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Chatterjee BK, Alam M, Chakravorty A, Lacy SM, Rech J, Brooks CL, Arvan PD, Truttmann MC. Small molecule FICD inhibitors suppress endogenous and pathologic FICD-mediated protein AMPylation. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.13.603377. [PMID: 39071275 PMCID: PMC11275912 DOI: 10.1101/2024.07.13.603377] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/30/2024]
Abstract
The AMP transferase, FICD, is an emerging drug target finetuning stress signaling in the endoplasmic reticulum (ER). FICD is a bi-functional enzyme, catalyzing both AMP addition (AMPylation) and removal (deAMPylation) from the ER resident chaperone BiP/GRP78. Despite increasing evidence linking excessive BiP/GRP78 AMPylation to human diseases, small molecules to inhibit pathogenic FICD variants are lacking. Using an in-vitro high-throughput screen, we identify two small-molecule FICD inhibitors, C22 and C73. Both molecules significantly inhibit FICD-mediated BiP/GRP78 AMPylation in intact cells while only weakly inhibiting BiP/GRP78 deAMPylation. C22 and C73 also efficiently inhibit pathogenic FICD variants and improve proinsulin processing in β cells. Our study identifies and validates FICD inhibitors, highlighting a novel therapeutic avenue against pathologic protein AMPylation.
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Lacy SM, Taubitz RJ, Urban ND, Turowski SN, Smith ED, Helms AS, Michele DE, Truttmann MC. FICD deficiency protects mice from hypertrophy-induced heart failure via BiP-mediated activation of the UPR ER and ER-phagy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.28.596287. [PMID: 38853840 PMCID: PMC11160590 DOI: 10.1101/2024.05.28.596287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Cardiomyocytes require the HSP70 chaperone BiP to maintain proteostasis in the endoplasmic reticulum (ER) following cardiac stress. The adenylyl transferase (AMPylase) FICD is increasingly recognized to regulate BiP activity through the post-translational addition of an adenosine monophosphate moiety to BiP surface residues. However, the physiological impact of FICD-mediated BiP regulation in the context of cardiovascular health is unknown. Here, we find that FICD deficiency prevents pressure overload-associated heart failure, hypertrophy, and fibrosis, and that FICD knockout mice maintain normal cardiac function after cardiac pressure overload. At a cellular level, we observe that FICD-mediated BiP AMPylation blunts the induction of the unfolded protein response (UPR ER ) and impairs BiP interaction with FAM134B, an ER-phagy receptor, thus limiting ER-phagy induction under stress. In contrast, FICD loss significantly increases BiP-dependent UPR ER induction and ER-phagy in stressed cardiomyocytes. We also uncover cell type-specific consequences of FICD activity in response to ER stress, positioning FICD as a critical proteostasis regulator in cardiac tissue. Our results highlight a novel regulatory paradigm controlling stress resilience in cardiomyocytes and offer a rationale to consider FICD as a therapeutic target to treat cardiac hypertrophy.
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Höpfner D, Cichy A, Pogenberg V, Krisp C, Mezouar S, Bach NC, Grotheer J, Zarza SM, Martinez E, Bonazzi M, Feige MJ, Sieber SA, Schlüter H, Itzen A. The DNA-binding induced (de)AMPylation activity of a Coxiella burnetii Fic enzyme targets Histone H3. Commun Biol 2023; 6:1124. [PMID: 37932372 PMCID: PMC10628234 DOI: 10.1038/s42003-023-05494-7] [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: 04/14/2023] [Accepted: 10/20/2023] [Indexed: 11/08/2023] Open
Abstract
The intracellular bacterial pathogen Coxiella burnetii evades the host response by secreting effector proteins that aid in establishing a replication-friendly niche. Bacterial filamentation induced by cyclic AMP (Fic) enzymes can act as effectors by covalently modifying target proteins with the posttranslational AMPylation by transferring adenosine monophosphate (AMP) from adenosine triphosphate (ATP) to a hydroxyl-containing side chain. Here we identify the gene product of C. burnetii CBU_0822, termed C. burnetii Fic 2 (CbFic2), to AMPylate host cell histone H3 at serine 10 and serine 28. We show that CbFic2 acts as a bifunctional enzyme, both capable of AMPylation as well as deAMPylation, and is regulated by the binding of DNA via a C-terminal helix-turn-helix domain. We propose that CbFic2 performs AMPylation in its monomeric state, switching to a deAMPylating dimer upon DNA binding. This study unveils reversible histone modification by a specific enzyme of a pathogenic bacterium.
