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Kalaj BN, La Clair JJ, Shen Y, Schwieters CD, Deshmukh L, Burkart MD. Quantitative Characterization of Chain-Flipping of Acyl Carrier Protein of Escherichia coli Using Chemical Exchange NMR. J Am Chem Soc 2024; 146:18650-18660. [PMID: 38875499 PMCID: PMC11299499 DOI: 10.1021/jacs.4c05509] [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: 06/16/2024]
Abstract
The acyl carrier protein of Escherichia coli, termed AcpP, is a prototypical example of type II fatty acid synthase systems found in many bacteria. It serves as a central hub by accepting diverse acyl moieties (4-18 carbons) and shuttling them between its multiple enzymatic partners to generate fatty acids. Prior structures of acyl-AcpPs established that thioester-linked acyl cargos are sequestered within AcpP's hydrophobic lumen. In contrast, structures of enzyme-bound acyl-AcpPs showed translocation of AcpP-tethered acyl chains into the active sites of enzymes. The mechanistic underpinnings of this conformational interplay, termed chain-flipping, are unclear. Here, using heteronuclear NMR spectroscopy, we reveal that AcpP-tethered acyl chains (6-10 carbons) spontaneously adopt lowly populated solvent-exposed conformations. To this end, we devised a new strategy to replace AcpP's thioester linkages with 15N-labeled amide bonds, which facilitated direct "visualization" of these excited states using NMR chemical exchange saturation transfer and relaxation dispersion measurements. Global fitting of the corresponding data yielded kinetic rate constants of the underlying equilibrium and populations and lifetimes of solvent-exposed states. The latter were influenced by acyl chain composition and ranged from milliseconds to submilliseconds for chains containing six, eight, and ten carbons, owing to their variable interactions with AcpP's hydrophobic core. Although transient, the exposure of AcpP-tethered acyl chains to the solvent may allow relevant enzymes to gain access to its active thioester, and the enzyme-induced selection of this conformation will culminate in the production of fatty acids.
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Affiliation(s)
- Brianna N. Kalaj
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - James J. La Clair
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Yang Shen
- Laboratory of Chemical Physics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Charles D. Schwieters
- Computational Biomolecular Magnetic Resonance Core, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Lalit Deshmukh
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
| | - Michael D. Burkart
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093, USA
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2
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Geijtenbeek KW, Aranda AS, Sanz AS, Janzen J, Bury AE, Kors S, Al Amery N, Schmitz NCM, Reits EAJ, Schipper-Krom S. Insulin-Degrading Enzyme Efficiently Degrades polyQ Peptides but not Expanded polyQ Huntingtin Fragments. J Huntingtons Dis 2024; 13:201-214. [PMID: 38640164 DOI: 10.3233/jhd-230583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/21/2024]
Abstract
Background Huntington's disease is an inheritable autosomal dominant disorder caused by an expanded CAG trinucleotide repeat within the Huntingtin gene, leading to a polyglutamine (polyQ) expansion in the mutant protein. Objective A potential therapeutic approach for delaying or preventing the onset of the disease involves enhancing the degradation of the aggregation-prone polyQ-expanded N-terminal mutant huntingtin (mHTT) exon1 fragment. A few proteases and peptidases have been identified that are able to cleave polyQ fragments with low efficiency. This study aims to identify a potent polyQ-degrading endopeptidase. Methods Here we used quenched polyQ peptides to identify a polyQ-degrading endopeptidase. Next we investigated its role on HTT turnover, using purified polyQ-expanded HTT fragments and striatal cells expressing mHTT exon1 peptides. Results We identified insulin-degrading enzyme (IDE) as a novel endopeptidase for degrading polyQ peptides. IDE was, however, ineffective in reducing purified polyQ-expanded HTT fragments. Similarly, in striatal cells expressing mHTT exon1 peptides, IDE did not enhance mHTT turnover. Conclusions This study shows that despite IDE's efficiency in degrading polyQ peptides, it does not contribute to the direct degradation of polyQ-expanded mHTT fragments.
