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Düring J, Wolter M, Toplak JJ, Torres C, Dybkov O, Fokkens TJ, Bohnsack KE, Urlaub H, Steinchen W, Dienemann C, Lorenz S. Structural mechanisms of autoinhibition and substrate recognition by the ubiquitin ligase HACE1. Nat Struct Mol Biol 2024; 31:364-377. [PMID: 38332367 PMCID: PMC10873202 DOI: 10.1038/s41594-023-01203-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Accepted: 12/07/2023] [Indexed: 02/10/2024]
Abstract
Ubiquitin ligases (E3s) are pivotal specificity determinants in the ubiquitin system by selecting substrates and decorating them with distinct ubiquitin signals. However, structure determination of the underlying, specific E3-substrate complexes has proven challenging owing to their transient nature. In particular, it is incompletely understood how members of the catalytic cysteine-driven class of HECT-type ligases (HECTs) position substrate proteins for modification. Here, we report a cryogenic electron microscopy (cryo-EM) structure of the full-length human HECT HACE1, along with solution-based conformational analyses by small-angle X-ray scattering and hydrogen-deuterium exchange mass spectrometry. Structure-based functional analyses in vitro and in cells reveal that the activity of HACE1 is stringently regulated by dimerization-induced autoinhibition. The inhibition occurs at the first step of the catalytic cycle and is thus substrate-independent. We use mechanism-based chemical crosslinking to reconstitute a complex of activated, monomeric HACE1 with its major substrate, RAC1, determine its structure by cryo-EM and validate the binding mode by solution-based analyses. Our findings explain how HACE1 achieves selectivity in ubiquitinating the active, GTP-loaded state of RAC1 and establish a framework for interpreting mutational alterations of the HACE1-RAC1 interplay in disease. More broadly, this work illuminates central unexplored aspects in the architecture, conformational dynamics, regulation and specificity of full-length HECTs.
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Affiliation(s)
- Jonas Düring
- Research Group 'Ubiquitin Signaling Specificity', Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Madita Wolter
- Research Group 'Ubiquitin Signaling Specificity', Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Julia J Toplak
- Research Group 'Ubiquitin Signaling Specificity', Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Camilo Torres
- Research Group 'Ubiquitin Signaling Specificity', Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Olexandr Dybkov
- Research Group 'Bioanalytical Mass Spectrometry', Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Thornton J Fokkens
- Research Group 'Ubiquitin Signaling Specificity', Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Katherine E Bohnsack
- Department of Molecular Biology, University Medical Center Göttingen, Göttingen, Germany
| | - Henning Urlaub
- Research Group 'Bioanalytical Mass Spectrometry', Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
- 'Bioanalytics', Department of Clinical Chemistry, University Medical Center Göttingen, Göttingen, Germany
- 'Multiscale Bioimaging: from Molecular Machines to Networks of Excitable Cells', University of Göttingen, Göttingen, Germany
| | - Wieland Steinchen
- Department of Chemistry, Philipps University Marburg, Marburg, Germany
- Center for Synthetic Microbiology, Philipps University Marburg, Marburg, Germany
| | - Christian Dienemann
- Department of Molecular Biology, Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany
| | - Sonja Lorenz
- Research Group 'Ubiquitin Signaling Specificity', Max Planck Institute for Multidisciplinary Sciences, Göttingen, Germany.