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Affiliation(s)
- Dorothea Höpfner
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany
| | - Adam Cichy
- Center for Integrated Protein Science Munich (CIPSM), Department Chemistry, Group of Proteinchemistry, Technical University of Munich, Lichtenbergstraße 4, 85747, Garching, Germany
| | - Vivian Pogenberg
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany
| | - Christoph Krisp
- Institute of Clinical Chemistry and Laboratory Medicine, Section Mass Spectrometry and Proteomics, University Medical Center Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany
| | - Soraya Mezouar
- Aix-Marseille University, Institut de Recherche pour la Développement (IRD), Assistance Publique-Hôpitaux de Marseille (APHM), Microbes Evolution Phylogeny and Infections (MEPHI), Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection, Boulevard Jean Moulin, 13005, Marseille, France
| | - Nina C Bach
- Technical University of Munich (TUM), TUM School of Natural Sciences, Department of Biosciences, Chair of Organic Chemistry II, Center for Functional Protein Assemblies (CPA), Ernst-Otto-Fischer Straße 8, 85748, Garching, Germany
| | - Jan Grotheer
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany
| | - Sandra Madariaga Zarza
- Aix-Marseille University, Institut de Recherche pour la Développement (IRD), Assistance Publique-Hôpitaux de Marseille (APHM), Microbes Evolution Phylogeny and Infections (MEPHI), Institut Hospitalo-Universitaire (IHU)-Méditerranée Infection, Boulevard Jean Moulin, 13005, Marseille, France
| | - Eric Martinez
- Cellular and Molecular Biology of Bacterial Infections, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, UMR 9004 - Centre national de la recherche scientifique (CNRS), 1919 Route de Mende, 34293, Montpellier, France
| | - Matteo Bonazzi
- Cellular and Molecular Biology of Bacterial Infections, Institut de Recherche en Infectiologie de Montpellier (IRIM), Université de Montpellier, UMR 9004 - Centre national de la recherche scientifique (CNRS), 1919 Route de Mende, 34293, Montpellier, France
| | - Matthias J Feige
- Center for Functional Protein Assemblies (CPA), Department of Bioscience, TUM School of Natural Sciences, Technical University of Munich, Lichtenbergstraße 4, 85748, Garching, Germany
| | - Stephan A Sieber
- Technical University of Munich (TUM), TUM School of Natural Sciences, Department of Biosciences, Chair of Organic Chemistry II, Center for Functional Protein Assemblies (CPA), Ernst-Otto-Fischer Straße 8, 85748, Garching, Germany
| | - Hartmut Schlüter
- Institute of Clinical Chemistry and Laboratory Medicine, Section Mass Spectrometry and Proteomics, University Medical Center Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany
| | - Aymelt Itzen
- Institute of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.
- Center for Structural Systems Biology (CSSB), University Medical Center Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany.
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4
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Groenendyk J, Michalak M. Interplay between calcium and endoplasmic reticulum stress. Cell Calcium 2023; 113:102753. [PMID: 37209448 DOI: 10.1016/j.ceca.2023.102753] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/05/2023] [Accepted: 05/06/2023] [Indexed: 05/22/2023]
Abstract
Cellular homeostasis is crucial for the healthy functioning of the organism. Disruption of cellular homeostasis activates endoplasmic reticulum (ER) stress coping responses including the unfolded protein response (UPR). There are three ER resident stress sensors responsible for UPR activation - IRE1α, PERK and ATF6. Ca2+ signaling plays an important role in stress responses including the UPR and the ER is the main Ca2+ storage organelle and a source of Ca2+ for cell signaling. The ER contains many proteins involved in Ca2+ import/export/ storage, Ca2+ movement between different cellular organelles and ER Ca2+ stores refilling. Here we focus on selected aspects of ER Ca2+ homeostasis and its role in activation of the ER stress coping responses.
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Affiliation(s)
- Jody Groenendyk
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, AB T6G 2H7, Canada.