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Affiliation(s)
- Karlijne W Geijtenbeek
- Amsterdam UMC, University of Amsterdam, Medical Biology, Meibergdreef, Amsterdam, Netherlands
| | - Angela Santiago Aranda
- Amsterdam UMC, University of Amsterdam, Medical Biology, Meibergdreef, Amsterdam, Netherlands
| | - Alicia Sanz Sanz
- Amsterdam UMC, University of Amsterdam, Medical Biology, Meibergdreef, Amsterdam, Netherlands
| | - Jolien Janzen
- Amsterdam UMC, University of Amsterdam, Medical Biology, Meibergdreef, Amsterdam, Netherlands
| | - Aleksandra E Bury
- Amsterdam UMC, University of Amsterdam, Medical Biology, Meibergdreef, Amsterdam, Netherlands
| | - Suzan Kors
- Amsterdam UMC, University of Amsterdam, Medical Biology, Meibergdreef, Amsterdam, Netherlands
| | | | - Nina C M Schmitz
- Amsterdam UMC, University of Amsterdam, Medical Biology, Meibergdreef, Amsterdam, Netherlands
| | - Eric A J Reits
- Amsterdam UMC, University of Amsterdam, Medical Biology, Meibergdreef, Amsterdam, Netherlands
| | - Sabine Schipper-Krom
- Amsterdam UMC, University of Amsterdam, Medical Biology, Meibergdreef, Amsterdam, Netherlands
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3
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Tundo GR, Grasso G, Persico M, Tkachuk O, Bellia F, Bocedi A, Marini S, Parravano M, Graziani G, Fattorusso C, Sbardella D. The Insulin-Degrading Enzyme from Structure to Allosteric Modulation: New Perspectives for Drug Design. Biomolecules 2023; 13:1492. [PMID: 37892174 PMCID: PMC10604886 DOI: 10.3390/biom13101492] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2023] [Revised: 09/11/2023] [Accepted: 09/17/2023] [Indexed: 10/29/2023] Open
Abstract
The insulin-degrading enzyme (IDE) is a Zn2+ peptidase originally discovered as the main enzyme involved in the degradation of insulin and other amyloidogenic peptides, such as the β-amyloid (Aβ) peptide. Therefore, a role for the IDE in the cure of diabetes and Alzheimer's disease (AD) has been long envisaged. Anyway, its role in degrading amyloidogenic proteins remains not clearly defined and, more recently, novel non-proteolytic functions of the IDE have been proposed. From a structural point of view, the IDE presents an atypical clamshell structure, underscoring unique enigmatic enzymological properties. A better understanding of the structure-function relationship may contribute to solving some existing paradoxes of IDE biology and, in light of its multifunctional activity, might lead to novel therapeutic approaches.
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Affiliation(s)
- Grazia Raffaella Tundo
- Department of Clinical Science and Traslational Medicine, University of Rome Tor Vergata, Via Della Ricerca Scientifica 1, 00133 Rome, Italy; (G.R.T.)
| | - Giuseppe Grasso
- Department of Chemical Sciences, University of Catania, Viale Andrea Doria 6, 95125 Catania, Italy;
| | - Marco Persico
- Department of Pharmacy, University of Naples “Federico II”, Via D. Montesano 49, 80131 Napoli, Italy; (M.P.); (O.T.)
| | - Oleh Tkachuk
- Department of Pharmacy, University of Naples “Federico II”, Via D. Montesano 49, 80131 Napoli, Italy; (M.P.); (O.T.)
| | - Francesco Bellia
- Institute of Crystallography, CNR, Via Paolo Gaifami 18, 95126 Catania, Italy
| | - Alessio Bocedi
- Department of Chemical Sciences and Technologies, University of Rome Tor Vergata, Via della Ricerca Scientifica 1, 00133 Rome, Italy
| | - Stefano Marini
- Department of Clinical Science and Traslational Medicine, University of Rome Tor Vergata, Via Della Ricerca Scientifica 1, 00133 Rome, Italy; (G.R.T.)
| | | | - Grazia Graziani
- Department of Systems Medicine, University of Rome Tor Vergata, Via Montpellier 1, 00133 Rome, Italy;
| | - Caterina Fattorusso
- Department of Pharmacy, University of Naples “Federico II”, Via D. Montesano 49, 80131 Napoli, Italy; (M.P.); (O.T.)
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4
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Shihora A, Elias RD, Hammond JA, Ghirlando R, Deshmukh L. ALS Variants of Annexin A11's Proline-Rich Domain Impair Its S100A6-Mediated Fibril Dissolution. ACS Chem Neurosci 2023; 14:2583-2589. [PMID: 37433222 PMCID: PMC10401653 DOI: 10.1021/acschemneuro.3c00169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2023] [Accepted: 07/05/2023] [Indexed: 07/13/2023] Open
Abstract
Mutations in the proline-rich domain (PRD) of annexin A11 are linked to amyotrophic lateral sclerosis (ALS), a fatal neurodegenerative disease, and generate abundant neuronal A11 inclusions by an unknown mechanism. Here, we demonstrate that recombinant A11-PRD and its ALS-associated variants form liquidlike condensates that transform into β-sheet-rich amyloid fibrils. Surprisingly, these fibrils dissolved in the presence of S100A6, an A11 binding partner overexpressed in ALS. The ALS variants of A11-PRD showed longer fibrillization half-times and slower dissolution, even though their binding affinities for S100A6 were not significantly affected. These findings indicate a slower fibril-to-monomer exchange for these ALS variants, resulting in a decreased level of S100A6-mediated fibril dissolution. These ALS-A11 variants are thus more likely to remain aggregated despite their slower fibrillization.
