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Cabral G, Moss WJ, Brown KM. Proteomic approaches for protein kinase substrate identification in Apicomplexa. Mol Biochem Parasitol 2024; 259:111633. [PMID: 38821187 PMCID: PMC11194964 DOI: 10.1016/j.molbiopara.2024.111633] [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: 03/30/2024] [Revised: 05/10/2024] [Accepted: 05/28/2024] [Indexed: 06/02/2024]
Abstract
Apicomplexa is a phylum of protist parasites, notable for causing life-threatening diseases including malaria, toxoplasmosis, cryptosporidiosis, and babesiosis. Apicomplexan pathogenesis is generally a function of lytic replication, dissemination, persistence, host cell modification, and immune subversion. Decades of research have revealed essential roles for apicomplexan protein kinases in establishing infections and promoting pathogenesis. Protein kinases modify their substrates by phosphorylating serine, threonine, tyrosine, or other residues, resulting in rapid functional changes in the target protein. Post-translational modification by phosphorylation can activate or inhibit a substrate, alter its localization, or promote interactions with other proteins or ligands. Deciphering direct kinase substrates is crucial to understand mechanisms of kinase signaling, yet can be challenging due to the transient nature of kinase phosphorylation and potential for downstream indirect phosphorylation events. However, with recent advances in proteomic approaches, our understanding of kinase function in Apicomplexa has improved dramatically. Here, we discuss methods that have been used to identify kinase substrates in apicomplexan parasites, classifying them into three main categories: i) kinase interactome, ii) indirect phosphoproteomics and iii) direct labeling. We briefly discuss each approach, including their advantages and limitations, and highlight representative examples from the Apicomplexa literature. Finally, we conclude each main category by introducing prospective approaches from other fields that would benefit kinase substrate identification in Apicomplexa.
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Affiliation(s)
- Gabriel Cabral
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - William J Moss
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Kevin M Brown
- Department of Microbiology and Immunology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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2
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Zhang Z, Fan H, Richardson W, Gao BZ, Ye T. Management of autofluorescence in formaldehyde-fixed myocardium: choosing the right treatment. Eur J Histochem 2023; 67:3812. [PMID: 37781779 PMCID: PMC10614721 DOI: 10.4081/ejh.2023.3812] [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: 06/21/2023] [Accepted: 08/28/2023] [Indexed: 10/03/2023] Open
Abstract
Autofluorescence (AF) poses challenges for detecting proteins of interest in situ when employing immunofluorescence (IF) microscopy. This interference is particularly pronounced in strongly autofluorescent tissues such as myocardium, where tissue AF can be comparable to IF. Although various histochemical methods have been developed to achieve effective AF suppression in different types of tissue, their applications on myocardial samples have not been well validated. Due to inconsistency across different autofluorescent structures in sometypes of tissue, it is unclear if these methods can effectively suppress AF across all autofluorescent structures within the myocardium. Here, we quantitatively evaluated the performance of several commonly used quenching treatments on formaldehyde-fixed myocardial samples, including 0.3 M glycine, 0.3% Sudan Black B (SBB), 0.1% and 1% sodium borohydride (NaBH4), TrueVIEW® and TrueBlack®. We further assessed their quenching performance by employing the pre-treatment and post-treatment protocols, designed to cover two common IF staining scenarios where buffers contained detergents or not. The results suggest that SBB and TrueBlack® outperform other reagents in AF suppression on formaldehyde-fixed myocardial samples in both protocols. Furthermore, we inspected the quenching performance of SBB and TrueBlack® on major autofluorescent myocardial structures and evaluated their influence on IF imaging. The results suggest that SBB outperforms TrueBlack® in quenching major autofluorescent structures, while TrueBlack® excels in preserving IF labeling signal. Surprisingly, we found the treatment of NaBH4 increased AF signal and enhanced the AF contrast of major autofluorescent structures. This finding suggests that NaBH4 has the potential to act as an AF enhancer and may facilitate the interpretation of myocardial structures without the need for counterstaining.
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Affiliation(s)
- Zhao Zhang
- Department of Bioengineering, Clemson University, Clemson, SC.
| | - Hongming Fan
- Department of Bioengineering, Clemson University, Clemson, SC.
| | - William Richardson
- Department of Chemical Engineering, University of Arkansas, Fayetteville, AR.
| | - Bruce Z Gao
- Department of Bioengineering, Clemson University, Clemson, SC.
| | - Tong Ye
- Department of Bioengineering, Clemson University, Clemson, SC; Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC.
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3
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Paggi RA, De Castro RE, Cerletti M. In Vivo Protein Cross-Linking and Coimmunoprecipitation in Haloferax volcanii. Methods Mol Biol 2022; 2522:301-317. [PMID: 36125758 DOI: 10.1007/978-1-0716-2445-6_19] [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: 06/15/2023]
Abstract
Coimmunoprecipitation is a powerful and commonly used method to identify protein-protein interactions in a physiological context. Here, we report a coimmunoprecipitation protocol that was adapted and optimized for the haloarchaeon Haloferax volcanii to identify interacting partners to the LonB protease. This protocol includes the in vivo cross-linking of H. volcanii proteins using two different crosslinker agents, dithiobis(succinimidyl propionate) and formaldehyde, followed by immunoprecipitation with anti-LonB antibody conjugated to Protein A - Sepharose beads. Tryptic on-bead protein digestion was performed combined with Mass Spectrometry analysis of peptides for the identification and quantification of LonB ligands.
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Affiliation(s)
- Roberto A Paggi
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata (UNMDP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata, Argentina
| | - Rosana E De Castro
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata (UNMDP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata, Argentina
| | - Micaela Cerletti
- Instituto de Investigaciones Biológicas, Universidad Nacional de Mar del Plata (UNMDP), Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Mar del Plata, Argentina.
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4
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Wang Y, Hu Y, Höti N, Huang L, Zhang H. Characterization of In Vivo Protein Complexes via Chemical Cross-Linking and Mass Spectrometry. Anal Chem 2021; 94:1537-1542. [PMID: 34962381 DOI: 10.1021/acs.analchem.1c02410] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
Cells perform various functions by proteins via protein complexes. Characterization of protein complexes is critical to understanding their biological and clinical significance and has been one of the major efforts of functional proteomics. To date, most protein complexes are characterized by the in vitro system from protein extracts after the cells or tissues are lysed, and it has been challenging to determine which of these protein complexes are formed in intact cells. Herein, we report an approach to preserve protein complexes using in vivo cross-linking, followed by size exclusion chromatography and data-independent acquisition mass spectrometry. This approach enables the characterization of in vivo protein complexes from cells or tissues, which allows the determination of protein complexes in clinical research. More importantly, the described approach can identify protein complexes that are not detected by the in vitro system, which provide unique protein function information.
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Affiliation(s)
- Yuefan Wang
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland 21231, United States
| | - Yingwei Hu
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland 21231, United States
| | - Naseruddin Höti
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland 21231, United States
| | - Lan Huang
- Department of Physiology and Biophysics, University of California, Irvine, California 92697, United States
| | - Hui Zhang
- Department of Pathology, Johns Hopkins University, Baltimore, Maryland 21231, United States
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5
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Chen H, Lin Y, Long YT, Minteer SD, Ying YL. Nanopore-based measurement of the interaction of P450cam monooxygenase and putidaredoxin at the single-molecule level. Faraday Discuss 2021; 233:295-302. [PMID: 34889330 DOI: 10.1039/d1fd00042j] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Protein-protein interactions occur in a wide range of biological processes and are of great significance to life function. Characterization of transient protein-protein interactions remains a significant barrier to our understanding of cellular processes. Nanopores provide unique nanoscale environments that accommodate single molecules from the surrounding bulk solution. This method permits label-free sensing at the single-molecule level with extremely high sensitivity. Herein, the interaction between a single P450cam monooxygenase and its redox partner putidaredoxin (Pdx) was monitored via transient ionic current by using functionalized glass nanopores. Results show that the volume of P450cam determines the blockage current while the interactions between the P450cam and Pdx give a long blockage duration. Our glass nanopore sensor with adjustable diameter could be applied for real-time sensing of protein-protein interactions between individual proteins with a wide range of molecular weight.
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Affiliation(s)
- Hui Chen
- Department of Chemistry, University of Utah, USA.
| | - Yao Lin
- Department of Chemistry, University of Utah, USA. .,State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, China.
| | - Yi-Tao Long
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, China.
| | | | - Yi-Lun Ying
- State Key Laboratory of Analytical Chemistry for Life Science, School of Chemistry and Chemical Engineering, Nanjing University, China. .,Chemistry and Biomedicine Innovation Center, Nanjing University, China
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6
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Abstract
Biological mass spectrometry (MS) encompasses a range of methods for characterizing proteins and other biomolecules. MS is uniquely powerful for the structural analysis of endogenous protein complexes, which are often heterogeneous, poorly abundant, and refractive to characterization by other methods. Here, we focus on how biological MS can contribute to the study of endogenous protein complexes, which we define as complexes expressed in the physiological host and purified intact, as opposed to reconstituted complexes assembled from heterologously expressed components. Biological MS can yield information on complex stoichiometry, heterogeneity, topology, stability, activity, modes of regulation, and even structural dynamics. We begin with a review of methods for isolating endogenous complexes. We then describe the various biological MS approaches, focusing on the type of information that each method yields. We end with future directions and challenges for these MS-based methods.
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Affiliation(s)
- Rivkah Rogawski
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
| | - Michal Sharon
- Department of Biomolecular Sciences, Weizmann Institute of Science, Rehovot 7610001, Israel
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7
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Protein interaction landscapes revealed by advanced in vivo cross-linking-mass spectrometry. Proc Natl Acad Sci U S A 2021; 118:2023360118. [PMID: 34349018 DOI: 10.1073/pnas.2023360118] [Citation(s) in RCA: 58] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Defining protein-protein interactions (PPIs) in their native environment is crucial to understanding protein structure and function. Cross-linking-mass spectrometry (XL-MS) has proven effective in capturing PPIs in living cells; however, the proteome coverage remains limited. Here, we have developed a robust in vivo XL-MS platform to facilitate in-depth PPI mapping by integrating a multifunctional MS-cleavable cross-linker with sample preparation strategies and high-resolution MS. The advancement of click chemistry-based enrichment significantly enhanced the detection of cross-linked peptides for proteome-wide analyses. This platform enabled the identification of 13,904 unique lysine-lysine linkages from in vivo cross-linked HEK 293 cells, permitting construction of the largest in vivo PPI network to date, comprising 6,439 interactions among 2,484 proteins. These results allowed us to generate a highly detailed yet panoramic portrait of human interactomes associated with diverse cellular pathways. The strategy presented here signifies a technological advancement for in vivo PPI mapping at the systems level and can be generalized for charting protein interaction landscapes in any organisms.