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5
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Liu M, Li L, Wang Z, Wang S, Tang X. Catalytic deAMPylation in AMPylation-inhibitory/assistant forms of FICD protein. Front Chem 2023; 11:1077188. [PMID: 36762200 PMCID: PMC9905249 DOI: 10.3389/fchem.2023.1077188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2022] [Accepted: 01/10/2023] [Indexed: 01/27/2023] Open
Abstract
DeAMPylation, as a reversible reaction of AMPylation and mediated by the endoplasmic reticulum-localized enzyme FICD (filamentation induced by cAMP domain protein, also known as HYPE), is an important process in protein posttranslational modifications (PTMs). Elucidating the function and catalytic details of FICD is of vital importance to provide a comprehensive understanding of protein folding homeostasis. However, the detailed deAMPylation mechanism is still unclear. Furthermore, the role of a conserved glutamine (Glu234), that plays an inhibitory role in the AMPylation response, is still an open question in the deAMPylation process. In the present work, the elaborated deAMPylation mechanisms with AMPylation-inhibitory/assistant forms of FICD (wild type and Glu234Ala mutant) were investigated based on the QM(DFT)/MM MD approach. The results revealed that deAMPylation was triggered by proton transfer from protonated histidine (His363) to AMPylated threonine, instead of a nucleophilic attack of water molecules adding to the phosphorus of AMP. The free energy barrier of deAMPylation in the wild type (∼17.3 kcal/mol) is consistent with that in the Glu234Ala mutant of FICD (∼17.1 kcal/mol), suggesting that the alteration of the Glu234 residue does not affect the deAMPylation reaction and indirectly verifying the inducement of deAMPylation in FICD. In the wild type, the proton in the nucleophilic water molecule is transferred to Glu234, whereas it is delivered to Asp367 through the hydrogen-bond network of coordinated water molecules in the Glu234Ala mutant. The present findings were inspirational for understanding the catalytic and inhibitory mechanisms of FICD-mediated AMP transfer, paving the way for further studies on the physiological role of FICD protein.
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Affiliation(s)
- Meili Liu
- Department of Medical Chemistry, School of Pharmacy, Qingdao University, Qingdao, China,Department of Civil and Architectural Engineering, University of Miami, Coral Gables, FL, United States
| | - Li Li
- Department of Medical Chemistry, School of Pharmacy, Qingdao University, Qingdao, China
| | - Zhiqin Wang
- Department of Medical Chemistry, School of Pharmacy, Qingdao University, Qingdao, China
| | - Shuang Wang
- Department of Medical Chemistry, School of Pharmacy, Qingdao University, Qingdao, China,Department of Stomatology, Huangdao District Central Hospital, Qingdao, China,*Correspondence: Shuang Wang, ; Xiaowen Tang,
| | - Xiaowen Tang
- Department of Medical Chemistry, School of Pharmacy, Qingdao University, Qingdao, China,*Correspondence: Shuang Wang, ; Xiaowen Tang,
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6
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A secreted effector with a dual role as a toxin and as a transcriptional factor. Nat Commun 2022; 13:7779. [PMID: 36522324 PMCID: PMC9755527 DOI: 10.1038/s41467-022-35522-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 12/08/2022] [Indexed: 12/23/2022] Open
Abstract
Bacteria have evolved multiple secretion systems for delivering effector proteins into the cytosol of neighboring cells, but the roles of many of these effectors remain unknown. Here, we show that Yersinia pseudotuberculosis secretes an effector, CccR, that can act both as a toxin and as a transcriptional factor. The effector is secreted by a type VI secretion system (T6SS) and can enter nearby cells of the same species and other species (such as Escherichia coli) via cell-cell contact and in a contact-independent manner. CccR contains an N-terminal FIC domain and a C-terminal DNA-binding domain. In Y. pseudotuberculosis cells, CccR inhibits its own expression by binding through its DNA-binding domain to the cccR promoter, and affects the expression of other genes through unclear mechanisms. In E. coli cells, the FIC domain of CccR AMPylates the cell division protein FtsZ, inducing cell filamentation and growth arrest. Thus, our results indicate that CccR has a dual role, modulating gene expression in neighboring cells of the same species, and inhibiting the growth of competitors.
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7
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A mechanism for SARS-CoV-2 RNA capping and its inhibition by nucleotide analog inhibitors. Cell 2022; 185:4347-4360.e17. [PMID: 36335936 PMCID: PMC9531661 DOI: 10.1016/j.cell.2022.09.037] [Citation(s) in RCA: 19] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 09/01/2022] [Accepted: 09/27/2022] [Indexed: 01/26/2023]
Abstract
Decoration of cap on viral RNA plays essential roles in SARS-CoV-2 proliferation. Here, we report a mechanism for SARS-CoV-2 RNA capping and document structural details at atomic resolution. The NiRAN domain in polymerase catalyzes the covalent link of RNA 5' end to the first residue of nsp9 (termed as RNAylation), thus being an intermediate to form cap core (GpppA) with GTP catalyzed again by NiRAN. We also reveal that triphosphorylated nucleotide analog inhibitors can be bonded to nsp9 and fit into a previously unknown "Nuc-pocket" in NiRAN, thus inhibiting nsp9 RNAylation and formation of GpppA. S-loop (residues 50-KTN-52) in NiRAN presents a remarkable conformational shift observed in RTC bound with sofosbuvir monophosphate, reasoning an "induce-and-lock" mechanism to design inhibitors. These findings not only improve the understanding of SARS-CoV-2 RNA capping and the mode of action of NAIs but also provide a strategy to design antiviral drugs.
