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Caohuy H, Eidelman O, Chen T, Mungunsukh O, Yang Q, Walton NI, Pollard BS, Khanal S, Hentschel S, Florez C, Herbert AS, Pollard HB. Inflammation in the COVID-19 airway is due to inhibition of CFTR signaling by the SARS-CoV-2 spike protein. Sci Rep 2024; 14:16895. [PMID: 39043712 DOI: 10.1038/s41598-024-66473-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Accepted: 07/01/2024] [Indexed: 07/25/2024] Open
Abstract
SARS-CoV-2-contributes to sickness and death in COVID-19 patients partly by inducing a hyper-proinflammatory immune response in the host airway. This hyper-proinflammatory state involves activation of signaling by NFκB, and unexpectedly, ENaC, the epithelial sodium channel. Post-infection inflammation may also contribute to "Long COVID"/PASC. Enhanced signaling by NFκB and ENaC also marks the airway of patients suffering from cystic fibrosis, a life-limiting proinflammatory genetic disease due to inactivating mutations in the CFTR gene. We therefore hypothesized that inflammation in the COVID-19 airway might similarly be due to inhibition of CFTR signaling by SARS-CoV-2 spike protein, and therefore activation of both NFκB and ENaC signaling. We used western blot and electrophysiological techniques, and an organoid model of normal airway epithelia, differentiated on an air-liquid-interface (ALI). We found that CFTR protein expression and CFTR cAMP-activated chloride channel activity were lost when the model epithelium was exposed to SARS-CoV-2 spike proteins. As hypothesized, the absence of CFTR led to activation of both TNFα/NFκB signaling and α and γ ENaC. We had previously shown that the cardiac glycoside drugs digoxin, digitoxin and ouabain blocked interaction of spike protein and ACE2. Consistently, addition of 30 nM concentrations of the cardiac glycoside drugs, prevented loss of both CFTR protein and CFTR channel activity. ACE2 and CFTR were found to co-immunoprecipitate in both basal cells and differentiated epithelia. Thus spike-dependent CFTR loss might involve ACE2 as a bridge between Spike and CFTR. In addition, spike exposure to the epithelia resulted in failure of endosomal recycling to return CFTR to the plasma membrane. Thus, failure of CFTR recovery from endosomal recycling might be a mechanism for spike-dependent loss of CFTR. Finally, we found that authentic SARS-CoV-2 virus infection induced loss of CFTR protein, which was rescued by the cardiac glycoside drugs digitoxin and ouabain. Based on experiments with this organoid model of small airway epithelia, and comparisons with 16HBE14o- and other cell types expressing normal CFTR, we predict that inflammation in the COVID-19 airway may be mediated by inhibition of CFTR signaling by the SARS-CoV-2 spike protein, thus inducing a cystic fibrosis-like clinical phenotype. To our knowledge this is the first time COVID-19 airway inflammation has been experimentally traced in normal subjects to a contribution from SARS-CoV-2 spike-dependent inhibition of CFTR signaling.
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Affiliation(s)
- Hung Caohuy
- Department of Anatomy, Physiology and Genetics, Uniformed Services University School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Collaborative Health Initiative Research Program (CHIRP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Consortium for Health and Military Performance (CHAMP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Ofer Eidelman
- Department of Anatomy, Physiology and Genetics, Uniformed Services University School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Collaborative Health Initiative Research Program (CHIRP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Tinghua Chen
- Department of Anatomy, Physiology and Genetics, Uniformed Services University School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Collaborative Health Initiative Research Program (CHIRP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Consortium for Health and Military Performance (CHAMP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Ognoon Mungunsukh
- Department of Anatomy, Physiology and Genetics, Uniformed Services University School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Consortium for Health and Military Performance (CHAMP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Center for Military Precision Health, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Qingfeng Yang
- Department of Anatomy, Physiology and Genetics, Uniformed Services University School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Center for the Study of Traumatic Stress (CSTS), and Department of Psychiatry, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | - Nathan I Walton
- Department of Anatomy, Physiology and Genetics, Uniformed Services University School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Collaborative Health Initiative Research Program (CHIRP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
- Consortium for Health and Military Performance (CHAMP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA
| | | | - Sara Khanal
- Virology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD, 21702, USA
- The Geneva Foundation, Tacoma, WA, 98402, USA
| | - Shannon Hentschel
- Virology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD, 21702, USA
- Cherokee Nation Assurance, Catoosa, OK, 74015, USA
| | - Catalina Florez
- Virology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD, 21702, USA
- The Geneva Foundation, Tacoma, WA, 98402, USA
| | - Andrew S Herbert
- Virology Division, United States Army Medical Research Institute of Infectious Diseases (USAMRIID), Fort Detrick, Frederick, MD, 21702, USA
| | - Harvey B Pollard
- Department of Anatomy, Physiology and Genetics, Uniformed Services University School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
- Collaborative Health Initiative Research Program (CHIRP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
- Consortium for Health and Military Performance (CHAMP), Uniformed Services University of the Health Sciences, Bethesda, MD, 20814, USA.
