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Zheng X, Li A, Qiu J, Yan G, Ji Y, Wang G. β-N-methylamino-L-alanine production, photosynthesis and transcriptional expression in a possible mutation strain and a wild strain of Thalassiosira minima. JOURNAL OF HAZARDOUS MATERIALS 2024; 477:135301. [PMID: 39053058 DOI: 10.1016/j.jhazmat.2024.135301] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/08/2024] [Revised: 07/02/2024] [Accepted: 07/21/2024] [Indexed: 07/27/2024]
Abstract
The neurotoxin β-N-methylamino-L-alanine (BMAA) produced by marine diatoms has been implicated as an important environmental trigger of neurodegenerative diseases in humans. However, the biosynthesis mechanism of BMAA in marine diatoms is still unknown. In the present study, the strain of diatom Thalassiosira minima almost lost the biosynthesis ability for BMAA after a long-term subculture in our laboratory. The production of BMAA-containing proteins in the mutant strain of T. minima reduced to 18.2 % of that in the wild strain, meanwhile the cell size decreased but pigment content increased in the mutant strain. Take consideration of our previous transcriptional data on the mixed diatom and cyanobacterium cultures, the current transcriptome analysis showed four identical and highly correlated KEGG pathways associated with the accumulation of misfolded proteins in diatom, including ribosome, proteasome, SNARE interactions in vesicle transport, and protein processing in the endoplasmic reticulum. Analysis of amino acids and transcriptional information suggested that amino acid synthesis and degradation are associated with the biosynthesis of BMAA-containing proteins. In addition, a reduction in the precision of ubiquitination-mediated protein hydrolysis and vesicular transport by the COPII system will exacerbate the accumulation of BMAA-containing proteins in diatoms.
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Affiliation(s)
- Xianyao Zheng
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Aifeng Li
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao 266100, China.
| | - Jiangbing Qiu
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China; Key Laboratory of Marine Environment and Ecology, Ocean University of China, Ministry of Education, Qingdao 266100, China
| | - Guowang Yan
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Ying Ji
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
| | - Guixiang Wang
- College of Environmental Science and Engineering, Ocean University of China, Qingdao 266100, China
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2
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Wang T, Song X, Tan J, Xian W, Zhou X, Yu M, Wang X, Xu Y, Wu T, Yuan K, Ran Y, Yang B, Fan G, Liu X, Zhou Y, Zhu Y. Legionella effector LnaB is a phosphoryl-AMPylase that impairs phosphosignalling. Nature 2024; 631:393-401. [PMID: 38776962 DOI: 10.1038/s41586-024-07573-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2022] [Accepted: 05/16/2024] [Indexed: 05/25/2024]
Abstract
AMPylation is a post-translational modification in which AMP is added to the amino acid side chains of proteins1,2. Here we show that, with ATP as the ligand and actin as the host activator, the effector protein LnaB of Legionella pneumophila exhibits AMPylase activity towards the phosphoryl group of phosphoribose on PRR42-Ub that is generated by the SidE family of effectors, and deubiquitinases DupA and DupB in an E1- and E2-independent ubiquitination process3-7. The product of LnaB is further hydrolysed by an ADP-ribosylhydrolase, MavL, to Ub, thereby preventing the accumulation of PRR42-Ub and ADPRR42-Ub and protecting canonical ubiquitination in host cells. LnaB represents a large family of AMPylases that adopt a common structural fold, distinct from those of the previously known AMPylases, and LnaB homologues are found in more than 20 species of bacterial pathogens. Moreover, LnaB also exhibits robust phosphoryl AMPylase activity towards phosphorylated residues and produces unique ADPylation modifications in proteins. During infection, LnaB AMPylates the conserved phosphorylated tyrosine residues in the activation loop of the Src family of kinases8,9, which dampens downstream phosphorylation signalling in the host. Structural studies reveal the actin-dependent activation and catalytic mechanisms of the LnaB family of AMPylases. This study identifies, to our knowledge, an unprecedented molecular regulation mechanism in bacterial pathogenesis and protein phosphorylation.
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Affiliation(s)
- Ting Wang
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Xiaonan Song
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Jiaxing Tan
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
- Shanghai Institute for Advanced Study, Zhejiang University, Shanghai, China
| | - Wei Xian
- Department of Microbiology and Infectious Disease Center, NHC Key Laboratory of Medical Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China
| | - Xingtong Zhou
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Mingru Yu
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Xiaofei Wang
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Yan Xu
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Ting Wu
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Keke Yuan
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Yu Ran
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Bing Yang
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Gaofeng Fan
- School of Life Science and Technology, ShanghaiTech University, Shanghai, China
| | - Xiaoyun Liu
- Department of Microbiology and Infectious Disease Center, NHC Key Laboratory of Medical Immunology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing, China.
| | - Yan Zhou
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China.
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, China.
| | - Yongqun Zhu
- Department of Gastroenterology of the Second Affiliated Hospital, School of Medicine and College of Animal Sciences, Life Sciences Institute, Zhejiang University, Hangzhou, China.
- MOE Key Laboratory of Biosystems Homeostasis and Protection, and Zhejiang Provincial Key Laboratory of Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou, China.
- Shanghai Institute for Advanced Study, Zhejiang University, Shanghai, China.
- State Key Laboratory of Transvascular Implantation Devices, Hangzhou, China.
- MOA Key Laboratory of Animal Virology, Center for Veterinary Sciences, Zhejiang University, Hangzhou, China.
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Fiore APZP, Maity S, Jeffery L, An D, Rendleman J, Iannitelli D, Choi H, Mazzoni E, Vogel C. Identification of molecular signatures defines the differential proteostasis response in induced spinal and cranial motor neurons. Cell Rep 2024; 43:113885. [PMID: 38457337 PMCID: PMC11018139 DOI: 10.1016/j.celrep.2024.113885] [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: 03/06/2023] [Revised: 12/12/2023] [Accepted: 02/13/2024] [Indexed: 03/10/2024] Open
Abstract
Amyotrophic lateral sclerosis damages proteostasis, affecting spinal and upper motor neurons earlier than a subset of cranial motor neurons. To aid disease understanding, we exposed induced cranial and spinal motor neurons (iCrMNs and iSpMNs) to proteotoxic stress, under which iCrMNs showed superior survival, quantifying the transcriptome and proteome for >8,200 genes at 0, 12, and 36 h. Two-thirds of the proteome showed cell-type differences. iSpMN-enriched proteins related to DNA/RNA metabolism, and iCrMN-enriched proteins acted in the endoplasmic reticulum (ER)/ER chaperone complex, tRNA aminoacylation, mitochondria, and the plasma/synaptic membrane, suggesting that iCrMNs expressed higher levels of proteins supporting proteostasis and neuronal function. When investigating the increased proteasome levels in iCrMNs, we showed that the activity of the 26S proteasome, but not of the 20S proteasome, was higher in iCrMNs than in iSpMNs, even after a stress-induced decrease. We identified Ublcp1 as an iCrMN-specific regulator of the nuclear 26S activity.
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Affiliation(s)
| | - Shuvadeep Maity
- New York University, Department of Biology, New York, NY 10003, USA; Department of Biological Sciences, Birla Institute of Technology and Science Pilani, Hyderabad Campus, Hyderabad, Telangana, India
| | - Lauren Jeffery
- New York University, Department of Biology, New York, NY 10003, USA
| | - Disi An
- New York University, Department of Biology, New York, NY 10003, USA
| | - Justin Rendleman
- New York University, Department of Biology, New York, NY 10003, USA
| | - Dylan Iannitelli
- New York University, Department of Biology, New York, NY 10003, USA
| | - Hyungwon Choi
- Department of Medicine, Yong Loo Lin School of Medicine, National University of Singapore, Singapore 119228, Singapore
| | - Esteban Mazzoni
- New York University, Department of Biology, New York, NY 10003, USA; Department of Cell Biology, NYU Grossman School of Medicine, New York, NY 10016, USA
| | - Christine Vogel
- New York University, Department of Biology, New York, NY 10003, USA.
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Soueid J, Hamze Z, Bedran J, Chahrour M, Boustany RM. A novel autism-associated UBLCP1 mutation impacts proteasome regulation/activity. Transl Psychiatry 2023; 13:404. [PMID: 38129378 PMCID: PMC10739866 DOI: 10.1038/s41398-023-02702-0] [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: 02/14/2023] [Revised: 11/16/2023] [Accepted: 12/05/2023] [Indexed: 12/23/2023] Open
Abstract
The landscape of autism spectrum disorder (ASD) in Lebanon is unique because of high rates of consanguinity, shared ancestry, and increased remote consanguinity. ASD prevalence in Lebanon is 1 in 68 with a male-to-female ratio of 2:1. This study aims to investigate the impact of an inherited deletion in UBLCP1 (Ubiquitin-Like Domain-Containing CTD Phosphatase 1) on the ubiquitin-proteasome system (UPS) and proteolysis. Whole exome sequencing in a Lebanese family with ASD without pathogenic copy number variations (CNVs) uncovered a deletion in UBLCP1. Functional evaluation of the identified variant is described in fibroblasts from the affected. The deletion in UBLCP1 exon 10 (g.158,710,261CAAAG > C) generates a premature stop codon interrupting the phosphatase domain and is predicted as pathogenic. It is absent from databases of normal variation worldwide and in Lebanon. Wild-type UBLCP1 is widely expressed in mouse brains. The mutation results in decreased UBLCP1 protein expression in patient-derived fibroblasts from the autistic patient compared to controls. The truncated UBLCP1 protein results in increased proteasome activity decreased ubiquitinated protein levels, and downregulation in expression of other proteasome subunits in samples from the affected compared to controls. Inhibition of the proteasome by using MG132 in proband cells reverses alterations in gene expression due to the restoration of protein levels of the common transcription factor, NRF1. Finally, treatment with gentamicin, which promotes premature termination codon read-through, restores UBLCP1 expression and function. Discovery of an ASD-linked mutation in UBLCP1 leading to overactivation of cell proteolysis is reported. This, in turn, leads to dysregulation of proteasome subunit transcript levels as a compensatory response.
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Affiliation(s)
- Jihane Soueid
- Department of Biochemistry and Molecular Genetics, American university of Beirut, Beirut, Lebanon
| | - Zeinab Hamze
- Department of Biochemistry and Molecular Genetics, American university of Beirut, Beirut, Lebanon
| | - Joe Bedran
- Department of Biochemistry and Molecular Genetics, American university of Beirut, Beirut, Lebanon
| | - Maria Chahrour
- Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Center for the Genetics of Host Defense, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
- Peter O'Donnell Jr. Brain Institute, University of Texas Southwestern Medical Center, Dallas, TX, 75390, USA
| | - Rose-Mary Boustany
- Department of Biochemistry and Molecular Genetics, American university of Beirut, Beirut, Lebanon.
- Departments of Pediatrics and Adolescent Medicine, American University of Beirut Medical Center Special Kids Clinic, Neurogenetics Program and Division of Pediatric Neurology, Beirut, Lebanon.
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5
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Zhang R, Pan S, Zheng S, Liao Q, Jiang Z, Wang D, Li X, Hu A, Li X, Zhu Y, Shen X, Lei J, Zhong S, Zhang X, Huang L, Wang X, Huang L, Shen L, Song BL, Zhao JW, Wang Z, Yang B, Guo X. Lipid-anchored proteasomes control membrane protein homeostasis. SCIENCE ADVANCES 2023; 9:eadj4605. [PMID: 38019907 PMCID: PMC10686573 DOI: 10.1126/sciadv.adj4605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Accepted: 10/30/2023] [Indexed: 12/01/2023]
Abstract
Protein degradation in eukaryotic cells is mainly carried out by the 26S proteasome, a macromolecular complex not only present in the cytosol and nucleus but also associated with various membranes. How proteasomes are anchored to the membrane and the biological meaning thereof have been largely unknown in higher organisms. Here, we show that N-myristoylation of the Rpt2 subunit is a general mechanism for proteasome-membrane interaction. Loss of this modification in the Rpt2-G2A mutant cells leads to profound changes in the membrane-associated proteome, perturbs the endomembrane system, and undermines critical cellular processes such as cell adhesion, endoplasmic reticulum-associated degradation and membrane protein trafficking. Rpt2G2A/G2A homozygous mutation is embryonic lethal in mice and is sufficient to abolish tumor growth in a nude mice xenograft model. These findings have defined an evolutionarily conserved mechanism for maintaining membrane protein homeostasis and underscored the significance of compartmentalized protein degradation by myristoyl-anchored proteasomes in health and disease.
