damaged chromatin. Nat Commun 2024; 15:4634. [PMID: 38821984 PMCID: PMC11143218 DOI: 10.1038/s41467-024-49071-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2023] [Accepted: 05/22/2024] [Indexed: 06/02/2024] Open
Abstract
The master DNA damage repair histone protein, H2AX, is essential for orchestrating the recruitment of downstream mediator and effector proteins at damaged chromatin. The phosphorylation of H2AX at S139, γH2AX, is well-studied for its DNA repair function. However, the extended C-terminal tail is not characterized. Here, we define the minimal motif on H2AX for the canonical function in activating the MDC1-RNF8-RNF168 phosphorylation-ubiquitination pathway that is important for recruiting repair proteins, such as 53BP1 and BRCA1. Interestingly, H2AX recruits 53BP1 independently from the MDC1-RNF8-RNF168 pathway through its evolved C-terminal linker region with S139 phosphorylation. Mechanistically, 53BP1 recruitment to damaged chromatin is mediated by the interaction between the H2AX C-terminal tail and the 53BP1 Oligomerization-Tudor domains. Moreover, γH2AX-linker mediated 53BP1 recruitment leads to camptothecin resistance in H2AX knockout cells. Overall, our study uncovers an evolved mechanism within the H2AX C-terminal tail for regulating DNA repair proteins at damaged chromatin.
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Affiliation(s)
- Jessica L Kelliher
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Melissa L Folkerts
- Department of Medicine, Division of Hematology/Oncology, University of California, Irvine, Irvine, CA, 92697, USA
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, 92626, USA
| | - Kaiyuan V Shen
- Department of Medicine, Division of Hematology/Oncology, University of California, Irvine, Irvine, CA, 92697, USA
- Department of Biological Chemistry, University of California, Irvine, Irvine, CA, 92626, USA
| | - Wan Song
- Department of Radiation Oncology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Kyle Tengler
- Department of Radiation Oncology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Clara M Stiefel
- Department of Radiation Oncology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Seong-Ok Lee
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Eloise Dray
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Weixing Zhao
- Department of Biochemistry and Structural Biology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA
| | - Brian Koss
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA
| | - Nicholas R Pannunzio
- Department of Medicine, Division of Hematology/Oncology, University of California, Irvine, Irvine, CA, 92697, USA.
| | - Justin W Leung
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, AR, 72205, USA.
- Department of Radiation Oncology, University of Texas Health and Science Center, San Antonio, TX, 78229, USA.
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2
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Zheng JX, Du TY, Shao GC, Ma ZH, Jiang ZD, Hu W, Suo F, He W, Dong MQ, Du LL. Ubiquitination-mediated Golgi-to-endosome sorting determines the toxin-antidote duality of fission yeast wtf meiotic drivers. Nat Commun 2023; 14:8334. [PMID: 38097609 PMCID: PMC10721834 DOI: 10.1038/s41467-023-44151-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2023] [Accepted: 12/01/2023] [Indexed: 12/17/2023] Open
Abstract
Killer meiotic drivers (KMDs) skew allele transmission in their favor by killing meiotic progeny not inheriting the driver allele. Despite their widespread presence in eukaryotes, the molecular mechanisms behind their selfish behavior are poorly understood. In several fission yeast species, single-gene KMDs belonging to the wtf gene family exert selfish killing by expressing a toxin and an antidote through alternative transcription initiation. Here we investigate how the toxin and antidote products of a wtf-family KMD gene can act antagonistically. Both the toxin and the antidote are multi-transmembrane proteins, differing only in their N-terminal cytosolic tails. We find that the antidote employs PY motifs (Leu/Pro-Pro-X-Tyr) in its N-terminal cytosolic tail to bind Rsp5/NEDD4 family ubiquitin ligases, which ubiquitinate the antidote. Mutating PY motifs or attaching a deubiquitinating enzyme transforms the antidote into a toxic protein. Ubiquitination promotes the transport of the antidote from the trans-Golgi network to the endosome, thereby preventing it from causing toxicity. A physical interaction between the antidote and the toxin enables the ubiquitinated antidote to translocate the toxin to the endosome and neutralize its toxicity. We propose that post-translational modification-mediated protein localization and/or activity changes may be a common mechanism governing the antagonistic duality of single-gene KMDs.
