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Zhan Y, Zhang Z, Yin A, Su X, Tang N, Chen Y, Zhang Z, Chen W, Wang J, Wang W. RBBP4: A novel diagnostic and prognostic biomarker for non-small-cell lung cancer correlated with autophagic cell death. Cancer Med 2024; 13:e70090. [PMID: 39109577 PMCID: PMC11304277 DOI: 10.1002/cam4.70090] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 06/07/2024] [Accepted: 07/24/2024] [Indexed: 08/10/2024] Open
Abstract
BACKGROUND Non-small-cell lung cancer (NSCLC) often presents at later stages, typically associated with poor prognosis. Autophagy genes play a role in the progression of tumors. This study investigated the clinical relevance, prognostic value, and biological significance of RBBP4 in NSCLC. METHODS We assessed RBBP4 expression using the GSE30219 and TCGA NSCLC datasets and NSCLC cells, exploring its links with clinical outcomes, tumor immunity, and autophagy genes through bioinformatics analysis after transcriptome sequencing of RBBP4-knockdown and control PC9 cells. We identified differentially expressed genes (DEGs) and conducted Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway enrichment, and protein-protein interaction network analyses. The significance of autophagy-related DEGs was evaluated for diagnosis and prognosis using the GSE30219 dataset. Experiments both in vivo and in vitro explored the biological mechanisms behind RBBP4-mediated autophagic cell death in NSCLC. RESULTS RBBP4 overexpression in NSCLC correlates with a poorer prognosis. Eighteen types of immune cell were significantly enriched in cultures that had low RBBP4 expression compared high expression. DEGs associated with RBBP4 are enriched in autophagy pathways. Transcriptomic profiling of the PC9 cell line identified autophagy-related DEGs associated with RBBP4 that exhibited differential expression in NSCLC, suggesting prognostic applications. In vitro experiments demonstrated that RBBP4 knockdown induced autophagy and apoptosis in PC9 cells, promoting cell death, which was inhibited by 3-MA. In vivo, targeted siRNA against RBBP4 significantly reduced tumor development in PC9 cell-injected nude mice, elevating autophagy-related protein levels and inducing apoptosis and necrosis in tumor tissues. CONCLUSION In NSCLC, RBBP4 upregulation correlates with poor prognosis and altered immunity. Its knockdown induces autophagic cell death in NSCLC cells. These results indicate RBBP4 as a potential NSCLC diagnostic marker and its autophagy modulation as a prospective therapeutic target.
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Affiliation(s)
- Yajing Zhan
- School of Medical Technology and Information Engineering, Zhejiang Chinese Medical UniversityHangzhouZhejiangChina
| | - Zhiqian Zhang
- Department of Clinical Laboratory CenterShaoxing People's Hospital (Shaoxing Hospital)ShaoxingZhejiangChina
| | - Ankang Yin
- School of Medical Technology and Information Engineering, Zhejiang Chinese Medical UniversityHangzhouZhejiangChina
| | - Xiyang Su
- Department of Laboratory MedicineThe Second Affiliated Hospital of Zhejiang Chinese Medical UniversityHangzhouZhejiangChina
| | - Nan Tang
- Department of Clinical LaboratoryPeople's Hospital of Wangcheng District ChangshaChangshaHunanChina
| | - Yi Chen
- School of Medical Technology and Information Engineering, Zhejiang Chinese Medical UniversityHangzhouZhejiangChina
| | - Zebin Zhang
- School of Medical Technology and Information Engineering, Zhejiang Chinese Medical UniversityHangzhouZhejiangChina
| | - Wei Chen
- Institute of Clinical Medicine Research, Zhejiang Provincial People's Hospital, Hangzhou Medical CollegeHangzhouZhejiangChina
- Cancer Institute of Integrated Tradition Chinese and Western Medicine, Zhejiang Academy of Traditional Chinese MedicineTongde Hospital of Zhejiang ProvinceHangzhouZhejiangChina
| | - Juan Wang
- Department of Clinical Laboratory, Key Laboratory of Cancer Prevention and Therapy Combining Traditional Chinese and Western Medicine of Zhejiang Province, Zhejiang Academy of Traditional Chinese MedicineTongde Hospital of Zhejiang ProvinceHangzhouZhejiangChina