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Affiliation(s)
- Aman Shihora
- Department
of Chemistry and Biochemistry, University
of California San Diego, La Jolla, California 92093, United States
| | - Ruben D. Elias
- Department
of Chemistry and Biochemistry, University
of California San Diego, La Jolla, California 92093, United States
| | - John A. Hammond
- Scripps
Research Biophysics and Biochemistry Core, The Scripps Research Institute, La Jolla, California 92037, United States
| | - Rodolfo Ghirlando
- Laboratory
of Molecular Biology, National Institute of Diabetes and Digestive
and Kidney Diseases, National Institutes
of Health, Bethesda, Maryland 20892, United States
| | - Lalit Deshmukh
- Department
of Chemistry and Biochemistry, University
of California San Diego, La Jolla, California 92093, United States
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5
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Elias RD, Zhu Y, Su Q, Ghirlando R, Zhang J, Deshmukh L. Reversible phase separation of ESCRT protein ALIX through tyrosine phosphorylation. SCIENCE ADVANCES 2023; 9:eadg3913. [PMID: 37450591 PMCID: PMC10348681 DOI: 10.1126/sciadv.adg3913] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/20/2022] [Accepted: 06/14/2023] [Indexed: 07/18/2023]
Abstract
Cytokinetic abscission, the last step of cell division, is regulated by the ESCRT machinery. In response to mitotic errors, ESCRT proteins, namely, ALIX, CHMP4B, and CHMP4C, accumulate in the cytosolic compartments termed "abscission checkpoint bodies" (ACBs) to delay abscission and prevent tumorigenesis. ALIX contributes to the biogenesis and stability of ACBs via an unknown mechanism. We show that ALIX phase separates into nondynamic condensates in vitro and in vivo, mediated by the amyloidogenic portion of its proline-rich domain. ALIX condensates confined CHMP4 paralogs in vitro. These condensates dissolved and reformed upon reversible tyrosine phosphorylation of ALIX, mediated by Src kinase and PTP1B, and sequestration of CHMP4C altered their Src-mediated dissolution. NMR analysis revealed how ALIX triggers the activation of CHMP4 proteins, which is required for successful abscission. These results implicate ALIX's phase separation in the modulation of ACBs. This study also highlights how posttranslational modifications can control protein phase separation.
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Affiliation(s)
- Ruben D. Elias
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Yingqi Zhu
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
| | - Qi Su
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
| | - Rodolfo Ghirlando
- Laboratory of Molecular Biology, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| | - Jin Zhang
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Pharmacology, University of California, San Diego, La Jolla, CA 92093, USA
- Department of Bioengineering, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lalit Deshmukh
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, CA 92093, USA
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Insights into Non-Proteolytic Inhibitory Mechanisms of Polymorphic Early-Stage Amyloid β Oligomers by Insulin Degrading Enzyme. Biomolecules 2022; 12:biom12121886. [PMID: 36551314 PMCID: PMC9776231 DOI: 10.3390/biom12121886] [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: 11/20/2022] [Revised: 12/11/2022] [Accepted: 12/15/2022] [Indexed: 12/23/2022] Open
Abstract
Insulin degrading enzyme (IDE) has been detected in the cerebrospinal fluid media and plays a role in encapsulating and degrading the amyloid β (Aβ) monomer, thus regulating the levels of Aβ monomers. The current work illustrates a first study by which IDE encapsulates polymorphic early-stage Aβ oligomers. The main goal of this study was to investigate the molecular mechanisms of IDE activity on the encapsulated early-stage Aβ dimers: fibril-like and random coil/α-helix dimers. Our work led to several findings. First, when the fibril-like Aβ dimer interacts with IDE-C domain, IDE does not impede the contact between the monomers, but plays a role as a 'dead-end' chaperone protein. Second, when the fibril-like Aβ dimer interacts with the IDE-N domain, IDE successfully impedes the contacts between monomers. Third, the inhibitory activity of IDE on random coil/α-helix dimers depends on the stability of the dimer. IDE could impede the contacts between monomers in relatively unstable random coil/α-helix dimers, but gets hard to impede in stable dimers. However, IDE encapsulates stable dimers and could serve as a 'dead-end' chaperone. Our results examine the molecular interactions between IDE and the dimers, and between the monomers within the dimers. Hence, this study provides insights into the inhibition mechanisms of the primary nucleation of Aβ aggregation and the basic knowledge for rational design to inhibit Aβ aggregation.