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Affiliation(s)
- Jin-Xin Zheng
- National Institute of Biological Sciences, Beijing, 102206, China
- Graduate School of Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing, 100730, China
| | - Tong-Yang Du
- National Institute of Biological Sciences, Beijing, 102206, China
- College of Life Sciences, Beijing Normal University, Beijing, 100875, China
| | - Guang-Can Shao
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Zhu-Hui Ma
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Zhao-Di Jiang
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Wen Hu
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Fang Suo
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Wanzhong He
- National Institute of Biological Sciences, Beijing, 102206, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, 102206, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, 102206, China.
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, 102206, China.
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3
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Zou CX, Ma ZH, Jiang ZD, Pan ZQ, Xu DD, Suo F, Shao GC, Dong MQ, Du LL. The ortholog of human REEP1-4 is required for autophagosomal enclosure of ER-phagy/nucleophagy cargos in fission yeast. PLoS Biol 2023; 21:e3002372. [PMID: 37939137 PMCID: PMC10659188 DOI: 10.1371/journal.pbio.3002372] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Revised: 11/20/2023] [Accepted: 10/10/2023] [Indexed: 11/10/2023] Open
Abstract
Selective macroautophagy of the endoplasmic reticulum (ER) and the nucleus, known as ER-phagy and nucleophagy, respectively, are processes whose mechanisms remain inadequately understood. Through an imaging-based screen, we find that in the fission yeast Schizosaccharomyces pombe, Yep1 (also known as Hva22 or Rop1), the ortholog of human REEP1-4, is essential for ER-phagy and nucleophagy but not for bulk autophagy. In the absence of Yep1, the initial phase of ER-phagy and nucleophagy proceeds normally, with the ER-phagy/nucleophagy receptor Epr1 coassembling with Atg8. However, ER-phagy/nucleophagy cargos fail to reach the vacuole. Instead, nucleus- and cortical-ER-derived membrane structures not enclosed within autophagosomes accumulate in the cytoplasm. Intriguingly, the outer membranes of nucleus-derived structures remain continuous with the nuclear envelope-ER network, suggesting a possible outer membrane fission defect during cargo separation from source compartments. We find that the ER-phagy role of Yep1 relies on its abilities to self-interact and shape membranes and requires its C-terminal amphipathic helices. Moreover, we show that human REEP1-4 and budding yeast Atg40 can functionally substitute for Yep1 in ER-phagy, and Atg40 is a divergent ortholog of Yep1 and REEP1-4. Our findings uncover an unexpected mechanism governing the autophagosomal enclosure of ER-phagy/nucleophagy cargos and shed new light on the functions and evolution of REEP family proteins.
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Affiliation(s)
- Chen-Xi Zou
- National Institute of Biological Sciences, Beijing, China
- College of Life Sciences, Beijing Normal University, Beijing, China
| | - Zhu-Hui Ma
- National Institute of Biological Sciences, Beijing, China
| | - Zhao-Di Jiang
- National Institute of Biological Sciences, Beijing, China
| | - Zhao-Qian Pan
- National Institute of Biological Sciences, Beijing, China
| | - Dan-Dan Xu
- National Institute of Biological Sciences, Beijing, China
| | - Fang Suo
- National Institute of Biological Sciences, Beijing, China
| | - Guang-Can Shao
- National Institute of Biological Sciences, Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
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4
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Kelliher J, Ghosal G, Leung JWC. New answers to the old RIDDLE: RNF168 and the DNA damage response pathway. FEBS J 2022; 289:2467-2480. [PMID: 33797206 PMCID: PMC8486888 DOI: 10.1111/febs.15857] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Revised: 03/12/2021] [Accepted: 03/31/2021] [Indexed: 12/31/2022]
Abstract
The chromatin-based DNA damage response pathway is tightly orchestrated by histone post-translational modifications, including histone H2A ubiquitination. Ubiquitination plays an integral role in regulating cellular processes including DNA damage signaling and repair. The ubiquitin E3 ligase RNF168 is essential in assembling a cohort of DNA repair proteins at the damaged chromatin via its enzymatic activity. RNF168 ubiquitinates histone H2A(X) at the N terminus and generates a specific docking scaffold for ubiquitin-binding motif-containing proteins. The regulation of RNF168 at damaged chromatin and the mechanistic implication in the recruitment of DNA repair proteins to the damaged sites remain an area of active investigation. Here, we review the function and regulation of RNF168 in the context of ubiquitin-mediated DNA damage signaling and repair. We will also discuss the unanswered questions that require further investigation and how understanding RNF168 targeting specificity could benefit the therapeutic development for cancer treatment.