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8
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Schaffer LV, Ideker T. Mapping the multiscale structure of biological systems. Cell Syst 2021; 12:622-635. [PMID: 34139169 PMCID: PMC8245186 DOI: 10.1016/j.cels.2021.05.012] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Revised: 05/04/2021] [Accepted: 05/14/2021] [Indexed: 01/14/2023]
Abstract
Biological systems are by nature multiscale, consisting of subsystems that factor into progressively smaller units in a deeply hierarchical structure. At any level of the hierarchy, an ever-increasing diversity of technologies can be applied to characterize the corresponding biological units and their relations, resulting in large networks of physical or functional proximities-e.g., proximities of amino acids within a protein, of proteins within a complex, or of cell types within a tissue. Here, we review general concepts and progress in using network proximity measures as a basis for creation of multiscale hierarchical maps of biological systems. We discuss the functionalization of these maps to create predictive models, including those useful in translation of genotype to phenotype, along with strategies for model visualization and challenges faced by multiscale modeling in the near future. Collectively, these approaches enable a unified hierarchical approach to biological data, with application from the molecular to the macroscopic.
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Affiliation(s)
- Leah V Schaffer
- Division of Genetics, Department of Medicine, University of California San Diego, San Diego, La Jolla, CA 92093, USA
| | - Trey Ideker
- Division of Genetics, Department of Medicine, University of California San Diego, San Diego, La Jolla, CA 92093, USA.
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9
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Kalathiya U, Padariya M, Faktor J, Coyaud E, Alfaro JA, Fahraeus R, Hupp TR, Goodlett DR. Interfaces with Structure Dynamics of the Workhorses from Cells Revealed through Cross-Linking Mass Spectrometry (CLMS). Biomolecules 2021; 11:382. [PMID: 33806612 PMCID: PMC8001575 DOI: 10.3390/biom11030382] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 02/26/2021] [Accepted: 03/01/2021] [Indexed: 12/28/2022] Open
Abstract
The fundamentals of how protein-protein/RNA/DNA interactions influence the structures and functions of the workhorses from the cells have been well documented in the 20th century. A diverse set of methods exist to determine such interactions between different components, particularly, the mass spectrometry (MS) methods, with its advanced instrumentation, has become a significant approach to analyze a diverse range of biomolecules, as well as bring insights to their biomolecular processes. This review highlights the principal role of chemistry in MS-based structural proteomics approaches, with a particular focus on the chemical cross-linking of protein-protein/DNA/RNA complexes. In addition, we discuss different methods to prepare the cross-linked samples for MS analysis and tools to identify cross-linked peptides. Cross-linking mass spectrometry (CLMS) holds promise to identify interaction sites in larger and more complex biological systems. The typical CLMS workflow allows for the measurement of the proximity in three-dimensional space of amino acids, identifying proteins in direct contact with DNA or RNA, and it provides information on the folds of proteins as well as their topology in the complexes. Principal CLMS applications, its notable successes, as well as common pipelines that bridge proteomics, molecular biology, structural systems biology, and interactomics are outlined.
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Affiliation(s)
- Umesh Kalathiya
- International Centre for Cancer Vaccine Science, University of Gdansk, ul. Kładki 24, 80-822 Gdansk, Poland; (M.P.); (J.F.); (J.A.A.); (R.F.); (T.R.H.)
| | - Monikaben Padariya
- International Centre for Cancer Vaccine Science, University of Gdansk, ul. Kładki 24, 80-822 Gdansk, Poland; (M.P.); (J.F.); (J.A.A.); (R.F.); (T.R.H.)
| | - Jakub Faktor
- International Centre for Cancer Vaccine Science, University of Gdansk, ul. Kładki 24, 80-822 Gdansk, Poland; (M.P.); (J.F.); (J.A.A.); (R.F.); (T.R.H.)
| | - Etienne Coyaud
- Protéomique Réponse Inflammatoire Spectrométrie de Mass—PRISM, Inserm U1192, University Lille, CHU Lille, F-59000 Lille, France;
| | - Javier A. Alfaro
- International Centre for Cancer Vaccine Science, University of Gdansk, ul. Kładki 24, 80-822 Gdansk, Poland; (M.P.); (J.F.); (J.A.A.); (R.F.); (T.R.H.)
- Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, Scotland EH4 2XR, UK
| | - Robin Fahraeus
- International Centre for Cancer Vaccine Science, University of Gdansk, ul. Kładki 24, 80-822 Gdansk, Poland; (M.P.); (J.F.); (J.A.A.); (R.F.); (T.R.H.)
| | - Ted R. Hupp
- International Centre for Cancer Vaccine Science, University of Gdansk, ul. Kładki 24, 80-822 Gdansk, Poland; (M.P.); (J.F.); (J.A.A.); (R.F.); (T.R.H.)
- Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, Scotland EH4 2XR, UK
| | - David R. Goodlett
- International Centre for Cancer Vaccine Science, University of Gdansk, ul. Kładki 24, 80-822 Gdansk, Poland; (M.P.); (J.F.); (J.A.A.); (R.F.); (T.R.H.)
- Department of Biochemistry & Microbiology, University of Victoria, Victoria, BC V8Z 7X8, Canada
- Genome BC Proteome Centre, University of Victoria, Victoria, BC V8Z 5N3, Canada
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10
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Folylpoly-ɣ-glutamate synthetase association to the cytoskeleton: Implications to folate metabolon compartmentalization. J Proteomics 2021; 239:104169. [PMID: 33676037 DOI: 10.1016/j.jprot.2021.104169] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Revised: 02/03/2021] [Accepted: 02/19/2021] [Indexed: 11/23/2022]
Abstract
Folates are essential for nucleotide biosynthesis, amino acid metabolism and cellular proliferation. Following carrier-mediated uptake, folates are polyglutamylated by folylpoly-ɣ-glutamate synthetase (FPGS), resulting in their intracellular retention. FPGS appears as a long isoform, directed to mitochondria via a leader sequence, and a short isoform reported as a soluble cytosolic protein (cFPGS). However, since folates are labile and folate metabolism is compartmentalized, we herein hypothesized that cFPGS is associated with the cytoskeleton, to couple folate uptake and polyglutamylation and channel folate polyglutamates to metabolon compartments. We show that cFPGS is a cytoskeleton-microtubule associated protein: Western blot analysis revealed that endogenous cFPGS is associated with the insoluble cellular fraction, i.e., cytoskeleton and membranes, but not with the cytosol. Mass spectrometry analysis identified the putative cFPGS interactome primarily consisting of microtubule subunits and cytoskeletal motor proteins. Consistently, immunofluorescence microscopy with cytosol-depleted cells demonstrated the association of cFPGS with the cytoskeleton and unconventional myosin-1c. Furthermore, since anti-microtubule, anti-actin cytoskeleton, and coatomer dissociation-inducing agents yielded perinuclear pausing of cFPGS, we propose an actin- and microtubule-dependent transport of cFPGS between the ER-Golgi and the plasma membrane. These novel findings support the coupling of folate transport with polyglutamylation and folate channeling to intracellular metabolon compartments. SIGNIFICANCE: FPGS, an essential enzyme catalyzing intracellular folate polyglutamylation and efficient retention, was described as a soluble cytosolic enzyme in the past 40 years. However, based on the lability of folates and the compartmentalization of folate metabolism and nucleotide biosynthesis, we herein hypothesized that cytoplasmic FPGS is associated with the cytoskeleton, to couple folate transport and polyglutamylation as well as channel folate polyglutamates to biosynthetic metabolon compartments. Indeed, using complementary techniques including Mass-spectrometry proteomics and fluorescence microscopy, we show that cytoplasmic FPGS is associated with the cytoskeleton and unconventional myosin-1c. This novel cytoskeletal localization of cytoplasmic FPGS supports the dynamic channeling of polyglutamylated folates to metabolon compartments to avoid oxidation and intracellular dilution of folates, while enhancing folate-dependent de novo biosynthesis of nucleotides and DNA/protein methylation.
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11
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Wang C, Chen B, He M, Hu B. Composition of Intracellular Protein Corona around Nanoparticles during Internalization. ACS NANO 2021; 15:3108-3122. [PMID: 33570905 DOI: 10.1021/acsnano.0c09649] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
It has been well established that the early-stage interactions of nanoparticles with cells are governed by the extracellular protein corona. However, after entering into the cells, the evolving protein corona is the key to subsequent processing of nanoparticles by cells. To identify the protein corona around intracellular nanoparticles, it is essential to maintain its original compositions during cell treatment. Herein, we develop a paraformaldehyde (PFA) cross-linking strategy to stabilize corona compositions when extracting protein coronas from cells, providing original information on protein coronas around intercellular gold nanoparticles (AuNPs). The stability of the protein corona after PFA cross-linking was carefully investigated with several characterization methods, and the results demonstrate that PFA cross-linking successfully prevents the dissociation and exchange of corona proteins. Then the recovered intracellular protein corona around AuNPs from living HepG2 cells with a PFA cross-linking strategy was subjected to nanoHPLC-MS/MS for proteomic analysis. It was found that the compositions of intracellular protein coronas are dominated by cell-derived proteins and undergo significant variation of protein species and amounts over time during internalization. Time-resolved analysis provides relevant proteins involved in nanoparticle cellular uptake and transportation, indicating that AuNPs are endocytosed mainly by a clathrin-mediated uptake mechanism and directed into an endolysosomal pathway toward their final destination. Such proteomic-based results are verified by pharmacological inhibition and TEM imaging analysis. This work provides a universal strategy to study compositions of protein corona around intercellular nanoparticles and could be a footstone to link the formation of protein corona around nanoparticles to their biological function in cells.
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Affiliation(s)
- Chuan Wang
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Beibei Chen
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Man He
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China
| | - Bin Hu
- Key Laboratory of Analytical Chemistry for Biology and Medicine (Ministry of Education), Department of Chemistry, Wuhan University, Wuhan 430072, China
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12
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Shidham VB. Cell-blocks and other ancillary studies (including molecular genetic tests and proteomics). Cytojournal 2021; 18:4. [PMID: 33880127 PMCID: PMC8053490 DOI: 10.25259/cytojournal_3_2021] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Accepted: 01/18/2021] [Indexed: 01/28/2023] Open
Abstract
Many types of elective ancillary tests may be required to support the cytopathologic interpretations. Most of these tests can be performed on cell-blocks of different cytology specimens. The cell-block sections can be used for almost any special stains including various histochemistry stains and for special stains for different microorganisms including fungi, Pneumocystis jirovecii (carinii), and various organisms including acid-fast organisms similar to the surgical biopsy specimens. Similarly, in addition to immunochemistry, different molecular tests can be performed on cell-blocks. Molecular tests broadly can be divided into two main types Molecular genetic tests and Proteomics.
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Affiliation(s)
- Vinod B Shidham
- Department of Pathology, Wayne State University School of Medicine, Karmanos Cancer Center, and Detroit Medical Center, Detroit, Michigan, United States
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13
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Peng X, Wang T, Gao H, Yue X, Bian W, Mei J, Zhang Y. The interplay between IQGAP1 and small GTPases in cancer metastasis. Biomed Pharmacother 2021; 135:111243. [PMID: 33434854 DOI: 10.1016/j.biopha.2021.111243] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Revised: 12/27/2020] [Accepted: 12/31/2020] [Indexed: 01/07/2023] Open
Abstract
The metastatic spread of tumor cells to distant anatomical locations is a critical cause for disease progression and leads to more than 90 % of cancer-related deaths. IQ motif-containing GTPase-activating protein 1 (IQGAP1), a prominent regulator in the cancer metastasis process, is a scaffold protein that interacts with components of the cytoskeleton. As a critical node within the small GTPase network, IQGAP1 acts as a binding partner of several small GTPases, which in turn function as molecular switches to control most cellular processes, including cell migration and invasion. Given the significant interaction between IQGAP1 and small GTPases in cancer metastasis, we briefly elucidate the role of IQGAP1 in regulating cancer metastasis and the varied interactions existing between IQGAP1 and small GTPases. In addition, the potential regulators for IQGAP1 activity and its interaction with small GTPases are also incorporated in this review. Overall, we comprehensively summarize the role of IQGAP1 in cancer tumorigenicity and metastasis, which may be a potential anti-tumor target to restrain cancer progression.