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2
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Elgazzaz M, Filipeanu C, Lazartigues E. Angiotensin-Converting Enzyme 2 Posttranslational Modifications and Implications for Hypertension and SARS-CoV-2: 2023 Lewis K. Dahl Memorial Lecture. Hypertension 2024; 81:1438-1449. [PMID: 38567498 PMCID: PMC11168885 DOI: 10.1161/hypertensionaha.124.22067] [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] [Indexed: 04/04/2024]
Abstract
ACE2 (angiotensin-converting enzyme 2), a multifunctional transmembrane protein, is well recognized as an important member of the (RAS) renin-angiotensin system with important roles in the regulation of cardiovascular function by opposing the harmful effects of Ang-II (angiotensin II) and AT1R (Ang-II type 1 receptor) activation. More recently, ACE2 was found to be the entry point for the SARS-CoV-2 virus into cells, causing COVID-19. This finding has led to an exponential rise in the number of publications focused on ACE2, albeit these studies often have opposite objectives to the preservation of ACE2 in cardiovascular regulation. However, notwithstanding accumulating data of the role of ACE2 in the generation of angiotensin-(1-7) and SARS-CoV-2 internalization, numerous other putative roles of this enzyme remain less investigated and not yet characterized. Currently, no drug modulating ACE2 function or expression is available in the clinic, and the development of new pharmacological tools should attempt targeting each step of the lifespan of the protein from synthesis to degradation. The present review expands on our presentation during the 2023 Lewis K. Dahl Memorial Lecture Sponsored by the American Heart Association Council on Hypertension. We provide a critical summary of the current knowledge of the mechanisms controlling ACE2 internalization and intracellular trafficking, the mutual regulation with GPCRs (G-protein-coupled receptors) and other proteins, and posttranslational modifications. A major focus is on ubiquitination which has become a critical step in the modulation of ACE2 cellular levels.
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Affiliation(s)
- Mona Elgazzaz
- Department of Physiology, Augusta University, Medical College of Georgia, Augusta, GA 30912, USA
- Genetics Unit, Department of Histology and Cell Biology, Faculty of Medicine, Suez Canal University, Ismailia, 41522, Egypt
| | - Catalin Filipeanu
- Department of Pharmacology, Howard University, Washington, DC 20059, USA
| | - Eric Lazartigues
- Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
- Southeast Louisiana Veterans Health Care System, New Orleans, LA 70119, USA
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3
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Tahti EF, Blount JM, Jackson SN, Gao M, Gill NP, Smith SN, Pederson NJ, Rumph SN, Struyvenberg SA, Mackley IGP, Madden DR, Amacher JF. Additive energetic contributions of multiple peptide positions determine the relative promiscuity of viral and human sequences for PDZ domain targets. Protein Sci 2023; 32:e4611. [PMID: 36851847 PMCID: PMC10022582 DOI: 10.1002/pro.4611] [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: 12/31/2022] [Revised: 02/13/2023] [Accepted: 02/23/2023] [Indexed: 03/01/2023]
Abstract
Protein-protein interactions that involve recognition of short peptides are critical in cellular processes. Protein-peptide interaction surface areas are relatively small and shallow, and there are often overlapping specificities in families of peptide-binding domains. Therefore, dissecting selectivity determinants can be challenging. PDZ domains are a family of peptide-binding domains located in several intracellular signaling and trafficking pathways. These domains are also directly targeted by pathogens, and a hallmark of many oncogenic viral proteins is a PDZ-binding motif. However, amidst sequences that target PDZ domains, there is a wide spectrum in relative promiscuity. For example, the viral HPV16 E6 oncoprotein recognizes over double the number of PDZ domain-containing proteins as the cystic fibrosis transmembrane conductance regulator (CFTR) in the cell, despite similar PDZ targeting-sequences and identical motif residues. Here, we determine binding affinities for PDZ domains known to bind either HPV16 E6 alone or both CFTR and HPV16 E6, using peptides matching WT and hybrid sequences. We also use energy minimization to model PDZ-peptide complexes and use sequence analyses to investigate this difference. We find that while the majority of single mutations had marginal effects on overall affinity, the additive effect on the free energy of binding accurately describes the selectivity observed. Taken together, our results describe how complex and differing PDZ interactomes can be programmed in the cell.