| | - Wei Wang
- School of Medical Technology and Information Engineering, Zhejiang Chinese Medical UniversityHangzhouZhejiangChina
- Department of Clinical Laboratory, Key Laboratory of Cancer Prevention and Therapy Combining Traditional Chinese and Western Medicine of Zhejiang Province, Zhejiang Academy of Traditional Chinese MedicineTongde Hospital of Zhejiang ProvinceHangzhouZhejiangChina
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2
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Cai L, Liu B, Cao Y, Sun T, Li Y. Unveiling the molecular structure and role of RBBP4/7: implications for epigenetic regulation and cancer research. Front Mol Biosci 2023; 10:1276612. [PMID: 38028543 PMCID: PMC10679446 DOI: 10.3389/fmolb.2023.1276612] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2023] [Accepted: 10/31/2023] [Indexed: 12/01/2023] Open
Abstract
Retinoblastoma-binding protein (RBBP) family is a class of proteins that can interact with tumor suppressor retinoblastoma protein (pRb). RBBP4 and RBBP7 are the only pair of homologous proteins in this family, serving as scaffold proteins whose main function is to offer a platform to indirectly connect two proteins. This characteristic allows them to extensively participate in the binding of various proteins and epigenetic complexes, indirectly influencing the function of effector proteins. As a result, they are often highlighted in organism activities involving active epigenetic modifications, such as embryonic development and cancer activation. In this review, we summarize the structural characteristics of RBBP4/7, the complexes they are involved in, their roles in embryonic development and cancer, as well as potential future research directions, which we hope to inspire the field of epigenetic research in the future.
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Affiliation(s)
- Lize Cai
- The First Affiliated Hospital of Soochow University, Suzhou University, Suzhou, China
| | - Bin Liu
- Department of Neurosurgery, Qinghai Provincial People’s Hospital, Xining, China
| | - Yufei Cao
- The First Affiliated Hospital of Soochow University, Suzhou University, Suzhou, China
| | - Ting Sun
- The First Affiliated Hospital of Soochow University, Suzhou University, Suzhou, China
| | - Yanyan Li
- The First Affiliated Hospital of Soochow University, Suzhou University, Suzhou, China
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3
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Zheng Z, Yao X, Liu Y. RBBP4 plays a vital role in the malignant progression of triple-negative breast cancer by regulating epithelial-mesenchymal transition. Genes Genomics 2022; 44:1301-1309. [PMID: 35622231 DOI: 10.1007/s13258-022-01262-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2022] [Accepted: 04/20/2022] [Indexed: 11/30/2022]
Abstract
BACKGROUND Mounting findings have revealed the increasingly appreciated functional importance of Retinoblastoma binding protein (RBBP) family members in tumorigenesis. However, the biological function of RBBP4 in breast cancer, especially in the most malignant and aggressive subtype, i.e., triple-negative breast cancer (TNBC), remains to be elucidated. OBJECTIVE The present study was aimed at elucidating the role of RBBP4 in TNBC pathogenesis. METHODS The expression of RBBP4 in TNBC tissues and cell lines was examined and its oncogenic-related functions were verified by performing a series of in vitro and in vivo experiments. RESULTS At the cellular and tissue level, a marked increase in the RBBP4 expression was observed. Functionally, RBBP4 knockdown dramatically inhibited the proliferation, invasion, and migration of TNBC cells in vitro. Further, mechanistically, RBBP4 downregulation regulated the inactivation of epithelial-mesenchymal transition (EMT) of TNBC cells. In vivo xenograft model in nude mice also validated these results. CONCLUSION Collectively, our results showed that the inhibition of RBBP4 suppresses the malignant progression of TNBC cells by regulating EMT. Thus, RBBP4 could serve as a novel biomarker and target for TNBC diagnosis and treatment.
