1
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Kruse T, Garvanska DH, Varga J, Garland W, McEwan B, Hein JB, Weisser MB, Puy IB, Chan CB, Parrila PS, Mendez BL, Arulanandam J, Schueler-Furman O, Jensen TH, Kettenbach A, Nilsson J. Substrate recognition principles for the PP2A-B55 protein phosphatase. bioRxiv 2024:2024.02.10.579793. [PMID: 38370611 PMCID: PMC10871369 DOI: 10.1101/2024.02.10.579793] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/20/2024]
Abstract
The PP2A-B55 phosphatase regulates a plethora of signaling pathways throughout eukaryotes. How PP2A-B55 selects its substrates presents a severe knowledge gap. By integrating AlphaFold modelling with comprehensive high resolution mutational scanning, we show that α-helices in substrates bind B55 through an evolutionary conserved mechanism. Despite a large diversity in sequence and composition, these α-helices share key amino acid determinants that engage discrete hydrophobic and electrostatic patches. Using deep learning protein design, we generate a specific and potent competitive peptide inhibitor of PP2A-B55 substrate interactions. With this inhibitor, we uncover that PP2A-B55 regulates the nuclear exosome targeting complex by binding to an α-helical recruitment module in RBM7. Collectively, our findings provide a framework for the understanding and interrogation of PP2A-B55 in health and disease.
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Affiliation(s)
- Thomas Kruse
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Dimitriya H Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Julia Varga
- Department of Microbiology and Molecular Genetics, Institute for Biomedical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 9112001, Israel
| | - William Garland
- Department of Molecular Biology and Genetics, Universitetsbyen 81, Aarhus University, Aarhus, Denmark
| | - Brennan McEwan
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
- Current address: Amgen Research Copenhagen, Rønnegade 8, 5, 2100 Copenhagen, Denmark
| | - Melanie Bianca Weisser
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Iker Benavides Puy
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Camilla Bachman Chan
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Paula Sotelo Parrila
- Gene Center Munich, Ludwig-Maximilians- Universität München, Munich, 81377, Germany
| | - Blanca Lopez Mendez
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
| | - Jeyaprakash Arulanandam
- Gene Center Munich, Ludwig-Maximilians- Universität München, Munich, 81377, Germany
- Wellcome Centre for Cell Biology, University of Edinburg, Edinburgh, EH9 3BF, UK
| | - Ora Schueler-Furman
- Department of Microbiology and Molecular Genetics, Institute for Biomedical Research Israel-Canada, Faculty of Medicine, The Hebrew University of Jerusalem, Jerusalem, 9112001, Israel
| | - Torben Heick Jensen
- Department of Molecular Biology and Genetics, Universitetsbyen 81, Aarhus University, Aarhus, Denmark
| | - Arminja Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, Blegdamsvej 3B, 2200 Copenhagen, Denmark
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2
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Padi SKR, Vos MR, Godek RJ, Fuller JR, Kruse T, Hein JB, Nilsson J, Kelker MS, Page R, Peti W. Cryo-EM structures of PP2A:B55-FAM122A and PP2A:B55-ARPP19. Nature 2024; 625:195-203. [PMID: 38123684 PMCID: PMC10765524 DOI: 10.1038/s41586-023-06870-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Accepted: 11/15/2023] [Indexed: 12/23/2023]
Abstract
Progression through the cell cycle is controlled by regulated and abrupt changes in phosphorylation1. Mitotic entry is initiated by increased phosphorylation of mitotic proteins, a process driven by kinases2, whereas mitotic exit is achieved by counteracting dephosphorylation, a process driven by phosphatases, especially PP2A:B553. Although the role of kinases in mitotic entry is well established, recent data have shown that mitosis is only successfully initiated when the counterbalancing phosphatases are also inhibited4. Inhibition of PP2A:B55 is achieved by the intrinsically disordered proteins ARPP195,6 and FAM122A7. Despite their critical roles in mitosis, the mechanisms by which they achieve PP2A:B55 inhibition is unknown. Here, we report the single-particle cryo-electron microscopy structures of PP2A:B55 bound to phosphorylated ARPP19 and FAM122A. Consistent with our complementary NMR spectroscopy studies, both intrinsically disordered proteins bind PP2A:B55, but do so in highly distinct manners, leveraging multiple distinct binding sites on B55. Our extensive structural, biophysical and biochemical data explain how substrates and inhibitors are recruited to PP2A:B55 and provide a molecular roadmap for the development of therapeutic interventions for PP2A:B55-related diseases.