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Affiliation(s)
- Elise F. Tahti
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Jadon M. Blount
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Sophie N. Jackson
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Melody Gao
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Nicholas P. Gill
- Department of BiochemistryGeisel School of Medicine at DartmouthHanoverNew HampshireUSA
| | - Sarah N. Smith
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Nick J. Pederson
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | | | | | - Iain G. P. Mackley
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
| | - Dean R. Madden
- Department of BiochemistryGeisel School of Medicine at DartmouthHanoverNew HampshireUSA
| | - Jeanine F. Amacher
- Department of ChemistryWestern Washington UniversityBellinghamWashingtonUSA
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4
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Li M, Du J, Liu W, Li Z, Lv F, Hu C, Dai Y, Zhang X, Zhang Z, Liu G, Pan Q, Yu Y, Wang X, Zhu P, Tan X, Garber PA, Zhou X. Comparative susceptibility of SARS-CoV-2, SARS-CoV, and MERS-CoV across mammals. THE ISME JOURNAL 2023; 17:549-560. [PMID: 36690780 PMCID: PMC9869846 DOI: 10.1038/s41396-023-01368-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/15/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 01/24/2023]
Abstract
Exploring wild reservoirs of pathogenic viruses is critical for their long-term control and for predicting future pandemic scenarios. Here, a comparative in vitro infection analysis was first performed on 83 cell cultures derived from 55 mammalian species using pseudotyped viruses bearing S proteins from SARS-CoV-2, SARS-CoV, and MERS-CoV. Cell cultures from Thomas's horseshoe bats, king horseshoe bats, green monkeys, and ferrets were found to be highly susceptible to SARS-CoV-2, SARS-CoV, and MERS-CoV pseudotyped viruses. Moreover, five variants (del69-70, D80Y, S98F, T572I, and Q675H), that beside spike receptor-binding domain can significantly alter the host tropism of SARS-CoV-2. An examination of phylogenetic signals of transduction rates revealed that closely related taxa generally have similar susceptibility to MERS-CoV but not to SARS-CoV and SARS-CoV-2 pseudotyped viruses. Additionally, we discovered that the expression of 95 genes, e.g., PZDK1 and APOBEC3, were commonly associated with the transduction rates of SARS-CoV, MERS-CoV, and SARS-CoV-2 pseudotyped viruses. This study provides basic documentation of the susceptibility, variants, and molecules that underlie the cross-species transmission of these coronaviruses.
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Affiliation(s)
- Meng Li
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Juan Du
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Weiqiang Liu
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zihao Li
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Fei Lv
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Chunyan Hu
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yichen Dai
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xiaoxiao Zhang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Zhan Zhang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Gaoming Liu
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Qi Pan
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
- University of Chinese Academy of Sciences, Beijing, 100049, China
| | - Yang Yu
- School of Life Sciences, University of Science and Technology of China, Anhui, China
| | - Xiao Wang
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Pingfen Zhu
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Xu Tan
- Beijing Advanced Center for Structural Biology, Beijing Frontier Innovation Center, School of Pharmaceutical Sciences, Tsinghua-Peking Center for Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Paul A Garber
- Department of Anthropology, Program in Ecology, Evolution, and Conservation Biology, University of Illinois, Urbana, IL, USA
| | - Xuming Zhou
- Key Laboratory of Animal Ecology and Conservation Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing, 100101, China.
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5
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Maginnis MS. β-arrestins and G protein-coupled receptor kinases in viral entry: A graphical review. Cell Signal 2023; 102:110558. [PMID: 36509265 PMCID: PMC9811579 DOI: 10.1016/j.cellsig.2022.110558] [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: 09/30/2022] [Revised: 12/07/2022] [Accepted: 12/08/2022] [Indexed: 12/14/2022]
Abstract
Viruses rely on host-cell machinery in order to invade host cells and carry out a successful infection. G-protein coupled receptor (GPCR)-mediated signaling pathways are master regulators of cellular physiological processing and are an attractive target for viruses to rewire cells during infection. In particular, the GPCR-associated scaffolding proteins β-arrestins and GPCR signaling effectors G-protein receptor kinases (GRKs) have been identified as key cellular factors that mediate viral entry and orchestrate signaling pathways that reprogram cells for viral replication. Interestingly, a broad range of viruses have been identified to activate and/or require GPCR-mediated pathways for infection, including polyomaviruses, flaviviruses, influenza virus, and SARS-CoV-2, demonstrating that these viruses may have conserved mechanisms of host-cell invasion. Thus, GPCR-mediated pathways highlight an attractive target for the development of broad antiviral therapies.
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Affiliation(s)
- Melissa S Maginnis
- Molecular and Biomedical Sciences, The University of Maine, Orono, ME 04469, United States of America; Graduate School of Biomedical Science and Engineering, The University of Maine, Orono, ME 04469, United States of America.