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Affiliation(s)
- Zitong Zheng
- Hengyang Medical School, The Second Affiliated Hospital, University of South China, Hengyang, 421001, Hunan, China
| | - Xu Yao
- Institute of Pharmacy and Pharmacology, School of Pharmaceutical Science, Hengyang Medical School, University of South China, Hengyang, 421001, China
| | - Yi Liu
- Hengyang Medical School, The Second Affiliated Hospital, University of South China, Hengyang, 421001, Hunan, China.
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4
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Owen BM, Davidovich C. DNA binding by polycomb-group proteins: searching for the link to CpG islands. Nucleic Acids Res 2022; 50:4813-4839. [PMID: 35489059 PMCID: PMC9122586 DOI: 10.1093/nar/gkac290] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2021] [Revised: 03/25/2022] [Accepted: 04/25/2022] [Indexed: 11/13/2022] Open
Abstract
Polycomb group proteins predominantly exist in polycomb repressive complexes (PRCs) that cooperate to maintain the repressed state of thousands of cell-type-specific genes. Targeting PRCs to the correct sites in chromatin is essential for their function. However, the mechanisms by which PRCs are recruited to their target genes in mammals are multifactorial and complex. Here we review DNA binding by polycomb group proteins. There is strong evidence that the DNA-binding subunits of PRCs and their DNA-binding activities are required for chromatin binding and CpG targeting in cells. In vitro, CpG-specific binding was observed for truncated proteins externally to the context of their PRCs. Yet, the mere DNA sequence cannot fully explain the subset of CpG islands that are targeted by PRCs in any given cell type. At this time we find very little structural and biophysical evidence to support a model where sequence-specific DNA-binding activity is required or sufficient for the targeting of CpG-dinucleotide sequences by polycomb group proteins while they are within the context of their respective PRCs, either PRC1 or PRC2. We discuss the current knowledge and open questions on how the DNA-binding activities of polycomb group proteins facilitate the targeting of PRCs to chromatin.
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Affiliation(s)
- Brady M Owen
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia
| | - Chen Davidovich
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Faculty of Medicine, Nursing and Health Sciences, Monash University, Clayton, VIC, Australia.,EMBL-Australia, Clayton, VIC, Australia
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5
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Structural insights into the interactions of Polycomb Repressive Complex 2 with chromatin. Biochem Soc Trans 2021; 49:2639-2653. [PMID: 34747969 DOI: 10.1042/bst20210450] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/21/2021] [Accepted: 10/18/2021] [Indexed: 12/12/2022]
Abstract
Polycomb repressive complexes are a family of chromatin modifier enzymes which are critical for regulating gene expression and maintaining cell-type identity. The reversible chemical modifications of histone H3 and H2A by the Polycomb proteins are central to its ability to function as a gene silencer. PRC2 is both a reader and writer of the tri-methylation of histone H3 lysine 27 (H3K27me3) which serves as a marker for transcription repression, and heterochromatin boundaries. Over the last few years, several studies have provided key insights into the mechanisms regulating the recruitment and activation of PRC2 at Polycomb target genes. In this review, we highlight the recent structural studies which have elucidated the roles played by Polycomb cofactor proteins in mediating crosstalk between histone post-translational modifications and the recruitment of PRC2 and the stimulation of PRC2 methyltransferase activity.
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6
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Lin X, Leicher R, Liu S, Zhang B. Cooperative DNA looping by PRC2 complexes. Nucleic Acids Res 2021; 49:6238-6248. [PMID: 34057467 PMCID: PMC8216278 DOI: 10.1093/nar/gkab441] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2020] [Revised: 04/25/2021] [Accepted: 05/07/2021] [Indexed: 01/14/2023] Open
Abstract
Polycomb repressive complex 2 (PRC2) is an essential protein complex that silences gene expression via post-translational modifications of chromatin. This paper combined homology modeling, atomistic and coarse-grained molecular dynamics simulations, and single-molecule force spectroscopy experiments to characterize both its full-length structure and PRC2-DNA interactions. Using free energy calculations with a newly parameterized protein-DNA force field, we studied a total of three potential PRC2 conformations and their impact on DNA binding and bending. Consistent with cryo-EM studies, we found that EZH2, a core subunit of PRC2, provides the primary interface for DNA binding, and its curved surface can induce DNA bending. Our simulations also predicted the C2 domain of the SUZ12 subunit to contact DNA. Multiple PRC2 complexes bind with DNA cooperatively via allosteric communication through the DNA, leading to a hairpin-like looped configuration. Single-molecule experiments support PRC2-mediated DNA looping and the role of AEBP2 in regulating such loop formation. The impact of AEBP2 can be partly understood from its association with the C2 domain, blocking C2 from DNA binding. Our study suggests that accessory proteins may regulate the genomic location of PRC2 by interfering with its DNA interactions.