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Affiliation(s)
- Sathish K R Padi
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, USA
| | - Margaret R Vos
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | - Rachel J Godek
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA
| | | | - Thomas Kruse
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Jamin B Hein
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | | | - Rebecca Page
- Department of Cell Biology, University of Connecticut Health Center, Farmington, CT, USA.
| | - Wolfgang Peti
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, CT, USA.
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3
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Hein JB, Nguyen HT, Garvanska DH, Nasa I, Kruse T, Feng Y, Lopez Mendez B, Davey N, Kettenbach AN, Fordyce PM, Nilsson J. Phosphatase specificity principles uncovered by MRBLE:Dephos and global substrate identification. Mol Syst Biol 2023; 19:e11782. [PMID: 37916966 PMCID: PMC10698503 DOI: 10.15252/msb.202311782] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2023] [Revised: 10/14/2023] [Accepted: 10/16/2023] [Indexed: 11/03/2023] Open
Abstract
Phosphoprotein phosphatases (PPPs) regulate major signaling pathways, but the determinants of phosphatase specificity are poorly understood. This is because methods to investigate this at scale are lacking. Here, we develop a novel in vitro assay, MRBLE:Dephos, that allows multiplexing of dephosphorylation reactions to determine phosphatase preferences. Using MRBLE:Dephos, we establish amino acid preferences of the residues surrounding the dephosphorylation site for PP1 and PP2A-B55, which reveals common and unique preferences. To compare the MRBLE:Dephos results to cellular substrates, we focused on mitotic exit that requires extensive dephosphorylation by PP1 and PP2A-B55. We use specific inhibition of PP1 and PP2A-B55 in mitotic exit lysates coupled with phosphoproteomics to identify more than 2,000 regulated sites. Importantly, the sites dephosphorylated during mitotic exit reveal key signatures that are consistent with MRBLE:Dephos. Furthermore, integration of our phosphoproteomic data with mitotic interactomes of PP1 and PP2A-B55 provides insight into how binding of phosphatases to substrates shapes dephosphorylation. Collectively, we develop novel approaches to investigate protein phosphatases that provide insight into mitotic exit regulation.
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Affiliation(s)
- Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
- Department of BioengineeringStanford UniversityStanfordCAUSA
| | - Hieu T Nguyen
- Biochemistry and Cell BiologyGeisel School of Medicine at Dartmouth CollegeHanoverNHUSA
| | - Dimitriya H Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Isha Nasa
- Department of BioengineeringStanford UniversityStanfordCAUSA
| | - Thomas Kruse
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Yinnian Feng
- Department of GeneticsStanford UniversityStanfordCAUSA
| | - Blanca Lopez Mendez
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
| | - Norman Davey
- Division of Cancer BiologyThe Institute of Cancer ResearchLondonUK
| | - Arminja N Kettenbach
- Biochemistry and Cell BiologyGeisel School of Medicine at Dartmouth CollegeHanoverNHUSA
| | - Polly M Fordyce
- Department of BioengineeringStanford UniversityStanfordCAUSA
- Department of GeneticsStanford UniversityStanfordCAUSA
- Sarafan ChEM‐HStanford UniversityStanfordCAUSA
- Chan Zuckerberg BiohubSan FranciscoCAUSA
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical SciencesUniversity of CopenhagenCopenhagenDenmark
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4
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Padi SK, Vos MR, Godek RJ, Fuller JR, Kruse T, Hein JB, Nilsson J, Kelker MS, Page R, Peti W. Cryo-EM structures of PP2A:B55-FAM122A and PP2A:B55-ARPP19. bioRxiv 2023:2023.08.31.555365. [PMID: 37693408 PMCID: PMC10491220 DOI: 10.1101/2023.08.31.555365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Progression through the cell cycle is controlled by regulated and abrupt changes in phosphorylation.1 Mitotic entry is initiated by increased phosphorylation of mitotic proteins, a process driven by kinases,2 while mitotic exit is achieved by counteracting dephosphorylation, a process driven by phosphatases, especially PP2A:B55.3 While the role of kinases in mitotic entry is well-established, recent data have shown that mitosis is only successfully initiated when the counterbalancing phosphatases are also inhibited.4 For PP2A:B55, inhibition is achieved by the two intrinsically disordered proteins (IDPs), ARPP19 (phosphorylation-dependent)6,7 and FAM122A5 (inhibition is phosphorylation-independent). Despite their critical roles in mitosis, the mechanisms by which they achieve PP2A:B55 inhibition is unknown. Here, we report the cryo-electron microscopy structures of PP2A:B55 bound to phosphorylated ARPP19 and FAM122A. Consistent with our complementary NMR spectroscopy studies both IDPs bind PP2A:B55, but do so in highly distinct manners, unexpectedly leveraging multiple distinct binding sites on B55. Our extensive structural, biophysical and biochemical data explain how substrates and inhibitors are recruited to PP2A:B55 and provides a molecular roadmap for the development of therapeutic interventions for PP2A:B55 related diseases.