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6
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Human Coronavirus Cell Receptors Provide Challenging Therapeutic Targets. Vaccines (Basel) 2023; 11:vaccines11010174. [PMID: 36680018 PMCID: PMC9862439 DOI: 10.3390/vaccines11010174] [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: 12/02/2022] [Revised: 01/06/2023] [Accepted: 01/11/2023] [Indexed: 01/15/2023] Open
Abstract
Coronaviruses interact with protein or carbohydrate receptors through their spike proteins to infect cells. Even if the known protein receptors for these viruses have no evolutionary relationships, they do share ontological commonalities that the virus might leverage to exacerbate the pathophysiology. ANPEP/CD13, DPP IV/CD26, and ACE2 are the three protein receptors that are known to be exploited by several human coronaviruses. These receptors are moonlighting enzymes involved in several physiological processes such as digestion, metabolism, and blood pressure regulation; moreover, the three proteins are expressed in kidney, intestine, endothelium, and other tissues/cell types. Here, we spot the commonalities between the three enzymes, the physiological functions of the enzymes are outlined, and how blocking either enzyme results in systemic deregulations and multi-organ failures via viral infection or therapeutic interventions is addressed. It can be difficult to pinpoint any coronavirus as the target when creating a medication to fight them, due to the multiple processes that receptors are linked to and their extensive expression.
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7
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Tahti EF, Blount JM, Jackson SN, Gao M, Gill NP, Smith SN, Pederson NJ, Rumph SN, Struyvenberg SA, Mackley IGP, Madden DR, Amacher JF. Additive energetic contributions of multiple peptide positions determine the relative promiscuity of viral and human sequences for PDZ domain targets. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2022.12.31.522388. [PMID: 36711692 PMCID: PMC9881875 DOI: 10.1101/2022.12.31.522388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
Protein-protein interactions that include recognition of short sequences of amino acids, or peptides, are critical in cellular processes. Protein-peptide interaction surface areas are relatively small and shallow, and there are often overlapping specificities in families of peptide-binding domains. Therefore, dissecting selectivity determinants can be challenging. PDZ domains are an example of a peptide-binding domain located in several intracellular signaling and trafficking pathways, which form interactions critical for the regulation of receptor endocytic trafficking, tight junction formation, organization of supramolecular complexes in neurons, and other biological systems. These domains are also directly targeted by pathogens, and a hallmark of many oncogenic viral proteins is a PDZ-binding motif. However, amidst sequences that target PDZ domains, there is a wide spectrum in relative promiscuity. For example, the viral HPV16 E6 oncoprotein recognizes over double the number of PDZ domain-containing proteins as the cystic fibrosis transmembrane conductance regulator (CFTR) in the cell, despite similar PDZ targeting-sequences and identical motif residues. Here, we determine binding affinities for PDZ domains known to bind either HPV16 E6 alone or both CFTR and HPV16 E6, using peptides matching WT and hybrid sequences. We also use energy minimization to model PDZ-peptide complexes and use sequence analyses to investigate this difference. We find that while the majority of single mutations had a marginal effect on overall affinity, the additive effect on the free energy of binding accurately describes the selectivity observed. Taken together, our results describe how complex and differing PDZ interactomes can be programmed in the cell.
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Affiliation(s)
- Elise F. Tahti
- Department of Chemistry, Western Washington University, Bellingham, WA, USA
| | - Jadon M. Blount
- Department of Chemistry, Western Washington University, Bellingham, WA, USA
| | - Sophie N. Jackson
- Department of Chemistry, Western Washington University, Bellingham, WA, USA
| | - Melody Gao
- Department of Chemistry, Western Washington University, Bellingham, WA, USA
| | - Nicholas P. Gill
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Sarah N. Smith
- Department of Chemistry, Western Washington University, Bellingham, WA, USA
| | - Nick J. Pederson
- Department of Chemistry, Western Washington University, Bellingham, WA, USA
| | - Simone N. Rumph
- Department of Biochemistry, Bowdoin College, Brunswick, ME, USA
| | | | - Iain G. P. Mackley
- Department of Chemistry, Western Washington University, Bellingham, WA, USA
| | - Dean R. Madden
- Department of Biochemistry, Geisel School of Medicine at Dartmouth, Hanover, NH, USA
| | - Jeanine F. Amacher
- Department of Chemistry, Western Washington University, Bellingham, WA, USA
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8
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Bezzerri V, Gentili V, Api M, Finotti A, Papi C, Tamanini A, Boni C, Baldisseri E, Olioso D, Duca M, Tedesco E, Leo S, Borgatti M, Volpi S, Pinton P, Cabrini G, Gambari R, Blasi F, Lippi G, Rimessi A, Rizzo R, Cipolli M. SARS-CoV-2 viral entry and replication is impaired in Cystic Fibrosis airways due to ACE2 downregulation. Nat Commun 2023; 14:132. [PMID: 36627352 PMCID: PMC9830623 DOI: 10.1038/s41467-023-35862-0] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2021] [Accepted: 01/04/2023] [Indexed: 01/11/2023] Open
Abstract
As an inherited disorder characterized by severe pulmonary disease, cystic fibrosis could be considered a comorbidity for coronavirus disease 2019. Instead, current clinical evidence seems to be heading in the opposite direction. To clarify whether host factors expressed by the Cystic Fibrosis epithelia may influence coronavirus disease 2019 progression, here we describe the expression of SARS-CoV-2 receptors in primary airway epithelial cells. We show that angiotensin converting enzyme 2 (ACE2) expression and localization are regulated by Cystic Fibrosis Transmembrane Conductance Regulator (CFTR) channel. Consistently, our results indicate that dysfunctional CFTR channels alter susceptibility to SARS-CoV-2 infection, resulting in reduced viral entry and replication in Cystic Fibrosis cells. Depending on the pattern of ACE2 expression, the SARS-CoV-2 spike (S) protein induced high levels of Interleukin 6 in healthy donor-derived primary airway epithelial cells, but a very weak response in primary Cystic Fibrosis cells. Collectively, these data support that Cystic Fibrosis condition may be at least partially protecting from SARS-CoV-2 infection.