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Affiliation(s)
- Ruizhu Zhang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Shuxian Pan
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Suya Zheng
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Qingqing Liao
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Zhaodi Jiang
- National Institute of Biological Sciences, Beijing 102206, China
- Tsinghua Institute of Multidisciplinary Biomedical Research, Tsinghua University, Beijing 100084, China
| | - Dixian Wang
- Department of Human Anatomy, Histology and Embryology, System Medicine Research Center, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Cryo-Electron Microscopy Center, Zhejiang University, Hangzhou 310058, China
| | - Xuemei Li
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Ao Hu
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Taikang Center for Life and Medical Sciences, Taikang Medical School, Wuhan University, Wuhan 430072, China
| | - Xinran Li
- Zhejiang University-Hangzhou Global Scientific and Technological Innovation Center, Hangzhou 311200, China
| | - Yezhang Zhu
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Xiaoqi Shen
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Jing Lei
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China
- The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Siming Zhong
- Zhejiang University-University of Edinburgh Institute, Zhejiang University, Haining 314400, China
- Deanery of Biomedical Sciences, College of Medicine and Veterinary Medicine, University of Edinburgh, Edinburgh EH8 9YL, UK
| | - Xiaomei Zhang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Lingyun Huang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Xiaorong Wang
- Department of Physiology and Biophysics, University of California-Irvine, Irvine, CA 92697, USA
- Department of Developmental and Cell Biology, University of California-Irvine, Irvine, CA 92697, USA
| | - Lan Huang
- Department of Physiology and Biophysics, University of California-Irvine, Irvine, CA 92697, USA
- Department of Developmental and Cell Biology, University of California-Irvine, Irvine, CA 92697, USA
| | - Li Shen
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Bao-Liang Song
- Hubei Key Laboratory of Cell Homeostasis, College of Life Sciences, Taikang Center for Life and Medical Sciences, Taikang Medical School, Wuhan University, Wuhan 430072, China
| | - Jing-Wei Zhao
- Department of Human Anatomy, Histology and Embryology, System Medicine Research Center, and Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China
- Cryo-Electron Microscopy Center, Zhejiang University, Hangzhou 310058, China
| | - Zhiping Wang
- Department of Neurobiology and Department of Neurology of Second Affiliated Hospital, NHC and CAMS Key Laboratory of Medical Neurobiology, Zhejiang University School of Medicine, Hangzhou 310058, China
- The MOE Frontier Science Center for Brain Research and Brain-Machine Integration, Zhejiang University School of Brain Science and Brain Medicine, Hangzhou 310058, China
| | - Bing Yang
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
| | - Xing Guo
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Life Sciences Institute, Zhejiang University, Hangzhou 310058, China
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6
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Wang Z, Li T, Zhang X, Feng J, Liu Z, Shan W, Joosten MHAJ, Govers F, Du Y. A Phytophthora infestans RXLR effector targets a potato ubiquitin-like domain-containing protein to inhibit the proteasome activity and hamper plant immunity. THE NEW PHYTOLOGIST 2023; 238:781-797. [PMID: 36653957 DOI: 10.1111/nph.18749] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/12/2023] [Indexed: 06/17/2023]
Abstract
Ubiquitin-like domain-containing proteins (UDPs) are involved in the ubiquitin-proteasome system because of their ability to interact with the 26S proteasome. Here, we identified potato StUDP as a target of the Phytophthora infestans RXLR effector Pi06432 (PITG_06432), which supresses the salicylic acid (SA)-related immune pathway. By overexpressing and silencing of StUDP in potato, we show that StUDP negatively regulates plant immunity against P. infestans. StUDP interacts with, and destabilizes, the 26S proteasome subunit that is referred to as REGULATORY PARTICLE TRIPLE-A ATP-ASE (RPT) subunit StRPT3b. This destabilization represses the proteasome activity. Proteomic analysis and Western blotting show that StUDP decreases the stability of the master transcription factor SYSTEMIC ACQUIRED RESISTANCE DEFICIENT 1 (SARD1) in SA biosynthesis. StUDP negatively regulates the SA signalling pathway by repressing the proteasome activity and destabilizing StSARD1, leading to a decreased expression of the SARD1-targeted gene ISOCHORISMATE SYNTHASE 1 and thereby a decrease in SA content. Pi06432 stabilizes StUDP, and it depends on StUDP to destabilize StRPT3b and thereby supress the proteasome activity. Our study reveals that the P. infestans effector Pi06432 targets StUDP to hamper the homeostasis of the proteasome by the degradation of the proteasome subunit StRPT3b and thereby suppresses SA-related immunity.
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Affiliation(s)
- Ziwei Wang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Tingting Li
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Shaanxi Engineering Research Center for Vegetables, Yangling, Shaanxi, 712100, China
| | - Xiaojiang Zhang
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Jiashu Feng
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Zhuting Liu
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Weixing Shan
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Agronomy, Northwest A&F University, Yangling, Shaanxi, 712100, China
| | - Matthieu H A J Joosten
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Francine Govers
- Laboratory of Phytopathology, Wageningen University, Droevendaalsesteeg 1, 6708 PB, Wageningen, the Netherlands
| | - Yu Du
- State Key Laboratory of Crop Stress Biology for Arid Areas and College of Horticulture, Northwest A&F University, Yangling, Shaanxi, 712100, China
- Shaanxi Engineering Research Center for Vegetables, Yangling, Shaanxi, 712100, China
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7
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Xu Y, Wang H, Sahu SK, Li L, Liang H, Günther G, Wong GKS, Melkonian B, Melkonian M, Liu H, Wang S. Chromosome-level genome of Pedinomonas minor (Chlorophyta) unveils adaptations to abiotic stress in a rapidly fluctuating environment. THE NEW PHYTOLOGIST 2022; 235:1409-1425. [PMID: 35560066 DOI: 10.1111/nph.18220] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2022] [Accepted: 05/04/2022] [Indexed: 06/15/2023]
Abstract
The Pedinophyceae (Viridiplantae) comprise a class of small uniflagellate algae with a pivotal position in the phylogeny of the Chlorophyta as the sister group of the 'core chlorophytes'. We present a chromosome-level genome assembly of the freshwater type species of the class, Pedinomonas minor. We sequenced the genome using Pacbio, Illumina and Hi-C technologies, performed comparative analyses of genome and gene family evolution, and analyzed the transcriptome under various abiotic stresses. Although the genome is relatively small (55 Mb), it shares many traits with core chlorophytes including number of introns and protein-coding genes, messenger RNA (mRNA) lengths, and abundance of transposable elements. Pedinomonas minor is only bounded by the plasma membrane, thriving in temporary habitats that frequently dry out. Gene family innovations and expansions and transcriptomic responses to abiotic stresses have shed light on adaptations of P. minor to its fluctuating environment. Horizontal gene transfers from bacteria and fungi have possibly contributed to the evolution of some of these traits. We identified a putative endogenization site of a nucleocytoplasmic large DNA virus and hypothesized that endogenous viral elements donated foreign genes to the host genome, their spread enhanced by transposable elements, located at gene boundaries in several of the expanded gene families.
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Affiliation(s)
- Yan Xu
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 10049, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Hongli Wang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 10049, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Sunil Kumar Sahu
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Linzhou Li
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, 518083, China
- Department of Biotechnology and Biomedicine, Technical University of Denmark, Kgs. Lyngby, 2800, Denmark
| | - Hongping Liang
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 10049, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Gerd Günther
- Private Laboratory, Knittkuhler Str. 61, Düsseldorf, 40629, Germany
| | - Gane Ka-Shu Wong
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
- Department of Medicine, University of Alberta, Edmonton, AB, T6G 2E9, Canada
| | - Barbara Melkonian
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | - Michael Melkonian
- Department of Plant Microbe Interactions, Max Planck Institute for Plant Breeding Research, Cologne, 50829, Germany
| | - Huan Liu
- College of Life Sciences, University of Chinese Academy of Sciences, Beijing, 10049, China
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, 518083, China
| | - Sibo Wang
- State Key Laboratory of Agricultural Genomics, BGI-Shenzhen, Shenzhen, 518083, China
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8
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Guo X. Localized Proteasomal Degradation: From the Nucleus to Cell Periphery. Biomolecules 2022; 12:biom12020229. [PMID: 35204730 PMCID: PMC8961600 DOI: 10.3390/biom12020229] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2022] [Revised: 01/25/2022] [Accepted: 01/27/2022] [Indexed: 12/31/2022] Open
Abstract
The proteasome is responsible for selective degradation of most cellular proteins. Abundantly present in the cell, proteasomes not only diffuse in the cytoplasm and the nucleus but also associate with the chromatin, cytoskeleton, various membranes and membraneless organelles/condensates. How and why the proteasome gets to these specific subcellular compartments remains poorly understood, although increasing evidence supports the hypothesis that intracellular localization may have profound impacts on the activity, substrate accessibility and stability/integrity of the proteasome. In this short review, I summarize recent advances on the functions, regulations and targeting mechanisms of proteasomes, especially those localized to the nuclear condensates and membrane structures of the cell, and I discuss the biological significance thereof in mediating compartmentalized protein degradation.
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Affiliation(s)
- Xing Guo
- Life Sciences Institute, Zhejiang University, Hangzhou 310058, China;
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Hangzhou 310058, China
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9
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Duan J, Li W, Shu X, Yang B, He X, Guo X. Conserved Mitotic Phosphorylation of a Proteasome Subunit Regulates Cell Proliferation. Cells 2021; 10:3075. [PMID: 34831298 PMCID: PMC8620773 DOI: 10.3390/cells10113075] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Revised: 11/04/2021] [Accepted: 11/06/2021] [Indexed: 11/17/2022] Open
Abstract
Reversible phosphorylation has emerged as an important mechanism for regulating proteasome function in various physiological processes. Essentially all proteasome phosphorylations characterized thus far occur on proteasome holoenzyme or subcomplexes to regulate substrate degradation. Here, we report a highly conserved phosphorylation that only exists on the unassembled α5 subunit of the proteasome. The modified residue, α5-Ser16, is within a SP motif typically recognized by cyclin-dependent kinases (CDKs). Using a phospho-specific antibody generated against this site, we found that α5-S16 phosphorylation is mitosis-specific in both yeast and mammalian cells. Blocking this site with a S16A mutation caused growth defect and G2/M arrest of the cell cycle. α5-S16 phosphorylation depends on CDK1 activity and is highly abundant in some but not all mitotic cells. Immunoprecipitation and mass spectrometry (IP-MS) studies identified numerous proteins that could interact with phosphorylated α5, including PLK1, a key regulator of mitosis. α5-PLK1 interaction increased upon mitosis and could be facilitated by S16 phosphorylation. CDK1 activation downstream of PLK1 activity was delayed in S16A mutant cells, suggesting an important role of α5-S16 phosphorylation in regulating PLK1 and mitosis. These data have revealed an unappreciated function of "exo-proteasome" phosphorylation of a proteasome subunit and may bring new insights to our understanding of cell cycle control.
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Affiliation(s)
- Jinyuan Duan
- Life Sciences Institute, Zhejiang University, Hangzhou 310058, China; (J.D.); (W.L.); (X.S.); (B.Y.); (X.H.)
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Hangzhou 310058, China
| | - Wenzhu Li
- Life Sciences Institute, Zhejiang University, Hangzhou 310058, China; (J.D.); (W.L.); (X.S.); (B.Y.); (X.H.)
| | - Xin Shu
- Life Sciences Institute, Zhejiang University, Hangzhou 310058, China; (J.D.); (W.L.); (X.S.); (B.Y.); (X.H.)
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Hangzhou 310058, China
| | - Bing Yang
- Life Sciences Institute, Zhejiang University, Hangzhou 310058, China; (J.D.); (W.L.); (X.S.); (B.Y.); (X.H.)
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Hangzhou 310058, China
| | - Xiangwei He
- Life Sciences Institute, Zhejiang University, Hangzhou 310058, China; (J.D.); (W.L.); (X.S.); (B.Y.); (X.H.)
| | - Xing Guo
- Life Sciences Institute, Zhejiang University, Hangzhou 310058, China; (J.D.); (W.L.); (X.S.); (B.Y.); (X.H.)
- Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Hangzhou 310058, China
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10
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Bui A, Liu J, Hong J, Hadeler E, Mosca M, Brownstone N, Liao W. Identifying Novel Psoriatic Disease Drug Targets Using a Genetics-Based Priority Index Pipeline. JOURNAL OF PSORIASIS AND PSORIATIC ARTHRITIS 2021; 6:185-197. [PMID: 35756599 PMCID: PMC9229908 DOI: 10.1177/24755303211026023] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
BACKGROUND Despite numerous genome-wide association studies conducted in psoriasis and psoriatic arthritis, only a small fraction of the identified genes has been therapeutically targeted. OBJECTIVE We sought to identify and analyze potential therapeutic targets for psoriasis and psoriatic arthritis (PsA) using the priority index (Pi), a genetics-dependent drug target prioritization approach. METHODS Significant genetic variants from GWAS for psoriasis, PsA, and combined psoriatic disease were annotated and run through the Pi pipeline. Potential drug targets were identified based on genomic predictors, annotation predictors, pathway enrichment, and pathway crosstalk. RESULTS Several gene targets were identified for psoriasis and PsA that demonstrated biological associations to their respective diseases. Some are currently being explored as potential therapeutic targets (i.e. ICAM1, NF-kB, REV3L, ADRA1B for psoriasis; CCL11 for PsA); others have not yet been investigated (i.e. LNPEP, LCE3 for psoriasis; UBLCP1 for PsA). Additionally, many nodal points of potential intervention were identified as promising therapeutic targets. Of these, some are currently being studied such as TYK2 for psoriasis, and others have yet to be explored (i.e. PPP2CA, YAP1, PI3K, AKT, FOXO1, RELA, CSF2, IFNGR1, IFNGR2 for psoriasis; GNAQ, PLCB1, GNAI2 for PsA). CONCLUSION Through Pi, we identified data-driven candidate therapeutic gene targets and pathways for psoriasis and PsA. Given the sparse PsA specific genetic studies and PsA specific drug targets, this analysis could prove to be particularly valuable in the pipeline for novel psoriatic therapies.