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8
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Zhou Z, Wang Q, Michalak M. Inositol Requiring Enzyme (IRE), a multiplayer in sensing endoplasmic reticulum stress. Anim Cells Syst (Seoul) 2022; 25:347-357. [PMID: 35059134 PMCID: PMC8765250 DOI: 10.1080/19768354.2021.2020901] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Affiliation(s)
- Zhixin Zhou
- Department of Biochemistry, University of Alberta, Edmonton, Canada
| | - Qian Wang
- Department of Biochemistry, University of Alberta, Edmonton, Canada
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, Canada
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9
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Fromm K, Dehio C. The Impact of Bartonella VirB/VirD4 Type IV Secretion System Effectors on Eukaryotic Host Cells. Front Microbiol 2022; 12:762582. [PMID: 34975788 PMCID: PMC8714903 DOI: 10.3389/fmicb.2021.762582] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2021] [Accepted: 10/29/2021] [Indexed: 12/14/2022] Open
Abstract
Bartonella spp. are facultative intracellular pathogens that infect a wide range of mammalian hosts including humans. The VirB/VirD4 type IV secretion system (T4SS) is a key virulence factor utilized to translocate Bartonella effector proteins (Beps) into host cells in order to subvert their functions. Crucial for effector translocation is the C-terminal Bep intracellular delivery (BID) domain that together with a positively charged tail sequence forms a bipartite translocation signal. Multiple BID domains also evolved secondary effector functions within host cells. The majority of Beps possess an N-terminal filamentation induced by cAMP (FIC) domain and a central connecting oligonucleotide binding (OB) fold. FIC domains typically mediate AMPylation or related post-translational modifications of target proteins. Some Beps harbor other functional modules, such as tandem-repeated tyrosine-phosphorylation (EPIYA-related) motifs. Within host cells the EPIYA-related motifs are phosphorylated, which facilitates the interaction with host signaling proteins. In this review, we will summarize our current knowledge on the molecular functions of the different domains present in Beps and highlight examples of Bep-dependent host cell modulation.
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Affiliation(s)
- Katja Fromm
- Biozentrum, University of Basel, Basel, Switzerland
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10
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Wang N, Wang H, Pan Q, Kang J, Liang Z, Zhang R. The Combination of β-Asarone and Icariin Inhibits Amyloid- β and Reverses Cognitive Deficits by Promoting Mitophagy in Models of Alzheimer's Disease. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:7158444. [PMID: 34887998 PMCID: PMC8651403 DOI: 10.1155/2021/7158444] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/23/2021] [Revised: 10/14/2021] [Accepted: 11/01/2021] [Indexed: 01/18/2023]
Abstract
β-Asarone is the main constituent of Acorus tatarinowii Schott and exhibits important effects in diseases such as neurodegenerative and neurovascular diseases. Icariin (ICA) is a major active ingredient of Epimedium that has attracted increasing attention because of its unique pharmacological effects in degenerative disease. In this paper, we primarily explored the effects of the combination of β-asarone and ICA in clearing noxious proteins and reversing cognitive deficits. The accumulation of damaged mitochondria and mitophagy are hallmarks of aging and age-related neurodegeneration, including Alzheimer's disease (AD). Here, we provide evidence that autophagy/mitophagy is impaired in the hippocampus of APP/PS1 mice and in Aβ1-42-induced PC12 cell models. Enhanced mitophagic activity has been reported to promote Aβ and tau clearance in in vitro and in vivo models. Meanwhile, there is growing evidence that treatment of AD should be preceded by intervention before the formation of pathological products. The efficacy of the combination therapy was better than that of the individual therapies applied separately. Then, we found that the combination therapy also inhibited cell and mitochondrial damage by inducing autophagy/mitophagy. These findings suggest that impaired removal of defective mitochondria is a pivotal event in AD pathogenesis, and that combination treatment with mitophagy inducers represents a potential strategy for therapeutic intervention.