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Wang S, Wu X, Zhang M, Chang S, Guo Y, Song S, Dai S, Wu K, Zeng S. NET1 is a critical regulator of spindle assembly and actin dynamics in mouse oocytes. Reprod Biol Endocrinol 2024; 22:5. [PMID: 38169395 PMCID: PMC10759572 DOI: 10.1186/s12958-023-01177-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 12/19/2023] [Indexed: 01/05/2024] Open
Abstract
BACKGROUND Neuroepithelial transforming gene 1 (NET1) is a RhoA subfamily guanine nucleotide exchange factor that governs a wide array of biological processes. However, its roles in meiotic oocyte remain unclear. We herein demonstrated that the NET1-HACE1-RAC1 pathway mediates meiotic defects in the progression of oocyte maturation. METHODS NET1 was reduced using a specific small interfering RNA in mouse oocytes. Spindle assembly, chromosomal alignment, the actin cap, and chromosomal spreads were visualized by immunostaining and analyzed under confocal microscopy. We also applied mass spectroscopy, and western blot analysis for this investigation. RESULTS Our results revealed that NET1 was localized to the nucleus at the GV stage, and that after GVBD, NET1 was localized to the cytoplasm and predominantly distributed around the chromosomes, commensurate with meiotic progression. NET1 resided in the cytoplasm and significantly accumulated on the spindle at the MI and MII stages. Mouse oocytes depleted of Net1 exhibited aberrant first polar body extrusion and asymmetric division defects. We also determined that Net1 depletion resulted in reduced RAC1 protein expression in mouse oocytes, and that NET1 protected RAC1 from degradation by HACE1, and it was essential for actin dynamics and meiotic spindle formation. Importantly, exogenous RAC1 expression in Net1-depleted oocytes significantly rescued these defects. CONCLUSIONS Our results suggest that NET1 exhibits multiple roles in spindle stability and actin dynamics during mouse oocyte meiosis.
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Affiliation(s)
- Shiwei Wang
- State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Xuan Wu
- State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Mengmeng Zhang
- State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Siyu Chang
- State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Yajun Guo
- State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Shuang Song
- State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Shizhen Dai
- State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Keliang Wu
- State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China
| | - Shenming Zeng
- State Key Laboratory of Animal Biotech Breeding, National Engineering Laboratory for Animal Breeding, Key Laboratory of Animal Genetics, Breeding and Reproduction of the Ministry of Agriculture, College of Animal Science and Technology, China Agricultural University, Beijing, China.
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Turgu B, El‐Naggar A, Kogler M, Tortola L, Zhang H, Hassan M, Lizardo MM, Kung SHY, Lam W, Penninger JM, Sorensen PH. The HACE1 E3 ligase mediates RAC1-dependent control of mTOR signaling complexes. EMBO Rep 2023; 24:e56815. [PMID: 37846480 PMCID: PMC10702814 DOI: 10.15252/embr.202356815] [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: 01/11/2023] [Revised: 09/25/2023] [Accepted: 09/29/2023] [Indexed: 10/18/2023] Open
Abstract
HACE1 is a HECT family E3 ubiquitin-protein ligase with broad but incompletely understood tumor suppressor activity. Here, we report a previously unrecognized link between HACE1 and signaling complexes containing mammalian target of rapamycin (mTOR). HACE1 blocks mTORC1 and mTORC2 activities by reducing mTOR stability in an E3 ligase-dependent manner. Mechanistically, HACE1 binds to and ubiquitylates Ras-related C3 botulinum toxin substrate 1 (RAC1) when RAC1 is associated with mTOR complexes, including at focal adhesions, leading to proteasomal degradation of RAC1. This in turn decreases the stability of mTOR to reduce mTORC1 and mTORC2 activity. HACE1 deficient cells show enhanced mTORC1/2 activity, which is reversed by chemical or genetic RAC1 inactivation but not in cells expressing the HACE1-insensitive mutant, RAC1K147R . In vivo, Rac1 deletion reverses enhanced mTOR expression in KRasG12D -driven lung tumors of Hace1-/- mice. HACE1 co-localizes with mTOR and RAC1, resulting in RAC1-dependent loss of mTOR protein stability. Together, our data demonstrate that HACE1 destabilizes mTOR by targeting RAC1 within mTOR-associated complexes, revealing a unique ubiquitin-dependent process to control the activity of mTOR signaling complexes.