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Affiliation(s)
- Audrey Bui
- Department of Dermatology, University of California, San Francisco, CA 94015
- Department of Biology, St. Bonaventure University, St. Bonaventure, NY 14778
| | - Jared Liu
- Department of Dermatology, University of California, San Francisco, CA 94015
| | - Julie Hong
- Department of Dermatology, University of California, San Francisco, CA 94015
| | - Edward Hadeler
- Department of Dermatology, University of California, San Francisco, CA 94015
| | - Megan Mosca
- Department of Dermatology, University of California, San Francisco, CA 94015
| | - Nicholas Brownstone
- Department of Dermatology, University of California, San Francisco, CA 94015
| | - Wilson Liao
- Department of Dermatology, University of California, San Francisco, CA 94015
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11
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Schaler AW, Runyan AM, Clelland CL, Sydney EJ, Fowler SL, Figueroa HY, Shioda S, Santa-Maria I, Duff KE, Myeku N. PAC1 receptor-mediated clearance of tau in postsynaptic compartments attenuates tau pathology in mouse brain. Sci Transl Med 2021; 13:13/595/eaba7394. [PMID: 34039738 DOI: 10.1126/scitranslmed.aba7394] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 09/22/2020] [Accepted: 01/09/2021] [Indexed: 12/30/2022]
Abstract
Accumulation of pathological tau in synapses has been identified as an early event in Alzheimer's disease (AD) and correlates with cognitive decline in patients with AD. Tau is a cytosolic axonal protein, but under disease conditions, tau accumulates in postsynaptic compartments and presynaptic terminals, due to missorting within neurons, transsynaptic transfer between neurons, or a failure of clearance pathways. Using subcellular fractionation of brain tissue from rTg4510 tau transgenic mice with tauopathy and human postmortem brain tissue from patients with AD, we found accumulation of seed-competent tau predominantly in postsynaptic compartments. Tau-mediated toxicity in postsynaptic compartments was exacerbated by impaired proteasome activity detected by measuring lysine-48 polyubiquitination of proteins targeted for proteasomal degradation. To combat the accumulation of tau and proteasome impairment in the postsynaptic compartments of rTg4510 mouse brain, we stimulated the pituitary adenylate cyclase-activating polypeptide (PACAP) type 1 receptor (PAC1R) with its ligand PACAP administered intracerebroventricularly to rTg4510 mice. We observed enhanced synaptic proteasome activity and reduced total tau in postsynaptic compartments in mouse brain after PACAP treatment. The clearance of tau from postsynaptic compartments correlated with attenuated tauopathy and improved cognitive performance of rTg4510 transgenic mice on two behavioral tests. These results suggest that activating PAC1R could prevent accumulation of aggregate-prone tau and indicate a potential therapeutic approach for AD and other tauopathies.
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Affiliation(s)
- Ari W Schaler
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Avery M Runyan
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Catherine L Clelland
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Eric J Sydney
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Stephanie L Fowler
- U.K. Dementia Research Institute, University College London, London WC1E 6BT, UK
| | - Helen Y Figueroa
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Seiji Shioda
- Innovative Drug Discovery, Global Research Center for Innovative Life Science, Hoshi University, Tokyo 142-8501, Japan
| | - Ismael Santa-Maria
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
| | - Karen E Duff
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA.,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA.,U.K. Dementia Research Institute, University College London, London WC1E 6BT, UK
| | - Natura Myeku
- Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Irving Medical Center, New York, NY 10032, USA. .,Department of Pathology and Cell Biology, Columbia University Irving Medical Center, New York, NY 10032, USA
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12
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Mechanisms That Activate 26S Proteasomes and Enhance Protein Degradation. Biomolecules 2021; 11:biom11060779. [PMID: 34067263 PMCID: PMC8224753 DOI: 10.3390/biom11060779] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 05/11/2021] [Accepted: 05/12/2021] [Indexed: 02/07/2023] Open
Abstract
Although ubiquitination is widely assumed to be the only regulated step in the ubiquitin–proteasome pathway, recent studies have demonstrated several important mechanisms that regulate the activities of the 26S proteasome. Most proteasomes in cells are inactive but, upon binding a ubiquitinated substrate, become activated by a two-step mechanism requiring an association of the ubiquitin chain with Usp14 and then a loosely folded protein domain with the ATPases. The initial activation step is signaled by Usp14’s UBL domain, and many UBL-domain-containing proteins (e.g., Rad23, Parkin) also activate the proteasome. ZFAND5 is a distinct type of activator that binds ubiquitin conjugates and the proteasome and stimulates proteolysis during muscle atrophy. The proteasome’s activities are also regulated through subunit phosphorylation. Agents that raise cAMP and activate PKA stimulate within minutes Rpn6 phosphorylation and enhance the selective degradation of short-lived proteins. Likewise, hormones, fasting, and exercise, which raise cAMP, activate proteasomes and proteolysis in target tissues. Agents that raise cGMP and activate PKG also stimulate 26S activities but modify different subunit(s) and stimulate also the degradation of long-lived cell proteins. Both kinases enhance the selective degradation of aggregation-prone proteins that cause neurodegenerative diseases. These new mechanisms regulating proteolysis thus have clear physiological importance and therapeutic potential.
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13
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Abstract
The 26S proteasome is the most complex ATP-dependent protease machinery, of ~2.5 MDa mass, ubiquitously found in all eukaryotes. It selectively degrades ubiquitin-conjugated proteins and plays fundamentally indispensable roles in regulating almost all major aspects of cellular activities. To serve as the sole terminal "processor" for myriad ubiquitylation pathways, the proteasome evolved exceptional adaptability in dynamically organizing a large network of proteins, including ubiquitin receptors, shuttle factors, deubiquitinases, AAA-ATPase unfoldases, and ubiquitin ligases, to enable substrate selectivity and processing efficiency and to achieve regulation precision of a vast diversity of substrates. The inner working of the 26S proteasome is among the most sophisticated, enigmatic mechanisms of enzyme machinery in eukaryotic cells. Recent breakthroughs in three-dimensional atomic-level visualization of the 26S proteasome dynamics during polyubiquitylated substrate degradation elucidated an extensively detailed picture of its functional mechanisms, owing to progressive methodological advances associated with cryogenic electron microscopy (cryo-EM). Multiple sites of ubiquitin binding in the proteasome revealed a canonical mode of ubiquitin-dependent substrate engagement. The proteasome conformation in the act of substrate deubiquitylation provided insights into how the deubiquitylating activity of RPN11 is enhanced in the holoenzyme and is coupled to substrate translocation. Intriguingly, three principal modes of coordinated ATP hydrolysis in the heterohexameric AAA-ATPase motor were discovered to regulate intermediate functional steps of the proteasome, including ubiquitin-substrate engagement, deubiquitylation, initiation of substrate translocation and processive substrate degradation. The atomic dissection of the innermost working of the 26S proteasome opens up a new era in our understanding of the ubiquitin-proteasome system and has far-reaching implications in health and disease.
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Affiliation(s)
- Youdong Mao
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute, Harvard Medical School, Boston, 02215, Massachusetts, USA. .,School of Physics, Center for Quantitative Biology, Peking University, Beijing, 100871, China.
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14
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Račková L, Csekes E. Proteasome Biology: Chemistry and Bioengineering Insights. Polymers (Basel) 2020; 12:E2909. [PMID: 33291646 PMCID: PMC7761984 DOI: 10.3390/polym12122909] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 11/22/2020] [Accepted: 11/23/2020] [Indexed: 12/12/2022] Open
Abstract
Proteasomal degradation provides the crucial machinery for maintaining cellular proteostasis. The biological origins of modulation or impairment of the function of proteasomal complexes may include changes in gene expression of their subunits, ubiquitin mutation, or indirect mechanisms arising from the overall impairment of proteostasis. However, changes in the physico-chemical characteristics of the cellular environment might also meaningfully contribute to altered performance. This review summarizes the effects of physicochemical factors in the cell, such as pH, temperature fluctuations, and reactions with the products of oxidative metabolism, on the function of the proteasome. Furthermore, evidence of the direct interaction of proteasomal complexes with protein aggregates is compared against the knowledge obtained from immobilization biotechnologies. In this regard, factors such as the structures of the natural polymeric scaffolds in the cells, their content of reactive groups or the sequestration of metal ions, and processes at the interface, are discussed here with regard to their influences on proteasomal function.
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Affiliation(s)
- Lucia Račková
- Centre of Experimental Medicine, Institute of Experimental Pharmacology and Toxicology, Slovak Academy of Sciences, Dúbravská cesta 9, 841 04 Bratislava, Slovakia;
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15
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Mishra S, Dunkerly-Eyring BL, Keceli G, Ranek MJ. Phosphorylation Modifications Regulating Cardiac Protein Quality Control Mechanisms. Front Physiol 2020; 11:593585. [PMID: 33281625 PMCID: PMC7689282 DOI: 10.3389/fphys.2020.593585] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Accepted: 09/28/2020] [Indexed: 12/12/2022] Open
Abstract
Many forms of cardiac disease, including heart failure, present with inadequate protein quality control (PQC). Pathological conditions often involve impaired removal of terminally misfolded proteins. This results in the formation of large protein aggregates, which further reduce cellular viability and cardiac function. Cardiomyocytes have an intricately collaborative PQC system to minimize cellular proteotoxicity. Increased expression of chaperones or enhanced clearance of misfolded proteins either by the proteasome or lysosome has been demonstrated to attenuate disease pathogenesis, whereas reduced PQC exacerbates pathogenesis. Recent studies have revealed that phosphorylation of key proteins has a potent regulatory role, both promoting and hindering the PQC machinery. This review highlights the recent advances in phosphorylations regulating PQC, the impact in cardiac pathology, and the therapeutic opportunities presented by harnessing these modifications.
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Affiliation(s)
- Sumita Mishra
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Brittany L Dunkerly-Eyring
- Department of Pharmacology and Molecular Sciences, Johns Hopkins University, Baltimore, MD, United States
| | - Gizem Keceli
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
| | - Mark J Ranek
- Division of Cardiology, Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, United States
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16
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Rallabandi HR, Ganesan P, Kim YJ. Targeting the C-Terminal Domain Small Phosphatase 1. Life (Basel) 2020; 10:life10050057. [PMID: 32397221 PMCID: PMC7281111 DOI: 10.3390/life10050057] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Revised: 05/05/2020] [Accepted: 05/07/2020] [Indexed: 12/15/2022] Open
Abstract
The human C-terminal domain small phosphatase 1 (CTDSP1/SCP1) is a protein phosphatase with a conserved catalytic site of DXDXT/V. CTDSP1’s major activity has been identified as dephosphorylation of the 5th Ser residue of the tandem heptad repeat of the RNA polymerase II C-terminal domain (RNAP II CTD). It is also implicated in various pivotal biological activities, such as acting as a driving factor in repressor element 1 (RE-1)-silencing transcription factor (REST) complex, which silences the neuronal genes in non-neuronal cells, G1/S phase transition, and osteoblast differentiation. Recent findings have denoted that negative regulation of CTDSP1 results in suppression of cancer invasion in neuroglioma cells. Several researchers have focused on the development of regulating materials of CTDSP1, due to the significant roles it has in various biological activities. In this review, we focused on this emerging target and explored the biological significance, challenges, and opportunities in targeting CTDSP1 from a drug designing perspective.
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Yan F, Huang C, Wang X, Tan J, Cheng S, Wan M, Wang Z, Wang S, Luo S, Li A, Guo X, Feng M, Liu X, Zhu Y, Zhou Y. Threonine ADP-Ribosylation of Ubiquitin by a Bacterial Effector Family Blocks Host Ubiquitination. Mol Cell 2020; 78:641-652.e9. [PMID: 32330457 DOI: 10.1016/j.molcel.2020.03.016] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 01/10/2020] [Accepted: 03/10/2020] [Indexed: 12/16/2022]
Abstract
Ubiquitination is essential for numerous eukaryotic cellular processes. Here, we show that the type III effector CteC from Chromobacterium violaceum functions as an adenosine diphosphate (ADP)-ribosyltransferase that specifically modifies ubiquitin via threonine ADP-ribosylation on residue T66. The covalent modification prevents the transfer of ubiquitin from ubiquitin-activating enzyme E1 to ubiquitin-conjugating enzyme E2, which inhibits subsequent ubiquitin activation by E2 and E3 enzymes in the ubiquitination cascade and leads to the shutdown of polyubiquitin synthesis in host cells. This unique modification also causes dysfunction of polyubiquitin chains in cells, thereby blocking host ubiquitin signaling. The disruption of host ubiquitination by CteC plays a crucial role in C. violaceum colonization in mice during infection. CteC represents a family of effector proteins in pathogens of hosts from different kingdoms. All the members of this family specifically ADP-ribosylate ubiquitin. The action of CteC reveals a new mechanism for interfering with host ubiquitination by pathogens.