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Affiliation(s)
- Xiafeng Peng
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China; First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Tiejun Wang
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China.
| | - Han Gao
- School of Medicine, Jiangnan University, Wuxi, 214122, China.
| | - Xin Yue
- First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Weiqi Bian
- First Clinical Medicine College, Nanjing Medical University, Nanjing, 211166, China.
| | - Jie Mei
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China; Wuxi Clinical Medical College, Nanjing Medical University, Wuxi, 214023, China.
| | - Yan Zhang
- Department of Gynecology and Obstetrics, Wuxi Maternal and Child Health Hospital, the Affiliated Hospital to Nanjing Medical University, Wuxi, 214023, China.
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14
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Jensen P, Patel B, Smith S, Sabnis R, Kaboord B. Improved Immunoprecipitation to Mass Spectrometry Method for the Enrichment of Low-Abundant Protein Targets. Methods Mol Biol 2021; 2261:229-246. [PMID: 33420993 DOI: 10.1007/978-1-0716-1186-9_14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Immunoprecipitation (IP) is commonly used upstream of mass spectrometry (MS) as an enrichment tool for low-abundant protein targets. However, several aspects of the classical IP procedure such as nonspecific protein binding to the isolation matrix, detergents or high salt concentrations in wash and elution buffers, and antibody chain contamination in elution fractions render it incompatible with downstream mass spectrometry analysis. Here, we discuss an improved IP-MS workflow that is designed to minimize sample prep time and these contaminants. The method employs biotinylated antibodies to the targets of interest and streptavidin magnetic beads that exhibit low background binding. In addition, alterations in the elution protocol and subsequent MS sample prep were made to reduce time and antibody leaching in the eluent, minimizing potential ion suppression effects and thereby maximizing detection of multiple target antigens and interacting proteins.
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Affiliation(s)
| | | | | | - Renuka Sabnis
- Nisarga Biotech Pvt. Ltd., Satara, Maharashtra, India
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15
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Luo Y, Li H. Structure-Based Inhibitor Discovery of Class I Histone Deacetylases (HDACs). Int J Mol Sci 2020; 21:E8828. [PMID: 33266366 PMCID: PMC7700698 DOI: 10.3390/ijms21228828] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Revised: 11/13/2020] [Accepted: 11/16/2020] [Indexed: 12/17/2022] Open
Abstract
Class I histone deacetylases (HDACs) are promising targets for epigenetic therapies for a range of diseases such as cancers, inflammations, infections and neurological diseases. Although six HDAC inhibitors are now licensed for clinical treatments, they are all pan-inhibitors with little or no HDAC isoform selectivity, exhibiting undesirable side effects. A major issue with the currently available HDAC inhibitors is that they have limited specificity and target multiple deacetylases. Except for HDAC8, Class I HDACs (1, 2 and 3) are recruited to large multiprotein complexes to function. Therefore, there are rising needs to develop new, hopefully, therapeutically efficacious HDAC inhibitors with isoform or complex selectivity. Here, upon the introduction of the structures of Class I HDACs and their complexes, we provide an up-to-date overview of the structure-based discovery of Class I HDAC inhibitors, including pan-, isoform-selective and complex-specific inhibitors, aiming to provide an insight into the discovery of additional HDAC inhibitors with greater selectivity, specificity and therapeutic utility.
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Affiliation(s)
- Yuxiang Luo
- School of Pharmaceutical Sciences, Sun Yat-sen University, No.132 Wai Huan Dong lu, Guangzhou Higher Education Mega Center, Guangzhou 510006, Guangdong, China;
| | - Huilin Li
- School of Pharmaceutical Sciences, Sun Yat-sen University, No.132 Wai Huan Dong lu, Guangzhou Higher Education Mega Center, Guangzhou 510006, Guangdong, China;
- Guangdong Key Laboratory of Chiral Molecule and Drug Discovery, School of Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510006, Guangdong, China
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16
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Haragan A, Liebler DC, Das DM, Soper MD, Morrison RD, Slebos RJC, Ackermann BL, Fill JA, Schade AE, Gosney JR, Gruver AM. Accelerated instability testing reveals quantitative mass spectrometry overcomes specimen storage limitations associated with PD-L1 immunohistochemistry. J Transl Med 2020; 100:874-886. [PMID: 31896815 PMCID: PMC7280177 DOI: 10.1038/s41374-019-0366-y] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Revised: 12/06/2019] [Accepted: 12/07/2019] [Indexed: 01/01/2023] Open
Abstract
Immunohistochemistry (IHC) using formalin-fixed, paraffin embedded (FFPE) tissue is limited by epitope masking, posttranslational modification and immunoreactivity loss that occurs in stored tissue by poorly characterized mechanisms. Conformational epitopes recognized by many programmed-death-ligand-1 (PD-L1) IHC assays are particularly susceptible to degradation and provide an ideal model for understanding signal loss in stored FFPE tissue. Here we assessed 1206 tissue sections to evaluate environmental factors impacting immunoreactivity loss. PD-L1 IHC using four antibodies (22C3, 28-8, E1L3N, and SP142), raised against intracellular and extracellular epitopes, was assessed in stored FFPE tissue alongside quantitative mass spectrometry (MS). Global proteome analyses were used to assess proteome-wide oxidation across an inventory of 3041 protein groups (24,737 distinct peptides). PD-L1 quantitation correlated well with IHC expression on unaged sections (R2 = 0.744; P < 0.001), with MS demonstrating no loss of PD-L1 protein, even in sections with significant signal loss by IHC impacting diagnostic category. Clones 22C3 and 28-8 were most susceptible to signal loss, with E1L3N demonstrating the most robust signal (56%, 58%, and 33% reduction respectively; p < 0.05). Increased humidity and temperature resulted in significant acceleration of immunoreactivity loss, which was mitigated by storage with desiccant. MS demonstrated only modest oxidation of 274 methionine-containing peptides and aligned with IHC results suggesting peptide oxidation is not a major factor. These data imply immunoreactivity loss driven by humidity and temperature results in structural distortion of epitopes rendering them unsuitable for antibody binding following epitope retrieval. Limitations of IHC biomarker analysis from stored tissue sections may be mitigated by cost-effective use of desiccant when appropriate. In some scenarios, complementary MS is a preferred approach for retrospective analyses of archival FFPE tissue collections.
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Affiliation(s)
- Alexander Haragan
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | | | - Dimple M Das
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Michael D Soper
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | | | | | | | - Jeff A Fill
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - Andrew E Schade
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA
| | - John R Gosney
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK
| | - Aaron M Gruver
- Institute of Translational Medicine, University of Liverpool, Liverpool, UK.
- Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN, USA.
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17
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Sinsky J, Majerova P, Kovac A, Kotlyar M, Jurisica I, Hanes J. Physiological Tau Interactome in Brain and Its Link to Tauopathies. J Proteome Res 2020; 19:2429-2442. [PMID: 32357304 DOI: 10.1021/acs.jproteome.0c00137] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Alzheimer's disease (AD) and most of the other tauopathies are incurable neurodegenerative diseases with unpleasant symptoms and consequences. The common hallmark of all of these diseases is tau pathology, but its connection with disease progress has not been completely understood so far. Therefore, uncovering novel tau-interacting partners and pathology affected molecular pathways can reveal the causes of diseases as well as potential targets for the development of AD treatment. Despite the large number of known tau-interacting partners, a limited number of studies focused on in vivo tau interactions in disease or healthy conditions are available. Here, we applied an in vivo cross-linking approach, capable of capturing weak and transient protein-protein interactions, to a unique transgenic rat model of progressive tau pathology similar to human AD. We have identified 175 potential novel and known tau-interacting proteins by MALDI-TOF mass spectrometry. Several of the most promising candidates for possible drug development were selected for validation by coimmunoprecipitation and colocalization experiments in animal and cellular models. Three proteins, Baiap2, Gpr37l1, and Nptx1, were confirmed as novel tau-interacting partners, and on the basis of their known functions and implications in neurodegenerative or psychiatric disorders, we proposed their potential role in tau pathology.
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Affiliation(s)
- Jakub Sinsky
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia
| | - Petra Majerova
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia.,AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, Bratislava 811 02, Slovakia
| | - Andrej Kovac
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia.,AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, Bratislava 811 02, Slovakia
| | - Max Kotlyar
- Krembil Research Institute, UHN, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada
| | - Igor Jurisica
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia.,Krembil Research Institute, UHN, 60 Leonard Avenue, Toronto, Ontario M5T 0S8, Canada.,Departments of Medical Biophysics and Computer Science, University of Toronto, 27 King's College Circle, Toronto, Ontario ON M5S, Canada
| | - Jozef Hanes
- Institute of Neuroimmunology, Slovak Academy of Sciences, Dubravska cesta 9, Bratislava 84510, Slovakia.,AXON Neuroscience R&D Services SE, Dvorakovo nabrezie 10, Bratislava 811 02, Slovakia
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18
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Uka R, Britschgi C, Krättli A, Matter C, Mihic D, Okoniewski MJ, Gualandi M, Stupp R, Cinelli P, Dummer R, Levesque MP, Shakhova O. Temporal activation of WNT/β-catenin signaling is sufficient to inhibit SOX10 expression and block melanoma growth. Oncogene 2020; 39:4132-4154. [PMID: 32238882 PMCID: PMC8076051 DOI: 10.1038/s41388-020-1267-7] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 03/05/2020] [Accepted: 03/10/2020] [Indexed: 12/23/2022]
Abstract
Despite advances in the systemic treatment of patients with metastatic melanoma using immune checkpoint and tyrosine kinase inhibitors (TKI), the majority of stage IV melanoma patients eventually succumb to the disease. We have previously identified the transcription factor Sox10 as a crucial player in melanoma, yet the underlying molecular mechanisms mediating Sox10-dependent tumorigenesis remain largely uncharacterized. Here, we show that MEK and RAF inhibitors do not suppress levels of SOX10 protein in patient-derived cells in vitro, as well as in melanoma patients in vivo. In a search for pharmacological inhibitors of SOX10, we performed a mass spectrometry-based screen in human melanoma cells. Subsequent analysis revealed that SOX10 directly interacts with β-catenin, which is a key mediator of canonical Wnt/β-catenin signaling. We demonstrate that inhibitors of glycogen synthase kinase 3 alpha/beta (GSK3α/β) efficiently abrogate SOX10 protein in human melanoma cells in vitro and in melanoma mouse models in vivo. The mechanism of action of GSK3-mediated SOX10 suppression is transcription-independent and relies on the presence of a proteasome degradable form of β-catenin. Taken together, we provide evidence that activation of canonical Wnt signaling has a profound effect on melanoma growth and is able to counteract Sox10-dependent melanoma maintenance both in vitro and in vivo.