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Affiliation(s)
- Jessica Kelliher
- Department of Radiation Oncology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States
| | - Gargi Ghosal
- Department of Genetics, Cell Biology and Anatomy, University of Nebraska Medical Center, Omaha, NE 68198, United States,To whom correspondence should be addressed: and
| | - Justin Wai Chung Leung
- Department of Radiation Oncology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, United States,To whom correspondence should be addressed: and
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5
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Yu ZQ, Liu XM, Zhao D, Xu DD, Du LL. Visual detection of binary, ternary and quaternary protein interactions in fission yeast using a Pil1 co-tethering assay. J Cell Sci 2021; 134:272452. [PMID: 34499173 DOI: 10.1242/jcs.258774] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 09/03/2021] [Indexed: 01/28/2023] Open
Abstract
Protein-protein interactions are vital for executing nearly all cellular processes. To facilitate the detection of protein-protein interactions in living cells of the fission yeast Schizosaccharomyces pombe, here we present an efficient and convenient method termed the Pil1 co-tethering assay. In its basic form, we tether a bait protein to mCherry-tagged Pil1, which forms cortical filamentary structures, and examine whether a GFP-tagged prey protein colocalizes with the bait. We demonstrate that this assay is capable of detecting pairwise protein-protein interactions of cytosolic proteins and nuclear proteins. Furthermore, we show that this assay can be used for detecting not only binary protein-protein interactions, but also ternary and quaternary protein-protein interactions. Using this assay, we systematically characterized the protein-protein interactions in the Atg1 complex and in the phosphatidylinositol 3-kinase (PtdIns3K) complexes and found that Atg38 is incorporated into the PtdIns3K complex I via an Atg38-Vps34 interaction. Our data show that this assay is a useful and versatile tool and should be added to the routine toolbox of fission yeast researchers. This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Zhong-Qiu Yu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Xiao-Man Liu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Dan Zhao
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Dan-Dan Xu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, 102206 Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China
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6
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Schmücker A, Lei B, Lorković ZJ, Capella M, Braun S, Bourguet P, Mathieu O, Mechtler K, Berger F. Crosstalk between H2A variant-specific modifications impacts vital cell functions. PLoS Genet 2021; 17:e1009601. [PMID: 34086674 PMCID: PMC8208582 DOI: 10.1371/journal.pgen.1009601] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2021] [Revised: 06/16/2021] [Accepted: 05/14/2021] [Indexed: 12/15/2022] Open
Abstract
Selection of C-terminal motifs participated in evolution of distinct histone H2A variants. Hybrid types of variants combining motifs from distinct H2A classes are extremely rare. This suggests that the proximity between the motif cases interferes with their function. We studied this question in flowering plants that evolved sporadically a hybrid H2A variant combining the SQ motif of H2A.X that participates in the DNA damage response with the KSPK motif of H2A.W that stabilizes heterochromatin. Our inventory of PTMs of H2A.W variants showed that in vivo the cell cycle-dependent kinase CDKA phosphorylates the KSPK motif of H2A.W but only in absence of an SQ motif. Phosphomimicry of KSPK prevented DNA damage response by the SQ motif of the hybrid H2A.W/X variant. In a synthetic yeast expressing the hybrid H2A.W/X variant, phosphorylation of KSPK prevented binding of the BRCT-domain protein Mdb1 to phosphorylated SQ and impaired response to DNA damage. Our findings illustrate that PTMs mediate interference between the function of H2A variant specific C-terminal motifs. Such interference could explain the mutual exclusion of motifs that led to evolution of H2A variants.