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Affiliation(s)
- Fujie Yan
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Chunfeng Huang
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaofei Wang
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Jiaxing Tan
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Sen Cheng
- Institute of Analytical Chemistry, College of Chemistry and Molecular Engineering, Peking University, Beijing, 100871, China
| | - Muyang Wan
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Zhao Wang
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Shuangyu Wang
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Shuhui Luo
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Arong Li
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xing Guo
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Mingguang Feng
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China
| | - Xiaoyun Liu
- Department of Microbiology, School of Basic Medical Sciences, Peking University Health Science Center, Beijing 100191, China
| | - Yongqun Zhu
- MOE Key Laboratory for Biosystems Homeostasis & Protection and Innovation Center for Cell Signaling Network, Life Sciences Institute, Zhejiang University, Hangzhou, Zhejiang 310058, China; Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang 310009, China.
| | - Yan Zhou
- Institute of Microbiology, College of Life Sciences, Zhejiang University, Hangzhou, Zhejiang 310058, China.
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18
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Okeke E, Chen L, Madura K. The Cellular Location of Rad23, a Polyubiquitin Chain-Binding Protein, Plays a Key Role in Its Interaction with Substrates of the Proteasome. J Mol Biol 2020; 432:2388-2404. [PMID: 32147457 DOI: 10.1016/j.jmb.2020.03.001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 02/28/2020] [Accepted: 03/02/2020] [Indexed: 11/30/2022]
Abstract
Well-studied structural motifs in Rad23 have been shown to bind polyubiquitin chains and the proteasome. These domains are predicted to enable Rad23 to transport polyubiquitylated (polyUb) substrates to the proteasome (Chen and Madura, 2002 [1]). The validation of this model, however, has been hindered by the lack of specific physiological substrates of Rad23. We report here that Rad23 can bind Ho-endonuclease (Ho-endo), a nuclear protein that initiates mating-type switching in Saccharomyces cerevisiae. We observed that the degradation of Ho-endo required export from the nucleus, in agreement with a previous report (Kaplun et al., 2003 [2]), and suggests that Rad23 can traffic proteins out of the nucleus. In agreement, the subcellular distribution of Rad23 is noticeably altered in genetic mutants that disrupt nucleocytoplasmic trafficking. Significantly, the location of Rad23 affected its binding to polyUb substrates. Mutations in nuclear export stabilized substrates, and caused accumulation in the nucleus. Importantly, Rad23 also accumulated in the nucleus in an export mutant, and bound to higher levels of polyUb proteins. In contrast, Rad23 is localized in the cytosol in rna1-1, a nucleocytoplasmic transport mutant, and it forms reduced binding to polyUb substrates. These and other studies indicate that substrates that are conjugated to polyubiquitin chains in the nucleus may rely on an export-dependent mechanism to be degraded by the proteasome. The evolutionary conservation of Rad23 and similar substrate-trafficking proteins predicts an important role for export in the turnover of nuclear proteins.
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Affiliation(s)
- Evelyn Okeke
- Department of Pharmacology - SPH 383, Robert Wood Johnson Medical School, Rutgers University, 683 Hoes Lane, Piscataway, NJ 08854, USA
| | - Li Chen
- Department of Pharmacology - SPH 383, Robert Wood Johnson Medical School, Rutgers University, 683 Hoes Lane, Piscataway, NJ 08854, USA
| | - Kiran Madura
- Department of Pharmacology - SPH 383, Robert Wood Johnson Medical School, Rutgers University, 683 Hoes Lane, Piscataway, NJ 08854, USA.
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Proteins containing ubiquitin-like (Ubl) domains not only bind to 26S proteasomes but also induce their activation. Proc Natl Acad Sci U S A 2020; 117:4664-4674. [PMID: 32071216 DOI: 10.1073/pnas.1915534117] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
During protein degradation by the ubiquitin-proteasome pathway, latent 26S proteasomes in the cytosol must assume an active form. Proteasomes are activated when ubiquitylated substrates bind to them and interact with the proteasome-bound deubiquitylase Usp14/Ubp6. The resulting increase in the proteasome's degradative activity was recently shown to be mediated by Usp14's ubiquitin-like (Ubl) domain, which, by itself, can trigger proteasome activation. Many other proteins with diverse cellular functions also contain Ubl domains and can associate with 26S proteasomes. We therefore tested if various Ubl-containing proteins that have important roles in protein homeostasis or disease also activate 26S proteasomes. All seven Ubl-containing proteins tested-the shuttling factors Rad23A, Rad23B, and Ddi2; the deubiquitylase Usp7, the ubiquitin ligase Parkin, the cochaperone Bag6, and the protein phosphatase UBLCP1-stimulated peptide hydrolysis two- to fivefold. Rather than enhancing already active proteasomes, Rad23B and its Ubl domain activated previously latent 26S particles. Also, Ubl-containing proteins (if present with an unfolded protein) increased proteasomal adenosine 5'-triphosphate (ATP) hydrolysis, the step which commits substrates to degradation. Surprisingly, some of these proteins also could stimulate peptide hydrolysis even when their Ubl domains were deleted. However, their Ubl domains were required for the increased ATPase activity. Thus, upon binding to proteasomes, Ubl-containing proteins not only deliver substrates (e.g., the shuttling factors) or provide additional enzymatic activities (e.g., Parkin) to proteasomes, but also increase their capacity for proteolysis.
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20
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Reversible phosphorylation of Rpn1 regulates 26S proteasome assembly and function. Proc Natl Acad Sci U S A 2019; 117:328-336. [PMID: 31843888 DOI: 10.1073/pnas.1912531117] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The fundamental importance of the 26S proteasome in health and disease suggests that its function must be finely controlled, and yet our knowledge about proteasome regulation remains limited. Posttranslational modifications, especially phosphorylation, of proteasome subunits have been shown to impact proteasome function through different mechanisms, although the vast majority of proteasome phosphorylation events have not been studied. Here, we have characterized 1 of the most frequently detected proteasome phosphosites, namely Ser361 of Rpn1, a base subunit of the 19S regulatory particle. Using a variety of approaches including CRISPR/Cas9-mediated gene editing and quantitative mass spectrometry, we found that loss of Rpn1-S361 phosphorylation reduces proteasome activity, impairs cell proliferation, and causes oxidative stress as well as mitochondrial dysfunction. A screen of the human kinome identified several kinases including PIM1/2/3 that catalyze S361 phosphorylation, while its level is reversibly controlled by the proteasome-resident phosphatase, UBLCP1. Mechanistically, Rpn1-S361 phosphorylation is required for proper assembly of the 26S proteasome, and we have utilized a genetic code expansion system to directly demonstrate that S361-phosphorylated Rpn1 more readily forms a precursor complex with Rpt2, 1 of the first steps of 19S base assembly. These findings have revealed a prevalent and biologically important mechanism governing proteasome formation and function.
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21
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Banerjee S, Wei T, Wang J, Lee JJ, Gutierrez HL, Chapman O, Wiley SE, Mayfield JE, Tandon V, Juarez EF, Chavez L, Liang R, Sah RL, Costello C, Mesirov JP, de la Vega L, Cooper KL, Dixon JE, Xiao J, Lei X. Inhibition of dual-specificity tyrosine phosphorylation-regulated kinase 2 perturbs 26S proteasome-addicted neoplastic progression. Proc Natl Acad Sci U S A 2019; 116:24881-24891. [PMID: 31754034 PMCID: PMC6900511 DOI: 10.1073/pnas.1912033116] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dependence on the 26S proteasome is an Achilles' heel for triple-negative breast cancer (TNBC) and multiple myeloma (MM). The therapeutic proteasome inhibitor, bortezomib, successfully targets MM but often leads to drug-resistant disease relapse and fails in breast cancer. Here we show that a 26S proteasome-regulating kinase, DYRK2, is a therapeutic target for both MM and TNBC. Genome editing or small-molecule mediated inhibition of DYRK2 significantly reduces 26S proteasome activity, bypasses bortezomib resistance, and dramatically delays in vivo tumor growth in MM and TNBC thereby promoting survival. We further characterized the ability of LDN192960, a potent and selective DYRK2-inhibitor, to alleviate tumor burden in vivo. The drug docks into the active site of DYRK2 and partially inhibits all 3 core peptidase activities of the proteasome. Our results suggest that targeting 26S proteasome regulators will pave the way for therapeutic strategies in MM and TNBC.
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Affiliation(s)
- Sourav Banerjee
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Tiantian Wei
- The State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871 Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, 100871 Beijing, China
| | - Jue Wang
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, 100871 Beijing, China
| | - Jenna J Lee
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093
| | - Haydee L Gutierrez
- Division of Biological Sciences, Section of Cellular and Developmental Biology, University of California San Diego, La Jolla, CA 92093
| | - Owen Chapman
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Sandra E Wiley
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Joshua E Mayfield
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Vasudha Tandon
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093
| | - Edwin F Juarez
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
| | - Lukas Chavez
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Ruqi Liang
- The State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871 Beijing, China
- Peking-Tsinghua Center for Life Sciences, Peking University, 100871 Beijing, China
| | - Robert L Sah
- Department of Bioengineering, University of California San Diego, La Jolla, CA 92093
| | - Caitlin Costello
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
- Division of Blood and Marrow Transplant, University of California San Diego, La Jolla, CA 92093
| | - Jill P Mesirov
- Department of Medicine, University of California San Diego, La Jolla, CA 92093
- Moores Cancer Center, University of California San Diego, La Jolla, CA 92093
| | - Laureano de la Vega
- Division of Cellular Medicine, School of Medicine, University of Dundee, Dundee, DD1 9SY, United Kingdom
| | - Kimberly L Cooper
- Division of Biological Sciences, Section of Cellular and Developmental Biology, University of California San Diego, La Jolla, CA 92093
| | - Jack E Dixon
- Department of Pharmacology, University of California San Diego, La Jolla, CA 92093;
- Department of Cellular and Molecular Medicine, University of California San Diego, La Jolla, CA 92093
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093
| | - Junyu Xiao
- The State Key Laboratory of Protein and Plant Gene Research, School of Life Sciences, Peking University, 100871 Beijing, China;
- Peking-Tsinghua Center for Life Sciences, Peking University, 100871 Beijing, China
| | - Xiaoguang Lei
- Peking-Tsinghua Center for Life Sciences, Peking University, 100871 Beijing, China;
- Beijing National Laboratory for Molecular Sciences, Key Laboratory of Bioorganic Chemistry and Molecular Engineering of Ministry of Education, College of Chemistry and Molecular Engineering, Peking University, 100871 Beijing, China
- Department of Chemical Biology, Synthetic and Functional Biomolecules Center, Peking University, 100871 Beijing, China
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22
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Abstract
The proteasome degrades most cellular proteins in a controlled and tightly regulated manner and thereby controls many processes, including cell cycle, transcription, signalling, trafficking and protein quality control. Proteasomal degradation is vital in all cells and organisms, and dysfunction or failure of proteasomal degradation is associated with diverse human diseases, including cancer and neurodegeneration. Target selection is an important and well-established way to control protein degradation. In addition, mounting evidence indicates that cells adjust proteasome-mediated degradation to their needs by regulating proteasome abundance through the coordinated expression of proteasome subunits and assembly chaperones. Central to the regulation of proteasome assembly is TOR complex 1 (TORC1), which is the master regulator of cell growth and stress. This Review discusses how proteasome assembly and the regulation of proteasomal degradation are integrated with cellular physiology, including the interplay between the proteasome and autophagy pathways. Understanding these mechanisms has potential implications for disease therapy, as the misregulation of proteasome function contributes to human diseases such as cancer and neurodegeneration.
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23
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Kors S, Geijtenbeek K, Reits E, Schipper-Krom S. Regulation of Proteasome Activity by (Post-)transcriptional Mechanisms. Front Mol Biosci 2019; 6:48. [PMID: 31380390 PMCID: PMC6646590 DOI: 10.3389/fmolb.2019.00048] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Accepted: 06/11/2019] [Indexed: 12/23/2022] Open
Abstract
Intracellular protein synthesis, folding, and degradation are tightly controlled processes to ensure proper protein homeostasis. The proteasome is responsible for the degradation of the majority of intracellular proteins, which are often targeted for degradation via polyubiquitination. However, the degradation rate of proteins is also affected by the capacity of proteasomes to recognize and degrade these substrate proteins. This capacity is regulated by a variety of proteasome modulations including (1) changes in complex composition, (2) post-translational modifications, and (3) altered transcription of proteasomal subunits and activators. Various diseases are linked to proteasome modulation and altered proteasome function. A better understanding of these modulations may offer new perspectives for therapeutic intervention. Here we present an overview of these three proteasome modulating mechanisms to give better insight into the diversity of proteasomes.