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Affiliation(s)
- Busra Turgu
- Department of Molecular OncologyBritish Columbia Cancer Research CentreVancouverBCCanada
- Faculty of MedicineUniversity of British ColumbiaVancouverBCCanada
| | - Amal El‐Naggar
- Department of Molecular OncologyBritish Columbia Cancer Research CentreVancouverBCCanada
- Department of Pathology and Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
- Department of Pathology, Faculty of MedicineMenoufia UniversityShibin El KomEgypt
| | - Melanie Kogler
- Institute of Molecular Biotechnology of the Austrian Academy of SciencesViennaAustria
| | - Luigi Tortola
- Institute of Molecular Biotechnology of the Austrian Academy of SciencesViennaAustria
- Department of Biology, Institute of Molecular Health SciencesETH ZurichZurichSwitzerland
| | - Hai‐Feng Zhang
- Department of Molecular OncologyBritish Columbia Cancer Research CentreVancouverBCCanada
| | - Mariam Hassan
- Department of Molecular OncologyBritish Columbia Cancer Research CentreVancouverBCCanada
| | - Michael M Lizardo
- Department of Molecular OncologyBritish Columbia Cancer Research CentreVancouverBCCanada
| | - Sonia HY Kung
- Department of Urological Sciences, Vancouver Prostate CentreUniversity of British ColumbiaVancouverBCCanada
| | - Wan Lam
- Department of Molecular OncologyBritish Columbia Cancer Research CentreVancouverBCCanada
- Department of Pathology and Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
| | - Josef M Penninger
- Institute of Molecular Biotechnology of the Austrian Academy of SciencesViennaAustria
- Department of Medical Genetics, Life Sciences InstituteUniversity of British ColumbiaVancouverBCCanada
- Department of Laboratory MedicineMedical University of ViennaViennaAustria
- Helmholtz Centre for Infection ResearchBraunschweigGermany
| | - Poul H Sorensen
- Department of Molecular OncologyBritish Columbia Cancer Research CentreVancouverBCCanada
- Department of Pathology and Laboratory MedicineUniversity of British ColumbiaVancouverBCCanada
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Singh S, Machida S, Tulsian NK, Choong YK, Ng J, Shankar S, Liu Y, Chandiramani KV, Shi J, Sivaraman J. Structural Basis for the Enzymatic Activity of the HACE1 HECT-Type E3 Ligase Through N-Terminal Helix Dimerization. ADVANCED SCIENCE (WEINHEIM, BADEN-WURTTEMBERG, GERMANY) 2023; 10:e2207672. [PMID: 37537642 PMCID: PMC10520629 DOI: 10.1002/advs.202207672] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/26/2022] [Revised: 06/15/2023] [Indexed: 08/05/2023]
Abstract
HACE1 is an ankyrin repeat (AKR) containing HECT-type E3 ubiquitin ligase that interacts with and ubiquitinates multiple substrates. While HACE1 is a well-known tumor suppressor, its structure and mode of ubiquitination are not understood. The authors present the cryo-EM structures of human HACE1 along with in vitro functional studies that provide insights into how the enzymatic activity of HACE1 is regulated. HACE1 comprises of an N-terminal AKR domain, a middle (MID) domain, and a C-terminal HECT domain. Its unique G-shaped architecture interacts as a homodimer, with monomers arranged in an antiparallel manner. In this dimeric arrangement, HACE1 ubiquitination activity is hampered, as the N-terminal helix of one monomer restricts access to the C-terminal domain of the other. The in vitro ubiquitination assays, hydrogen-deuterium exchange mass spectrometry (HDX-MS) analysis, mutagenesis, and in silico modeling suggest that the HACE1 MID domain plays a crucial role along with the AKRs in RAC1 substrate recognition.