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Affiliation(s)
- Anna Schmücker
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Bingkun Lei
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Zdravko J. Lorković
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Matías Capella
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University of Munich, Planegg-Martinsried, Germany
| | - Sigurd Braun
- Biomedical Center, Department of Physiological Chemistry, Ludwig-Maximilians-University of Munich, Planegg-Martinsried, Germany
- International Max Planck Research School for Molecular and Cellular Life Sciences, Planegg-Martinsried, Germany
| | - Pierre Bourguet
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
- CNRS, Université Clermont Auvergne, Inserm, Génétique Reproduction et Développement, Clermont-Ferrand, France
| | - Olivier Mathieu
- CNRS, Université Clermont Auvergne, Inserm, Génétique Reproduction et Développement, Clermont-Ferrand, France
| | - Karl Mechtler
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
| | - Frédéric Berger
- Gregor Mendel Institute, Austrian Academy of Sciences, Vienna BioCenter, Vienna, Austria
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7
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Pan ZQ, Shao GC, Liu XM, Chen Q, Dong MQ, Du LL. Atg1 kinase in fission yeast is activated by Atg11-mediated dimerization and cis-autophosphorylation. eLife 2020; 9:58073. [PMID: 32909946 PMCID: PMC7511232 DOI: 10.7554/elife.58073] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2020] [Accepted: 09/10/2020] [Indexed: 12/28/2022] Open
Abstract
Autophagy is a proteolytic pathway that is conserved from yeasts to mammals. Atg1 kinase is essential for autophagy, but how its activity is controlled remains insufficiently understood. Here, we show that, in the fission yeast Schizosaccharomyces pombe, Atg1 kinase activity requires Atg11, the ortholog of mammalian FIP200/RB1CC1, but does not require Atg13, Atg17, or Atg101. Remarkably, a 62 amino acid region of Atg11 is sufficient for the autophagy function of Atg11 and for supporting the Atg1 kinase activity. This region harbors an Atg1-binding domain and a homodimerization domain. Dimerizing Atg1 is the main role of Atg11, as it can be bypassed by artificially dimerizing Atg1. In an Atg1 dimer, only one Atg1 molecule needs to be catalytically active, suggesting that Atg1 activation can be achieved through cis-autophosphorylation. We propose that mediating Atg1 oligomerization and activation may be a conserved function of Atg11/FIP200 family proteins and cis-autophosphorylation may be a general mechanism of Atg1 activation.
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Affiliation(s)
- Zhao-Qian Pan
- College of Life Sciences, Beijing Normal University, Beijing, China.,National Institute of Biological Sciences, Beijing, China
| | - Guang-Can Shao
- National Institute of Biological Sciences, Beijing, China
| | - Xiao-Man Liu
- National Institute of Biological Sciences, Beijing, China
| | - Quan Chen
- National Institute of Biological Sciences, Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, China.,Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing, China
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8
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Zhao D, Zou CX, Liu XM, Jiang ZD, Yu ZQ, Suo F, Du TY, Dong MQ, He W, Du LL. A UPR-Induced Soluble ER-Phagy Receptor Acts with VAPs to Confer ER Stress Resistance. Mol Cell 2020; 79:963-977.e3. [PMID: 32735772 DOI: 10.1016/j.molcel.2020.07.019] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 07/01/2020] [Accepted: 07/20/2020] [Indexed: 01/07/2023]
Abstract
Autophagic degradation of the endoplasmic reticulum (ER-phagy) is triggered by ER stress in diverse organisms. However, molecular mechanisms governing ER stress-induced ER-phagy remain insufficiently understood. Here we report that ER stress-induced ER-phagy in the fission yeast Schizosaccharomyces pombe requires Epr1, a soluble Atg8-interacting ER-phagy receptor. Epr1 localizes to the ER through interacting with integral ER membrane proteins VAPs. Bridging an Atg8-VAP association is the main ER-phagy role of Epr1, as it can be bypassed by an artificial Atg8-VAP tether. VAPs contribute to ER-phagy not only by tethering Atg8 to the ER membrane, but also by maintaining the ER-plasma membrane contact. Epr1 is upregulated during ER stress by the unfolded protein response (UPR) regulator Ire1. Loss of Epr1 reduces survival against ER stress. Conversely, increasing Epr1 expression suppresses the ER-phagy defect and ER stress sensitivity of cells lacking Ire1. Our findings expand and deepen the molecular understanding of ER-phagy.
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Affiliation(s)
- Dan Zhao
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Chen-Xi Zou
- College of Life Sciences, Beijing Normal University, 100875 Beijing, China; National Institute of Biological Sciences, 102206 Beijing, China
| | - Xiao-Man Liu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Zhao-Di Jiang
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Zhong-Qiu Yu
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Fang Suo
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Tong-Yang Du
- College of Life Sciences, Beijing Normal University, 100875 Beijing, China; National Institute of Biological Sciences, 102206 Beijing, China
| | - Meng-Qiu Dong
- National Institute of Biological Sciences, 102206 Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China
| | - Wanzhong He
- National Institute of Biological Sciences, 102206 Beijing, China
| | - Li-Lin Du
- National Institute of Biological Sciences, 102206 Beijing, China; Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, 102206 Beijing, China.