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Affiliation(s)
- Suzan Kors
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Karlijne Geijtenbeek
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Eric Reits
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Sabine Schipper-Krom
- Department of Medical Biology, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
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24
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Marshall RS, Vierstra RD. Dynamic Regulation of the 26S Proteasome: From Synthesis to Degradation. Front Mol Biosci 2019; 6:40. [PMID: 31231659 PMCID: PMC6568242 DOI: 10.3389/fmolb.2019.00040] [Citation(s) in RCA: 143] [Impact Index Per Article: 28.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2019] [Accepted: 05/09/2019] [Indexed: 01/12/2023] Open
Abstract
All eukaryotes rely on selective proteolysis to control the abundance of key regulatory proteins and maintain a healthy and properly functioning proteome. Most of this turnover is catalyzed by the 26S proteasome, an intricate, multi-subunit proteolytic machine. Proteasomes recognize and degrade proteins first marked with one or more chains of poly-ubiquitin, the addition of which is actuated by hundreds of ligases that individually identify appropriate substrates for ubiquitylation. Subsequent proteasomal digestion is essential and influences a myriad of cellular processes in species as diverse as plants, fungi and humans. Importantly, dysfunction of 26S proteasomes is associated with numerous human pathologies and profoundly impacts crop performance, thus making an understanding of proteasome dynamics critically relevant to almost all facets of human health and nutrition. Given this widespread significance, it is not surprising that sophisticated mechanisms have evolved to tightly regulate 26S proteasome assembly, abundance and activity in response to demand, organismal development and stress. These include controls on transcription and chaperone-mediated assembly, influences on proteasome localization and activity by an assortment of binding proteins and post-translational modifications, and ultimately the removal of excess or damaged particles via autophagy. Intriguingly, the autophagic clearance of damaged 26S proteasomes first involves their modification with ubiquitin, thus connecting ubiquitylation and autophagy as key regulatory events in proteasome quality control. This turnover is also influenced by two distinct biomolecular condensates that coalesce in the cytoplasm, one attracting damaged proteasomes for autophagy, and the other reversibly storing proteasomes during carbon starvation to protect them from autophagic clearance. In this review, we describe the current state of knowledge regarding the dynamic regulation of 26S proteasomes at all stages of their life cycle, illustrating how protein degradation through this proteolytic machine is tightly controlled to ensure optimal growth, development and longevity.
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Affiliation(s)
- Richard S Marshall
- Department of Biology, Washington University in St. Louis, St. Louis, MO, United States
| | - Richard D Vierstra
- Department of Biology, Washington University in St. Louis, St. Louis, MO, United States
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25
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UBL domain of Usp14 and other proteins stimulates proteasome activities and protein degradation in cells. Proc Natl Acad Sci U S A 2018; 115:E11642-E11650. [PMID: 30487212 DOI: 10.1073/pnas.1808731115] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The best-known function of ubiquitin-like (UBL) domains in proteins is to enable their binding to 26S proteasomes. The proteasome-associated deubiquitinating enzyme Usp14/UBP6 contains an N-terminal UBL domain and is an important regulator of proteasomal activity. Usp14 by itself represses multiple proteasomal activities but, upon binding a ubiquitin chain, Usp14 stimulates these activities and promotes ubiquitin-conjugate degradation. Here, we demonstrate that Usp14's UBL domain alone mimics this activation of proteasomes by ubiquitin chains. Addition of this UBL domain to purified 26S proteasomes stimulated the same activities inhibited by Usp14: peptide entry and hydrolysis, protein-dependent ATP hydrolysis, deubiquitination by Rpn11, and the degradation of ubiquitinated and nonubiquitinated proteins. Thus, the binding of Usp14's UBL (apparently to Rpn1's T2 site) seems to mediate the activation of proteasomes by ubiquitinated substrates. However, the stimulation of these various activities was greater in proteasomes lacking Usp14 than in wild-type particles and thus is a general response that does not involve some displacement of Usp14. Furthermore, the UBL domains from hHR23 and hPLIC1/UBQLN1 also stimulated peptide hydrolysis, and the expression of hHR23A's UBL domain in HeLa cells stimulated overall protein degradation. Therefore, many UBL-containing proteins that bind to proteasomes may also enhance allosterically its proteolytic activity.
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26
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NEDDylation promotes nuclear protein aggregation and protects the Ubiquitin Proteasome System upon proteotoxic stress. Nat Commun 2018; 9:4376. [PMID: 30349034 PMCID: PMC6197266 DOI: 10.1038/s41467-018-06365-0] [Citation(s) in RCA: 67] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Accepted: 08/24/2018] [Indexed: 11/23/2022] Open
Abstract
Spatial management of stress-induced protein aggregation is an integral part of the proteostasis network. Protein modification by the ubiquitin-like molecule NEDD8 increases upon proteotoxic stress and it is characterised by the formation of hybrid NEDD8/ubiquitin conjugates. However, the biological significance of this response is unclear. Combination of quantitative proteomics with biological analysis shows that, during proteotoxic stress, NEDDylation promotes nuclear protein aggregation, including ribosomal proteins as a major group. This correlates with protection of the nuclear Ubiquitin Proteasome System from stress-induced dysfunction. Correspondingly, we show that NEDD8 compromises ubiquitination and prevents targeting and processing of substrates by the proteasome. Moreover, we identify HUWE1 as a key E3-ligase that is specifically required for NEDDylation during proteotoxic stress. The study reveals a specific role for NEDD8 in nuclear protein aggregation upon stress and is consistent with the concept that transient aggregate formation is part of a defence mechanism against proteotoxicity. Protein NEDDylation increases upon proteotoxic stress but the function of this response remains to be elucidated. Here, the authors show that NEDDylation contributes to the cellular defence against proteotoxicity by promoting nuclear protein aggregation and protecting the ubiquitin proteasome system.
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27
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Protein Degradation and the Pathologic Basis of Disease. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 189:94-103. [PMID: 30312581 DOI: 10.1016/j.ajpath.2018.09.004] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/13/2018] [Revised: 09/05/2018] [Accepted: 09/17/2018] [Indexed: 12/27/2022]
Abstract
The abundance of any protein is determined by the balance of protein synthesis and protein degradation. Regulated protein degradation has emerged as a powerful means of precisely controlling individual protein abundance within cells and is largely mediated by the ubiquitin-proteasome system (UPS). By controlling the levels of key regulatory proteins, the UPS contributes to nearly every aspect of cellular function. The UPS also functions in protein quality control, rapidly identifying and destroying misfolded or otherwise aberrant proteins that may be toxic to cells. Increasingly, we understand that dysregulation of protein degradation pathways is critical for many human diseases. Conversely, the versatility and scope of the UPS provides opportunities for therapeutic intervention. In this review, we will discuss the basic mechanisms of protein degradation by the UPS. We will then consider some paradigms of human disease related to protein degradation using selected examples. Finally, we will highlight several established and emerging therapeutic strategies based on altering pathways of protein degradation.
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28
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Sun S, Liu S, Zhang Z, Zeng W, Sun C, Tao T, Lin X, Feng XH. Phosphatase UBLCP1 controls proteasome assembly. Open Biol 2018; 7:rsob.170042. [PMID: 28539385 PMCID: PMC5451543 DOI: 10.1098/rsob.170042] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Accepted: 04/20/2017] [Indexed: 12/26/2022] Open
Abstract
Ubiquitin-like domain-containing C-terminal domain phosphatase 1 (UBLCP1), an FCP/SCP phosphatase family member, was identified as the first proteasome phosphatase. UBLCP1 binds to proteasome subunit Rpn1 and dephosphorylates the proteasome in vitro. However, it is still unclear which proteasome subunit(s) are the bona fide substrate(s) of UBLCP1 and the precise mechanism for proteasome regulation remains elusive. Here, we show that UBLCP1 selectively binds to the 19S regulatory particle (RP) through its interaction with Rpn1, but not the 20S core particle (CP) or the 26S proteasome holoenzyme. In the RP, UBLCP1 dephosphorylates the subunit Rpt1, impairs its ATPase activity, and consequently disrupts the 26S proteasome assembly, yet it has no effects on the RP assembly from precursor complexes. The Rpn1-binding and phosphatase activities of UBLCP1 are essential for its function on Rpt1 dephosphorylation and proteasome activity both in vivo and in vitro. Our study establishes the essential role of the UBLCP1/Rpn1/Rpt1 complex in regulating proteasome assembly.
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Affiliation(s)
- Shuangwu Sun
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Sisi Liu
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Zhengmao Zhang
- Michael E. DeBakey, Department of Surgery, Houston, TX, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Wang Zeng
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China
| | - Chuang Sun
- Michael E. DeBakey, Department of Surgery, Houston, TX, USA
| | - Tao Tao
- State Key Laboratory of Stress Cell Biology, School of Life Sciences, Xiamen University, Xiamen, Fujian, People's Republic of China
| | - Xia Lin
- Michael E. DeBakey, Department of Surgery, Houston, TX, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
| | - Xin-Hua Feng
- Life Sciences Institute and Innovation Center for Cell Signaling Network, Zhejiang University, Hangzhou, Zhejiang, People's Republic of China .,Michael E. DeBakey, Department of Surgery, Houston, TX, USA.,Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX, USA
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29
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Yu C, Huang L. Cross-Linking Mass Spectrometry: An Emerging Technology for Interactomics and Structural Biology. Anal Chem 2018; 90:144-165. [PMID: 29160693 PMCID: PMC6022837 DOI: 10.1021/acs.analchem.7b04431] [Citation(s) in RCA: 222] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Clinton Yu
- Department of Physiology & Biophysics, University of California, Irvine, Irvine, CA 92697
| | - Lan Huang
- Department of Physiology & Biophysics, University of California, Irvine, Irvine, CA 92697
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30
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Myeku N, Duff KE. Targeting the 26S Proteasome To Protect Against Proteotoxic Diseases. Trends Mol Med 2017; 24:18-29. [PMID: 29233753 DOI: 10.1016/j.molmed.2017.11.006] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 11/21/2017] [Accepted: 11/21/2017] [Indexed: 12/16/2022]
Abstract
Aggregates of misfolded proteins can compromise the function of the 26S proteasome complex, leaving neurons susceptible to accelerated and impaired protein homeostasis, thereby contributing to the pathogenesis of neurodegeneration. Strategies aimed at enhancing the function of the 26S proteasome via phosphorylation of key subunit epitopes have been effective in reducing protein aggregates in mouse models of disease. We discuss how phosphodiesterase (PDE) inhibitors and G protein-coupled receptor (GPCR)-targeted drugs might be considered as candidate therapeutics, acting on second messenger signal transduction. The range of candidates might address the need for region-, cell-, or even cellular compartment-specific modulation. Given the array of clinical and experimental drugs targeting cAMP/cGMP signaling, we propose that proteasome activators targeting secondary messengers might be exploited as novel agents for the treatment or prevention of some neurodegenerative diseases.
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Affiliation(s)
- Natura Myeku
- Department of Pathology and Cell Biology, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA.
| | - Karen E Duff
- Department of Pathology and Cell Biology, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA; Division of Integrative Neuroscience, New York State Psychiatric Institute, New York, NY, USA.
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31
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Regulating protein breakdown through proteasome phosphorylation. Biochem J 2017; 474:3355-3371. [PMID: 28947610 DOI: 10.1042/bcj20160809] [Citation(s) in RCA: 82] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 08/28/2017] [Accepted: 08/30/2017] [Indexed: 12/31/2022]
Abstract
The ubiquitin proteasome system degrades the great majority of proteins in mammalian cells. Countless studies have described how ubiquitination promotes the selective degradation of different cell proteins. However, there is a small but the growing literature that protein half-lives can also be regulated by post-translational modifications of the 26S proteasome. The present study reviews the ability of several kinases to alter proteasome function through subunit phosphorylation. For example, PKA (protein kinase A) and DYRK2 (dual-specificity tyrosine-regulated kinase 2) stimulate the proteasome's ability to degrade ubiquitinated proteins, peptides, and adenosine triphosphate, while one kinase, ASK1 (apoptosis signal-regulating kinase 1), inhibits proteasome function during apoptosis. Proteasome phosphorylation is likely to be important in regulating protein degradation because it occurs downstream from many hormones and neurotransmitters, in conditions that raise cyclic adenosine monophosphate or cyclic guanosine monophosphate levels, after calcium influx following synaptic depolarization, and during phases of the cell cycle. Beyond its physiological importance, pharmacological manipulation of proteasome phosphorylation has the potential to combat various diseases. Inhibitors of phosphodiesterases by activating PKA or PKG (protein kinase G) can stimulate proteasomal degradation of misfolded proteins that cause neurodegenerative or myocardial diseases and even reduce the associated pathology in mouse models. These observations are promising since in many proteotoxic diseases, aggregation-prone proteins impair proteasome function, and disrupt protein homeostasis. Conversely, preventing subunit phosphorylation by DYRK2 slows cell cycle progression and tumor growth. However, further research is essential to determine how phosphorylation of different subunits by these (or other) kinases alters the properties of this complex molecular machine and thus influence protein degradation rates.