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Affiliation(s)
- Rexhep Uka
- Department of Medical Oncology and Hematology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, UK
| | - Christian Britschgi
- Department of Medical Oncology and Hematology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, UK
| | - Anja Krättli
- Department of Medical Oncology and Hematology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, UK
| | - Claudia Matter
- Department of Medical Oncology and Hematology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, UK
| | - Daniela Mihic
- Department of Surgical Pathology, University Hospital Zurich, University of Zurich, Schmelzbergstrasse 12, 8091, Zurich, UK
| | - Michal J Okoniewski
- Scientific IT Services ETH Zurich, ETH Zurich, Weinbergstrasse 11, 8092, Zürich, UK
| | - Marco Gualandi
- Department of Medical Oncology and Hematology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, UK
| | - Roger Stupp
- Department of Medical Oncology and Hematology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, UK
- Ken and Ruth Davee Department of Neurology, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
- The Lou and Jean Malnati Brain Tumor Institute, The Robert H. Lurie Comprehensive Cancer Center, Northwestern University Feinberg School of Medicine, Chicago, IL, 60611, USA
| | - Paolo Cinelli
- Department of Trauma Surgery, University Hospital Zurich, University of Zurich, Sternwartstrasse 14, 8091, Zürich, UK
| | - Reinhard Dummer
- Department of Dermatology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, UK
| | - Mitchell P Levesque
- Department of Dermatology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, UK
| | - Olga Shakhova
- Department of Medical Oncology and Hematology, University Hospital Zurich, University of Zurich, Wagistrasse 14, 8952, Schlieren, UK.
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19
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Pertl-Obermeyer H, Obermeyer G. In Vivo Cross-Linking to Analyze Transient Protein-Protein Interactions. Methods Mol Biol 2020; 2139:273-287. [PMID: 32462593 DOI: 10.1007/978-1-0716-0528-8_20] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Cross-linking converts noncovalent interactions between proteins into covalent bonds. The now artificially fused molecules are stable during purification steps (e.g., immunoprecipitation). In combination with a variety of techniques, including Western blotting, mass spectrometry (MS), and bioinformatics, this technology provides improved opportunities for modelling structural details of functional complexes in living cells and protein-protein interaction networks. The presented strategy of immunoaffinity purification and mass spectrometry (AP-MS) coupled with in vivo cross-linking can easily be adapted as a robust workflow in interactome analyses of various species, also nonmodel organisms.
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Affiliation(s)
- Heidi Pertl-Obermeyer
- Department of Biosciences, Membrane Biophysics, Paris-Lodron-University of Salzburg, Billrothstrasse 11, Salzburg, Austria.
| | - Gerhard Obermeyer
- Department of Biosciences, Membrane Biophysics, Paris-Lodron-University of Salzburg, Billrothstrasse 11, Salzburg, Austria
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20
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Stevens LM, Zhang Y, Volnov Y, Chen G, Stein DS. Isolation of secreted proteins from Drosophila ovaries and embryos through in vivo BirA-mediated biotinylation. PLoS One 2019; 14:e0219878. [PMID: 31658274 PMCID: PMC6816556 DOI: 10.1371/journal.pone.0219878] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Accepted: 10/15/2019] [Indexed: 02/07/2023] Open
Abstract
The extraordinarily strong non-covalent interaction between biotin and avidin (kD = 10-14-10-16) has permitted this interaction to be used in a wide variety of experimental contexts. The Biotin Acceptor Peptide (BAP), a 15 amino acid motif that can be biotinylated by the E. coli BirA protein, has been fused to proteins-of-interest, making them substrates for in vivo biotinylation. Here we report on the construction and characterization of a modified BirA bearing signals for secretion and endoplasmic reticulum (ER) retention, for use in experimental contexts requiring biotinylation of secreted proteins. When expressed in the Drosophila female germline or ovarian follicle cells under Gal4-mediated transcriptional control, the modified BirA protein could be detected and shown to be enzymatically active in ovaries and progeny embryos. Surprisingly, however, it was not efficiently retained in the ER, and instead appeared to be secreted. To determine whether this secreted protein, now designated secBirA, could biotinylate secreted proteins, we generated BAP-tagged versions of two secreted Drosophila proteins, Torsolike (Tsl) and Gastrulation Defective (GD), which are normally expressed maternally and participate in embryonic pattern formation. Both Tsl-BAP and GD-BAP were shown to exhibit normal patterning activity. Co-expression of Tsl-BAP together with secBirA in ovarian follicle cells resulted in its biotinylation, which permitted its isolation from both ovaries and progeny embryos using Avidin-coupled affinity matrix. In contrast, co-expression with secBirA in the female germline did not result in detectable biotinylation of GD-BAP, possibly because the C-terminal location of the BAP tag made it inaccessible to BirA in vivo. Our results indicate that secBirA directs biotinylation of proteins bound for secretion in vivo, providing access to powerful experimental approaches for secreted proteins-of-interest. However, efficient biotinylation of target proteins may vary depending upon the location of the BAP tag or other structural features of the protein.
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Affiliation(s)
- Leslie M. Stevens
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
- Section of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Yuan Zhang
- Section of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Yuri Volnov
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - Geng Chen
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
- Section of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
| | - David S. Stein
- Department of Molecular Biosciences, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
- Section of Molecular Cell and Developmental Biology, Institute for Cellular and Molecular Biology, The University of Texas at Austin, Austin, Texas, United States of America
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21
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Rakow S, Pullamsetti SS, Bauer UM, Bouchard C. Assaying epigenome functions of PRMTs and their substrates. Methods 2019; 175:53-65. [PMID: 31542509 DOI: 10.1016/j.ymeth.2019.09.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 09/09/2019] [Accepted: 09/16/2019] [Indexed: 12/20/2022] Open
Abstract
Among the widespread and increasing number of identified post-translational modifications (PTMs), arginine methylation is catalyzed by the protein arginine methyltransferases (PRMTs) and regulates fundamental processes in cells, such as gene regulation, RNA processing, translation, and signal transduction. As epigenetic regulators, PRMTs play key roles in pluripotency, differentiation, proliferation, survival, and apoptosis, which are essential biological programs leading to development, adult homeostasis but also pathological conditions including cancer. A full understanding of the molecular mechanisms that underlie PRMT-mediated gene regulation requires the genome wide mapping of each player, i.e., PRMTs, their substrates and epigenetic marks, methyl-marks readers as well as interaction partners, in a thorough and unambiguous manner. However, despite the tremendous advances in high throughput sequencing technologies and the numerous efforts from the scientific community, the epigenomic profiling of PRMTs as well as their histone and non-histone substrates still remains a big challenge owing to obvious limitations in tools and methodologies. This review will summarize the present knowledge about the genome wide mapping of PRMTs and their substrates as well as the technical approaches currently in use. The limitations and pitfalls of the technical tools along with conventional approaches will be then discussed in detail. Finally, potential new strategies for chromatin profiling of PRMTs and histone substrates will be proposed and described.
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Affiliation(s)
- Sinja Rakow
- Institute for Molecular Biology and Tumor Research (IMT), Philipps University of Marburg, Hans-Meerwein-Str. 2, BMFZ, 35043 Marburg, Germany
| | - Soni Savai Pullamsetti
- Department of Lung Development and Remodeling, Max Planck Institute for Heart and Lung Research, Member of the German Center for Lung Research (DZL), Bad Nauheim, Germany
| | - Uta-Maria Bauer
- Institute for Molecular Biology and Tumor Research (IMT), Philipps University of Marburg, Hans-Meerwein-Str. 2, BMFZ, 35043 Marburg, Germany
| | - Caroline Bouchard
- Institute for Molecular Biology and Tumor Research (IMT), Philipps University of Marburg, Hans-Meerwein-Str. 2, BMFZ, 35043 Marburg, Germany.
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22
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Mu R, Shinde P, Zou Z, Kreth J, Merritt J. Examining the Protein Interactome and Subcellular Localization of RNase J2 Complexes in Streptococcus mutans. Front Microbiol 2019; 10:2150. [PMID: 31620106 PMCID: PMC6759994 DOI: 10.3389/fmicb.2019.02150] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Accepted: 09/02/2019] [Indexed: 12/18/2022] Open
Abstract
Regulated RNA turnover is vital for the control of gene expression in all cellular life. In Escherichia coli, this process is largely controlled by a stable degradosome complex containing RNase E and a variety of additional enzymes. In the Firmicutes phylum, species lack RNase E and often encode the paralogous enzymes RNase J1 and RNase J2. Unlike RNase J1, surprisingly little is known about the regulatory function and protein interactions of RNase J2, despite being a central pleiotropic regulator for the streptococci and other closely related organisms. Using crosslink coimmunoprecipitation in Streptococcus mutans, we have identified the major proteins found within RNase J2 protein complexes located in the cytoplasm and at the cell membrane. In both subcellular fractions, RNase J2 exhibited the most robust interactions with RNase J1, while additional transient and/or weaker "degradosome-like" interactions were also detected. In addition, RNase J2 exhibits multiple novel interactions that have not been previously reported for any RNase J proteins, some of which were highly biased for either the cytoplasmic or membrane fractions. We also determined that the RNase J2 C-terminal domain (CTD) encodes a structure that is likely conserved among RNase J enzymes and may have an analogous function to the C-terminal portion of RNase E. While we did observe a number of parallels between the RNase J2 interactome and the E. coli degradosome paradigm, our results suggest that S. mutans degradosomes are either unlikely to exist or are quite distinct from those of E. coli.
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Affiliation(s)
- Rong Mu
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, United States
| | - Pushkar Shinde
- Emory College of Arts and Sciences, Atlanta, GA, United States
| | - Zhengzhong Zou
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, United States
| | - Jens Kreth
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, United States.,Department of Molecular Microbiology and Immunology, School of Medicine, Oregon Health and Science University, Portland, OR, United States
| | - Justin Merritt
- Department of Restorative Dentistry, School of Dentistry, Oregon Health and Science University, Portland, OR, United States.,Department of Molecular Microbiology and Immunology, School of Medicine, Oregon Health and Science University, Portland, OR, United States
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23
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Morgan CJ, Hedman AC, Li Z, Sacks DB. Endogenous IQGAP1 and IQGAP3 do not functionally interact with Ras. Sci Rep 2019; 9:11057. [PMID: 31363101 PMCID: PMC6667474 DOI: 10.1038/s41598-019-46677-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Accepted: 06/28/2019] [Indexed: 02/07/2023] Open
Abstract
The Ras family of small GTPases modulates numerous essential processes. Activating Ras mutations result in hyper-activation of selected signaling cascades, which leads to human diseases. The high frequency of Ras mutations in human malignant neoplasms has led to Ras being a desirable chemotherapeutic target. The IQGAP family of scaffold proteins binds to and regulates multiple signaling molecules, including the Rho family GTPases Rac1 and Cdc42. There are conflicting data in the published literature regarding interactions between IQGAP and Ras proteins. Initial reports showed no binding, but subsequent studies claim associations of IQGAP1 and IQGAP3 with K-Ras and H-Ras, respectively. Therefore, we set out to resolve this controversy. Here we demonstrate that neither endogenous IQGAP1 nor endogenous IQGAP3 binds to the major Ras isoforms, namely H-, K-, and N-Ras. Importantly, Ras activation by epidermal growth factor is not altered when IQGAP1 or IQGAP3 proteins are depleted from cells. These data strongly suggest that IQGAP proteins are not functional interactors of H-, K-, or N-Ras and challenge the rationale for targeting the interaction of Ras with IQGAP for the development of therapeutic agents.