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7
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Zheng Q, Lee B, Kebede MT, Ivancic VA, Kemeh MM, Brito HL, Spratt DE, Lazo ND. Exchange Broadening Underlies the Enhancement of IDE-Dependent Degradation of Insulin by Anionic Membranes. ACS OMEGA 2022; 7:24757-24765. [PMID: 35874268 PMCID: PMC9301717 DOI: 10.1021/acsomega.2c02747] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Insulin-degrading enzyme (IDE) is an evolutionarily conserved ubiquitous zinc metalloprotease implicated in the efficient degradation of insulin monomer. However, IDE also degrades monomers of amyloidogenic peptides associated with disease, complicating the development of IDE inhibitors. In this work, we investigated the effects of the lipid composition of membranes on the IDE-dependent degradation of insulin. Kinetic analysis based on chromatography and insulin's helical circular dichroic signal showed that the presence of anionic lipids in membranes enhances IDE's activity toward insulin. Using NMR spectroscopy, we discovered that exchange broadening underlies the enhancement of IDE's activity. These findings, together with the adverse effects of anionic membranes in the self-assembly of IDE's amyloidogenic substrates, suggest that the lipid composition of membranes is a key determinant of IDE's ability to balance the levels of its physiologically and pathologically relevant substrates and achieve proteostasis.
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Affiliation(s)
| | | | | | - Valerie A. Ivancic
- Gustaf H. Carlson School
of Chemistry and Biochemistry, Clark University, Worcester, Massachusetts 01610, United States
| | - Merc M. Kemeh
- Gustaf H. Carlson School
of Chemistry and Biochemistry, Clark University, Worcester, Massachusetts 01610, United States
| | - Henrique Lemos Brito
- Gustaf H. Carlson School
of Chemistry and Biochemistry, Clark University, Worcester, Massachusetts 01610, United States
| | - Donald E. Spratt
- Gustaf H. Carlson School
of Chemistry and Biochemistry, Clark University, Worcester, Massachusetts 01610, United States
| | - Noel D. Lazo
- Gustaf H. Carlson School
of Chemistry and Biochemistry, Clark University, Worcester, Massachusetts 01610, United States
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8
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Lesire L, Leroux F, Deprez-Poulain R, Deprez B. Insulin-Degrading Enzyme, an Under-Estimated Potential Target to Treat Cancer? Cells 2022; 11:1228. [PMID: 35406791 PMCID: PMC8998118 DOI: 10.3390/cells11071228] [Citation(s) in RCA: 2] [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: 02/14/2022] [Revised: 03/31/2022] [Accepted: 04/01/2022] [Indexed: 02/04/2023] Open
Abstract
Insulin-degrading enzyme (IDE) is a multifunctional protease due to the variety of its substrates, its various cellular locations, its conservation between species and its many non-proteolytic functions. Numerous studies have successfully demonstrated its implication in two main therapeutic areas: metabolic and neuronal diseases. In recent years, several reports have underlined the overexpression of this enzyme in different cancers. Still, the exact role of IDE in the physiopathology of cancer remains to be elucidated. Known as the main enzyme responsible for the degradation of insulin, an essential growth factor for healthy cells and cancer cells, IDE has also been shown to behave like a chaperone and interact with the proteasome. The pharmacological modulation of IDE (siRNA, chemical compounds, etc.) has demonstrated interesting results in cancer models. All these results point towards IDE as a potential target in cancer. In this review, we will discuss evidence of links between IDE and cancer development or resistance, IDE's functions, catalytic or non-catalytic, in the context of cell proliferation, cancer development and the impact of the pharmacomodulation of IDE via cancer therapeutics.
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Affiliation(s)
| | | | - Rebecca Deprez-Poulain
- INSERM U1177 Drugs and Molecules for Living Systems, Institut Pasteur de Lille, European Genomic Institute for Diabetes, University of Lille, F-59000 Lille, France; (L.L.); (F.L.); (B.D.)