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32
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Wang X, Cimermancic P, Yu C, Schweitzer A, Chopra N, Engel JL, Greenberg C, Huszagh AS, Beck F, Sakata E, Yang Y, Novitsky EJ, Leitner A, Nanni P, Kahraman A, Guo X, Dixon JE, Rychnovsky SD, Aebersold R, Baumeister W, Sali A, Huang L. Molecular Details Underlying Dynamic Structures and Regulation of the Human 26S Proteasome. Mol Cell Proteomics 2017; 16:840-854. [PMID: 28292943 DOI: 10.1074/mcp.m116.065326] [Citation(s) in RCA: 74] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2016] [Revised: 02/13/2017] [Indexed: 12/28/2022] Open
Abstract
The 26S proteasome is the macromolecular machine responsible for ATP/ubiquitin dependent degradation. As aberration in proteasomal degradation has been implicated in many human diseases, structural analysis of the human 26S proteasome complex is essential to advance our understanding of its action and regulation mechanisms. In recent years, cross-linking mass spectrometry (XL-MS) has emerged as a powerful tool for elucidating structural topologies of large protein assemblies, with its unique capability of studying protein complexes in cells. To facilitate the identification of cross-linked peptides, we have previously developed a robust amine reactive sulfoxide-containing MS-cleavable cross-linker, disuccinimidyl sulfoxide (DSSO). To better understand the structure and regulation of the human 26S proteasome, we have established new DSSO-based in vivo and in vitro XL-MS workflows by coupling with HB-tag based affinity purification to comprehensively examine protein-protein interactions within the 26S proteasome. In total, we have identified 447 unique lysine-to-lysine linkages delineating 67 interprotein and 26 intraprotein interactions, representing the largest cross-link dataset for proteasome complexes. In combination with EM maps and computational modeling, the architecture of the 26S proteasome was determined to infer its structural dynamics. In particular, three proteasome subunits Rpn1, Rpn6, and Rpt6 displayed multiple conformations that have not been previously reported. Additionally, cross-links between proteasome subunits and 15 proteasome interacting proteins including 9 known and 6 novel ones have been determined to demonstrate their physical interactions at the amino acid level. Our results have provided new insights on the dynamics of the 26S human proteasome and the methodologies presented here can be applied to study other protein complexes.
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Affiliation(s)
- Xiaorong Wang
- From the ‡Department of Physiology & Biophysics, University of California, Irvine, Irvine, California 92697
| | - Peter Cimermancic
- §Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California 94143
| | - Clinton Yu
- From the ‡Department of Physiology & Biophysics, University of California, Irvine, Irvine, California 92697
| | - Andreas Schweitzer
- ¶Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Nikita Chopra
- §Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California 94143
| | - James L Engel
- ‖Department of Pharmacology, University of California, San Diego, La Jolla, California, 92093
| | - Charles Greenberg
- §Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California 94143
| | - Alexander S Huszagh
- From the ‡Department of Physiology & Biophysics, University of California, Irvine, Irvine, California 92697
| | - Florian Beck
- ¶Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Eri Sakata
- ¶Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Yingying Yang
- From the ‡Department of Physiology & Biophysics, University of California, Irvine, Irvine, California 92697
| | - Eric J Novitsky
- **Department of Chemistry, University of California, Irvine, Irvine, California 92697
| | - Alexander Leitner
- ‡‡Department of Biology, Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zurich, Switzerland
| | - Paolo Nanni
- §§Functional Genomics Center Zurich (FGCZ), University of Zurich, ETH Zurich, CH-8057 Zurich, Switzerland
| | - Abdullah Kahraman
- ¶¶Institute of Molecular Life Sciences, University of Zurich, CH-8057 Zurich, Switzerland
| | - Xing Guo
- ‖Department of Pharmacology, University of California, San Diego, La Jolla, California, 92093
| | - Jack E Dixon
- ‖Department of Pharmacology, University of California, San Diego, La Jolla, California, 92093
| | - Scott D Rychnovsky
- **Department of Chemistry, University of California, Irvine, Irvine, California 92697
| | - Ruedi Aebersold
- ‡‡Department of Biology, Institute of Molecular Systems Biology, Eidgenössische Technische Hochschule (ETH) Zürich, Zurich, Switzerland.,Faculty of Science, University of Zurich, Zurich, Switzerland
| | - Wolfgang Baumeister
- ¶Department of Molecular Structural Biology, Max Planck Institute of Biochemistry, Martinsried 82152, Germany
| | - Andrej Sali
- §Department of Bioengineering and Therapeutic Sciences, Department of Pharmaceutical Chemistry, California Institute for Quantitative Biosciences, University of California, San Francisco, San Francisco, California 94143
| | - Lan Huang
- From the ‡Department of Physiology & Biophysics, University of California, Irvine, Irvine, California 92697;
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33
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Guo X, Huang X, Chen MJ. Reversible phosphorylation of the 26S proteasome. Protein Cell 2017; 8:255-272. [PMID: 28258412 PMCID: PMC5359188 DOI: 10.1007/s13238-017-0382-x] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Accepted: 01/26/2017] [Indexed: 01/09/2023] Open
Abstract
The 26S proteasome at the center of the ubiquitin-proteasome system (UPS) is essential for virtually all cellular processes of eukaryotes. A common misconception about the proteasome is that, once made, it remains as a static and uniform complex with spontaneous and constitutive activity for protein degradation. Recent discoveries have provided compelling evidence to support the exact opposite insomuch as the 26S proteasome undergoes dynamic and reversible phosphorylation under a variety of physiopathological conditions. In this review, we summarize the history and current understanding of proteasome phosphorylation, and advocate the idea of targeting proteasome kinases/phosphatases as a new strategy for clinical interventions of several human diseases.
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Affiliation(s)
- Xing Guo
- The Life Sciences Institute of Zhejiang University, Hangzhou, 310058, China.
| | - Xiuliang Huang
- Ministry of Education Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Mark J Chen
- Department of Bioinformatics and Computational Biology, Genentech Inc., South San Francisco, CA, 94080, USA
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Jain N, Rai A, Mishra R, Ganesh S. Loss of malin, but not laforin, results in compromised autophagic flux and proteasomal dysfunction in cells exposed to heat shock. Cell Stress Chaperones 2017; 22:307-315. [PMID: 27975203 PMCID: PMC5352594 DOI: 10.1007/s12192-016-0754-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Revised: 12/04/2016] [Accepted: 12/05/2016] [Indexed: 11/29/2022] Open
Abstract
Heat stress to a cell leads to the activation of heat shock response, which is required for the management of misfolded and unfolded proteins. Macroautophagy and proteasome-mediated degradation are the two cellular processes that degrade polyubiquitinated, misfolded proteins. Contrasting pieces of evidence exist on the effect of heat stress on the activation of the above-mentioned degradative pathways. Laforin phosphatase and malin E3 ubiquitin ligase, the two proteins defective in Lafora neurodegenerative disorder, are involved in cellular stress response pathways and are required for the activation of heat shock transcription factor - the heat shock factor 1 (HSF1) - and, consequently, for cellular protection under heat shock. While the role of laforin and malin in the proteolytic pathways is well established, their role in cellular recovery from heat shock was not explored. To address this, we investigated autophagic flux, proteasomal activity, and the level of polyubiquitinated proteins in Neuro2a cells partially silenced for laforin or malin protein and exposed to heat shock. We found that heat shock was able to induce autophagic flux, proteasomal activity and reduce the polyubiquitinated proteins load in the laforin-silenced cells but not in the malin-deficient cells. Loss of malin leads to reduced proteasomal activity in the heat-shocked cells. Taken together, our results suggest a distinct mode of action for laforin and malin in the heat shock-induced proteolytic processes.
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Affiliation(s)
- Navodita Jain
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, 208016, India
| | - Anupama Rai
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, 208016, India
| | - Rohit Mishra
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, 208016, India
| | - Subramaniam Ganesh
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology, Kanpur, 208016, India.
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35
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Amin E, Jaiswal M, Derewenda U, Reis K, Nouri K, Koessmeier KT, Aspenström P, Somlyo AV, Dvorsky R, Ahmadian MR. Deciphering the Molecular and Functional Basis of RHOGAP Family Proteins: A SYSTEMATIC APPROACH TOWARD SELECTIVE INACTIVATION OF RHO FAMILY PROTEINS. J Biol Chem 2016; 291:20353-71. [PMID: 27481945 PMCID: PMC5034035 DOI: 10.1074/jbc.m116.736967] [Citation(s) in RCA: 77] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Revised: 07/15/2016] [Indexed: 12/30/2022] Open
Abstract
RHO GTPase-activating proteins (RHOGAPs) are one of the major classes of regulators of the RHO-related protein family that are crucial in many cellular processes, motility, contractility, growth, differentiation, and development. Using database searches, we extracted 66 distinct human RHOGAPs, from which 57 have a common catalytic domain capable of terminating RHO protein signaling by stimulating the slow intrinsic GTP hydrolysis (GTPase) reaction. The specificity of the majority of the members of RHOGAP family is largely uncharacterized. Here, we comprehensively investigated the sequence-structure-function relationship between RHOGAPs and RHO proteins by combining our in vitro data with in silico data. The activity of 14 representatives of the RHOGAP family toward 12 RHO family proteins was determined in real time. We identified and structurally verified hot spots in the interface between RHOGAPs and RHO proteins as critical determinants for binding and catalysis. We have found that the RHOGAP domain itself is nonselective and in some cases rather inefficient under cell-free conditions. Thus, we propose that other domains of RHOGAPs confer substrate specificity and fine-tune their catalytic efficiency in cells.
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Affiliation(s)
- Ehsan Amin
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Mamta Jaiswal
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Urszula Derewenda
- the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, and
| | - Katarina Reis
- the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Kazem Nouri
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Katja T Koessmeier
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany
| | - Pontus Aspenström
- the Department of Microbiology, Tumor and Cell Biology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Avril V Somlyo
- the Department of Molecular Physiology and Biological Physics, University of Virginia, Charlottesville, Virginia 22908, and
| | - Radovan Dvorsky
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany,
| | - Mohammad R Ahmadian
- From the Institute of Biochemistry and Molecular Biology II, Medical Faculty, Heinrich-Heine-University, 40225 Düsseldorf, Germany,
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Mayor T, Sharon M, Glickman MH. Tuning the proteasome to brighten the end of the journey. Am J Physiol Cell Physiol 2016; 311:C793-C804. [PMID: 27605452 DOI: 10.1152/ajpcell.00198.2016] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 09/04/2016] [Indexed: 02/07/2023]
Abstract
Degradation by the proteasome is the fate for a large portion of cellular proteins, and it plays a major role in maintaining protein homeostasis, as well as in regulating many cellular processes like cell cycle progression. A decrease in proteasome activity has been linked to aging and several age-related neurodegenerative pathologies and highlights the importance of the ubiquitin proteasome system regulation. While the proteasome has been traditionally viewed as a constitutive element of proteolysis, major studies have highlighted how different regulatory mechanisms can impact its activity. Importantly, alterations of proteasomal activity may have major impacts for its function and in therapeutics. On one hand, increasing proteasome activity could be beneficial to prevent the age-related downfall of protein homeostasis, whereas inhibiting or reducing its activity can prevent the proliferation of cancer cells.
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Affiliation(s)
- Thibault Mayor
- Department of Biochemistry and Molecular Biology, Michael Smith Laboratories, University of British Columbia, Vancouver, Canada;
| | - Michal Sharon
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot, Israel; and
| | - Michael H Glickman
- Department of Biology, Technion-Israel Institute of Technology, Haifa, Israel
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37
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The life cycle of the 26S proteasome: from birth, through regulation and function, and onto its death. Cell Res 2016; 26:869-85. [PMID: 27444871 PMCID: PMC4973335 DOI: 10.1038/cr.2016.86] [Citation(s) in RCA: 213] [Impact Index Per Article: 26.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The 26S proteasome is a large, ∼2.5 MDa, multi-catalytic ATP-dependent protease complex that serves as the degrading arm of the ubiquitin system, which is the major pathway for regulated degradation of cytosolic, nuclear and membrane proteins in all eukaryotic organisms.