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Affiliation(s)
- Sunil Singh
- Department of Biological SciencesNational University of Singapore14 Science Drive 4Singapore117558Singapore
| | - Satoru Machida
- Department of Biological SciencesNational University of Singapore14 Science Drive 4Singapore117558Singapore
| | - Nikhil Kumar Tulsian
- Department of Biological SciencesNational University of Singapore14 Science Drive 4Singapore117558Singapore
- Department of BiochemistryNational University of Singapore28 Medical DriveSingapore117546Singapore
| | - Yeu Khai Choong
- Department of Biological SciencesNational University of Singapore14 Science Drive 4Singapore117558Singapore
| | - Joel Ng
- Department of Biological SciencesNational University of Singapore14 Science Drive 4Singapore117558Singapore
| | - Srihari Shankar
- Department of Biological SciencesNational University of Singapore14 Science Drive 4Singapore117558Singapore
| | - Yaochen Liu
- Department of Biological SciencesNational University of Singapore14 Science Drive 4Singapore117558Singapore
| | | | - Jian Shi
- Department of Biological SciencesNational University of Singapore14 Science Drive 4Singapore117558Singapore
| | - J Sivaraman
- Department of Biological SciencesNational University of Singapore14 Science Drive 4Singapore117558Singapore
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5
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Key role of Rho GTPases in motor disorders associated with neurodevelopmental pathologies. Mol Psychiatry 2023; 28:118-126. [PMID: 35918397 DOI: 10.1038/s41380-022-01702-8] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2021] [Revised: 06/24/2022] [Accepted: 07/02/2022] [Indexed: 01/07/2023]
Abstract
Growing evidence suggests that Rho GTPases and molecules involved in their signaling pathways play a major role in the development of the central nervous system (CNS). Whole exome sequencing (WES) and de novo examination of mutations, including SNP (Single Nucleotide Polymorphism) in genes coding for the molecules of their signaling cascade, has allowed the recent discovery of dominant autosomic mutations and duplication or deletion of candidates in the field of neurodevelopmental diseases (NDD). Epidemiological studies show that the co-occurrence of several of these neurological pathologies may indeed be the rule. The regulators of Rho GTPases have often been considered for cognitive diseases such as intellectual disability (ID) and autism. But, in a remarkable way, mild to severe motor symptoms are now reported in autism and other cognitive NDD. Although a more abundant litterature reports the involvement of Rho GTPases and signaling partners in cognitive development, molecular investigations on their roles in central nervous system (CNS) development or degenerative CNS pathologies also reveal their role in embryonic and perinatal motor wiring through axon guidance and later in synaptic plasticity. Thus, Rho family small GTPases have been revealed to play a key role in brain functions including learning and memory but their precise role in motor development and associated symptoms in NDD has been poorly scoped so far, despite increasing clinical data highlighting the links between cognition and motor development. Indeed, early impairements in fine or gross motor performance is often an associated feature of NDDs, which then impact social communication, cognition, emotion, and behavior. We review here recent insights derived from clinical developmental neurobiology in the field of Rho GTPases and NDD (autism spectrum related disorder (ASD), ID, schizophrenia, hypotonia, spastic paraplegia, bipolar disorder and dyslexia), with a specific focus on genetic alterations affecting Rho GTPases that are involved in motor circuit development.
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6
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Zang CX, Wang L, Yang HY, Shang JM, Liu H, Zhang ZH, Ju C, Yuan FY, Li FY, Bao XQ, Zhang D. HACE1 negatively regulates neuroinflammation through ubiquitylating and degrading Rac1 in Parkinson's disease models. Acta Pharmacol Sin 2022; 43:285-294. [PMID: 34593974 PMCID: PMC8792019 DOI: 10.1038/s41401-021-00778-2] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Revised: 09/13/2021] [Accepted: 09/13/2021] [Indexed: 02/03/2023] Open
Abstract
Neuroinflammation plays an important role in neurodegenerative diseases, such as Parkinson's disease (PD) and Alzheimer's disease. HACE1 (HECT domain and Ankyrin repeat Containing E3 ubiquitin-protein ligase 1) is a tumor suppressor. Recent evidence suggests that HACE1 may be involved in oxidative stress responses. Due to the critical role of ROS in neuroinflammation, we speculated that HACE1 might participate in neuroinflammation and related neurodegenerative diseases, such as PD. In this study, we investigated the role of HACE1 in neuroinflammation of PD models. We showed that HACE1 knockdown exacerbated LPS-induced neuroinflammation in BV2 microglial cells in vitro through suppressing ubiquitination and degradation of activated Rac1, an NADPH oxidase subunit. Furthermore, we showed that HACE1 exerted vital neuronal protection through increasing Rac1 activity and stability in LPS-treated SH-SY5Y cells, as HACE1 knockdown leading to lower tolerance to LPS challenge. In MPTP-induced acute PD mouse model, HACE1 knockdown exacerbated motor deficits by activating Rac1. Finally, mutant α-synuclein (A53T)-overexpressing mice, a chronic PD mouse model, exhibited age-dependent reduction of HACE1 levels in the midbrain and striatum, implicating that HACE1 participated in PD pathological progression. This study for the first time demonstrates that HACE1 is a negative regulator of neuroinflammation and involved in the PD pathogenesis by regulating Rac1 activity. The data support HACE1 as a potential target for PD and other neurodegenerative diseases.