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Affiliation(s)
- Chase J Morgan
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - Andrew C Hedman
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - Zhigang Li
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA
| | - David B Sacks
- From the Department of Laboratory Medicine, National Institutes of Health, 10 Center Drive, Bethesda, Maryland, 20892, USA.
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24
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Abstract
Crosslinking of proteins for their irreversible immobilization on surfaces is a proven and popular method. However, many protocols lead to random orientation and the formation of undefined or even inactive by-products. Most concepts to obtain a more targeted conjugation or immobilization requires the recombinant modification of at least one binding partner, which is often impractical or prohibitively expensive. Here a novel method is presented, which is based on the chemical preactivation of Protein A or G with selected conventional crosslinkers. In a second step, the antibody is added, which is subsequently crosslinked in the Fc part. This leads to an oriented and covalent immobilization of the immunoglobulin with a very high yield. Protocols for Protein A and Protein G with murine and human IgG are presented. This method may be useful for the preparation of columns for affinity chromatography, immunoprecipitation, antibodies conjugated to magnetic particles, permanent and oriented immobilization of antibodies in biosensor systems, microarrays, microtitration plates or any other system, where the loss of antibodies needs to be avoided, and maximum binding capacity is desired. This method is directly applicable even to antibodies in crude cell culture supernatants, raw sera or protein-stabilized antibody preparations without any purification nor enrichment of the IgG. This new method delivered much higher signals as a traditional method and, hence, seems to be preferable in many applications.
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25
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Minic Z, Dahms TES, Babu M. Chromatographic separation strategies for precision mass spectrometry to study protein-protein interactions and protein phosphorylation. J Chromatogr B Analyt Technol Biomed Life Sci 2018; 1102-1103:96-108. [PMID: 30380468 DOI: 10.1016/j.jchromb.2018.10.022] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Revised: 10/19/2018] [Accepted: 10/22/2018] [Indexed: 11/30/2022]
Abstract
Investigating protein-protein interactions and protein phosphorylation can be of great significance when studying biological processes and human diseases at the molecular level. However, sample complexity, presence of low abundance proteins, and dynamic nature of the proteins often impede in achieving sufficient analytical depth in proteomics research. In this regard, chromatographic separation methodologies have played a vital role in the identification and quantification of proteins in complex sample mixtures. The combination of peptide and protein fractionation techniques with advanced high-performance mass spectrometry has allowed the researchers to successfully study the protein-protein interactions and protein phosphorylation. Several new fractionation strategies for large scale analysis of proteins and peptides have been developed to study protein-protein interactions and protein phosphorylation. These emerging chromatography methodologies have enabled the identification of several hundred protein complexes and even thousands of phosphorylation sites in a single study. In this review, we focus on current workflow strategies and chromatographic tools, highlighting their advantages and disadvantages, and examining their associated challenges and future potential.
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Affiliation(s)
- Zoran Minic
- Department of Chemistry and Biomolecular Science, University of Ottawa, John L. Holmes, Mass Spectrometry Facility, 10 Marie-Curie, Marion Hall, Room 02, Ottawa, ON K1N 1A2, Canada.
| | - Tanya E S Dahms
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
| | - Mohan Babu
- Department of Chemistry and Biochemistry, University of Regina, 3737 Wascana Parkway, Regina, SK S4S 0A2, Canada
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26
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Kaur U, Meng H, Lui F, Ma R, Ogburn RN, Johnson JHR, Fitzgerald MC, Jones LM. Proteome-Wide Structural Biology: An Emerging Field for the Structural Analysis of Proteins on the Proteomic Scale. J Proteome Res 2018; 17:3614-3627. [PMID: 30222357 DOI: 10.1021/acs.jproteome.8b00341] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Over the past decade, a suite of new mass-spectrometry-based proteomics methods has been developed that now enables the conformational properties of proteins and protein-ligand complexes to be studied in complex biological mixtures, from cell lysates to intact cells. Highlighted here are seven of the techniques in this new toolbox. These techniques include chemical cross-linking (XL-MS), hydroxyl radical footprinting (HRF), Drug Affinity Responsive Target Stability (DARTS), Limited Proteolysis (LiP), Pulse Proteolysis (PP), Stability of Proteins from Rates of Oxidation (SPROX), and Thermal Proteome Profiling (TPP). The above techniques all rely on conventional bottom-up proteomics strategies for peptide sequencing and protein identification. However, they have required the development of unconventional proteomic data analysis strategies. Discussed here are the current technical challenges associated with these different data analysis strategies as well as the relative analytical capabilities of the different techniques. The new biophysical capabilities that the above techniques bring to bear on proteomic research are also highlighted in the context of several different application areas in which these techniques have been used, including the study of protein ligand binding interactions (e.g., protein target discovery studies and protein interaction network analyses) and the characterization of biological states.
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Affiliation(s)
- Upneet Kaur
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
| | - He Meng
- Department of Chemistry , Duke University , Durham , North Carolina 27708-0346 , United States
| | | | - Renze Ma
- Department of Chemistry , Duke University , Durham , North Carolina 27708-0346 , United States
| | - Ryenne N Ogburn
- Department of Chemistry , Duke University , Durham , North Carolina 27708-0346 , United States
| | - Julia H R Johnson
- Department of Chemistry , Duke University , Durham , North Carolina 27708-0346 , United States
| | - Michael C Fitzgerald
- Department of Chemistry , Duke University , Durham , North Carolina 27708-0346 , United States
| | - Lisa M Jones
- Department of Pharmaceutical Sciences , University of Maryland , Baltimore , Maryland 21201 , United States
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27
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Identification of progesterone receptor membrane component-1 as an interaction partner and possible regulator of fatty acid 2-hydroxylase. Biochem J 2018; 475:853-871. [PMID: 29438993 DOI: 10.1042/bcj20170963] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2017] [Revised: 02/02/2018] [Accepted: 02/08/2018] [Indexed: 12/20/2022]
Abstract
The fatty acid 2-hydroxylase (FA2H) is essential for synthesis of 2-hydroxylated fatty acids in myelinating and other cells, and deficiency of this enzyme causes a complicated form of hereditary spastic paraplegia also known as fatty acid hydroxylase-associated neurodegeneration. Despite its important role in sphingolipid metabolism, regulation of FA2H and its interaction with other proteins involved in the same or other metabolic pathways is poorly understood. To identify potential interaction partners of the enzyme, quantitative mass spectrometry using stable isotope labeling of cells was combined with formaldehyde cross-linking and proximity biotinylation, respectively. Besides other enzymes involved in sphingolipid synthesis and intermembrane transfer of ceramide, and putative redox partners of FA2H, progesterone receptor membrane component-1 (PGRMC1) and PGRMC2 were identified as putative interaction partners. These two related heme-binding proteins are known to regulate several cytochrome P450 enzymes. Bimolecular fluorescence complementation experiments confirmed the interaction of FA2H with PGRMC1. Moreover, the PGRMC1 inhibitor AG-205 significantly reduced synthesis of hydroxylated ceramide and glucosylceramide in FA2H-expressing cells. This suggests that PGRMC1 may regulate FA2H activity, possibly through its heme chaperone activity.
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28
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Egami Y, Araki N. Transient recruitment of M-Ras GTPase to phagocytic cups in RAW264 macrophages during FcγR-mediated phagocytosis. Microscopy (Oxf) 2018; 67:68-74. [DOI: 10.1093/jmicro/dfx131] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2017] [Accepted: 12/17/2017] [Indexed: 12/22/2022] Open
Affiliation(s)
- Youhei Egami
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Miki, Kagawa 761-0793, Japan
| | - Nobukazu Araki
- Department of Histology and Cell Biology, School of Medicine, Kagawa University, Miki, Kagawa 761-0793, Japan
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29
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Yu C, Huang L. Cross-Linking Mass Spectrometry: An Emerging Technology for Interactomics and Structural Biology. Anal Chem 2018; 90:144-165. [PMID: 29160693 PMCID: PMC6022837 DOI: 10.1021/acs.analchem.7b04431] [Citation(s) in RCA: 222] [Impact Index Per Article: 37.0] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Clinton Yu
- Department of Physiology & Biophysics, University of California, Irvine, Irvine, CA 92697
| | - Lan Huang
- Department of Physiology & Biophysics, University of California, Irvine, Irvine, CA 92697
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30
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Prothymosin α interacts with SET, ANP32A and ANP32B and other cytoplasmic and mitochondrial proteins in proliferating cells. Arch Biochem Biophys 2017; 635:74-86. [DOI: 10.1016/j.abb.2017.10.014] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Revised: 10/23/2017] [Accepted: 10/24/2017] [Indexed: 12/11/2022]
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31
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Suttapitugsakul S, Xiao H, Smeekens J, Wu R. Evaluation and optimization of reduction and alkylation methods to maximize peptide identification with MS-based proteomics. MOLECULAR BIOSYSTEMS 2017; 13:2574-2582. [PMID: 29019370 PMCID: PMC5698164 DOI: 10.1039/c7mb00393e] [Citation(s) in RCA: 58] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Mass spectrometry (MS) has become an increasingly important technique to analyze proteins. In popular bottom-up MS-based proteomics, reduction and alkylation are routine steps to facilitate peptide identification. However, incomplete reactions and side reactions may occur, which compromise the experimental results. In this work, we systematically evaluated the reduction step with commonly used reagents, i.e., dithiothreitol, 2-mercaptoethanol, tris(2-carboxyethyl)phosphine, or tris(3-hydroxypropyl)phosphine, and alkylation with iodoacetamide, acrylamide, N-ethylmaleimide, or 4-vinylpyridine. By using digested peptides from a yeast whole-cell lysate, the number of proteins and peptides identified were very similar using four different reducing reagents. The results from four alkylating reagents, however, were dramatically different with iodoacetamide giving the highest number of peptides with alkylated cysteine and the lowest number of peptides with incomplete cysteine alkylation and side reactions. Alkylation conditions with iodoacetamide were further optimized. To identify more peptides with cysteine, thiopropyl-sepharose 6B resins were used to enrich them, and the optimal conditions were employed for the reduction and alkylation. The enrichment resulted in over three times more cysteine-containing peptides than without enrichment. Systematic evaluation of the reduction and alkylation with different reagents can aid in a better design of bottom-up proteomic experiments.
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Affiliation(s)
- Suttipong Suttapitugsakul
- School of Chemistry and Biochemistry and the Petit Institute for Bioengineering and Bioscience, Georgia Institute of Technology, Atlanta, Georgia 30332, USA.