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38
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Phosphorylation of the C-terminal tail of proteasome subunit α7 is required for binding of the proteasome quality control factor Ecm29. Sci Rep 2016; 6:27873. [PMID: 27302526 PMCID: PMC4908598 DOI: 10.1038/srep27873] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2015] [Accepted: 05/26/2016] [Indexed: 12/15/2022] Open
Abstract
The proteasome degrades many short-lived proteins that are labeled with an ubiquitin chain. The identification of phosphorylation sites on the proteasome subunits suggests that degradation of these substrates can also be regulated at the proteasome. In yeast and humans, the unstructured C-terminal region of α7 contains an acidic patch with serine residues that are phosphorylated. Although these were identified more than a decade ago, the molecular implications of α7 phosphorylation have remained unknown. Here, we showed that yeast Ecm29, a protein involved in proteasome quality control, requires the phosphorylated tail of α7 for its association with proteasomes. This is the first example of proteasome phosphorylation dependent binding of a proteasome regulatory factor. Ecm29 is known to inhibit proteasomes and is often found enriched on mutant proteasomes. We showed that the ability of Ecm29 to bind to mutant proteasomes requires the α7 tail binding site, besides a previously characterized Rpt5 binding site. The need for these two binding sites, which are on different proteasome subcomplexes, explains the specificity of Ecm29 for proteasome holoenzymes. We propose that alterations in the relative position of these two sites in different conformations of the proteasome provides Ecm29 the ability to preferentially bind specific proteasome conformations.
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39
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Guo X, Dixon JE. The 26S proteasome: A cell cycle regulator regulated by cell cycle. Cell Cycle 2016; 15:875-6. [PMID: 26940127 PMCID: PMC4889267 DOI: 10.1080/15384101.2016.1151728] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2016] [Accepted: 01/31/2016] [Indexed: 12/19/2022] Open
Affiliation(s)
- Xing Guo
- Life Sciences Institute, Zhejiang University, Hangzhou, China
| | - Jack E. Dixon
- Department of Pharmacology, University of California-San Diego School of Medicine, La Jolla, CA, USA
- Department of Chemistry and Biochemistry, University of California-San Diego School of Medicine, La Jolla, CA, USA
- Department of Cellular and Molecular Medicine, University of California-San Diego School of Medicine, La Jolla, CA, USA
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40
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Sobota RS, Stein CM, Kodaman N, Scheinfeldt LB, Maro I, Wieland-Alter W, Igo RP, Magohe A, Malone LL, Chervenak K, Hall NB, Modongo C, Zetola N, Matee M, Joloba M, Froment A, Nyambo TB, Moore JH, Scott WK, Lahey T, Boom WH, von Reyn CF, Tishkoff SA, Sirugo G, Williams SM. A Locus at 5q33.3 Confers Resistance to Tuberculosis in Highly Susceptible Individuals. Am J Hum Genet 2016; 98:514-524. [PMID: 26942285 PMCID: PMC4800052 DOI: 10.1016/j.ajhg.2016.01.015] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 01/26/2016] [Indexed: 12/22/2022] Open
Abstract
Immunosuppression resulting from HIV infection increases the risk of progression to active tuberculosis (TB) both in individuals newly exposed to Mycobacterium tuberculosis (MTB) and in those with latent infections. We hypothesized that HIV-positive individuals who do not develop TB, despite living in areas where it is hyperendemic, provide a model of natural resistance. We performed a genome-wide association study of TB resistance by using 581 HIV-positive Ugandans and Tanzanians enrolled in prospective cohort studies of TB; 267 of these individuals developed active TB, and 314 did not. A common variant, rs4921437 at 5q33.3, was significantly associated with TB (odds ratio = 0.37, p = 2.11 × 10(-8)). This variant lies within a genomic region that includes IL12B and is embedded in an H3K27Ac histone mark. The locus also displays consistent patterns of linkage disequilibrium across African populations and has signals of strong selection in populations from equatorial Africa. Along with prior studies demonstrating that therapy with IL-12 (the cytokine encoded in part by IL12B, associated with longer survival following MTB infection in mice deficient in CD4 T cells), our results suggest that this pathway might be an excellent target for the development of new modalities for treating TB, especially for HIV-positive individuals. Our results also indicate that studying extreme disease resistance in the face of extensive exposure can increase the power to detect associations in complex infectious disease.
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Affiliation(s)
- Rafal S Sobota
- Vanderbilt Genetics Institute, Vanderbilt University, Nashville, TN 37232, USA; Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - Catherine M Stein
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44106, USA; Tuberculosis Research Unit, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Nuri Kodaman
- Vanderbilt Genetics Institute, Vanderbilt University, Nashville, TN 37232, USA; Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA; Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Laura B Scheinfeldt
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA; Coriell Institute for Medical Research, Camden, NJ 08103, USA
| | - Isaac Maro
- Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8510, Japan
| | | | - Robert P Igo
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Albert Magohe
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - LaShaunda L Malone
- Tuberculosis Research Unit, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Keith Chervenak
- Tuberculosis Research Unit, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Noemi B Hall
- Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44106, USA
| | - Chawangwa Modongo
- Division of Infectious Diseases, University of Pennsylvania, Philadelphia, PA 19104, USA; Botswana-UPenn Partnership, 214 Independence Avenue, Gaborone, Botswana; Department of Medicine, University of Botswana, Gaborone, Botswana
| | - Nicola Zetola
- Division of Infectious Diseases, University of Pennsylvania, Philadelphia, PA 19104, USA; Botswana-UPenn Partnership, 214 Independence Avenue, Gaborone, Botswana; Department of Medicine, University of Botswana, Gaborone, Botswana
| | - Mecky Matee
- Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Moses Joloba
- Uganda-CWRU Research Collaboration, Kampala, Uganda; College of Health Sciences Makerere University and Mulago Hospital, Kampala, Uganda
| | - Alain Froment
- UMR 208, Institut de Recherche pour le Développement and Musée de l'Homme, Muséum National d'Histoire Naturelle, 75116 Paris, France
| | - Thomas B Nyambo
- Department of Biochemistry, Muhimbili University of Health and Allied Sciences, Dar es Salaam, Tanzania
| | - Jason H Moore
- Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA; Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - William K Scott
- John P. Hussman Institute for Human Genomics, University of Miami, Miami, FL 33136, USA
| | - Timothy Lahey
- Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA
| | - W Henry Boom
- Tuberculosis Research Unit, Case Western Reserve University, Cleveland, OH 44106, USA; Uganda-CWRU Research Collaboration, Kampala, Uganda
| | | | - Sarah A Tishkoff
- Department of Genetics, University of Pennsylvania, Philadelphia, PA 19104, USA; Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Giorgio Sirugo
- Centro di Ricerca, Ospedale San Pietro Fatebenefratelli, 00189 Rome, Italy
| | - Scott M Williams
- Geisel School of Medicine, Dartmouth College, Hanover, NH 03755, USA; Department of Epidemiology and Biostatistics, Case Western Reserve University, Cleveland, OH 44106, USA.
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Guo X, Wang X, Wang Z, Banerjee S, Yang J, Huang L, Dixon JE. Site-specific proteasome phosphorylation controls cell proliferation and tumorigenesis. Nat Cell Biol 2016; 18:202-12. [PMID: 26655835 PMCID: PMC4844191 DOI: 10.1038/ncb3289] [Citation(s) in RCA: 122] [Impact Index Per Article: 15.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2015] [Accepted: 11/12/2015] [Indexed: 02/07/2023]
Abstract
Despite the fundamental importance of proteasomal degradation in cells, little is known about whether and how the 26S proteasome itself is regulated in coordination with various physiological processes. Here we show that the proteasome is dynamically phosphorylated during the cell cycle at Thr 25 of the 19S subunit Rpt3. CRISPR/Cas9-mediated genome editing, RNA interference and biochemical studies demonstrate that blocking Rpt3-Thr25 phosphorylation markedly impairs proteasome activity and impedes cell proliferation. Through a kinome-wide screen, we have identified dual-specificity tyrosine-regulated kinase 2 (DYRK2) as the primary kinase that phosphorylates Rpt3-Thr25, leading to enhanced substrate translocation and degradation. Importantly, loss of the single phosphorylation of Rpt3-Thr25 or knockout of DYRK2 significantly inhibits tumour formation by proteasome-addicted human breast cancer cells in mice. These findings define an important mechanism for proteasome regulation and demonstrate the biological significance of proteasome phosphorylation in regulating cell proliferation and tumorigenesis.
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Affiliation(s)
- Xing Guo
- Department of Pharmacology, University of California-San Diego, La Jolla, CA 92093
| | - Xiaorong Wang
- Departments of Physiology and Biophysics and of Developmental and Cell Biology, University of California, Irvine, CA 92697
| | - Zhiping Wang
- Division of Biological Sciences, University of California-San Diego, La Jolla, CA 92093
| | - Sourav Banerjee
- Department of Pharmacology, University of California-San Diego, La Jolla, CA 92093
| | - Jing Yang
- Department of Pharmacology, University of California-San Diego, La Jolla, CA 92093
| | - Lan Huang
- Departments of Physiology and Biophysics and of Developmental and Cell Biology, University of California, Irvine, CA 92697
| | - Jack E. Dixon
- Department of Pharmacology, University of California-San Diego, La Jolla, CA 92093
- Departments of Cellular and Molecular Medicine and of Chemistry and Biochemistry, University of California-San Diego, La Jolla, CA 92093
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42
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Mayfield JE, Burkholder NT, Zhang YJ. Dephosphorylating eukaryotic RNA polymerase II. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2016; 1864:372-87. [PMID: 26779935 DOI: 10.1016/j.bbapap.2016.01.007] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2015] [Revised: 01/11/2016] [Accepted: 01/14/2016] [Indexed: 12/20/2022]
Abstract
The phosphorylation state of the C-terminal domain of RNA polymerase II is required for the temporal and spatial recruitment of various factors that mediate transcription and RNA processing throughout the transcriptional cycle. Therefore, changes in CTD phosphorylation by site-specific kinases/phosphatases are critical for the accurate transmission of information during transcription. Unlike kinases, CTD phosphatases have been traditionally neglected as they are thought to act as passive negative regulators that remove all phosphate marks at the conclusion of transcription. This over-simplified view has been disputed in recent years and new data assert the active and regulatory role phosphatases play in transcription. We now know that CTD phosphatases ensure the proper transition between different stages of transcription, balance the distribution of phosphorylation for accurate termination and re-initiation, and prevent inappropriate expression of certain genes. In this review, we focus on the specific roles of CTD phosphatases in regulating transcription. In particular, we emphasize how specificity and timing of dephosphorylation are achieved for these phosphatases and consider the various regulatory factors that affect these dynamics.
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Affiliation(s)
- Joshua E Mayfield
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Nathaniel T Burkholder
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA
| | - Yan Jessie Zhang
- Department of Molecular Biosciences and Institute for Cellular and Molecular Biology, University of Texas at Austin, Austin, TX 78712, USA.
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cAMP-induced phosphorylation of 26S proteasomes on Rpn6/PSMD11 enhances their activity and the degradation of misfolded proteins. Proc Natl Acad Sci U S A 2015; 112:E7176-85. [PMID: 26669444 DOI: 10.1073/pnas.1522332112] [Citation(s) in RCA: 178] [Impact Index Per Article: 19.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Although rates of protein degradation by the ubiquitin-proteasome pathway (UPS) are determined by their rates of ubiquitination, we show here that the proteasome's capacity to degrade ubiquitinated proteins is also tightly regulated. We studied the effects of cAMP-dependent protein kinase (PKA) on proteolysis by the UPS in several mammalian cell lines. Various agents that raise intracellular cAMP and activate PKA (activators of adenylate cyclase or inhibitors of phosphodiesterase 4) promoted degradation of short-lived (but not long-lived) cell proteins generally, model UPS substrates having different degrons, and aggregation-prone proteins associated with major neurodegenerative diseases, including mutant FUS (Fused in sarcoma), SOD1 (superoxide dismutase 1), TDP43 (TAR DNA-binding protein 43), and tau. 26S proteasomes purified from these treated cells or from control cells and treated with PKA degraded ubiquitinated proteins, small peptides, and ATP more rapidly than controls, but not when treated with protein phosphatase. Raising cAMP levels also increased amounts of doubly capped 26S proteasomes. Activated PKA phosphorylates the 19S subunit, Rpn6/PSMD11 (regulatory particle non-ATPase 6/proteasome subunit D11) at Ser14. Overexpression of a phosphomimetic Rpn6 mutant activated proteasomes similarly, whereas a nonphosphorylatable mutant decreased activity. Thus, proteasome function and protein degradation are regulated by cAMP through PKA and Rpn6, and activation of proteasomes by this mechanism may be useful in treating proteotoxic diseases.