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9
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Kraupner N, Dinh CP, Wen X, Landry V, Herledan A, Leroux F, Bosc D, Charton J, Maillard C, Warenghem S, Duplan I, Piveteau C, Hennuyer N, Staels B, Deprez B, Deprez-Poulain R. Identification of indole-based activators of insulin degrading enzyme. Eur J Med Chem 2022; 228:113982. [PMID: 34815130 DOI: 10.1016/j.ejmech.2021.113982] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2021] [Revised: 11/05/2021] [Accepted: 11/06/2021] [Indexed: 11/29/2022]
Abstract
Insulin degrading enzyme (IDE) is a zinc metalloprotease that cleaves numerous substrates among which amyloid-β and insulin. It has been linked through genetic studies to the risk of type-2 diabetes (T2D) or Alzheimer's disease (AD). Pharmacological activation of IDE is an attractive therapeutic strategy in AD. While IDE inhibition gave paradoxal activity in glucose homeostasis, recent studies, in particular in the liver suggest that IDE activators could be also of interest in diabetes. Here we describe the discovery of an original series of IDE activators by screening and structure-activity relationships. Early cellular studies show that hit 1 decreases glucose-stimulating insulin secretion. Docking studies revealed it has an unprecedented extended binding to the polyanion-binding site of IDE. These indole-based pharmacological tools are activators of both Aβ and insulin hydrolysis by IDE and could be helpful to explore the multiple roles of IDE.
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Affiliation(s)
- Nicolas Kraupner
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France
| | - Chau Phi Dinh
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France
| | - Xiaoan Wen
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France
| | - Valérie Landry
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France
| | - Adrien Herledan
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France
| | - Florence Leroux
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France; European Genomic Institute for Diabetes, EGID, University of Lille, F-59000, France
| | - Damien Bosc
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France
| | - Julie Charton
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France; European Genomic Institute for Diabetes, EGID, University of Lille, F-59000, France
| | - Clara Maillard
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France
| | - Sandrine Warenghem
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France
| | - Isabelle Duplan
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000, Lille, France; European Genomic Institute for Diabetes, EGID, University of Lille, F-59000, France
| | - Catherine Piveteau
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France
| | - Nathalie Hennuyer
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000, Lille, France; European Genomic Institute for Diabetes, EGID, University of Lille, F-59000, France
| | - Bart Staels
- Univ. Lille, Inserm, CHU Lille, Institut Pasteur de Lille, U1011-EGID, F-59000, Lille, France; European Genomic Institute for Diabetes, EGID, University of Lille, F-59000, France
| | - Benoit Deprez
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France; European Genomic Institute for Diabetes, EGID, University of Lille, F-59000, France
| | - Rebecca Deprez-Poulain
- Univ. Lille, Inserm, Institut Pasteur de Lille, U1177 - Drugs and Molecules for Living Systems, F-59000, Lille, France; European Genomic Institute for Diabetes, EGID, University of Lille, F-59000, France.
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Mechanistic roles of tyrosine phosphorylation in reversible amyloids, autoinhibition, and endosomal membrane association of ALIX. J Biol Chem 2021; 297:101328. [PMID: 34688656 PMCID: PMC8577116 DOI: 10.1016/j.jbc.2021.101328] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Revised: 10/05/2021] [Accepted: 10/06/2021] [Indexed: 11/26/2022] Open
Abstract
Human apoptosis-linked gene-2 interacting protein X (ALIX), a versatile adapter protein, regulates essential cellular processes by shuttling between late endosomal membranes and the cytosol, determined by its interactions with Src kinase. Here, we investigate the molecular basis of these transitions and the effects of tyrosine phosphorylation on the interplay between structure, assembly, and intramolecular and intermolecular interactions of ALIX. As evidenced by transmission electron microscopy, fluorescence and circular dichroism spectroscopy, the proline-rich domain of ALIX, which encodes binding epitopes of multiple cellular partners, formed rope-like β-sheet–rich reversible amyloid fibrils that dissolved upon Src-mediated phosphorylation and were restored on protein-tyrosine phosphatase 1B–mediated dephosphorylation of its conserved tyrosine residues. Analyses of the Bro1 domain of ALIX by solution NMR spectroscopy elucidated the conformational changes originating from its phosphorylation by Src and established that Bro1 binds to hyperphosphorylated proline-rich domain and to analogs of late endosomal membranes via its highly basic surface. These results uncover the autoinhibition mechanism that relocates ALIX to the cytosol and the diverse roles played by tyrosine phosphorylation in cellular and membrane functions of ALIX.
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