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Affiliation(s)
- Sathish K.R. Padi
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, USA
| | - Margaret R. Vos
- Department of Cell Biology, University of Connecticut Health Center, Farmington, USA
| | - Rachel J. Godek
- Department of Cell Biology, University of Connecticut Health Center, Farmington, USA
| | | | - Thomas Kruse
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Jamin B. Hein
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | - Jakob Nilsson
- The Novo Nordisk Foundation Center for Protein Research, University of Copenhagen, Copenhagen, Denmark
| | | | - Rebecca Page
- Department of Cell Biology, University of Connecticut Health Center, Farmington, USA
| | - Wolfgang Peti
- Department of Molecular Biology and Biophysics, University of Connecticut Health Center, Farmington, USA
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5
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Hein JB, Garvanska DH, Nasa I, Kettenbach AN, Nilsson J. Coupling of Cdc20 inhibition and activation by BubR1. J Cell Biol 2021; 220:211939. [PMID: 33819340 PMCID: PMC8025235 DOI: 10.1083/jcb.202012081] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2020] [Revised: 02/18/2021] [Accepted: 02/25/2021] [Indexed: 12/25/2022] Open
Abstract
Tight regulation of the APC/C-Cdc20 ubiquitin ligase that targets cyclin B1 for degradation is important for mitotic fidelity. The spindle assembly checkpoint (SAC) inhibits Cdc20 through the mitotic checkpoint complex (MCC). In addition, phosphorylation of Cdc20 by cyclin B1–Cdk1 independently inhibits APC/C–Cdc20 activation. This creates a conundrum for how Cdc20 is activated before cyclin B1 degradation. Here, we show that the MCC component BubR1 harbors both Cdc20 inhibition and activation activities, allowing for cross-talk between the two Cdc20 inhibition pathways. Specifically, BubR1 acts as a substrate specifier for PP2A-B56 to enable efficient Cdc20 dephosphorylation in the MCC. A mutant Cdc20 mimicking the dephosphorylated state escapes a mitotic checkpoint arrest, arguing that restricting Cdc20 dephosphorylation to the MCC is important. Collectively, our work reveals how Cdc20 can be dephosphorylated in the presence of cyclin B1-Cdk1 activity without causing premature anaphase onset.
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Affiliation(s)
- Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, Copenhagen, Denmark
| | - Dimitriya H Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, Copenhagen, Denmark
| | - Isha Nasa
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Arminja N Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Science, Copenhagen, Denmark
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6
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Feng Y, White AK, Hein JB, Appel EA, Fordyce PM. MRBLES 2.0: High-throughput generation of chemically functionalized spectrally and magnetically encoded hydrogel beads using a simple single-layer microfluidic device. Microsyst Nanoeng 2020; 6:109. [PMID: 33299601 PMCID: PMC7704393 DOI: 10.1038/s41378-020-00220-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 09/09/2020] [Accepted: 09/20/2020] [Indexed: 05/04/2023]
Abstract
The widespread adoption of bead-based multiplexed bioassays requires the ability to easily synthesize encoded microspheres and conjugate analytes of interest to their surface. Here, we present a simple method (MRBLEs 2.0) for the efficient high-throughput generation of microspheres with ratiometric barcode lanthanide encoding (MRBLEs) that bear functional groups for downstream surface bioconjugation. Bead production in MRBLEs 2.0 relies on the manual mixing of lanthanide/polymer mixtures (each of which comprises a unique spectral code) followed by droplet generation using single-layer, parallel flow-focusing devices and the off-chip batch polymerization of droplets into beads. To streamline downstream analyte coupling, MRBLEs 2.0 crosslinks copolymers bearing functional groups on the bead surface during bead generation. Using the MRBLEs 2.0 pipeline, we generate monodisperse MRBLEs containing 48 distinct well-resolved spectral codes with high throughput (>150,000/min and can be boosted to 450,000/min). We further demonstrate the efficient conjugation of oligonucleotides and entire proteins to carboxyl MRBLEs and of biotin to amino MRBLEs. Finally, we show that MRBLEs can also be magnetized via the simultaneous incorporation of magnetic nanoparticles with only a minor decrease in the potential code space. With the advantages of dramatically simplified device fabrication, elimination of the need for custom-made equipment, and the ability to produce spectrally and magnetically encoded beads with direct surface functionalization with high throughput, MRBLEs 2.0 can be directly applied by many labs towards a wide variety of downstream assays, from basic biology to diagnostics and other translational research.