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Affiliation(s)
- Xingcheng Lin
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Rachel Leicher
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY 10065, USA.,Tri-Institutional PhD Program in Chemical Biology, New York, NY 10065, USA
| | - Shixin Liu
- Laboratory of Nanoscale Biophysics and Biochemistry, The Rockefeller University, New York, NY 10065, USA
| | - Bin Zhang
- Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA, USA
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7
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Kasinath V, Beck C, Sauer P, Poepsel S, Kosmatka J, Faini M, Toso D, Aebersold R, Nogales E. JARID2 and AEBP2 regulate PRC2 in the presence of H2AK119ub1 and other histone modifications. Science 2021; 371:371/6527/eabc3393. [PMID: 33479123 DOI: 10.1126/science.abc3393] [Citation(s) in RCA: 119] [Impact Index Per Article: 39.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 11/16/2020] [Indexed: 12/14/2022]
Abstract
Polycomb repressive complexes 1 and 2 (PRC1 and PRC2) cooperate to determine cell identity by epigenetic gene expression regulation. However, the mechanism of PRC2 recruitment by means of recognition of PRC1-mediated H2AK119ub1 remains poorly understood. Our PRC2 cryo-electron microscopy structure with cofactors JARID2 and AEBP2 bound to a H2AK119ub1-containing nucleosome reveals a bridge helix in EZH2 that connects the SET domain, H3 tail, and nucleosomal DNA. JARID2 and AEBP2 each interact with one ubiquitin and the H2A-H2B surface. JARID2 stimulates PRC2 through interactions with both the polycomb protein EED and the H2AK119-ubiquitin, whereas AEBP2 has an additional scaffolding role. The presence of these cofactors partially overcomes the inhibitory effect that H3K4me3 and H3K36me3 exert on core PRC2 (in the absence of cofactors). Our results support a key role for JARID2 and AEBP2 in the cross-talk between histone modifications and PRC2 activity.
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Affiliation(s)
- Vignesh Kasinath
- QB3 Institute, Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.
| | - Curtis Beck
- Department of Molecular and Cellular Biology, University of California, Berkeley, CA, USA
| | - Paul Sauer
- QB3 Institute, Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA, USA
| | - Simon Poepsel
- University of Cologne, Center for Molecular Medicine Cologne (CMMC), Faculty of Medicine and University Hospital, Cologne, Germany.,Cologne Excellence Cluster for Cellular Stress Responses in Ageing-Associated Diseases (CECAD), University of Cologne, Cologne, Germany
| | - Jennifer Kosmatka
- Department of Molecular and Cellular Biology, University of California, Berkeley, CA, USA
| | - Marco Faini
- Department of Biology, Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland
| | - Daniel Toso
- QB3 Institute, Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA
| | - Ruedi Aebersold
- Department of Biology, Institute of Molecular Systems Biology, ETH Zürich, Zürich, Switzerland.,Faculty of Science, University of Zürich, Zürich, Switzerland
| | - Eva Nogales
- QB3 Institute, Department of Molecular and Cell Biology, University of California, Berkeley, CA, USA. .,Department of Molecular and Cellular Biology, University of California, Berkeley, CA, USA.,Howard Hughes Medical Institute, University of California, Berkeley, CA, USA.,Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