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9
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Schizosaccharomyces pombe Assays to Study Mitotic Recombination Outcomes. Genes (Basel) 2020; 11:genes11010079. [PMID: 31936815 PMCID: PMC7016768 DOI: 10.3390/genes11010079] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 01/07/2020] [Accepted: 01/07/2020] [Indexed: 01/16/2023] Open
Abstract
The fission yeast—Schizosaccharomyces pombe—has emerged as a powerful tractable system for studying DNA damage repair. Over the last few decades, several powerful in vivo genetic assays have been developed to study outcomes of mitotic recombination, the major repair mechanism of DNA double strand breaks and stalled or collapsed DNA replication forks. These assays have significantly increased our understanding of the molecular mechanisms underlying the DNA damage response pathways. Here, we review the assays that have been developed in fission yeast to study mitotic recombination.
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10
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Thompson R, Gatenby R, Sidi S. How Cells Handle DNA Breaks during Mitosis: Detection, Signaling, Repair, and Fate Choice. Cells 2019; 8:cells8091049. [PMID: 31500247 PMCID: PMC6770852 DOI: 10.3390/cells8091049] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2019] [Revised: 09/01/2019] [Accepted: 09/05/2019] [Indexed: 12/15/2022] Open
Abstract
Mitosis is controlled by a complex series of signaling pathways but mitotic control following DNA damage remains poorly understood. Effective DNA damage sensing and repair is integral to survival but is largely thought to occur primarily in interphase and be repressed during mitosis due to the risk of telomere fusion. There is, however, increasing evidence to suggest tight control of mitotic progression in the incidence of DNA damage, whether induced in mitotic cells or having progressed from failed interphase checkpoints. Here we will discuss what is known to date about signaling pathways controlling mitotic progression and resulting cell fate in the incidence of mitotic DNA damage.
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Affiliation(s)
- Ruth Thompson
- Department of Oncology and Metabolism, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX, UK.
| | - Rachel Gatenby
- Department of Oncology and Metabolism, University of Sheffield Medical School, Beech Hill Road, Sheffield S10 2RX, UK.
| | - Samuel Sidi
- Department of Medicine, Division of Hematology and Medical Oncology, The Tisch Cancer Institute, Icahn School of Medicine at Mount Sinai, New York, NY 10025, USA.
- Department of Cell, Developmental and Regenerative Biology, The Graduate School of Biomedical Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10025, USA.
- Department of Oncological Sciences, Icahn School of Medicine at Mount Sinai, New York, NY 10025, USA.
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11
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Liu XM, Yamasaki A, Du XM, Coffman VC, Ohsumi Y, Nakatogawa H, Wu JQ, Noda NN, Du LL. Lipidation-independent vacuolar functions of Atg8 rely on its noncanonical interaction with a vacuole membrane protein. eLife 2018; 7:41237. [PMID: 30451685 PMCID: PMC6279349 DOI: 10.7554/elife.41237] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2018] [Accepted: 11/18/2018] [Indexed: 11/18/2022] Open
Abstract
The ubiquitin-like protein Atg8, in its lipidated form, plays central roles in autophagy. Yet, remarkably, Atg8 also carries out lipidation-independent functions in non-autophagic processes. How Atg8 performs its moonlighting roles is unclear. Here we report that in the fission yeast Schizosaccharomyces pombe and the budding yeast Saccharomyces cerevisiae, the lipidation-independent roles of Atg8 in maintaining normal morphology and functions of the vacuole require its interaction with a vacuole membrane protein Hfl1 (homolog of human TMEM184 proteins). Crystal structures revealed that the Atg8-Hfl1 interaction is not mediated by the typical Atg8-family-interacting motif (AIM) that forms an intermolecular β-sheet with Atg8. Instead, the Atg8-binding regions in Hfl1 proteins adopt a helical conformation, thus representing a new type of AIMs (termed helical AIMs here). These results deepen our understanding of both the functional versatility of Atg8 and the mechanistic diversity of Atg8 binding.