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32
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Proteomic and network analysis of human serum albuminome by integrated use of quick crosslinking and two-step precipitation. Sci Rep 2017; 7:9856. [PMID: 28851998 PMCID: PMC5575314 DOI: 10.1038/s41598-017-09563-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Accepted: 07/24/2017] [Indexed: 11/23/2022] Open
Abstract
Affinity- and chemical-based methods are usually employed to prepare human serum albuminome; however, these methods remain technically challenging. Herein, we report the development of a two-step precipitation (TSP) method by combined use of polyethylene glycol (PEG) and ethanol. PEG precipitation was newly applied to remove immunoglobulin G for albuminome preparation, which is simple, cost effective, efficient and compatible with downstream ethanol precipitation. Nonetheless, chemical extraction using TSP may disrupt weak and transient protein interactions with human serum albumin (HSA) leading to an incomplete albuminome. Accordingly, rapid fixation based on formaldehyde crosslinking (FC) was introduced into the TSP procedure. The developed FC-TSP method increased the number of identified proteins, probably by favouring real-time capture of weakly bound proteins in the albuminome. A total of 171 proteins excluding HSA were identified from the fraction obtained with FC-TSP. Further interaction network and cluster analyses revealed 125 HSA-interacting proteins and 14 highly-connected clusters. Compared with five previous studies, 55 new potential albuminome proteins including five direct and 50 indirect binders were only identified by our strategy and 12 were detected as common low-abundance proteins. Thus, this new strategy has the potential to effectively survey the human albuminome, especially low-abundance proteins of clinical interest.
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33
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LCCL protein complex formation in Plasmodium is critically dependent on LAP1. Mol Biochem Parasitol 2017; 214:87-90. [PMID: 28414172 PMCID: PMC5482319 DOI: 10.1016/j.molbiopara.2017.04.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2017] [Revised: 04/03/2017] [Accepted: 04/12/2017] [Indexed: 01/09/2023]
Abstract
Successful sporogony of Plasmodium berghei in vector mosquitoes requires expression of a family of six modular proteins named LCCL lectin domain adhesive-like proteins (LAPs). The LAPs share a subcellular localization in the crystalloid, a unique parasite organelle that forms during ookinete development. Here, LAP interactions in P. berghei were studied using a series of parasite lines stably expressing reporter-tagged LAPs combined with affinity purification and high accuracy label free quantitative mass spectrometry. Our results show that abundant complexes containing LAP1, LAP2 and LAP3 are formed in gametocytes through high avidity interactions. Following fertilization, LAP4, LAP5 and LAP6 are recruited to this complex, a process that is facilitated by LAP1 chiefly through its scavenger receptor cysteine-rich modules. These collective findings provide new insight into the temporal and molecular dynamics of protein complex formation that lead up to, and are required for, crystalloid biogenesis and downstream sporozoite transmission of malaria parasites.
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34
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Galectin-3 is a non-classic RNA binding protein that stabilizes the mucin MUC4 mRNA in the cytoplasm of cancer cells. Sci Rep 2017; 7:43927. [PMID: 28262838 PMCID: PMC5338267 DOI: 10.1038/srep43927] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Accepted: 02/01/2017] [Indexed: 12/22/2022] Open
Abstract
Pancreatic cancer cells express high levels of MUC1, MUC4 and MUC16 mRNAs that encode membrane-bound mucins. These mRNAs share unusual features such as a long half-life. However, it remains unknown how mucin mRNA stability is regulated. Galectin-3 (Gal-3) is an endogenous lectin playing important biological functions in epithelial cells. Gal-3 is encoded by LGALS3 which is up-regulated in pancreatic cancer. Despite the absence of a RNA-recognition motif, Gal-3 interacts indirectly with pre-mRNAs in the nucleus and promotes constitutive splicing. However a broader role of Gal-3 in mRNA fate is unexplored. We report herein that Gal-3 increases MUC4 mRNA stability through an intermediate, hnRNP-L which binds to a conserved CA repeat element in the 3′UTR in a Gal-3 dependent manner and also controls Muc4 mRNA levels in epithelial tissues of Gal3−/− mice. Gal-3 interacts with hnRNP-L in the cytoplasm, especially during cell mitosis, but only partly associates with protein markers of P-Bodies or Stress Granules. By RNA-IP plus RNA-seq analysis and imaging, we demonstrate that Gal-3 binds to mature spliced MUC4 mRNA in the perinuclear region, probably in hnRNP-L-containing RNA granules. Our findings highlight a new role for Gal-3 as a non-classic RNA-binding protein that regulates MUC4 mRNA post-transcriptionally.
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35
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Chen Y, Wilson R, O'Dell S, Guenaga J, Feng Y, Tran K, Chiang CI, Arendt HE, DeStefano J, Mascola JR, Wyatt RT, Li Y. An HIV-1 Env-Antibody Complex Focuses Antibody Responses to Conserved Neutralizing Epitopes. THE JOURNAL OF IMMUNOLOGY 2016; 197:3982-3998. [PMID: 27815444 DOI: 10.4049/jimmunol.1601134] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2016] [Accepted: 08/31/2016] [Indexed: 11/19/2022]
Abstract
Elicitation of broadly neutralizing Ab (bNAb) responses to the conserved elements of the HIV-1 envelope glycoproteins (Env), including the primary receptor CD4 binding site (CD4bs), is a major focus of vaccine development yet to be accomplished. However, a large number of CD4bs-directed bNAbs have been isolated from HIV-1-infected individuals. Comparison of the routes of binding used by the CD4bs-directed bNAbs from patients and the vaccine-elicited CD4bs-directed mAbs indicates that the latter fail to neutralize primary virus isolates because they approach the Env spike with a vertical angle and contact the specific surface residues occluded in the native spike, including the bridging sheet on gp120. To preferentially expose the CD4bs and direct the immune response away from the bridging sheet, resulting in an altered angle of approach, we engineered an immunogen consisting of gp120 core in complex with the prototypic CD4-induced Ab, 17b. This mAb directly contacts the bridging sheet but not the CD4bs. The complex was further stabilized by chemical crosslinking to prevent dissociation. Rabbits immunized with the crosslinked complex displayed earlier affinity maturation, achieving tier 1 virus neutralization compared with animals immunized with gp120 core alone. Immunization with the crosslinked complex induced transient Ab responses with binding specificity similar to the CD4bs-directed bNAbs. mAbs derived from complex-immunized rabbits displayed footprints on gp120 more distal from the bridging sheet as compared with previous vaccine-elicited CD4bs Abs, indicating that Env-Ab complexes effectively dampen immune responses to undesired immunodominant bridging sheet determinants.
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Affiliation(s)
- Yajing Chen
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037
| | - Richard Wilson
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037
| | - Sijy O'Dell
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Javier Guenaga
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037
| | - Yu Feng
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037
| | - Karen Tran
- International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037
| | - Chi-I Chiang
- Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
| | | | | | - John R Mascola
- Vaccine Research Center, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD 20892
| | - Richard T Wyatt
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037.,International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037.,Scripps Center for HIV Vaccine Immunogen Discovery, La Jolla, CA 92037
| | - Yuxing Li
- Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037; .,International AIDS Vaccine Initiative Neutralizing Antibody Center, The Scripps Research Institute, La Jolla, CA 92037.,Institute for Bioscience and Biotechnology Research, University of Maryland, Rockville, MD 20850
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36
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Morgan CP, Krey JF, Grati M, Zhao B, Fallen S, Kannan-Sundhari A, Liu XZ, Choi D, Müller U, Barr-Gillespie PG. PDZD7-MYO7A complex identified in enriched stereocilia membranes. eLife 2016; 5:e18312. [PMID: 27525485 PMCID: PMC5005036 DOI: 10.7554/elife.18312] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2016] [Accepted: 08/14/2016] [Indexed: 12/15/2022] Open
Abstract
While more than 70 genes have been linked to deafness, most of which are expressed in mechanosensory hair cells of the inner ear, a challenge has been to link these genes into molecular pathways. One example is Myo7a (myosin VIIA), in which deafness mutations affect the development and function of the mechanically sensitive stereocilia of hair cells. We describe here a procedure for the isolation of low-abundance protein complexes from stereocilia membrane fractions. Using this procedure, combined with identification and quantitation of proteins with mass spectrometry, we demonstrate that MYO7A forms a complex with PDZD7, a paralog of USH1C and DFNB31. MYO7A and PDZD7 interact in tissue-culture cells, and co-localize to the ankle-link region of stereocilia in wild-type but not Myo7a mutant mice. Our data thus describe a new paradigm for the interrogation of low-abundance protein complexes in hair cell stereocilia and establish an unanticipated link between MYO7A and PDZD7.
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Affiliation(s)
- Clive P Morgan
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States
| | - Jocelyn F Krey
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States
| | - M'hamed Grati
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, United States
| | - Bo Zhao
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Shannon Fallen
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States
| | | | - Xue Zhong Liu
- Department of Otolaryngology, Miller School of Medicine, University of Miami, Miami, United States
| | - Dongseok Choi
- OHSU-PSU School of Public Health, Oregon Health and Science University, Portland, United States
- Graduate School of Dentistry, Kyung Hee University, Seoul, Korea
| | - Ulrich Müller
- Dorris Neuroscience Center, The Scripps Research Institute, La Jolla, United States
| | - Peter G Barr-Gillespie
- Oregon Hearing Research Center and Vollum Institute, Oregon Health and Science University, Portland, United States
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37
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Ouimet CM, Shao H, Rauch JN, Dawod M, Nordhues B, Dickey CA, Gestwicki JE, Kennedy RT. Protein Cross-Linking Capillary Electrophoresis for Protein-Protein Interaction Analysis. Anal Chem 2016; 88:8272-8. [PMID: 27434096 DOI: 10.1021/acs.analchem.6b02126] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Capillary electrophoresis (CE) has been identified as a useful platform for detecting, quantifying, and screening for modulators of protein-protein interactions (PPIs). In this method, one protein binding partner is labeled with a fluorophore, the protein binding partners are mixed, and then, the complex is separated from free protein to allow direct determination of bound to free ratios. Although it possesses many advantages for PPI studies, the method is limited by the need to have separation conditions that both prevent protein adsorption to capillary and maintain protein interactions during the separation. In this work, we use protein cross-linking capillary electrophoresis (PXCE) to overcome this limitation. In PXCE, the proteins are cross-linked under binding conditions and then separated. This approach eliminates the need to maintain noncovalent interactions during electrophoresis and facilitates method development. We report PXCE methods for an antibody-antigen interaction and heterodimer and homodimer heat shock protein complexes. Complexes are cross-linked by short treatments with formaldehyde after reaching binding equilibrium. Cross-linked complexes are separated by electrophoretic mobility using free solution CE or by size using sieving electrophoresis of SDS complexes. The method gives good quantitative results; e.g., a lysozyme-antibody interaction was found to have Kd = 24 ± 3 nM by PXCE and Kd = 17 ± 2 nM using isothermal calorimetry (ITC). Heat shock protein 70 (Hsp70) in complex with bcl2 associated athanogene 3 (Bag3) was found to have Kd = 25 ± 5 nM by PXCE which agrees with Kd values reported without cross-linking. Hsp70-Bag3 binding site mutants and small molecule inhibitors of Hsp70-Bag3 were characterized by PXCE with good agreement to inhibitory constants and IC50 values obtained by a bead-based flow cytometry protein interaction assay (FCPIA). PXCE allows rapid method development for quantitative analysis of PPIs.