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44
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Finley D, Chen X, Walters KJ. Gates, Channels, and Switches: Elements of the Proteasome Machine. Trends Biochem Sci 2015; 41:77-93. [PMID: 26643069 DOI: 10.1016/j.tibs.2015.10.009] [Citation(s) in RCA: 199] [Impact Index Per Article: 22.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2015] [Revised: 10/27/2015] [Accepted: 10/30/2015] [Indexed: 12/14/2022]
Abstract
The proteasome has emerged as an intricate machine that has dynamic mechanisms to regulate the timing of its activity, its selection of substrates, and its processivity. The 19-subunit regulatory particle (RP) recognizes ubiquitinated proteins, removes ubiquitin, and injects the target protein into the proteolytic chamber of the core particle (CP) via a narrow channel. Translocation into the CP requires substrate unfolding, which is achieved through mechanical force applied by a hexameric ATPase ring of the RP. Recent cryoelectron microscopy (cryoEM) studies have defined distinct conformational states of the RP, providing illustrative snapshots of what appear to be progressive steps of substrate engagement. Here, we bring together this new information with molecular analyses to describe the principles of proteasome activity and regulation.
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Affiliation(s)
- Daniel Finley
- Department of Cell Biology, Harvard Medical School, 240 Longwood Ave, Boston, MA 02115, USA.
| | - Xiang Chen
- Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA
| | - Kylie J Walters
- Protein Processing Section, Structural Biophysics Laboratory, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
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45
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He Y, Guo X, Yu ZH, Wu L, Gunawan AM, Zhang Y, Dixon JE, Zhang ZY. A potent and selective inhibitor for the UBLCP1 proteasome phosphatase. Bioorg Med Chem 2015; 23:2798-809. [PMID: 25907364 DOI: 10.1016/j.bmc.2015.03.066] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Revised: 03/23/2015] [Accepted: 03/24/2015] [Indexed: 11/17/2022]
Abstract
The ubiquitin-like domain-containing C-terminal domain phosphatase 1 (UBLCP1) has been implicated as a negative regulator of the proteasome, a key mediator in the ubiquitin-dependent protein degradation. Small molecule inhibitors that block UBLCP1 activity would be valuable as research tools and potential therapeutics for human diseases caused by the cellular accumulation of misfold/damaged proteins. We report a salicylic acid fragment-based library approach aimed at targeting both the phosphatase active site and its adjacent binding pocket for enhanced affinity and selectivity. Screening of the focused libraries led to the identification of the first potent and selective UBLCP1 inhibitor 13. Compound 13 exhibits an IC50 of 1.0μM for UBLCP1 and greater than 5-fold selectivity against a large panel of protein phosphatases from several distinct families. Importantly, the inhibitor possesses efficacious cellular activity and is capable of inhibiting UBLCP1 function in cells, which in turn up-regulates nuclear proteasome activity. These studies set the groundwork for further developing compound 13 into chemical probes or potential therapeutic agents targeting the UBLCP1 phosphatase.
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Affiliation(s)
- Yantao He
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Xing Guo
- Department of Pharmacology, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Zhi-Hong Yu
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Li Wu
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Andrea M Gunawan
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA
| | - Yan Zhang
- Department of Chemistry and Biochemistry, The University of Texas at Austin, 1 University Station A5300, Austin, TX 78712, USA
| | - Jack E Dixon
- Department of Pharmacology, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Cellular and Molecular Medicine, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA; Department of Chemistry and Biochemistry, University of California-San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Zhong-Yin Zhang
- Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, 635 Barnhill Drive, Indianapolis, IN 46202, USA.
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46
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Rice stripe tenuivirus nonstructural protein 3 hijacks the 26S proteasome of the small brown planthopper via direct interaction with regulatory particle non-ATPase subunit 3. J Virol 2015; 89:4296-310. [PMID: 25653432 DOI: 10.1128/jvi.03055-14] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED The ubiquitin/26S proteasome system plays a vital role in regulating host defenses against pathogens. Previous studies have highlighted different roles for the ubiquitin/26S proteasome in defense during virus infection in both mammals and plants, but their role in the vectors that transmit those viruses is still unclear. In this study, we determined that the 26S proteasome is present in the small brown planthopper (SBPH) (Laodelphax striatellus) and has components similar to those in plants and mammals. There was an increase in the accumulation of Rice stripe virus (RSV) in the transmitting vector SBPH after disrupting the 26S proteasome, indicating that the SBPH 26S proteasome plays a role in defense against RSV infection by regulating RSV accumulation. Yeast two-hybrid analysis determined that a subunit of the 26S proteasome, named RPN3, could interact with RSV NS3. Transient overexpression of RPN3 had no effect on the RNA silencing suppressor activity of RSV NS3. However, NS3 could inhibit the ability of SBPH rpn3 to complement an rpn3 mutation in yeast. Our findings also indicate that the direct interaction between RPN3 and NS3 was responsible for inhibiting the complementation ability of RPN3. In vivo, we found an accumulation of ubiquitinated protein in SBPH tissues where the RSV titer was high, and silencing of rpn3 resulted in malfunction of the SBPH proteasome-mediated proteolysis. Consequently, viruliferous SBPH in which RPN3 was repressed transmitted the virus more effectively as a result of higher accumulation of RSV. Our results suggest that the RSV NS3 protein is able to hijack the 26S proteasome in SBPH via a direct interaction with the RPN3 subunit to attenuate the host defense response. IMPORTANCE We show, for the first time, that the 26S proteasome components are present in the small brown planthopper and play a role in defense against its vectored plant virus (RSV). In turn, RSV encodes a protein that subverts the SBPH 26S proteasome via direct interaction with the 26S proteasome subunit RPN3. Our results imply that the molecular arms race observed in plant hosts can be extended to the insect vector that transmits those viruses.
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Meiners S, Keller IE, Semren N, Caniard A. Regulation of the proteasome: evaluating the lung proteasome as a new therapeutic target. Antioxid Redox Signal 2014; 21:2364-82. [PMID: 24437504 DOI: 10.1089/ars.2013.5798] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
SIGNIFICANCE Lung diseases are on the second rank worldwide with respect to morbidity and mortality. For most respiratory diseases, no effective therapies exist. Whereas the proteasome has been successfully evaluated as a novel target for therapeutic interventions in cancer, neurodegenerative, and cardiac disorders, there is a profound lack of knowledge on the regulation of proteasome activity in chronic and acute lung diseases. RECENT ADVANCES There are various means of how the amount of active proteasome complexes in the cell can be regulated such as transcriptional regulation of proteasomal subunit expression, association with different regulators, assembly and half-life of proteasomes and regulatory complexes, as well as post-translational modifications. It also becomes increasingly evident that proteasome activity is fine-tuned and depends on the state of the cell. We propose here that 20S proteasomes and their regulators can be regarded as dynamic building blocks, which assemble or disassemble in response to cellular needs. The composition of proteasome complexes in a cell may vary depending on tissue, cell type and compartment, stage of development, or pathological context. CRITICAL ISSUES AND FUTURE DIRECTIONS Dissecting the expression and regulation of the various catalytic forms of 20S proteasomes, such as constitutive, immuno-, and mixed proteasomes, together with their associated regulatory complexes will not only greatly enhance our understanding of proteasome function in lung pathogenesis but will also pave the way to develop new classes of drugs that inhibit or activate proteasome function in a defined setting for treatment of lung diseases.
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Affiliation(s)
- Silke Meiners
- Comprehensive Pneumology Center (CPC), University Hospital , Ludwig-Maximilians University, Helmholtz Zentrum München, Member of the German Center for Lung Research (DZL), Munich, Germany
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Kaake RM, Kao A, Yu C, Huang L. Characterizing the dynamics of proteasome complexes by proteomics approaches. Antioxid Redox Signal 2014; 21:2444-56. [PMID: 24423446 PMCID: PMC4241863 DOI: 10.1089/ars.2013.5815] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
SIGNIFICANCE The proteasome is the degradation machine of the ubiquitin-proteasome system, which is critical in controlling many essential biological processes. Aberrant regulation of proteasome-dependent protein degradation can lead to various human diseases, and general proteasome inhibitors have shown efficacy for cancer treatments. Though clinically effective, current proteasome inhibitors have detrimental side effects and, thus, better therapeutic strategies targeting proteasomes are needed. Therefore, a comprehensive characterization of proteasome complexes will provide the molecular details that are essential for developing new and improved drugs. RECENT ADVANCES New mass spectrometry (MS)-based proteomics approaches have been developed to study protein interaction networks and structural topologies of proteasome complexes. The results have helped define the dynamic proteomes of proteasome complexes, thus providing new insights into the mechanisms underlying proteasome function and regulation. CRITICAL ISSUES The proteasome exists as heterogeneous populations in tissues/cells, and its proteome is highly dynamic and complex. In addition, proteasome complexes are regulated by various mechanisms under different physiological conditions. Consequently, complete proteomic profiling of proteasome complexes remains a major challenge for the field. FUTURE DIRECTIONS We expect that proteomic methodologies enabling full characterization of proteasome complexes will continue to evolve. Further advances in MS instrumentation and protein separation techniques will be needed to facilitate the detailed proteomic analysis of low-abundance components and subpopulations of proteasome complexes. The results will help us understand proteasome biology as well as provide new therapeutic targets for disease diagnostics and treatment.
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Affiliation(s)
- Robyn M Kaake
- Department of Physiology and Biophysics, University of California , Irvine, Irvine, California
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Gu ZC, Enenkel C. Proteasome assembly. Cell Mol Life Sci 2014; 71:4729-45. [PMID: 25107634 PMCID: PMC11113775 DOI: 10.1007/s00018-014-1699-8] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2014] [Revised: 07/30/2014] [Accepted: 07/31/2014] [Indexed: 10/24/2022]
Abstract
In eukaryotic cells, proteasomes are highly conserved protease complexes and eliminate unwanted proteins which are marked by poly-ubiquitin chains for degradation. The 26S proteasome consists of the proteolytic core particle, the 20S proteasome, and the 19S regulatory particle, which are composed of 14 and 19 different subunits, respectively. Proteasomes are the second-most abundant protein complexes and are continuously assembled from inactive precursor complexes in proliferating cells. The modular concept of proteasome assembly was recognized in prokaryotic ancestors and applies to eukaryotic successors. The efficiency and fidelity of eukaryotic proteasome assembly is achieved by several proteasome-dedicated chaperones that initiate subunit incorporation and control the quality of proteasome assemblies by transiently interacting with proteasome precursors. It is important to understand the mechanism of proteasome assembly as the proteasome has key functions in the turnover of short-lived proteins regulating diverse biological processes.
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Affiliation(s)
- Zhu Chao Gu
- Department of Biochemistry, University of Toronto, Medical Sciences Building, 1 King’s College Circle, Toronto, ON M5S 1A8 Canada
| | - Cordula Enenkel
- Department of Biochemistry, University of Toronto, Medical Sciences Building, 1 King’s College Circle, Toronto, ON M5S 1A8 Canada
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Zhang F, Wang Z, Dong W, Sun C, Wang H, Song A, He L, Fang W, Chen F, Teng N. Transcriptomic and proteomic analysis reveals mechanisms of embryo abortion during chrysanthemum cross breeding. Sci Rep 2014; 4:6536. [PMID: 25288482 PMCID: PMC4187010 DOI: 10.1038/srep06536] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2014] [Accepted: 08/26/2014] [Indexed: 12/25/2022] Open
Abstract
Embryo abortion is the main cause of failure in chrysanthemum cross breeding, and the genes and proteins associated with embryo abortion are poorly understood. Here, we applied RNA sequencing and isobaric tags for relative and absolute quantitation (iTRAQ) to analyse transcriptomic and proteomic profiles of normal and abortive embryos. More than 68,000 annotated unigenes and 700 proteins were obtained from normal and abortive embryos. Functional analysis showed that 140 differentially expressed genes (DEGs) and 41 differentially expressed proteins (DEPs) were involved in embryo abortion. Most DEGs and DEPs associated with cell death, protein degradation, reactive oxygen species scavenging, and stress-response transcriptional factors were significantly up-regulated in abortive embryos relative to normal embryos. In contrast, most genes and proteins related to cell division and expansion, the cytoskeleton, protein synthesis and energy metabolism were significantly down-regulated in abortive embryos. Furthermore, abortive embryos had the highest activity of three executioner caspase-like enzymes. These results indicate that embryo abortion may be related to programmed cell death and the senescence- or death-associated genes or proteins contribute to embryo abortion. This adds to our understanding of embryo abortion and will aid in the cross breeding of chrysanthemum and other crops in the future.
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Affiliation(s)
- Fengjiao Zhang
- 1] College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China [2] Jiangsu Province Engineering Lab for Modern Facility Agriculture Technology &Equipment, Nanjing 210095, China
| | - Zhiquan Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Wen Dong
- China Rural Technology Development Center, Beijing 100045, China
| | - Chunqing Sun
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Haibin Wang
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Aiping Song
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Lizhong He
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Weimin Fang
- College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China
| | - Fadi Chen
- 1] College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China [2] Jiangsu Province Engineering Lab for Modern Facility Agriculture Technology &Equipment, Nanjing 210095, China
| | - Nianjun Teng
- 1] College of Horticulture, Nanjing Agricultural University, Nanjing 210095, China [2] Jiangsu Province Engineering Lab for Modern Facility Agriculture Technology &Equipment, Nanjing 210095, China
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