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8
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Hart P', Hommen P, Noisier A, Krzyzanowski A, Schüler D, Porfetye AT, Akbarzadeh M, Vetter IR, Adihou H, Waldmann H. Structure Based Design of Bicyclic Peptide Inhibitors of RbAp48. Angew Chem Int Ed Engl 2021. [DOI: 10.1002/ange.202009749] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Affiliation(s)
- Peter 't Hart
- Department of Chemical Biology Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
- Chemical Genomics Centre of the Max Planck Society Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Pascal Hommen
- Department of Chemical Biology Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
- Chemical Genomics Centre of the Max Planck Society Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Anaïs Noisier
- Medicinal Chemistry, Research and Early Development Cardiovascular Renal and Metabolism, BioPharmaceutical R&D AstraZeneca Gothenburg Sweden
| | - Adrian Krzyzanowski
- Department of Chemical Biology Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Darijan Schüler
- Department of Chemical Biology Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Arthur T. Porfetye
- Department of Mechanistic Cell Biology Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Mohammad Akbarzadeh
- Department of Chemical Biology Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Ingrid R. Vetter
- Department of Mechanistic Cell Biology Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Hélène Adihou
- Medicinal Chemistry, Research and Early Development Cardiovascular Renal and Metabolism, BioPharmaceutical R&D AstraZeneca Gothenburg Sweden
- AstraZeneca MPI Satellite Unit Department of Chemical Biology Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
| | - Herbert Waldmann
- Department of Chemical Biology Max Planck Institute of Molecular Physiology Otto-Hahn-Strasse 11 44227 Dortmund Germany
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9
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Hart P', Hommen P, Noisier A, Krzyzanowski A, Schüler D, Porfetye AT, Akbarzadeh M, Vetter IR, Adihou H, Waldmann H. Structure Based Design of Bicyclic Peptide Inhibitors of RbAp48. Angew Chem Int Ed Engl 2021; 60:1813-1820. [PMID: 33022847 PMCID: PMC7894522 DOI: 10.1002/anie.202009749] [Citation(s) in RCA: 13] [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: 07/15/2020] [Indexed: 12/11/2022]
Abstract
The scaffolding protein RbAp48 is part of several epigenetic regulation complexes and is overexpressed in a variety of cancers. In order to develop tool compounds for the study of RbAp48 function, we have developed peptide inhibitors targeting the protein-protein interaction interface between RbAp48 and the scaffold protein MTA1. Based on a MTA1-derived linear peptide with low micromolar affinity and informed by crystallographic analysis, a bicyclic peptide was developed that inhibits the RbAp48/MTA1 interaction with a very low nanomolar KD value of 8.56 nM, and which showed appreciable stability against cellular proteases. Design included exchange of a polar amide cyclization strategy to hydrophobic aromatic linkers enabling mono- and bicyclization by means of cysteine alkylation, which improved affinity by direct interaction of the linkers with a hydrophobic residue on RbAp48. Our results demonstrate that stepwise evolution of a structure-based design is a suitable strategy for inhibitor development targeting PPIs.