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Affiliation(s)
- Cai-xia Zang
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Lu Wang
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Han-yu Yang
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Jun-mei Shang
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Hui Liu
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Zi-hong Zhang
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Cheng Ju
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Fang-yu Yuan
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Fang-yuan Li
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Xiu-qi Bao
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
| | - Dan Zhang
- grid.506261.60000 0001 0706 7839State Key Laboratory of Bioactive Substance and Function of Natural Medicines, Department of Pharmacology, Institute of Materia Medica, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing, 100050 China
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7
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Kane EI, Waters KL, Spratt DE. Intersection of Redox Chemistry and Ubiquitylation: Post-Translational Modifications Required for Maintaining Cellular Homeostasis and Neuroprotection. Cells 2021; 10:2121. [PMID: 34440890 PMCID: PMC8394436 DOI: 10.3390/cells10082121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/09/2021] [Accepted: 08/12/2021] [Indexed: 12/15/2022] Open
Abstract
Neurodegeneration has been predominantly recognized as neuronal breakdown induced by the accumulation of aggregated and/or misfolded proteins and remains a preliminary factor in age-dependent disease. Recently, critical regulating molecular mechanisms and cellular pathways have been shown to induce neurodegeneration long before aggregate accumulation could occur. Although this opens the possibility of identifying biomarkers for early onset diagnosis, many of these pathways vary in their modes of dysfunction while presenting similar clinical phenotypes. With selectivity remaining difficult, it is promising that these neuroprotective pathways are regulated through the ubiquitin-proteasome system (UPS). This essential post-translational modification (PTM) involves the specific attachment of ubiquitin onto a substrate, specifically marking the ubiquitin-tagged protein for its intracellular fate based upon the site of attachment, the ubiquitin chain type built, and isopeptide linkages between different ubiquitin moieties. This review highlights both the direct and indirect impact ubiquitylation has in oxidative stress response and neuroprotection, and how irregularities in these intricate processes lead towards the onset of neurodegenerative disease (NDD).
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Affiliation(s)
| | | | - Donald E. Spratt
- Gustaf H. Carlson School of Chemistry and Biochemistry, Clark University, 950 Main St., Worcester, MA 01610, USA; (E.I.K.); (K.L.W.)
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8
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Lorimer IAJ. Aberrant Rac pathway signalling in glioblastoma. Small GTPases 2021; 12:81-95. [PMID: 31032735 PMCID: PMC7849730 DOI: 10.1080/21541248.2019.1612694] [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: 03/11/2019] [Revised: 04/23/2019] [Accepted: 04/25/2019] [Indexed: 10/26/2022] Open
Abstract
Glioblastoma is an aggressive and incurable form of brain cancer. Both mutation analysis in human glioblastoma and mouse modelling studies have shown that aberrant activation of the PI 3-kinase pathway is a central driver of glioblastoma malignancy. The small GTPase Rac is activated downstream of this pathway, mediating a subset of the effects of aberrant PI 3-kinase pathway activation. Here I discuss the current state of our knowledge on Rac activation mechanisms in glioblastoma. Current knowledge on roles for specific PI 3-kinase pathway responsive Rac guanine nucleotide exchange factors in glioblastoma is reviewed. Rac is best known for its role in promoting cell motility and invasion, but there is also evidence for roles in multiple other cellular processes with cancer relevance, including proliferation, differentiation, apoptosis, DNA damage responses, metabolism, angiogenesis and immunosuppression. I review what is known about the role of Rac in these processes in glioblastoma. Finally, I assess possible strategies to inhibit this pathway in glioblastoma through either direct inhibition of Rac or inhibition of upstream activators or downstream mediators of Rac signalling.