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Affiliation(s)
- Claire M Ouimet
- Department of Chemistry, University of Michigan , 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Hao Shao
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco , 675 Nelson Rising Ln., San Francisco, California 94158, United States
| | - Jennifer N Rauch
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco , 675 Nelson Rising Ln., San Francisco, California 94158, United States
| | - Mohamed Dawod
- Department of Chemistry, University of Michigan , 930 N. University Ave., Ann Arbor, Michigan 48109, United States
| | - Bryce Nordhues
- Department of Molecular Medicine, University of South Florida , 4001 E. Fletcher Ave., MDC 36, Tampa, Florida 33613, United States
| | - Chad A Dickey
- Department of Molecular Medicine, University of South Florida , 4001 E. Fletcher Ave., MDC 36, Tampa, Florida 33613, United States
| | - Jason E Gestwicki
- Department of Pharmaceutical Chemistry and the Institute for Neurodegenerative Disease, University of California at San Francisco , 675 Nelson Rising Ln., San Francisco, California 94158, United States
| | - Robert T Kennedy
- Department of Chemistry, University of Michigan , 930 N. University Ave., Ann Arbor, Michigan 48109, United States.,Department of Pharmacology, University of Michigan , 1150 W. Medical Center Dr., Ann Arbor, Michigan 48109, United States
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38
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Larance M, Kirkwood KJ, Tinti M, Brenes Murillo A, Ferguson MAJ, Lamond AI. Global Membrane Protein Interactome Analysis using In vivo Crosslinking and Mass Spectrometry-based Protein Correlation Profiling. Mol Cell Proteomics 2016; 15:2476-90. [PMID: 27114452 PMCID: PMC4937518 DOI: 10.1074/mcp.o115.055467] [Citation(s) in RCA: 51] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2015] [Revised: 03/11/2016] [Indexed: 12/30/2022] Open
Abstract
We present a methodology using in vivo crosslinking combined with HPLC-MS for the global analysis of endogenous protein complexes by protein correlation profiling. Formaldehyde crosslinked protein complexes were extracted with high yield using denaturing buffers that maintained complex solubility during chromatographic separation. We show this efficiently detects both integral membrane and membrane-associated protein complexes,in addition to soluble complexes, allowing identification and analysis of complexes not accessible in native extracts. We compare the protein complexes detected by HPLC-MS protein correlation profiling in both native and formaldehyde crosslinked U2OS cell extracts. These proteome-wide data sets of both in vivo crosslinked and native protein complexes from U2OS cells are freely available via a searchable online database (www.peptracker.com/epd). Raw data are also available via ProteomeXchange (identifier PXD003754).
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Affiliation(s)
- Mark Larance
- From the ‡Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Kathryn J Kirkwood
- From the ‡Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Michele Tinti
- §Biological Chemistry and Drug Discovery Division, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Alejandro Brenes Murillo
- From the ‡Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Michael A J Ferguson
- §Biological Chemistry and Drug Discovery Division, School of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Angus I Lamond
- From the ‡Centre for Gene Regulation and Expression, School of Life Sciences, University of Dundee, Dundee, United Kingdom;
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39
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Zhou M, Li Q, Wang R. Current Experimental Methods for Characterizing Protein-Protein Interactions. ChemMedChem 2016; 11:738-56. [PMID: 26864455 PMCID: PMC7162211 DOI: 10.1002/cmdc.201500495] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2015] [Revised: 01/08/2016] [Indexed: 12/14/2022]
Abstract
Protein molecules often interact with other partner protein molecules in order to execute their vital functions in living organisms. Characterization of protein-protein interactions thus plays a central role in understanding the molecular mechanism of relevant protein molecules, elucidating the cellular processes and pathways relevant to health or disease for drug discovery, and charting large-scale interaction networks in systems biology research. A whole spectrum of methods, based on biophysical, biochemical, or genetic principles, have been developed to detect the time, space, and functional relevance of protein-protein interactions at various degrees of affinity and specificity. This article presents an overview of these experimental methods, outlining the principles, strengths and limitations, and recent developments of each type of method.
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Affiliation(s)
- Mi Zhou
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Qing Li
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Renxiao Wang
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China.
- State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Avenida Wai Long, Macau, 999078, People's Republic of China.
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40
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Zhou M, Li Q, Wang R. Current Experimental Methods for Characterizing Protein-Protein Interactions. ChemMedChem 2016. [PMID: 26864455 DOI: 10.1002/cmdc.201500495.] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Protein molecules often interact with other partner protein molecules in order to execute their vital functions in living organisms. Characterization of protein-protein interactions thus plays a central role in understanding the molecular mechanism of relevant protein molecules, elucidating the cellular processes and pathways relevant to health or disease for drug discovery, and charting large-scale interaction networks in systems biology research. A whole spectrum of methods, based on biophysical, biochemical, or genetic principles, have been developed to detect the time, space, and functional relevance of protein-protein interactions at various degrees of affinity and specificity. This article presents an overview of these experimental methods, outlining the principles, strengths and limitations, and recent developments of each type of method.
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Affiliation(s)
- Mi Zhou
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Qing Li
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China
| | - Renxiao Wang
- State Key Laboratory of Bioorganic & Natural Products Chemistry, Collaborative Innovation Center of Chemistry for Life Sciences, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, 345 Lingling Rd, Shanghai, 200032, People's Republic of China. .,State Key Laboratory of Quality Research in Chinese Medicine, Macau Institute for Applied Research in Medicine and Health, Macau University of Science and Technology, Avenida Wai Long, Macau, 999078, People's Republic of China.
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41
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Richards MJ, Hsia CY, Singh RR, Haider H, Kumpf J, Kawate T, Daniel S. Membrane Protein Mobility and Orientation Preserved in Supported Bilayers Created Directly from Cell Plasma Membrane Blebs. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2016; 32:2963-74. [PMID: 26812542 DOI: 10.1021/acs.langmuir.5b03415] [Citation(s) in RCA: 72] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Membrane protein interactions with lipids are crucial for their native biological behavior, yet traditional characterization methods are often carried out on purified protein in the absence of lipids. We present a simple method to transfer membrane proteins expressed in mammalian cells to an assay-friendly, cushioned, supported lipid bilayer platform using cell blebs as an intermediate. Cell blebs, expressing either GPI-linked yellow fluorescent proteins or neon-green fused transmembrane P2X2 receptors, were induced to rupture on glass surfaces using PEGylated lipid vesicles, which resulted in planar supported membranes with over 50% mobility for multipass transmembrane proteins and over 90% for GPI-linked proteins. Fluorescent proteins were tracked, and their diffusion in supported bilayers characterized, using single molecule tracking and moment scaling spectrum (MSS) analysis. Diffusion was characterized for individual proteins as either free or confined, revealing details of the local lipid membrane heterogeneity surrounding the protein. A particularly useful result of our bilayer formation process is the protein orientation in the supported planar bilayer. For both the GPI-linked and transmembrane proteins used here, an enzymatic assay revealed that protein orientation in the planar bilayer results in the extracellular domains facing toward the bulk, and that the dominant mode of bleb rupture is via the "parachute" mechanism. Mobility, orientation, and preservation of the native lipid environment of the proteins using cell blebs offers advantages over proteoliposome reconstitution or disrupted cell membrane preparations, which necessarily result in significant scrambling of protein orientation and typically immobilized membrane proteins in SLBs. The bleb-based bilayer platform presented here is an important step toward integrating membrane proteomic studies on chip, especially for future studies aimed at understanding fundamental effects of lipid interactions on protein activity and the roles of membrane proteins in disease pathways.
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Affiliation(s)
- Mark J Richards
- School of Chemical and Biomolecular Engineering, and ‡Department of Molecular Medicine, Cornell University , Ithaca, New York 14853, United States
| | - Chih-Yun Hsia
- School of Chemical and Biomolecular Engineering, and ‡Department of Molecular Medicine, Cornell University , Ithaca, New York 14853, United States
| | - Rohit R Singh
- School of Chemical and Biomolecular Engineering, and ‡Department of Molecular Medicine, Cornell University , Ithaca, New York 14853, United States
| | - Huma Haider
- School of Chemical and Biomolecular Engineering, and ‡Department of Molecular Medicine, Cornell University , Ithaca, New York 14853, United States
| | - Julia Kumpf
- School of Chemical and Biomolecular Engineering, and ‡Department of Molecular Medicine, Cornell University , Ithaca, New York 14853, United States
| | - Toshimitsu Kawate
- School of Chemical and Biomolecular Engineering, and ‡Department of Molecular Medicine, Cornell University , Ithaca, New York 14853, United States
| | - Susan Daniel
- School of Chemical and Biomolecular Engineering, and ‡Department of Molecular Medicine, Cornell University , Ithaca, New York 14853, United States
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42
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KRAS Engages AGO2 to Enhance Cellular Transformation. Cell Rep 2016; 14:1448-1461. [PMID: 26854235 DOI: 10.1016/j.celrep.2016.01.034] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 12/17/2015] [Accepted: 01/07/2016] [Indexed: 01/06/2023] Open
Abstract
Oncogenic mutations in RAS provide a compelling yet intractable therapeutic target. Using co-immunoprecipitation mass spectrometry, we uncovered an interaction between RAS and Argonaute 2 (AGO2). Endogenously, RAS and AGO2 co-sediment and co-localize in the endoplasmic reticulum. The AGO2 N-terminal domain directly binds the Switch II region of KRAS, agnostic of nucleotide (GDP/GTP) binding. Functionally, AGO2 knockdown attenuates cell proliferation in mutant KRAS-dependent cells and AGO2 overexpression enhances KRAS(G12V)-mediated transformation. Using AGO2-/- cells, we demonstrate that the RAS-AGO2 interaction is required for maximal mutant KRAS expression and cellular transformation. Mechanistically, oncogenic KRAS attenuates AGO2-mediated gene silencing. Overall, the functional interaction with AGO2 extends KRAS function beyond its canonical role in signaling.
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43
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Engidawork E, Aradska J, Lubec G. Neurotransmitter receptor complexes: methods for bioanalysis, their potentials and limitations. Rev Neurosci 2016; 27:111-33. [DOI: 10.1515/revneuro-2015-0034] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 08/11/2015] [Indexed: 12/15/2022]
Abstract
AbstractNeurotransmitter receptors are key elements for brain function, but work so far has been focusing on the individual receptor subunits. It is, however, the receptor complexes that execute work rather than the subunits; of course, the multitude of possible combinations of the many receptors forming homomeric or heteromeric complexes is hampering studies. Moreover, not only receptors are observed in the complexes but also their corresponding protein kinases, phosphatases, and anchoring proteins, to name a few. Studying receptor complexes is still an analytical challenge. Thus far, no methods exist to unequivocally characterize or even quantify these assemblies. Major problems and limitations for the analysis exist, such as solubility, as the use of detergents is critical and may dissociate the receptor complexes as well as their separation in the native state. Gel-based techniques are able to separate and semiquantitatively quantify receptor complexes by subsequent immunochemical methods but do not allow the characterization of complex components. Immunoprecipitation methods are highly dependent on antibody availability and specificity, and the result of coimmunoprecipitation does not verify the direct physical interaction of proteins in the immunoprecipitate. Antibody shift assays are suitable to identify individual known proteins within a complex as are immunogold electron microscopic techniques and energy transfer technologies. Most techniques are simply showing the proximity of proteins rather than their physical interaction. Although fluorescence correlation spectroscopy is a promising technique, the use for quantification or comparing biological samples is limited. A lot of work remains to be done to provide tools for the characterization and quantification of receptor complexes in the brain.