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Affiliation(s)
- Xiao-Man Liu
- National Institute of Biological Sciences, Beijing, China
| | | | - Xiao-Min Du
- National Institute of Biological Sciences, Beijing, China.,College of Life Sciences, Beijing Normal University, Beijing, China
| | | | - Yoshinori Ohsumi
- Unit for Cell Biology, Institute of Innovative Research, Tokyo Institute of Technology, Yokohama, Japan
| | - Hitoshi Nakatogawa
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Jian-Qiu Wu
- The Ohio State University, Columbus, United States
| | | | - Li-Lin Du
- National Institute of Biological Sciences, Beijing, China
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12
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Day M, Rappas M, Ptasinska K, Boos D, Oliver AW, Pearl LH. BRCT domains of the DNA damage checkpoint proteins TOPBP1/Rad4 display distinct specificities for phosphopeptide ligands. eLife 2018; 7:e39979. [PMID: 30295604 PMCID: PMC6175577 DOI: 10.7554/elife.39979] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Accepted: 09/24/2018] [Indexed: 12/28/2022] Open
Abstract
TOPBP1 and its fission yeast homologueRad4, are critical players in a range of DNA replication, repair and damage signalling processes. They are composed of multiple BRCT domains, some of which bind phosphorylated motifs in other proteins. They thus act as multi-point adaptors bringing proteins together into functional combinations, dependent on post-translational modifications downstream of cell cycle and DNA damage signals. We have now structurally and/or biochemically characterised a sufficient number of high-affinity complexes for the conserved N-terminal region of TOPBP1 and Rad4 with diverse phospho-ligands, including human RAD9 and Treslin, and Schizosaccharomyces pombe Crb2 and Sld3, to define the determinants of BRCT domain specificity. We use this to identify and characterise previously unknown phosphorylation-dependent TOPBP1/Rad4-binding motifs in human RHNO1 and the fission yeast homologue of MDC1, Mdb1. These results provide important insights into how multiple BRCT domains within TOPBP1/Rad4 achieve selective and combinatorial binding of their multiple partner proteins.
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Affiliation(s)
- Matthew Day
- Cancer Research UK DNA Repair Enzymes GroupGenome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Mathieu Rappas
- Cancer Research UK DNA Repair Enzymes GroupGenome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Katie Ptasinska
- Genome Damage and Stability CentreSchool of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Dominik Boos
- Fakultät für BiologieUniversität Duisburg-EssenGermanyUnited Kingdom
| | - Antony W Oliver
- Cancer Research UK DNA Repair Enzymes GroupGenome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
| | - Laurence H Pearl
- Cancer Research UK DNA Repair Enzymes GroupGenome Damage and Stability Centre, School of Life Sciences, University of SussexFalmerUnited Kingdom
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Multi-BRCT Domain Protein Brc1 Links Rhp18/Rad18 and γH2A To Maintain Genome Stability during S Phase. Mol Cell Biol 2017; 37:MCB.00260-17. [PMID: 28784724 DOI: 10.1128/mcb.00260-17] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 08/04/2017] [Indexed: 12/17/2022] Open
Abstract
DNA replication involves the inherent risk of genome instability, since replisomes invariably encounter DNA lesions or other structures that stall or collapse replication forks during the S phase. In the fission yeast Schizosaccharomyces pombe, the multi-BRCT domain protein Brc1, which is related to budding yeast Rtt107 and mammalian PTIP, plays an important role in maintaining genome integrity and cell viability when cells experience replication stress. The C-terminal pair of BRCT domains in Brc1 were previously shown to bind phosphohistone H2A (γH2A) formed by Rad3/ATR checkpoint kinase at DNA lesions; however, the putative scaffold interactions involving the N-terminal BRCT domains 1 to 4 of Brc1 have remained obscure. Here, we show that these domains bind Rhp18/Rad18, which is an E3 ubiquitin protein ligase that has crucial functions in postreplication repair. A missense allele in BRCT domain 4 of Brc1 disrupts binding to Rhp18 and causes sensitivity to replication stress. Brc1 binding to Rhp18 and γH2A are required for the Brc1 overexpression suppression of smc6-74, a mutation that impairs the Smc5/6 structural maintenance of chromosomes complex required for chromosome integrity and repair of collapsed replication forks. From these findings, we propose that Brc1 provides scaffolding functions linking γH2A, Rhp18, and Smc5/6 complex at damaged replication forks.