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Affiliation(s)
- Ian AJ Lorimer
- Cancer Therapeutics Program, Ottawa Hospital Research Institute, Ottawa, Canada
- Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
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9
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Singh S, Ng J, Sivaraman J. Exploring the "Other" subfamily of HECT E3-ligases for therapeutic intervention. Pharmacol Ther 2021; 224:107809. [PMID: 33607149 DOI: 10.1016/j.pharmthera.2021.107809] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 12/13/2020] [Accepted: 01/26/2021] [Indexed: 12/14/2022]
Abstract
The HECT E3 ligase family regulates key cellular signaling pathways, with its 28 members divided into three subfamilies: NEDD4 subfamily (9 members), HERC subfamily (6 members) and "Other" subfamily (13 members). Here, we focus on the less-explored "Other" subfamily and discuss the recent findings pertaining to their biological roles. The N-terminal regions preceding the conserved HECT domains are significantly diverse in length and sequence composition, and are mostly unstructured, except for short regions that incorporate known substrate-binding domains. In some of the better-characterized "Other" members (e.g., HUWE1, AREL1 and UBE3C), structure analysis shows that the extended region (~ aa 50) adjacent to the HECT domain affects the stability and activity of the protein. The enzymatic activity is also influenced by interactions with different adaptor proteins and inter/intramolecular interactions. Primarily, the "Other" subfamily members assemble atypical ubiquitin linkages, with some cooperating with E3 ligases from the other subfamilies to form branched ubiquitin chains on substrates. Viruses and pathogenic bacteria target and hijack the activities of "Other" subfamily members to evade host immune responses and cause diseases. As such, these HECT E3 ligases have emerged as potential candidates for therapeutic drug development.
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Affiliation(s)
- Sunil Singh
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, 117543, Singapore
| | - Joel Ng
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, 117543, Singapore
| | - J Sivaraman
- Department of Biological Sciences, 14 Science Drive 4, National University of Singapore, 117543, Singapore.
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10
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HACE1 blocks HIF1α accumulation under hypoxia in a RAC1 dependent manner. Oncogene 2021; 40:1988-2001. [PMID: 33603169 PMCID: PMC7979542 DOI: 10.1038/s41388-021-01680-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2020] [Revised: 12/21/2020] [Accepted: 01/25/2021] [Indexed: 01/30/2023]
Abstract
Uncovering the mechanisms that underpin how tumor cells adapt to microenvironmental stress is essential to better understand cancer progression. The HACE1 (HECT domain and ankyrin repeat-containing E3 ubiquitin-protein ligase) gene is a tumor suppressor that inhibits the growth, invasive capacity, and metastasis of cancer cells. However, the direct regulatory pathways whereby HACE1 confers this tumor-suppressive effect remain to be fully elucidated. In this report, we establish a link between HACE1 and the major stress factor, hypoxia-inducible factor 1 alpha (HIF1α). We find that HACE1 blocks the accumulation of HIF1α during cellular hypoxia through decreased protein stability. This property is dependent on HACE1 E3 ligase activity and loss of Ras-related C3 botulinum toxin substrate 1 (RAC1), an established target of HACE1 mediated ubiquitinylation and degradation. In vivo, genetic deletion of Rac1 reversed the increased HIF1α expression observed in Hace1-/- mice in murine KRasG12D-driven lung tumors. An inverse relationship was observed between HACE1 and HIF1α levels in tumors compared to patient-matched normal kidney tissues, highlighting the potential pathophysiological significance of our findings. Together, our data uncover a previously unrecognized function for the HACE1 tumor suppressor in blocking HIF1α accumulation under hypoxia in a RAC1-dependent manner.