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Affiliation(s)
- Valentino Bezzerri
- Cystic Fibrosis Center of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy.,Section of Clinical Biochemistry, University of Verona, Verona, Italy
| | - Valentina Gentili
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy
| | - Martina Api
- Cystic Fibrosis Center of Ancona, Azienda Ospedaliero Universitaria Ospedali Riuniti, Ancona, Italy
| | - Alessia Finotti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,Center on Innovative Therapies for Cystic Fibrosis, University of Ferrara, Ferrara, Italy
| | - Chiara Papi
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy
| | - Anna Tamanini
- Section of Molecular Pathology, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Christian Boni
- Cystic Fibrosis Center of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Elena Baldisseri
- Cystic Fibrosis Center of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Debora Olioso
- Section of Clinical Biochemistry, University of Verona, Verona, Italy
| | - Martina Duca
- Cystic Fibrosis Center of Ancona, Azienda Ospedaliero Universitaria Ospedali Riuniti, Ancona, Italy
| | - Erika Tedesco
- Cystic Fibrosis Center of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Sara Leo
- Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Monica Borgatti
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,Center on Innovative Therapies for Cystic Fibrosis, University of Ferrara, Ferrara, Italy
| | - Sonia Volpi
- Cystic Fibrosis Center of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy
| | - Paolo Pinton
- Center on Innovative Therapies for Cystic Fibrosis, University of Ferrara, Ferrara, Italy.,Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Giulio Cabrini
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,Center on Innovative Therapies for Cystic Fibrosis, University of Ferrara, Ferrara, Italy
| | - Roberto Gambari
- Department of Life Sciences and Biotechnology, University of Ferrara, Ferrara, Italy.,Center on Innovative Therapies for Cystic Fibrosis, University of Ferrara, Ferrara, Italy
| | - Francesco Blasi
- Internal Medicine Department, Respiratory Unit and Cystic Fibrosis Center, Fondazione IRCCS Cà Granda Ospedale Maggiore Policlinico Milano, Milan, Italy.,Department of Pathophysiology and Transplantation, Università degli Studi di Milano, Milan, Italy
| | - Giuseppe Lippi
- Section of Clinical Biochemistry, University of Verona, Verona, Italy
| | - Alessandro Rimessi
- Center on Innovative Therapies for Cystic Fibrosis, University of Ferrara, Ferrara, Italy.,Department of Medical Sciences, University of Ferrara, Ferrara, Italy
| | - Roberta Rizzo
- Department of Chemical and Pharmaceutical Sciences, University of Ferrara, Ferrara, Italy
| | - Marco Cipolli
- Cystic Fibrosis Center of Verona, Azienda Ospedaliera Universitaria Integrata, Verona, Italy. .,Center on Innovative Therapies for Cystic Fibrosis, University of Ferrara, Ferrara, Italy.