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Affiliation(s)
- Peter 't Hart
- Department of Chemical BiologyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
- Chemical Genomics Centre of the Max Planck SocietyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
| | - Pascal Hommen
- Department of Chemical BiologyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
- Chemical Genomics Centre of the Max Planck SocietyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
| | - Anaïs Noisier
- Medicinal Chemistry, Research and Early Development CardiovascularRenal and Metabolism, BioPharmaceutical R&DAstraZenecaGothenburgSweden
| | - Adrian Krzyzanowski
- Department of Chemical BiologyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
| | - Darijan Schüler
- Department of Chemical BiologyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
| | - Arthur T. Porfetye
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
| | - Mohammad Akbarzadeh
- Department of Chemical BiologyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
| | - Ingrid R. Vetter
- Department of Mechanistic Cell BiologyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
| | - Hélène Adihou
- Medicinal Chemistry, Research and Early Development CardiovascularRenal and Metabolism, BioPharmaceutical R&DAstraZenecaGothenburgSweden
- AstraZeneca MPI Satellite UnitDepartment of Chemical BiologyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
| | - Herbert Waldmann
- Department of Chemical BiologyMax Planck Institute of Molecular PhysiologyOtto-Hahn-Strasse 1144227DortmundGermany
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10
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Liu X. A Structural Perspective on Gene Repression by Polycomb Repressive Complex 2. Subcell Biochem 2020; 96:519-562. [PMID: 33252743 DOI: 10.1007/978-3-030-58971-4_17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/30/2023]
Abstract
Polycomb Repressive Complex 2 (PRC2) is a major repressive chromatin complex formed by the Polycomb Group (PcG) proteins. PRC2 mediates trimethylation of histone H3 lysine 27 (H3K27me3), a hallmark of gene silencing. PRC2 is a key regulator of development, impacting many fundamental biological processes, like stem cell differentiation in mammals and vernalization in plants. Misregulation of PRC2 function is linked to a variety of human cancers and developmental disorders. In correlation with its diverse roles in development, PRC2 displays a high degree of compositional complexity and plasticity. Structural biology research over the past decade has shed light on the molecular mechanisms of the assembly, catalysis, allosteric activation, autoinhibition, chemical inhibition, dimerization and chromatin targeting of various developmentally regulated PRC2 complexes. In addition to these aspects, structure-function analysis is also discussed in connection with disease data in this chapter.
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Affiliation(s)
- Xin Liu
- Cecil H. and Ida Green Center for Reproductive Biology Sciences, UT Southwestern Medical Center, Dallas, TX, 75390, USA.
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11
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Bhopatkar AA, Uversky VN, Rangachari V. Disorder and cysteines in proteins: A design for orchestration of conformational see-saw and modulatory functions. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2020; 174:331-373. [PMID: 32828470 DOI: 10.1016/bs.pmbts.2020.06.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Being responsible for more than 90% of cellular functions, protein molecules are workhorses in all the life forms. In order to cater for such a high demand, proteins have evolved to adopt diverse structures that allow them to perform myriad of functions. Beginning with the genetically directed amino acid sequence, the classical understanding of protein function involves adoption of hierarchically complex yet ordered structures. However, advances made over the last two decades have revealed that inasmuch as 50% of eukaryotic proteome exists as partially or fully disordered structures. Significance of such intrinsically disordered proteins (IDPs) is further realized from their ability to exhibit multifunctionality, a feature attributable to their conformational plasticity. Among the coded amino acids, cysteines are considered to be "order-promoting" due to their ability to form inter- or intramolecular disulfide bonds, which confer robust thermal stability to the protein structure in oxidizing conditions. The co-existence of order-promoting cysteines with disorder-promoting sequences seems counter-intuitive yet many proteins have evolved to contain such sequences. In this chapter, we review some of the known cysteine-containing protein domains categorized based on the number of cysteines they possess. We show that many protein domains contain disordered sequences interspersed with cysteines. We show that a positive correlation exists between the degree of cysteines and disorder within the sequences that flank them. Furthermore, based on the computational platform, IUPred2A, we show that cysteine-rich sequences display significant disorder in the reduced but not the oxidized form, increasing the potential for such sequences to function in a redox-sensitive manner. Overall, this chapter provides insights into an exquisite evolutionary design wherein disordered sequences with interspersed cysteines enable potential modulatory protein functions under stress and environmental conditions, which thus far remained largely inconspicuous.
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Affiliation(s)
- Anukool A Bhopatkar
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, MS, United States
| | - Vladimir N Uversky
- Department of Molecular Medicine and Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL, United States; Laboratory of New Methods in Biology, Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center "Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences", Pushchino, Moscow Region, Russia
| | - Vijayaraghavan Rangachari
- Department of Chemistry and Biochemistry, School of Mathematics and Natural Sciences, University of Southern Mississippi, Hattiesburg, MS, United States; Center of Molecular and Cellular Biosciences, University of Southern Mississippi, Hattiesburg, MS, United States.