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14
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Exploring the dark foldable proteome by considering hydrophobic amino acids topology. Sci Rep 2017; 7:41425. [PMID: 28134276 PMCID: PMC5278394 DOI: 10.1038/srep41425] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Accepted: 12/19/2016] [Indexed: 12/18/2022] Open
Abstract
The protein universe corresponds to the set of all proteins found in all organisms. A way to explore it is by taking into account the domain content of the proteins. However, some part of sequences and many entire sequences remain un-annotated despite a converging number of domain families. The un-annotated part of the protein universe is referred to as the dark proteome and remains poorly characterized. In this study, we quantify the amount of foldable domains within the dark proteome by using the hydrophobic cluster analysis methodology. These un-annotated foldable domains were grouped using a combination of remote homology searches and domain annotations, leading to define different levels of darkness. The dark foldable domains were analyzed to understand what make them different from domains stored in databases and thus difficult to annotate. The un-annotated domains of the dark proteome universe display specific features relative to database domains: shorter length, non-canonical content and particular topology in hydrophobic residues, higher propensity for disorder, and a higher energy. These features make them hard to relate to known families. Based on these observations, we emphasize that domain annotation methodologies can still be improved to fully apprehend and decipher the molecular evolution of the protein universe.
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15
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Zhao D, Liu XM, Yu ZQ, Sun LL, Xiong X, Dong MQ, Du LL. Atg20- and Atg24-family proteins promote organelle autophagy in fission yeast. J Cell Sci 2016; 129:4289-4304. [PMID: 27737912 DOI: 10.1242/jcs.194373] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 10/06/2016] [Indexed: 12/17/2022] Open
Abstract
Autophagy cargos include not only soluble cytosolic materials but also bulky organelles, such as ER and mitochondria. In budding yeast, two proteins that contain the PX domain and the BAR domain, Atg20 and Atg24 (also known as Snx42 and Snx4, respectively) are required for organelle autophagy and contribute to general autophagy in a way that can be masked by compensatory mechanisms. It remains unclear why these proteins are important for organelle autophagy. Here, we show that in a distantly related fungal organism, the fission yeast Schizosaccharomyces pombe, autophagy of ER and mitochondria is induced by nitrogen starvation and is promoted by three Atg20- and Atg24-family proteins - Atg20, Atg24 and SPBC1711.11 (named here as Atg24b). These proteins localize at the pre-autophagosomal structure, or phagophore assembly site (PAS), during starvation. S. pombe Atg24 forms a homo-oligomer and acts redundantly with Atg20 and Atg24b, and the latter two proteins can form a hetero-oligomer. The organelle autophagy defect caused by the loss of these proteins is associated with a reduction of autophagosome size and a decrease in Atg8 accumulation at the PAS. These results provide new insights into the autophagic function of Atg20- and Atg24-family proteins.
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Affiliation(s)
- Dan Zhao
- PTN Graduate Program, School of Life Sciences, Peking University, Beijing 100871, China.,National Institute of Biological Sciences, Beijing 102206, China
| | - Xiao-Man Liu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Zhong-Qiu Yu
- National Institute of Biological Sciences, Beijing 102206, China
| | - Ling-Ling Sun
- National Institute of Biological Sciences, Beijing 102206, China
| | | | - Meng-Qiu Dong
- National Institute of Biological Sciences, Beijing 102206, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing 102206, China
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16
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Mejia-Ramirez E, Limbo O, Langerak P, Russell P. Critical Function of γH2A in S-Phase. PLoS Genet 2015; 11:e1005517. [PMID: 26368543 PMCID: PMC4569340 DOI: 10.1371/journal.pgen.1005517] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2015] [Accepted: 08/20/2015] [Indexed: 11/24/2022] Open
Abstract