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9
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Devaux CA, Camoin-Jau L. An update on angiotensin-converting enzyme 2 structure/functions, polymorphism, and duplicitous nature in the pathophysiology of coronavirus disease 2019: Implications for vascular and coagulation disease associated with severe acute respiratory syndrome coronavirus infection. Front Microbiol 2022; 13:1042200. [PMID: 36519165 PMCID: PMC9742611 DOI: 10.3389/fmicb.2022.1042200] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 11/07/2022] [Indexed: 08/01/2023] Open
Abstract
It has been known for many years that the angiotensin-converting enzyme 2 (ACE2) is a cell surface enzyme involved in the regulation of blood pressure. More recently, it was proven that the severe acute respiratory syndrome coronavirus (SARS-CoV-2) interacts with ACE2 to enter susceptible human cells. This functional duality of ACE2 tends to explain why this molecule plays such an important role in the clinical manifestations of coronavirus disease 2019 (COVID-19). At the very start of the pandemic, a publication from our Institute (entitled "ACE2 receptor polymorphism: susceptibility to SARS-CoV-2, hypertension, multi-organ failure, and COVID-19 disease outcome"), was one of the first reviews linking COVID-19 to the duplicitous nature of ACE2. However, even given that COVID-19 pathophysiology may be driven by an imbalance in the renin-angiotensin system (RAS), we were still far from understanding the complexity of the mechanisms which are controlled by ACE2 in different cell types. To gain insight into the physiopathology of SARS-CoV-2 infection, it is essential to consider the polymorphism and expression levels of the ACE2 gene (including its alternative isoforms). Over the past 2 years, an impressive amount of new results have come to shed light on the role of ACE2 in the pathophysiology of COVID-19, requiring us to update our analysis. Genetic linkage studies have been reported that highlight a relationship between ACE2 genetic variants and the risk of developing hypertension. Currently, many research efforts are being undertaken to understand the links between ACE2 polymorphism and the severity of COVID-19. In this review, we update the state of knowledge on the polymorphism of ACE2 and its consequences on the susceptibility of individuals to SARS-CoV-2. We also discuss the link between the increase of angiotensin II levels among SARS-CoV-2-infected patients and the development of a cytokine storm associated microvascular injury and obstructive thrombo-inflammatory syndrome, which represent the primary causes of severe forms of COVID-19 and lethality. Finally, we summarize the therapeutic strategies aimed at preventing the severe forms of COVID-19 that target ACE2. Changing paradigms may help improve patients' therapy.
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Affiliation(s)
- Christian A. Devaux
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU–Méditerranée Infection, Marseille, France
- Center National de la Recherche Scientifique, Marseille, France
| | - Laurence Camoin-Jau
- Aix-Marseille Université, IRD, APHM, MEPHI, IHU–Méditerranée Infection, Marseille, France
- Laboratoire d’Hématologie, Hôpital de La Timone, APHM, Boulevard Jean-Moulin, Marseille, France
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10
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Prasad V, Bartenschlager R. A snapshot of protein trafficking in SARS-CoV-2 infection. Biol Cell 2022; 115:e2200073. [PMID: 36314261 PMCID: PMC9874443 DOI: 10.1111/boc.202200073] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2022] [Revised: 09/27/2022] [Accepted: 10/13/2022] [Indexed: 02/07/2023]
Abstract
SARS-CoV-2 is a human pathogenic virus responsible for the COVID-19 (coronavirus disease 2019) pandemic. The infection cycle of SARS-CoV-2 involves several related steps, including virus entry, gene expression, RNA replication, assembly of infectious virions and their egress. For all of these steps, the virus relies on and exploits host cell factors, cellular organelles, and processes such as endocytosis, nuclear transport, protein secretion, metabolite transport at membrane contact sites (MSC) and exocytotic pathways. To do this, SARS-CoV-2 has evolved multifunctional viral proteins that hijack cellular factors and modulate their function by unique strategies. In this Review, we highlight cellular trafficking factors, processes, and organelles of relevance to the SARS-CoV-2 infection cycle and how viral proteins make use of and perturb cellular transport during the viral infection cycle.
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Affiliation(s)
- Vibhu Prasad
- Department of Infectious DiseasesMolecular VirologyHeidelberg UniversityHeidelbergGermany
| | - Ralf Bartenschlager
- Department of Infectious DiseasesMolecular VirologyHeidelberg UniversityHeidelbergGermany,Division Virus‐Associated CarcinogenesisGerman Cancer Research CenterHeidelbergGermany,German Center for Infection ResearchHeidelberg Partner SiteHeidelbergGermany
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11
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The ACE2 Receptor for Coronavirus Entry Is Localized at Apical Cell—Cell Junctions of Epithelial Cells. Cells 2022; 11:cells11040627. [PMID: 35203278 PMCID: PMC8870730 DOI: 10.3390/cells11040627] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Revised: 02/03/2022] [Accepted: 02/09/2022] [Indexed: 02/04/2023] Open
Abstract
Transmembrane proteins of adherens and tight junctions are known targets for viruses and bacterial toxins. The coronavirus receptor ACE2 has been localized at the apical surface of epithelial cells, but it is not clear whether ACE2 is localized at apical Cell—Cell junctions and whether it associates with junctional proteins. Here we explored the expression and localization of ACE2 and its association with transmembrane and tight junction proteins in epithelial tissues and cultured cells by data mining, immunoblotting, immunofluorescence microscopy, and co-immunoprecipitation experiments. ACE2 mRNA is abundant in epithelial tissues, where its expression correlates with the expression of the tight junction proteins cingulin and occludin. In cultured epithelial cells ACE2 mRNA is upregulated upon differentiation and ACE2 protein is widely expressed and co-immunoprecipitates with the transmembrane proteins ADAM17 and CD9. We show by immunofluorescence microscopy that ACE2 colocalizes with ADAM17 and CD9 and the tight junction protein cingulin at apical junctions of intestinal (Caco-2), mammary (Eph4) and kidney (mCCD) epithelial cells. These observations identify ACE2, ADAM17 and CD9 as new epithelial junctional transmembrane proteins and suggest that the cytokine-enhanced endocytic internalization of junction-associated protein complexes comprising ACE2 may promote coronavirus entry.