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12
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Kaushik M, Nehra A, Gakhar SK, Gill SS, Gill R. The multifaceted histone chaperone RbAp46/48 in Plasmodium falciparum: structural insights, production, and characterization. Parasitol Res 2020; 119:1753-1765. [PMID: 32363442 DOI: 10.1007/s00436-020-06669-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2019] [Accepted: 03/15/2020] [Indexed: 12/31/2022]
Abstract
RbAp46/RBBP7 and RbAp48/RBBP4 are WD40-repeat histone chaperones and chromatin adaptors that reside in multiple complexes involved in maintenance of chromatin structure. RbAp48 is the essential subunit of the chromatin assembly factor-1 (CAF-1) complex, therefore also named as CAF-1C. A detailed in silico sequence and structure analysis of homologs of RbAp46/48 in Plasmodium falciparum (PF3D7_0110700 and PF3D7_1433300) exhibited conservation of characteristic features in both the protein-seven-bladed WD40 β-propeller conformation and different binding interfaces. A comparative structural analysis highlighted species-specific features of the parasite, yeast, drosophila, and human RbAp46/48. In the present study, we report cloning, expression, and characterization of P. falciparum PF3D7_0110700, a putative RbAp46/48 (PfRbAp46/48). PfRbAp46/48 was cloned into pTEM11 vector in fusion with 6xHistidine tag and over-expressed in Escherichia coli B834 cells. The protein was purified by Ni-NTA followed by gel permeation chromatography. The protein expressed in all the three asexual blood stages and exhibited nuclear localization. We showed direct interaction of the purified rPfRbAp46/48 with the histone H4. These findings further our understanding of RbAp46/48 proteins and role of these proteins in the parasite biology.
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Affiliation(s)
- Manjeri Kaushik
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India
| | - Ashima Nehra
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India
| | - Surendra Kumar Gakhar
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India
| | - Sarvajeet Singh Gill
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India
| | - Ritu Gill
- Centre for Biotechnology, Maharshi Dayanand University, Rohtak, Haryana, 124 001, India.
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Zhang Q, Wang W, Gao Q. β-TRCP-mediated AEBP2 ubiquitination and destruction controls cisplatin resistance in ovarian cancer. Biochem Biophys Res Commun 2019; 523:274-279. [PMID: 31864706 DOI: 10.1016/j.bbrc.2019.12.050] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2019] [Accepted: 12/10/2019] [Indexed: 02/07/2023]
Abstract
AEBP2 is a zinc finger protein and a potential targeting protein for the mammalian Polycomb Repression Complex 2 (PRC2). The role of AEBP2 in the regulation of the migration and development of the neural crest cells through the PRC2-mediated epigenetic mechanism has been well-documented. However, whether AEBP2 plays a role in cancer and how to regulate AEBP2 itself remains largely unknown. Here, we show that genetic knockout of AEBP2 inhibited ovarian cancer cells proliferation and increased cisplatin sensitivity. Moreover, AEBP2 contains a non-canonical phosphodegron and is constantly targeted for ubiquitylation and proteasomal degradation by a SKP1-CUL1-F-box protein (SCF) β-TrCP ubiquitin ligase complex. Failure to degrade AEBP2 conferred cisplatin resistance in ovarian cancer. Overall, this study reveals an oncogenic role of AEBP2 in ovarian cancer and provides a rationale to target β-TRCP-AEBP2 axis in ovarian cancer that may be therapeutically beneficial.
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Affiliation(s)
- Qin Zhang
- Obstetrics and Gynecology Department of the First People's Hospital of Jing Zhou, The First Clinical Medical College of Yangtze University, China
| | - Wei Wang
- Reproductive Center of Jingzhou Central Hospital, The Second Clinical Medical College of Yangtze University, China
| | - Qun Gao
- Jingzhou Maternal and Child Health Care Hospital, No.233 Jingzhong Road, Jingzhou, Hubei, China.