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Affiliation(s)
- Nanbu Wang
- The First Affiliated Hospital, Guangzhou University of Chinese Medicine, Guangzhou, China
- The First Affiliated Hospital, Jinan University, Guangzhou, China
| | - Haoyu Wang
- College of Traditional Chinese Medicine, Jinan University, Guangzhou, China
| | - Qi Pan
- College of Traditional Chinese Medicine, Jinan University, Guangzhou, China
| | - Jian Kang
- Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Ziwen Liang
- College of Pharmacy, Jinan University, Guangzhou, China
| | - Ronghua Zhang
- The First Affiliated Hospital, Jinan University, Guangzhou, China
- College of Pharmacy, Jinan University, Guangzhou, China
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11
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Gulen B, Itzen A. Revisiting AMPylation through the lens of Fic enzymes. Trends Microbiol 2021; 30:350-363. [PMID: 34531089 DOI: 10.1016/j.tim.2021.08.003] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Revised: 08/04/2021] [Accepted: 08/09/2021] [Indexed: 11/30/2022]
Abstract
AMPylation, a post-translational modification (PTM) first discovered in the late 1960s, is catalyzed by adenosine monophosphate (AMP)-transferring enzymes. The observation that filamentation-induced-by-cyclic-AMP (fic) enzymes are associated with this unique PTM revealed that AMPylation plays a major role in hijacking of host signaling by pathogenic bacteria during infection. Studies over the past decade showed that AMPylation is conserved across all kingdoms of life and, outside their role in infection, also modulates cellular functions. Many aspects of AMPylation are yet to be uncovered. In this review we present the advancement in research on AMPylation and Fic enzymes as well as other distinct classes of enzymes that catalyze AMPylation.
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Affiliation(s)
- Burak Gulen
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf (UKE), Martinistr. 52, 20246, Hamburg, Germany; Present address: Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, TX, USA.
| | - Aymelt Itzen
- Department of Biochemistry and Signal Transduction, University Medical Center Hamburg-Eppendorf (UKE), Martinistr. 52, 20246, Hamburg, Germany.
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12
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Deletion of mFICD AMPylase alters cytokine secretion and affects visual short-term learning in vivo. J Biol Chem 2021; 297:100991. [PMID: 34419450 PMCID: PMC8441161 DOI: 10.1016/j.jbc.2021.100991] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2021] [Revised: 07/07/2021] [Accepted: 07/19/2021] [Indexed: 11/21/2022] Open
Abstract
Fic domain-containing AMP transferases (fic AMPylases) are conserved enzymes that catalyze the covalent transfer of AMP to proteins. This posttranslational modification regulates the function of several proteins, including the ER-resident chaperone Grp78/BiP. Here we introduce a mouse FICD (mFICD) AMPylase knockout mouse model to study fic AMPylase function in vertebrates. We find that mFICD deficiency is well tolerated in unstressed mice. We also show that mFICD-deficient mouse embryonic fibroblasts are depleted of AMPylated proteins. mFICD deletion alters protein synthesis and secretion in splenocytes, including that of IgM, an antibody secreted early during infections, and the proinflammatory cytokine IL-1β, without affecting the unfolded protein response. Finally, we demonstrate that visual nonspatial short-term learning is stronger in old mFICD−/− mice than in wild-type controls while other measures of cognition, memory, and learning are unaffected. Together, our results suggest a role for mFICD in adaptive immunity and neuronal plasticity in vivo.
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13
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Structures of a deAMPylation complex rationalise the switch between antagonistic catalytic activities of FICD. Nat Commun 2021; 12:5004. [PMID: 34408154 PMCID: PMC8373988 DOI: 10.1038/s41467-021-25076-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2021] [Accepted: 07/15/2021] [Indexed: 12/22/2022] Open
Abstract
The endoplasmic reticulum (ER) Hsp70 chaperone BiP is regulated by AMPylation, a reversible inactivating post-translational modification. Both BiP AMPylation and deAMPylation are catalysed by a single ER-localised enzyme, FICD. Here we present crystallographic and solution structures of a deAMPylation Michaelis complex formed between mammalian AMPylated BiP and FICD. The latter, via its tetratricopeptide repeat domain, binds a surface that is specific to ATP-state Hsp70 chaperones, explaining the exquisite selectivity of FICD for BiP’s ATP-bound conformation both when AMPylating and deAMPylating Thr518. The eukaryotic deAMPylation mechanism thus revealed, rationalises the role of the conserved Fic domain Glu234 as a gatekeeper residue that both inhibits AMPylation and facilitates hydrolytic deAMPylation catalysed by dimeric FICD. These findings point to a monomerisation-induced increase in Glu234 flexibility as the basis of an oligomeric state-dependent switch between FICD’s antagonistic activities, despite a similar mode of engagement of its two substrates — unmodified and AMPylated BiP. The ER chaperone BiP is regulated by FICD-mediated AMPylation and deAMPylation. Here, the authors characterise the structure of mammalian AMPylated BiP bound to FICD, by X-ray crystallography and neutron scattering, providing insights into the mechanism of BiP AMPylation and deAMPylation.