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Yang B, Jia Y, Meng Y, Xue Y, Liu K, Li Y, Liu S, Li X, Cui K, Shang L, Cheng T, Zhang Z, Hou Y, Yang X, Yan H, Duan L, Tong Z, Wu C, Liu Z, Gao S, Zhuo S, Huang W, Gao GF, Qi J, Shang G. SNX27 suppresses SARS-CoV-2 infection by inhibiting viral lysosome/late endosome entry. Proc Natl Acad Sci U S A 2022; 119:e2117576119. [PMID: 35022217 PMCID: PMC8794821 DOI: 10.1073/pnas.2117576119] [Citation(s) in RCA: 18] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2021] [Accepted: 12/08/2021] [Indexed: 12/28/2022] Open
Abstract
After binding to its cell surface receptor angiotensin converting enzyme 2 (ACE2), severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) enters the host cell through directly fusing with plasma membrane (cell surface pathway) or undergoing endocytosis traveling to lysosome/late endosome for membrane fusion (endocytic pathway). However, the endocytic entry regulation by host cell remains elusive. Recent studies show ACE2 possesses a type I PDZ binding motif (PBM) through which it could interact with a PDZ domain-containing protein such as sorting nexin 27 (SNX27). In this study, we determined the ACE2-PBM/SNX27-PDZ complex structure, and, through a series of functional analyses, we found SNX27 plays an important role in regulating the homeostasis of ACE2 receptor. More importantly, we demonstrated SNX27, together with retromer complex (the core component of the endosomal protein sorting machinery), prevents ACE2/virus complex from entering lysosome/late endosome, resulting in decreased viral entry in cells where the endocytic pathway dominates. The ACE2/virus retrieval mediated by SNX27-retromer could be considered as a countermeasure against invasion of ACE2 receptor-using SARS coronaviruses.
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Affiliation(s)
- Bo Yang
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
- Shanxi Provincial Key Laboratory for Major Infectious Disease Response, Taiyuan 030012, China
| | - Yuanyuan Jia
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Yumin Meng
- Chinese Academy of Sciences Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Ying Xue
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Kefang Liu
- Chinese Academy of Sciences Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Yan Li
- Chinese Academy of Sciences Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Shichao Liu
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Xiaoxiong Li
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Kaige Cui
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Lina Shang
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Tianyou Cheng
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Zhichao Zhang
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Yingxiang Hou
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
- Institutes of Biomedical Sciences, Shanxi University, Taiyuan 030006, China
| | - Xiaozhu Yang
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Hong Yan
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Liqiang Duan
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Zhou Tong
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
- Chinese Academy of Sciences Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Changxin Wu
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
- Institutes of Biomedical Sciences, Shanxi University, Taiyuan 030006, China
| | - Zhida Liu
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Shan Gao
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China
| | - Shu Zhuo
- Signet Therapeutics Inc, Shenzhen 518000, China
| | - Weijin Huang
- Division of HIV/AIDS and Sex-Transmitted Virus Vaccines, National Institutes for Food and Drug Control, Beijing 102629, China
| | - George Fu Gao
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China;
- Chinese Academy of Sciences Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jianxun Qi
- Chinese Academy of Sciences Key Laboratory of Pathogen Microbiology and Immunology, Institute of Microbiology, Chinese Academy of Sciences, Beijing 100101, China;
| | - Guijun Shang
- Shanxi Academy of Advanced Research and Innovation, Taiyuan 030032, China;
- Shanxi Provincial Key Laboratory for Major Infectious Disease Response, Taiyuan 030012, China
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Caillet-Saguy C, Wolff N. PDZ-Containing Proteins Targeted by the ACE2 Receptor. Viruses 2021; 13:2281. [PMID: 34835087 PMCID: PMC8624105 DOI: 10.3390/v13112281] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 11/09/2021] [Accepted: 11/10/2021] [Indexed: 12/28/2022] Open
Abstract
Angiotensin-converting enzyme 2 (ACE2) is a main receptor for SARS-CoV-2 entry to the host cell. Indeed, the first step in viral entry is the binding of the viral trimeric spike (S) protein to ACE2. Abundantly present in human epithelial cells of many organs, ACE2 is also expressed in the human brain. ACE2 is a type I membrane protein with an extracellular N-terminal peptidase domain and a C-terminal collectrin-like domain that ends with a single transmembrane helix and an intracellular 44-residue segment. This C-terminal segment contains a PDZ-binding motif (PBM) targeting protein-interacting domains called PSD-95/Dlg/ZO-1 (PDZ). Here, we identified the human PDZ specificity profile of the ACE2 PBM using the high-throughput holdup assay and measuring the binding intensities of the PBM of ACE2 against the full human PDZome. We discovered 14 human PDZ binders of ACE2 showing significant binding with dissociation constants' values ranging from 3 to 81 μM. NHERF, SHANK, and SNX27 proteins found in this study are involved in protein trafficking. The PDZ/PBM interactions with ACE2 could play a role in ACE2 internalization and recycling that could be of benefit for the virus entry. Interestingly, most of the ACE2 partners we identified are expressed in neuronal cells, such as SHANK and MAST families, and modifications of the interactions between ACE2 and these neuronal proteins may be involved in the neurological symptoms of COVID-19.