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14
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Zeng X, Li C, Li Y, Yu H, Fu P, Hong HG, Zhang W. A network-based variable selection approach for identification of modules and biomarker genes associated with end-stage kidney disease. Nephrology (Carlton) 2019; 25:775-784. [PMID: 31464346 DOI: 10.1111/nep.13655] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 08/21/2019] [Indexed: 02/05/2023]
Abstract
AIMS Intervention for end-stage kidney disease (ESKD), which is associated with adverse prognoses and major economic burdens, is challenging due to its complex pathogenesis. The study was performed to identify biomarker genes and molecular mechanisms for ESKD by bioinformatics approach. METHODS Using the Gene Expression Omnibus dataset GSE37171, this study identified pathways and genomic biomarkers associated with ESKD via a multi-stage knowledge discovery process, including identification of modules of genes by weighted gene co-expression network analysis, discovery of important involved pathways by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses, selection of differentially expressed genes by the empirical Bayes method, and screening biomarker genes by the least absolute shrinkage and selection operator (Lasso) logistic regression. The results were validated using GSE70528, an independent testing dataset. RESULTS Three clinically important gene modules associated with ESKD, were identified by weighted gene co-expression network analysis. Within these modules, Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analyses revealed important biological pathways involved in ESKD, including transforming growth factor-β and Wnt signalling, RNA-splicing, autophagy and chromatin and histone modification. Furthermore, Lasso logistic regression was conducted to identify five final genes, namely, CNOT8, MST4, PPP2CB, PCSK7 and RBBP4 that are differentially expressed and associated with ESKD. The accuracy of the final model in distinguishing the ESKD cases and controls was 96.8% and 91.7% in the training and validation datasets, respectively. CONCLUSION Network-based variable selection approaches can identify biological pathways and biomarker genes associated with ESKD. The findings may inform more in-depth follow-up research and effective therapy.
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Affiliation(s)
- Xiaoxi Zeng
- West China Biomedical Big Data Center, West China School of Medicine (West China Hospital), Sichuan University, Chengdu, China.,Division of Nephrology, Kidney Research Institute, West China Hospital, Sichuan University, Chengdu, China.,Medical Big Data Center, Sichuan University, Chengdu, China
| | - Chunyang Li
- West China Biomedical Big Data Center, West China School of Medicine (West China Hospital), Sichuan University, Chengdu, China.,Medical Big Data Center, Sichuan University, Chengdu, China
| | - Yi Li
- Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA
| | - Haopeng Yu
- West China Biomedical Big Data Center, West China School of Medicine (West China Hospital), Sichuan University, Chengdu, China.,Medical Big Data Center, Sichuan University, Chengdu, China
| | - Ping Fu
- Division of Nephrology, Kidney Research Institute, West China Hospital, Sichuan University, Chengdu, China.,Medical Big Data Center, Sichuan University, Chengdu, China
| | - Hyokyoung G Hong
- Department of Statistics and Probability, Michigan State University, East Lansing, Michigan, USA
| | - Wei Zhang
- West China Biomedical Big Data Center, West China School of Medicine (West China Hospital), Sichuan University, Chengdu, China.,Medical Big Data Center, Sichuan University, Chengdu, China
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15
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Tokodai Y, Yakushiji F. Polycomb Repressive Complex 2: Modulator Development for Functional Regulation of a Multiprotein Complex by Using Structural Information. Chembiochem 2019; 20:2046-2053. [PMID: 31062458 DOI: 10.1002/cbic.201900212] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2019] [Indexed: 12/19/2022]
Abstract
Functional regulation of a protein complex is generally difficult because information of the target complex as a whole is limited. However, regulation of a protein complex is important for understanding complicated biological events in cells and therapeutic possibilities. This concept article introduces the potential for the functional regulation of a multiprotein complex, polycomb repressive complex 2 (PRC2), by developing chemical modulators. Functional regulatory mechanisms of PRC2 are described by using protein interaction information found through structural analyses. Subsequently, possibilities of novel chemical modulator development of PRC2 based on structural insights into the complex and related interactions are discussed.
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Affiliation(s)
- Yasuaki Tokodai
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan
| | - Fumika Yakushiji
- Faculty of Pharmaceutical Sciences, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan.,Center for Research and Education on Drug Discovery, Hokkaido University, Kita-12, Nishi-6, Kita-ku, Sapporo, 060-0812, Japan
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