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11
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Kotelevets L, Chastre E. Rac1 Signaling: From Intestinal Homeostasis to Colorectal Cancer Metastasis. Cancers (Basel) 2020; 12:cancers12030665. [PMID: 32178475 PMCID: PMC7140047 DOI: 10.3390/cancers12030665] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Revised: 03/06/2020] [Accepted: 03/08/2020] [Indexed: 12/14/2022] Open
Abstract
The small GTPase Rac1 has been implicated in a variety of dynamic cell biological processes, including cell proliferation, cell survival, cell-cell contacts, epithelial mesenchymal transition (EMT), cell motility, and invasiveness. These processes are orchestrated through the fine tuning of Rac1 activity by upstream cell surface receptors and effectors that regulate the cycling Rac1-GDP (off state)/Rac1-GTP (on state), but also through the tuning of Rac1 accumulation, activity, and subcellular localization by post translational modifications or recruitment into molecular scaffolds. Another level of regulation involves Rac1 transcripts stability and splicing. Downstream, Rac1 initiates a series of signaling networks, including regulatory complex of actin cytoskeleton remodeling, activation of protein kinases (PAKs, MAPKs) and transcription factors (NFkB, Wnt/β-catenin/TCF, STAT3, Snail), production of reactive oxygen species (NADPH oxidase holoenzymes, mitochondrial ROS). Thus, this GTPase, its regulators, and effector systems might be involved at different steps of the neoplastic progression from dysplasia to the metastatic cascade. After briefly placing Rac1 and its effector systems in the more general context of intestinal homeostasis and in wound healing after intestinal injury, the present review mainly focuses on the several levels of Rac1 signaling pathway dysregulation in colorectal carcinogenesis, their biological significance, and their clinical impact.
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Affiliation(s)
- Larissa Kotelevets
- Institut National de la Santé et de la Recherche Médicale, UMR S 938, Centre de Recherche Saint-Antoine, 75012 Paris, France
- Sorbonne Université, Hôpital Saint-Antoine, Site Bâtiment Kourilsky, 75012 Paris, France
- Correspondence: (L.K.); (E.C.)
| | - Eric Chastre
- Institut National de la Santé et de la Recherche Médicale, UMR S 938, Centre de Recherche Saint-Antoine, 75012 Paris, France
- Sorbonne Université, Hôpital Saint-Antoine, Site Bâtiment Kourilsky, 75012 Paris, France
- Correspondence: (L.K.); (E.C.)
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12
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El-Naggar AM, Clarkson PW, Negri GL, Turgu B, Zhang F, Anglesio MS, Sorensen PH. HACE1 is a potential tumor suppressor in osteosarcoma. Cell Death Dis 2019; 10:21. [PMID: 30622235 PMCID: PMC6325116 DOI: 10.1038/s41419-018-1276-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 11/23/2018] [Accepted: 12/06/2018] [Indexed: 12/24/2022]
Abstract
Osteosarcoma is a malignant bone sarcoma characterized by extensive genomic disruption and a propensity for metastatic spread. Osteoid production suggests a close relationship with normal osteoblasts, and the latter are the presumptive cell of origin of this disease. The HACE1 gene, localized to human chromosome 6q21, encodes the HACE1 HECT E3 ligase, a tumor suppressor in diverse tumors that acts in part by targeting the activated form of RAC1 GTPase for proteasomal degradation. Disruption or loss of 6q21 is relatively common in osteosarcomas, and Hace1-/-/Tp53+/- mice frequently develop osteosarcomas, in contrast to Tp53+/- mice, which do not. This suggests an unexplored link between HACE1 loss and osteosarcoma. Here we compared HACE1 expression in normal osteoblasts and osteosarcoma cell lines in vitro by western blotting and quantitative RT-PCR, and in human osteosarcoma specimens by immunohistochemistry. Both HACE1 transcript and protein levels were reduced in osteosarcoma compared to osteoblasts in vitro. Reduced HACE1 expression in osteosarcoma tumors was observed in 76% of cases and associated with high-grade lesions. Further, clonally derived pairs of high and low metastatic osteosarcoma cell lines showed significant downregulation in the high compared to corresponding low metastatic cells. Ectopic expression of HACE1 markedly inhibited anchorage-independent growth and cell motility of HACE1 osteosarcoma cell lines, and was associated with reduced RAC1 activation and decreased reactive oxygen species (ROS). Finally, HACE1 overexpression blocked osteosarcoma xenograft growth and dramatically reduced pulmonary metastases. These findings point to a potential tumor suppressor function for HACE1 in osteosarcoma.