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Affiliation(s)
- Yinnian Feng
- Department of Genetics, Stanford University, Stanford, CA 94305 USA
| | - Adam K. White
- Department of Genetics, Stanford University, Stanford, CA 94305 USA
- Department of Bioengineering, Stanford University, Stanford, CA 94305 USA
| | - Jamin B. Hein
- Department of Biology, Stanford University, Stanford, CA 94305 USA
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark
| | - Eric A. Appel
- Department of Materials Science & Engineering, Stanford University, Stanford, CA 94305 USA
| | - Polly M. Fordyce
- Department of Genetics, Stanford University, Stanford, CA 94305 USA
- Department of Bioengineering, Stanford University, Stanford, CA 94305 USA
- Stanford ChEM-H, Stanford University, Stanford, CA 94305 USA
- Chan Zuckerberg Biohub, San Francisco, CA 94110 USA
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7
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Hein JB, Nguyen HQ, Cyert M, Fordyce PM. Protocol for Peptide Synthesis on Spectrally Encoded Beads for MRBLE-pep Assays. Bio Protoc 2020; 10:e3669. [PMID: 33659339 DOI: 10.21769/bioprotoc.3669] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Revised: 03/25/2020] [Accepted: 05/18/2020] [Indexed: 01/20/2023] Open
Abstract
Every living cell relies on signal transduction pathways comprised of protein-protein interactions (PPIs). In many cases, these PPIs are between a folded protein domain and a short linear motif (SLiM) within an unstructured region of a protein. As a result of this small interaction interface (3-10 amino acids), the affinities of SLiM-mediated interactions are typically weak (K ds of ~1-10 µM), allowing physiologically relevant changes in cellular concentrations of either protein partner to dictate changes in occupancy and thereby transmit cellular signals. However, these weak affinities also render detection and quantitative measurement of these interactions challenging and labor intensive. To address this, we recently developed MRBLE-pep, a technology that employs peptide libraries synthesized on spectrally encoded hydrogel beads to allow multiplexed affinity measurements between a protein and many different peptides in parallel. This approach dramatically reduces both the amount of protein and peptide as well as the time required to measure protein-peptide affinities compared to traditional methods. Here, we provide a detailed protocol describing how to: (1) functionalize polyethylene glycol diacrylate (PEG-DA) MRBLE beads with free amine groups, (2) synthesize peptide libraries on functionalized MRBLEs, (3) validate synthesized peptide sequences via MALDI mass spectrometry and quantify evenness of peptide coverage on MRBLEs, (4) use MRBLE-bound peptide libraries in multiplexed protein binding assays, and (5) analyze binding data to determine binding affinities. We anticipate that this protocol should prove useful for other researchers seeking to use MRBLE-pep in their own laboratories as well as for researchers broadly interested in solid-phase peptide synthesis and protein-protein binding assay development.