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14
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Evolutionary Diversification of Host-Targeted Bartonella Effectors Proteins Derived from a Conserved FicTA Toxin-Antitoxin Module. Microorganisms 2021; 9:microorganisms9081645. [PMID: 34442725 PMCID: PMC8401265 DOI: 10.3390/microorganisms9081645] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2021] [Revised: 07/25/2021] [Accepted: 07/27/2021] [Indexed: 12/17/2022] Open
Abstract
Proteins containing a FIC domain catalyze AMPylation and other post-translational modifications (PTMs). In bacteria, they are typically part of FicTA toxin-antitoxin modules that control conserved biochemical processes such as topoisomerase activity, but they have also repeatedly diversified into host-targeted virulence factors. Among these, Bartonella effector proteins (Beps) comprise a particularly diverse ensemble of FIC domains that subvert various host cellular functions. However, no comprehensive comparative analysis has been performed to infer molecular mechanisms underlying the biochemical and functional diversification of FIC domains in the vast Bep family. Here, we used X-ray crystallography, structural modelling, and phylogenetic analyses to unravel the expansion and diversification of Bep repertoires that evolved in parallel in three Bartonella lineages from a single ancestral FicTA toxin-antitoxin module. Our analysis is based on 99 non-redundant Bep sequences and nine crystal structures. Inferred from the conservation of the FIC signature motif that comprises the catalytic histidine and residues involved in substrate binding, about half of them represent AMP transferases. A quarter of Beps show a glutamate in a strategic position in the putative substrate binding pocket that would interfere with triphosphate-nucleotide binding but may allow binding of an AMPylated target for deAMPylation or another substrate to catalyze a distinct PTM. The β-hairpin flap that registers the modifiable target segment to the active site exhibits remarkable structural variability. The corresponding sequences form few well-defined groups that may recognize distinct target proteins. The binding of Beps to promiscuous FicA antitoxins is well conserved, indicating a role of the antitoxin to inhibit enzymatic activity or to serve as a chaperone for the FIC domain before translocation of the Bep into host cells. Taken together, our analysis indicates a remarkable functional plasticity of Beps that is mostly brought about by structural changes in the substrate pocket and the target dock. These findings may guide future structure–function analyses of the highly versatile FIC domains.
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15
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Champion M, Truttmann MC. Over-expression of the constitutive AMPylase FIC-1(E274G) does not deplete cellular ATP pools in C. elegans. MICROPUBLICATION BIOLOGY 2021; 2021. [PMID: 34189425 PMCID: PMC8233689 DOI: 10.17912/micropub.biology.000409] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Protein AMPylation has emerged as a posttranslational protein modification regulating cellular proteostasis. AMPylation is conferred by Fic AMPylases, which catalyze the covalent attachment of AMP to target proteins at the expense of ATP. Over-expression of constitutive-active Fic AMPylases is toxic. Here, we test the hypothesis that excessive Fic AMPylase activity could deplete cellular ATP pools, leading to cell death. We find that increased/decreased Fic AMPylase activity only alters cellular ATP concentrations by approximately 15%. This suggests that hyper-AMPylation-mediated cell death is likely not the consequence of cellular ATP depletion.
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Affiliation(s)
- Margaret Champion
- University of Michigan Medical School, Department of Molecular & Integrative Physiology, Ann Arbor, MI
| | - Matthias C Truttmann
- University of Michigan Medical School, Department of Molecular & Integrative Physiology, Ann Arbor, MI
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16
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Groenendyk J, Agellon LB, Michalak M. Calcium signaling and endoplasmic reticulum stress. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 363:1-20. [PMID: 34392927 DOI: 10.1016/bs.ircmb.2021.03.003] [Citation(s) in RCA: 57] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Cellular homeostasis is essential for healthy functioning of cells and tissues as well as proper organ development and maintenance. A disruption in cellular homeostasis triggers stress responses including the unfolded protein response (UPR), an endoplasmic reticulum (ER) stress coping response. There is increasing evidence that Ca2+ signaling plays a pivotal role in stress responses, as Ca2+ is involved many cellular activities. The ER is the main Ca2+ storage organelle and the source of Ca2+ for intracellular signaling. The ER is equipped with a variety of stress sensors and contains many Ca2+ handling proteins that support a role for Ca2+ in stress sensing and in coordinating strategies required to cope with cellular stress. Maintenance of ER Ca2+ homeostasis is therefore vital in sustaining cellular functions especially during times of cellular stress. Here we focus on selected aspects of ER Ca2+ homeostasis, its links to ER stress, and activation of the ER stress coping response.
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Affiliation(s)
- Jody Groenendyk
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.
| | - Luis B Agellon
- School of Human Nutrition, McGill University, Ste. Anne de Bellevue, QC, Canada.
| | - Marek Michalak
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada.