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Affiliation(s)
| | - Jana Aradska
- 1Department of Pediatrics, Medical University of Vienna, Waehringer Guertel 18-20, A-1090 Vienna, Austria
| | - Gert Lubec
- 3Department of Pharmaceutical Chemistry, University of Vienna, Althanstrasse 14, A-1090 Vienna, Austria
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Mohammed H, Taylor C, Brown GD, Papachristou EK, Carroll JS, D'Santos CS. Rapid immunoprecipitation mass spectrometry of endogenous proteins (RIME) for analysis of chromatin complexes. Nat Protoc 2016; 11:316-26. [PMID: 26797456 DOI: 10.1038/nprot.2016.020] [Citation(s) in RCA: 187] [Impact Index Per Article: 23.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Rapid immunoprecipitation mass spectrometry of endogenous protein (RIME) is a method that allows the study of protein complexes, in particular chromatin and transcription factor complexes, in a rapid and robust manner by mass spectrometry (MS). The method can be used in parallel with chromatin immunoprecipitation-sequencing (ChIP-seq) experiments to provide information on both the cistrome and interactome for a given protein. The method uses formaldehyde fixation to stabilize protein complexes. By using antibodies against the endogenous target, the cross-linked complex is immunoprecipitated, rigorously washed, and then digested into peptides while avoiding antibody contamination (on-bead digestion). By using this method, MS identification of the target protein and several dozen interacting proteins is possible using a 100-min LC-MS/MS run. The protocol does not require substantial proteomics expertise, and it typically takes 2-3 d from the collection of material to results.
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Affiliation(s)
- Hisham Mohammed
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
| | - Christopher Taylor
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
| | - Gordon D Brown
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
| | | | - Jason S Carroll
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
| | - Clive S D'Santos
- Cancer Research UK Cambridge Institute, University of Cambridge, Cambridge, UK
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45
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Protein-Protein Interaction Detection Via Mass Spectrometry-Based Proteomics. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 919:383-396. [DOI: 10.1007/978-3-319-41448-5_18] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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46
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Irudayanathan FJ, Trasatti JP, Karande P, Nangia S. Molecular Architecture of the Blood Brain Barrier Tight Junction Proteins–A Synergistic Computational and In Vitro Approach. J Phys Chem B 2015; 120:77-88. [DOI: 10.1021/acs.jpcb.5b09977] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
| | - John P. Trasatti
- Department
of Chemistry and Chemical Biology, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Pankaj Karande
- Department
of Chemical and Biological Engineering, Rensselaer Polytechnic Institute, Troy, New York 12180, United States
| | - Shikha Nangia
- Department
of Biomedical and Chemical Engineering, Syracuse University, Syracuse New York 13244, United States
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47
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Yang J, Wagner SA, Beli P. Illuminating Spatial and Temporal Organization of Protein Interaction Networks by Mass Spectrometry-Based Proteomics. Front Genet 2015; 6:344. [PMID: 26648978 PMCID: PMC4665136 DOI: 10.3389/fgene.2015.00344] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2015] [Accepted: 11/20/2015] [Indexed: 11/13/2022] Open
Abstract
Protein–protein interactions are at the core of all cellular functions and dynamic alterations in protein interactions regulate cellular signaling. In the last decade, mass spectrometry (MS)-based proteomics has delivered unprecedented insights into human protein interaction networks. Affinity purification-MS (AP-MS) has been extensively employed for focused and high-throughput studies of steady state protein–protein interactions. Future challenges remain in mapping transient protein interactions after cellular perturbations as well as in resolving the spatial organization of protein interaction networks. AP-MS can be combined with quantitative proteomics approaches to determine the relative abundance of purified proteins in different conditions, thereby enabling the identification of transient protein interactions. In addition to affinity purification, methods based on protein co-fractionation have been combined with quantitative MS to map transient protein interactions during cellular signaling. More recently, approaches based on proximity tagging that preserve the spatial dimension of protein interaction networks have been introduced. Here, we provide an overview of MS-based methods for analyzing protein–protein interactions with a focus on approaches that aim to dissect the temporal and spatial aspects of protein interaction networks.
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Affiliation(s)
- Jiwen Yang
- Institute of Molecular Biology , Mainz, Germany
| | - Sebastian A Wagner
- Department of Medicine, Hematology and Oncology, Goethe University , Frankfurt, Germany
| | - Petra Beli
- Institute of Molecular Biology , Mainz, Germany
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48
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Hoffman EA, Frey BL, Smith LM, Auble DT. Formaldehyde crosslinking: a tool for the study of chromatin complexes. J Biol Chem 2015; 290:26404-11. [PMID: 26354429 DOI: 10.1074/jbc.r115.651679] [Citation(s) in RCA: 241] [Impact Index Per Article: 26.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Formaldehyde has been used for decades to probe macromolecular structure and function and to trap complexes, cells, and tissues for further analysis. Formaldehyde crosslinking is routinely employed for detection and quantification of protein-DNA interactions, interactions between chromatin proteins, and interactions between distal segments of the chromatin fiber. Despite widespread use and a rich biochemical literature, important aspects of formaldehyde behavior in cells have not been well described. Here, we highlight features of formaldehyde chemistry relevant to its use in analyses of chromatin complexes, focusing on how its properties may influence studies of chromatin structure and function.
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Affiliation(s)
- Elizabeth A Hoffman
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908 and
| | - Brian L Frey
- the Department of Chemistry and Genome Center of Wisconsin, University of Wisconsin, Madison, Wisconsin 53706
| | - Lloyd M Smith
- the Department of Chemistry and Genome Center of Wisconsin, University of Wisconsin, Madison, Wisconsin 53706
| | - David T Auble
- From the Department of Biochemistry and Molecular Genetics, University of Virginia Health System, Charlottesville, Virginia 22908 and
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49
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Saavedra P, Girona J, Bosquet A, Guaita S, Canela N, Aragonès G, Heras M, Masana L. New insights into circulating FABP4: Interaction with cytokeratin 1 on endothelial cell membranes. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:2966-74. [PMID: 26343611 DOI: 10.1016/j.bbamcr.2015.09.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 08/07/2015] [Accepted: 09/03/2015] [Indexed: 01/12/2023]
Abstract
Fatty acid-binding protein 4 (FABP4) is an adipose tissue-secreted adipokine that is involved in the regulation of energetic metabolism and inflammation. Increased levels of circulating FABP4 have been detected in individuals with cardiovascular risk factors. Recent studies have demonstrated that FABP4 has a direct effect on peripheral tissues, specifically promoting vascular dysfunction; however, its mechanism of action is unknown. The objective of this work was to assess the specific interactions between exogenous FABP4 and the plasma membranes of endothelial cells. Immunofluorescence assays showed that exogenous FABP4 localized along the plasma membranes of human umbilical vein endothelial cells (HUVECs), interacting specifically with plasma membrane proteins. Anti-FABP4 immunoblotting revealed two covalent protein complexes containing FABP4 and its putative receptor; these complexes were approximately 108 kDa and 77 kDa in size. Proteomics and mass spectrometry experiments revealed that cytokeratin 1 (CK1) was the FABP4-binding protein. An anti-CK1 immunoblot confirmed the presence of CK1. FABP4-CK1 complexes were also detected in HAECs, HCASMCs, HepG2 cells and THP-1 cells. Pharmacological FABP4 inhibition by BMS309403 results in a slight decrease in the formation of these complexes, indicating that fatty acids may play a role in FABP4 functionality. In addition, we demonstrated that exogenous FABP4 crosses the plasma membrane to enter the cytoplasm and nucleus in HUVECs. These findings indicate that exogenous FABP4 interacts with plasma membrane proteins, specifically CK1. These data contribute to our current knowledge regarding the mechanism of action of circulating FABP4.
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Affiliation(s)
- Paula Saavedra
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Josefa Girona
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Alba Bosquet
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Sandra Guaita
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Núria Canela
- Centre for Omics Science, Universitat Rovira i Virgili, Reus, Spain
| | - Gemma Aragonès
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Mercedes Heras
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain
| | - Lluís Masana
- Research Unit on Lipids and Atherosclerosis, "Sant Joan" University Hospital, IISPV, CIBERDEM, Universitat Rovira i Virgili, Reus, Spain.
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50
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Wang L, Zhang L, Li S, Zheng Y, Yan X, Chen M, Wang H, Putney JW, Luo D. Retrograde regulation of STIM1-Orai1 interaction and store-operated Ca2+ entry by calsequestrin. Sci Rep 2015; 5:11349. [PMID: 26087026 PMCID: PMC4471903 DOI: 10.1038/srep11349] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 05/22/2015] [Indexed: 12/13/2022] Open
Abstract
Interaction between the endoplasmic reticulum (ER)-located stromal interaction molecue1 (STIM1) and the plasma membrane-located Ca2+ channel subunit, Orai1, underlies store-operated Ca2+ entry (SOCE). Calsequestrin1 (CSQ1), a sarcoplasmic reticulum Ca2+ buffering protein, inhibits SOCE, but the mechanism of action is unknown. We identified an interaction between CSQ1 and STIM1 in HEK293 cells. An increase in monomeric CSQ1 induced by depleted Ca2+ stores, or trifluoperazine (TFP), a blocker of CSQ folding and aggregation, enhanced the CSQ1-STIM1 interaction. In cells with Ca2+ stores depleted, TFP further increased CSQ1 monomerization and CSQ1-STIM1 interaction, but reduced the association of STIM1 with Orai1 and SOCE. Over-expression of CSQ1 or a C-terminal (amino acid 388–396) deletion mutant significantly promoted the association of CSQ1 with STIM1, but suppressed both STIM1-Orai1 interaction and SOCE, while over-expression of the C-terminal (amino acid 362–396) deletion mutant had no effect. The physical interaction between low polymeric forms of CSQ1 and STIM1 likely acts by interfering with STIM1 oligimerization and inhibits STIM1-Orai1 interaction, providing a brake to SOCE under physiological conditions. This novel regulatory mechanism for SOCE may also contribute to the pathological Ca2+ overload in calsequestrin deficient diseases, such as malignant hyperthermia and ventricular tachycardia.
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Affiliation(s)
- Limin Wang
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Lane Zhang
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Shu Li
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Yuanyuan Zheng
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Xinxin Yan
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Min Chen
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - Haoyang Wang
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
| | - James W Putney
- Laboratory of Signal Transduction, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC 27709, USA
| | - Dali Luo
- Department of Pharmacology, Capital Medical University, Beijing 100069, P.R. China
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