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Affiliation(s)
- Célia Caillet-Saguy
- Unité Récepteurs-Canaux, Institut Pasteur, UMR CNRS 3571, 75015 Paris, France
| | - Nicolas Wolff
- Unité Récepteurs-Canaux, Institut Pasteur, UMR CNRS 3571, 75015 Paris, France
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Zhang Q, Friedman PA. Receptor-Loaded Virion Endangers GPCR Signaling: Mechanistic Exploration of SARS-CoV-2 Infections and Pharmacological Implications. Int J Mol Sci 2021; 22:ijms222010963. [PMID: 34681624 PMCID: PMC8535999 DOI: 10.3390/ijms222010963] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2021] [Revised: 10/07/2021] [Accepted: 10/09/2021] [Indexed: 01/14/2023] Open
Abstract
SARS-CoV-2 exploits the respiratory tract epithelium including lungs as the primary entry point and reaches other organs through hematogenous expansion, consequently causing multiorgan injury. Viral E protein interacts with cell junction-associated proteins PALS1 or ZO-1 to gain massive penetration by disrupting the inter-epithelial barrier. Conversely, receptor-mediated viral invasion ensures limited but targeted infections in multiple organs. The ACE2 receptor represents the major virion loading site by virtue of its wide tissue distribution as demonstrated in highly susceptible lung, intestine, and kidney. In brain, NRP1 mediates viral endocytosis in a similar manner to ACE2. Prominently, PDZ interaction involves the entire viral loading process either outside or inside the host cells, whereas E, ACE2, and NRP1 provide the PDZ binding motif required for interacting with PDZ domain-containing proteins PALS1, ZO-1, and NHERF1, respectively. Hijacking NHERF1 and β-arrestin by virion loading may impair specific sensory GPCR signalosome assembling and cause disordered cellular responses such as loss of smell and taste. PDZ interaction enhances SARS-CoV-2 invasion by supporting viral receptor membrane residence, implying that the disruption of these interactions could diminish SARS-CoV-2 infections and be another therapeutic strategy against COVID-19 along with antibody therapy. GPCR-targeted drugs are likely to alleviate pathogenic symptoms-associated with SARS-CoV-2 infection.
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Domain Analysis and Motif Matcher (DAMM): A Program to Predict Selectivity Determinants in Monosiga brevicollis PDZ Domains Using Human PDZ Data. Molecules 2021; 26:molecules26196034. [PMID: 34641578 PMCID: PMC8512817 DOI: 10.3390/molecules26196034] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2021] [Revised: 09/30/2021] [Accepted: 10/01/2021] [Indexed: 11/17/2022] Open
Abstract
Choanoflagellates are single-celled eukaryotes with complex signaling pathways. They are considered the closest non-metazoan ancestors to mammals and other metazoans and form multicellular-like states called rosettes. The choanoflagellate Monosiga brevicollis contains over 150 PDZ domains, an important peptide-binding domain in all three domains of life (Archaea, Bacteria, and Eukarya). Therefore, an understanding of PDZ domain signaling pathways in choanoflagellates may provide insight into the origins of multicellularity. PDZ domains recognize the C-terminus of target proteins and regulate signaling and trafficking pathways, as well as cellular adhesion. Here, we developed a computational software suite, Domain Analysis and Motif Matcher (DAMM), that analyzes peptide-binding cleft sequence identity as compared with human PDZ domains and that can be used in combination with literature searches of known human PDZ-interacting sequences to predict target specificity in choanoflagellate PDZ domains. We used this program, protein biochemistry, fluorescence polarization, and structural analyses to characterize the specificity of A9UPE9_MONBE, a M. brevicollis PDZ domain-containing protein with no homology to any metazoan protein, finding that its PDZ domain is most similar to those of the DLG family. We then identified two endogenous sequences that bind A9UPE9 PDZ with <100 μM affinity, a value commonly considered the threshold for cellular PDZ-peptide interactions. Taken together, this approach can be used to predict cellular targets of previously uncharacterized PDZ domains in choanoflagellates and other organisms. Our data contribute to investigations into choanoflagellate signaling and how it informs metazoan evolution.
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