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17
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Chatterjee BK, Truttmann MC. Fic and non-Fic AMPylases: protein AMPylation in metazoans. Open Biol 2021; 11:210009. [PMID: 33947243 PMCID: PMC8097203 DOI: 10.1098/rsob.210009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Protein AMPylation refers to the covalent attachment of an AMP moiety to the amino acid side chains of target proteins using ATP as nucleotide donor. This process is catalysed by dedicated AMP transferases, called AMPylases. Since this initial discovery, several research groups have identified AMPylation as a critical post-translational modification relevant to normal and pathological cell signalling in both bacteria and metazoans. Bacterial AMPylases are abundant enzymes that either regulate the function of endogenous bacterial proteins or are translocated into host cells to hijack host cell signalling processes. By contrast, only two classes of metazoan AMPylases have been identified so far: enzymes containing a conserved filamentation induced by cAMP (Fic) domain (Fic AMPylases), which primarily modify the ER-resident chaperone BiP, and SelO, a mitochondrial AMPylase involved in redox signalling. In this review, we compare and contrast bacterial and metazoan Fic and non-Fic AMPylases, and summarize recent technological and conceptual developments in the emerging field of AMPylation.
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Affiliation(s)
- Bhaskar K Chatterjee
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA
| | - Matthias C Truttmann
- Cellular and Molecular Biology Program, University of Michigan, Ann Arbor, MI 48109, USA.,Department of Molecular and Integrative Physiology, University of Michigan, Ann Arbor, MI 48109, USA.,Geriatrics Center, University of Michigan, Ann Arbor, MI 48109, USA
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18
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Specificity of AMPylation of the human chaperone BiP is mediated by TPR motifs of FICD. Nat Commun 2021; 12:2426. [PMID: 33893288 PMCID: PMC8065156 DOI: 10.1038/s41467-021-22596-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 03/18/2021] [Indexed: 02/02/2023] Open
Abstract
To adapt to fluctuating protein folding loads in the endoplasmic reticulum (ER), the Hsp70 chaperone BiP is reversibly modified with adenosine monophosphate (AMP) by the ER-resident Fic-enzyme FICD/HYPE. The structural basis for BiP binding and AMPylation by FICD has remained elusive due to the transient nature of the enzyme-substrate-complex. Here, we use thiol-reactive derivatives of the cosubstrate adenosine triphosphate (ATP) to covalently stabilize the transient FICD:BiP complex and determine its crystal structure. The complex reveals that the TPR-motifs of FICD bind specifically to the conserved hydrophobic linker of BiP and thus mediate specificity for the domain-docked conformation of BiP. Furthermore, we show that both AMPylation and deAMPylation of BiP are not directly regulated by the presence of unfolded proteins. Together, combining chemical biology, crystallography and biochemistry, our study provides structural insights into a key regulatory mechanism that safeguards ER homeostasis.
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19
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Lu CH, McCloskey A, Chen FR, Nakayasu ES, Zhang LQ, Luo ZQ. Fic Proteins Inhibit the Activity of Topoisomerase IV by AMPylation in Diverse Bacteria. Front Microbiol 2020; 11:2084. [PMID: 32983060 PMCID: PMC7479194 DOI: 10.3389/fmicb.2020.02084] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2020] [Accepted: 08/07/2020] [Indexed: 12/14/2022] Open
Abstract
The Fic (filamentation induced by cyclic AMP) domain is a widely distributed motif with a conserved sequence of HPFx[D/E]GN[G/K]R, some of which regulate cellular activity by catalyzing the transfer of the AMP moiety from ATP to protein substrates. Some Fic proteins, including Fic-1 from the soil bacterium Pseudomonas fluorescens strain 2P24, have been shown to inhibit bacterial DNA replication by AMPylating the subunit B of DNA gyrase (GyrB), but the biochemical activity and cellular target of most Fic proteins remain unknown. Here, we report that Fic-2, which is another Fic protein from strain 2P24 and Fic-1 AMPylate the topoisomerase IV ParE at Tyr109. We also examined Fic proteins from several phylogenetically diverse bacteria and found that those from Yersinia pseudotuberculosis and Staphylococcus aureus AMPylate ParE and GrlB, the counterpart of ParE in Gram-positive bacteria, respectively. Modification by Fic-1 of P. fluorescens and FicY of Y. pseudotuberculosis inhibits the relaxation activity of topoisomerase IV. Consistent with the inhibition of ParE activity, ectopic expression of these Fic proteins causes cell filamentation akin to the canonical par phenotype in which nucleoids are assembled in the center of elongated cells, a process accompanied by the induction of the SOS response. Our results establish that Fic proteins from diverse bacterial species regulate chromosome division and cell separation in bacteria by targeting ParE.