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Affiliation(s)
- Jamin B Hein
- Department of Biology, Stanford University, Stanford, CA 94305, USA.,The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3b, 2200 Copenhagen, Denmark.,Department of Bioengineering, Stanford University, Stanford, CA 94305, USA
| | - Huy Q Nguyen
- Department of Genetics, Stanford University, Stanford, CA 94305, USA
| | - Martha Cyert
- Department of Biology, Stanford University, Stanford, CA 94305, USA
| | - Polly M Fordyce
- Department of Genetics, Stanford University, Stanford, CA 94305, USA.,Department of Bioengineering, Stanford University, Stanford, CA 94305, USA.,ChEM-H Institute, Stanford University, Stanford, CA 94305, USA.,Chan Zuckerberg Biohub, San Francisco, CA 94110, USA
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8
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Kruse T, Gnosa SP, Nasa I, Garvanska DH, Hein JB, Nguyen H, Samsøe-Petersen J, Lopez-Mendez B, Hertz EPT, Schwarz J, Pena HS, Nikodemus D, Kveiborg M, Kettenbach AN, Nilsson J. Mechanisms of site-specific dephosphorylation and kinase opposition imposed by PP2A regulatory subunits. EMBO J 2020; 39:e103695. [PMID: 32400009 PMCID: PMC7327492 DOI: 10.15252/embj.2019103695] [Citation(s) in RCA: 55] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Revised: 04/03/2020] [Accepted: 04/21/2020] [Indexed: 12/11/2022] Open
Abstract
PP2A is an essential protein phosphatase that regulates most cellular processes through the formation of holoenzymes containing distinct regulatory B‐subunits. Only a limited number of PP2A‐regulated phosphorylation sites are known. This hampers our understanding of the mechanisms of site‐specific dephosphorylation and of its tumor suppressor functions. Here, we develop phosphoproteomic strategies for global substrate identification of PP2A‐B56 and PP2A‐B55 holoenzymes. Strikingly, we find that B‐subunits directly affect the dephosphorylation site preference of the PP2A catalytic subunit, resulting in unique patterns of kinase opposition. For PP2A‐B56, these patterns are further modulated by affinity and position of B56 binding motifs. Our screens identify phosphorylation sites in the cancer target ADAM17 that are regulated through a conserved B56 binding site. Binding of PP2A‐B56 to ADAM17 protease decreases growth factor signaling and tumor development in mice. This work provides a roadmap for the identification of phosphatase substrates and reveals unexpected mechanisms governing PP2A dephosphorylation site specificity and tumor suppressor function.
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Affiliation(s)
- Thomas Kruse
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Sebastian Peter Gnosa
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Isha Nasa
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.,Norris Cotton Cancer Center, Lebanon, NH, USA
| | - Dimitriya Hristoforova Garvanska
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jamin B Hein
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Hieu Nguyen
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.,Norris Cotton Cancer Center, Lebanon, NH, USA
| | - Jacob Samsøe-Petersen
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Blanca Lopez-Mendez
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Emil Peter Thrane Hertz
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Jeanette Schwarz
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Hanna Sofia Pena
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Denise Nikodemus
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Marie Kveiborg
- Biotech Research and Innovation Centre (BRIC), University of Copenhagen, Copenhagen, Denmark
| | - Arminja N Kettenbach
- Biochemistry and Cell Biology, Geisel School of Medicine at Dartmouth College, Hanover, NH, USA.,Norris Cotton Cancer Center, Lebanon, NH, USA
| | - Jakob Nilsson
- Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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9
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Abstract
The spindle assembly checkpoint (SAC) delays progression into anaphase until all chromosomes have aligned on the metaphase plate by inhibiting Cdc20, the mitotic co-activator of the APC/C. Mad2 and BubR1 bind and inhibit Cdc20, thereby forming the mitotic checkpoint complex (MCC), which can bind stably to the APC/C. Whether MCC formation per se is sufficient for a functional SAC or MCC association with the APC/C is required remains unclear. Here, we analyze the role of two conserved motifs in Cdc20, IR and C-Box, in binding of the MCC to the APC/C. Mutants in both motifs assemble the MCC normally, but IR motif integrity is particularly important for stable binding to the APC/C. Cells expressing Cdc20 with a mutated IR motif have a compromised SAC, as uninhibited Cdc20 can compete with the MCC for APC/C binding and activate it. We thus show that stable MCC association with the APC/C is critical for a functional SAC.
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Affiliation(s)
- Jamin B Hein
- The Novo Nordisk Foundation Center for Protein Research, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
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10
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Hein JB, Hennersdorf G. [Pulmonary embolism. An emergency as a diagnostic trap]. MMW Fortschr Med 2000; 142:49-50. [PMID: 11072700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/18/2023]
Affiliation(s)
- J B Hein
- Med. Klinik I, Kardiologie, SHG Herzzentrum Völklingen
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