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Affiliation(s)
- Amal M El-Naggar
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, BC, Canada.,Department of Pathology, Faculty of Medicine, Menoufia University, Menoufia Governorate, Egypt
| | - Paul W Clarkson
- Department of Orthopedics, University of British Columbia, Vancouver, British Columbia, Canada
| | - Gian Luca Negri
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, BC, Canada
| | - Busra Turgu
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, BC, Canada
| | - Fan Zhang
- Vancouver Prostate Centre, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael S Anglesio
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.,Department of Obstetrics and Gynecology, University of British Columbia, Vancouver, British Columbia, Canada
| | - Poul H Sorensen
- Department of Pathology and Laboratory Medicine, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada. .,Department of Molecular Oncology, British Columbia Cancer Research Centre, Vancouver, BC, Canada.
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13
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Zhou Z, Zhang HS, Zhang ZG, Sun HL, Liu HY, Gou XM, Yu XY, Huang YH. Loss of HACE1 promotes colorectal cancer cell migration via upregulation of YAP1. J Cell Physiol 2018; 234:9663-9672. [PMID: 30362561 DOI: 10.1002/jcp.27653] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2018] [Accepted: 10/02/2018] [Indexed: 12/12/2022]
Abstract
Colorectal cancer (CRC) is the third-leading cause of cancer mortality worldwide. HACE1 function as a tumor-suppressor gene and is downregulated in several kinds of cancers. However, the distribution and clinical significance of HACE1 in CRC is still not clarified. In this study, we found that the HACE1 expression is greatly downregulated in CRC tissues and cell lines. Moreover, the HACE1 expression was significantly associated with inhibition of CRC cell proliferation, metastasis, and invasion. HACE1 inhibited epithelial-mesenchymal transition in CRC cells. Furthermore, we found that HACE1 altered the protein expression of the Hippo pathway by downregulation of YAP1. HACE1 suppresses the invasive ability of CRC cells by negatively regulating the YAP1 pathway. Our data indicates that HACE1 directly targets YAP1 and induces downregulation of YAP1, thereby increasing the activity of the Hippo pathway. In summary, these findings demonstrated that HACE1-YAP1 axis had an important part in the CRC development and progression.
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Affiliation(s)
- Zhen Zhou
- Department of Biotechnology, College of Life Science & Bioengineering, Beijing University of Technology, Chaoyang, Beijing, China
| | - Hong-Sheng Zhang
- Department of Biotechnology, College of Life Science & Bioengineering, Beijing University of Technology, Chaoyang, Beijing, China
| | - Zhong-Guo Zhang
- Department of Biotechnology, College of Life Science & Bioengineering, Beijing University of Technology, Chaoyang, Beijing, China
| | - Hong-Liang Sun
- Department of Biotechnology, College of Life Science & Bioengineering, Beijing University of Technology, Chaoyang, Beijing, China
| | - Hui-Yun Liu
- Department of Biotechnology, College of Life Science & Bioengineering, Beijing University of Technology, Chaoyang, Beijing, China
| | - Xiao-Meng Gou
- Department of Biotechnology, College of Life Science & Bioengineering, Beijing University of Technology, Chaoyang, Beijing, China
| | - Xiao-Ying Yu
- Department of Biotechnology, College of Life Science & Bioengineering, Beijing University of Technology, Chaoyang, Beijing, China
| | - Ying-Hui Huang
- Department of Biotechnology, College of Life Science & Bioengineering, Beijing University of Technology, Chaoyang, Beijing, China
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