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Affiliation(s)
- Can-Hua Lu
- Yunnan Academy of Tobacco Agriculture Science, Kunming, China.,Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China.,Department of Biological Sciences, Purdue University, West Lafayette, IN, United States
| | - Alix McCloskey
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States
| | - Fu-Rong Chen
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Ernesto S Nakayasu
- Biological Science Division, Pacific Northwest National Laboratory, Richland, WA, United States
| | - Li-Qun Zhang
- Department of Plant Pathology and MOA Key Lab of Pest Monitoring and Green Management, College of Plant Protection, China Agricultural University, Beijing, China
| | - Zhao-Qing Luo
- Department of Biological Sciences, Purdue University, West Lafayette, IN, United States
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20
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Sieber SA, Cappello S, Kielkowski P. From Young to Old: AMPylation Hits the Brain. Cell Chem Biol 2020; 27:773-779. [PMID: 32521229 DOI: 10.1016/j.chembiol.2020.05.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Revised: 04/19/2020] [Accepted: 05/20/2020] [Indexed: 01/08/2023]
Abstract
Protein post-translational modifications (PTMs) are implicated in numerous physiological processes and significantly contribute to complex regulatory networks of protein functions. Recently, a protein PTM called AMPylation was found to play a role in modulation of neurodevelopment and neurodegeneration. Combination of biochemical and chemical proteomic studies has uncovered the prevalence of this PTM in regulation of diverse metabolic pathways. In metazoans, thus far two protein AMP transferases have been identified to introduce AMPylation: FICD and SELO. These two proteins were found to be involved in unfolded protein response and redox homeostasis on the cellular level and in the case of FICD to adjust the development of glial cells and neurons in Drosophila and cerebral organoids, respectively. Together with findings on AMPylation and its association with toxic protein aggregation, we summarize in this Perspective the knowledge and putative future directions of protein AMPylation research.
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Affiliation(s)
- Stephan A Sieber
- Department of Chemistry, Chair of Organic Chemistry II, Center for Integrated Protein Science (CIPSM), Technische Universität München, Lichtenbergstraße 4, 85748 Garching, Germany
| | - Silvia Cappello
- Max Planck Institute of Psychiatry, Kraepelinstraße 2, 80804 München, Germany
| | - Pavel Kielkowski
- Department of Chemistry, Ludwig-Maximilians-Universität München, Butenandtstraße 5-13, 81377 München, Germany.
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21
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Perera LA, Rato C, Yan Y, Neidhardt L, McLaughlin SH, Read RJ, Preissler S, Ron D. An oligomeric state-dependent switch in the ER enzyme FICD regulates AMPylation and deAMPylation of BiP. EMBO J 2019; 38:e102177. [PMID: 31531998 PMCID: PMC6826200 DOI: 10.15252/embj.2019102177] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 07/25/2019] [Accepted: 07/26/2019] [Indexed: 11/23/2022] Open
Abstract
AMPylation is an inactivating modification that alters the activity of the major endoplasmic reticulum (ER) chaperone BiP to match the burden of unfolded proteins. A single ER-localised Fic protein, FICD (HYPE), catalyses both AMPylation and deAMPylation of BiP. However, the basis for the switch in FICD's activity is unknown. We report on the transition of FICD from a dimeric enzyme, that deAMPylates BiP, to a monomer with potent AMPylation activity. Mutations in the dimer interface, or of residues along an inhibitory pathway linking the dimer interface to the enzyme's active site, favour BiP AMPylation in vitro and in cells. Mechanistically, monomerisation relieves a repressive effect allosterically propagated from the dimer interface to the inhibitory Glu234, thereby permitting AMPylation-competent binding of MgATP. Moreover, a reciprocal signal, propagated from the nucleotide-binding site, provides a mechanism for coupling the oligomeric state and enzymatic activity of FICD to the energy status of the ER.
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Affiliation(s)
- Luke A Perera
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Claudia Rato
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Yahui Yan
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Lisa Neidhardt
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | | | - Randy J Read
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - Steffen Preissler
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
| | - David Ron
- Cambridge Institute for Medical ResearchUniversity of CambridgeCambridgeUK
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Abstract
Over the past decade the number and variety of protein post-translational modifications that have been detected and characterized in bacteria have rapidly increased. Most post-translational protein modifications occur in a relatively low number of bacterial proteins in comparison with eukaryotic proteins, and most of the modified proteins carry low, substoichiometric levels of modification; therefore, their structural and functional analysis is particularly challenging. The number of modifying enzymes differs greatly among bacterial species, and the extent of the modified proteome strongly depends on environmental conditions. Nevertheless, evidence is rapidly accumulating that protein post-translational modifications have vital roles in various cellular processes such as protein synthesis and turnover, nitrogen metabolism, the cell cycle, dormancy, sporulation, spore germination, persistence and virulence. Further research of protein post-translational modifications will fill current gaps in the understanding of bacterial physiology and open new avenues for treatment of infectious diseases.
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