Phosphorylation of histone H2AX by ATM and ATR establishes a chromatin recruitment platform for DNA damage response proteins. Phospho-H2AX (γH2AX) has been most intensively studied in the context of DNA double-strand breaks caused by exogenous clastogens, but recent studies suggest that DNA replication stress also triggers formation of γH2A (ortholog of γH2AX) in Schizosaccharomyces pombe. Here, a focused genetic screen in fission yeast reveals that γH2A is critical when there are defects in Replication Factor C (RFC), which loads proliferating cell nuclear antigen (PCNA) clamp onto duplex DNA. Surprisingly Chk1, Cds1/Chk2 and the Rad9-Hus1-Rad1 checkpoint clamp, which are crucial for surviving many genotoxins, are fully dispensable in RFC-defective cells. Immunoblot analysis confirms that Rad9-Hus1-Rad1 is not required for formation of γH2A by Rad3/ATR in S-phase. Defects in DNA polymerase epsilon, which binds PCNA in the replisome, also create an acute need for γH2A. These requirements for γH2A were traced to its role in docking with Brc1, which is a 6-BRCT-domain protein that is structurally related to budding yeast Rtt107 and mammalian PTIP. Brc1, which localizes at stalled replication forks by binding γH2A, prevents aberrant formation of Replication Protein A (RPA) foci in RFC-impaired cells, suggesting that Brc1-coated chromatin stabilizes replisomes when PCNA or DNA polymerase availability limits DNA synthesis. ATM (ataxia telangiectasia mutated) and ATR (ATM and Rad3 related) are evolutionary conserved protein kinases that phosphorylate the carboxyl-tail of histone H2AX in chromatin flanking DNA lesions. Phosphorylated histone H2AX (aka γH2AX) tethers important DNA damage response (DDR) proteins to DNA double-strand breaks but its function during DNA replication is unclear. A novel genetic screen reveals that a partial defect in Replication Factor C (RFC) creates a critical requirement for γH2AX in fission yeast. These studies indicate that γH2AX stabilizes replication forks by recruiting Brc1 when RFC is unable to load the DNA clamp known as proliferating cell nuclear antigen (PCNA) onto duplex DNA. Surprisingly, this activity of γH2AX is more critical than ATM/ATR-mediated activation of the checkpoint kinase Chk1 and Chk2.
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Affiliation(s)
- Eva Mejia-Ramirez
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Oliver Limbo
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Petra Langerak
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America
| | - Paul Russell
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California, United States of America
- * E-mail:
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17
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Luo S, Xin X, Du LL, Ye K, Wei Y. Dimerization Mediated by a Divergent Forkhead-associated Domain Is Essential for the DNA Damage and Spindle Functions of Fission Yeast Mdb1. J Biol Chem 2015; 290:21054-21066. [PMID: 26160178 DOI: 10.1074/jbc.m115.642538] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2015] [Indexed: 01/13/2023] Open
Abstract
MDC1 is a key factor of DNA damage response in mammalian cells. It possesses two phospho-binding domains. In its C terminus, a tandem BRCA1 C-terminal domain binds phosphorylated histone H2AX, and in its N terminus, a forkhead-associated (FHA) domain mediates a phosphorylation-enhanced homodimerization. The FHA domain of the Drosophila homolog of MDC1, MU2, also forms a homodimer but utilizes a different dimer interface. The functional importance of the dimerization of MDC1 family proteins is uncertain. In the fission yeast Schizosaccharomyces pombe, a protein sharing homology with MDC1 in the tandem BRCA1 C-terminal domain, Mdb1, regulates DNA damage response and mitotic spindle functions. Here, we report the crystal structure of the N-terminal 91 amino acids of Mdb1. Despite a lack of obvious sequence conservation to the FHA domain of MDC1, this region of Mdb1 adopts an FHA-like fold and is therefore termed Mdb1-FHA. Unlike canonical FHA domains, Mdb1-FHA lacks all the conserved phospho-binding residues. It forms a stable homodimer through an interface distinct from those of MDC1 and MU2. Mdb1-FHA is important for the localization of Mdb1 to DNA damage sites and the spindle midzone, contributes to the roles of Mdb1 in cellular responses to genotoxins and an antimicrotubule drug, and promotes in vitro binding of Mdb1 to a phospho-H2A peptide. The defects caused by the loss of Mdb1-FHA can be rescued by fusion with either of two heterologous dimerization domains, suggesting that the main function of Mdb1-FHA is mediating dimerization. Our data support that FHA-mediated dimerization is conserved for MDC1 family proteins.
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Affiliation(s)
- Shukun Luo
- National Institute of Biological Sciences, Beijing 102206, China
| | - Xiaoran Xin
- National Institute of Biological Sciences, Beijing 102206, China
| | - Li-Lin Du
- National Institute of Biological Sciences, Beijing 102206, China.
| | - Keqiong Ye
- National Institute of Biological Sciences, Beijing 102206, China; Key Laboratory of RNA Biology, Institute of Biophysics, Chinese Academy of Sciences, Beijing 100101, China.
| | - Yi Wei
- National Institute of Biological Sciences, Beijing 102206, China
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