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Zhou X, Lee YK, Li X, Kim H, Sanchez-Priego C, Han X, Tan H, Zhou S, Fu Y, Purtell K, Wang Q, Holstein GR, Tang B, Peng J, Yang N, Yue Z. Integrated proteomics reveals autophagy landscape and an autophagy receptor controlling PKA-RI complex homeostasis in neurons. Nat Commun 2024; 15:3113. [PMID: 38600097 PMCID: PMC11006854 DOI: 10.1038/s41467-024-47440-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2023] [Accepted: 04/02/2024] [Indexed: 04/12/2024] Open
Abstract
Autophagy is a conserved, catabolic process essential for maintaining cellular homeostasis. Malfunctional autophagy contributes to neurodevelopmental and neurodegenerative diseases. However, the exact role and targets of autophagy in human neurons remain elusive. Here we report a systematic investigation of neuronal autophagy targets through integrated proteomics. Deep proteomic profiling of multiple autophagy-deficient lines of human induced neurons, mouse brains, and brain LC3-interactome reveals roles of neuronal autophagy in targeting proteins of multiple cellular organelles/pathways, including endoplasmic reticulum (ER), mitochondria, endosome, Golgi apparatus, synaptic vesicle (SV) for degradation. By combining phosphoproteomics and functional analysis in human and mouse neurons, we uncovered a function of neuronal autophagy in controlling cAMP-PKA and c-FOS-mediated neuronal activity through selective degradation of the protein kinase A - cAMP-binding regulatory (R)-subunit I (PKA-RI) complex. Lack of AKAP11 causes accumulation of the PKA-RI complex in the soma and neurites, demonstrating a constant clearance of PKA-RI complex through AKAP11-mediated degradation in neurons. Our study thus reveals the landscape of autophagy degradation in human neurons and identifies a physiological function of autophagy in controlling homeostasis of PKA-RI complex and specific PKA activity in neurons.
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Affiliation(s)
- Xiaoting Zhou
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Department of Geriatrics, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - You-Kyung Lee
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Xianting Li
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Henry Kim
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Carlos Sanchez-Priego
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Institute for Regenerative Medicine, Alper Center for Neural Development and Regeneration, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Xian Han
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Integrated Biomedical Sciences Program, University of Tennessee Health Science Center, Memphis, TN, 38163, USA
| | - Haiyan Tan
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Suiping Zhou
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Yingxue Fu
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA
| | - Kerry Purtell
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Qian Wang
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Gay R Holstein
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA
| | - Beisha Tang
- Department of Neurology, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
- National Clinical Research Center for Geriatric Disorders, Xiangya Hospital, Central South University, Changsha, 410008, Hunan, China
| | - Junmin Peng
- Department of Structural Biology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
- Department of Developmental Neurobiology, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
- Center for Proteomics and Metabolomics, St. Jude Children's Research Hospital, Memphis, TN, 38105, USA.
| | - Nan Yang
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Institute for Regenerative Medicine, Alper Center for Neural Development and Regeneration, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
| | - Zhenyu Yue
- Department of Neurology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Nash Family Department of Neuroscience, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, New York, NY, 10029, USA.
- Center of Parkinson's Disease Neurobiology, The Friedman Brain Institute, Icahn School of Medicine at Mount Sinai, 1470 Madison Avenue, New York, NY, 10029, USA.
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Søberg K, Skålhegg BS. The Molecular Basis for Specificity at the Level of the Protein Kinase a Catalytic Subunit. Front Endocrinol (Lausanne) 2018; 9:538. [PMID: 30258407 PMCID: PMC6143667 DOI: 10.3389/fendo.2018.00538] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/22/2018] [Accepted: 08/24/2018] [Indexed: 12/16/2022] Open
Abstract
Assembly of multi enzyme complexes at subcellular localizations by anchoring- and scaffolding proteins represents a pivotal mechanism for achieving spatiotemporal regulation of cellular signaling after hormone receptor targeting [for review, see (1)]. In the 3' 5'-cyclic adenosine monophosphate (cAMP) dependent protein kinase (PKA) signaling pathway it is generally accepted that specificity is secured at several levels. This includes at the first level stimulation of receptors coupled to heterotrimeric G proteins which through stimulation of adenylyl cyclase (AC) forms the second messenger cAMP. Cyclic AMP has several receptors including PKA. PKA is a tetrameric holoenzyme consisting of a regulatory (R) subunit dimer and two catalytic (C) subunits. The R subunit is the receptor for cAMP and compartmentalizes cAMP signals through binding to cell and tissue-specifically expressed A kinase anchoring proteins (AKAPs). The current dogma tells that in the presence of cAMP, PKA dissociates into an R subunit dimer and two C subunits which are free to phosphorylate relevant substrates in the cytosol and nucleus. The release of the C subunit has raised the question how specificity of the cAMP and PKA signaling pathway is maintained when the C subunit no longer is attached to the R subunit-AKAP complex. An increasing body of evidence points toward a regulatory role of the cAMP and PKA signaling pathway by targeting the C subunits to various C subunit binding proteins in the cytosol and nucleus. Moreover, recent identification of isoform specific amino acid sequences, motifs and three dimensional structures have together provided new insight into how PKA at the level of the C subunit may act in a highly isoform-specific fashion. Here we discuss recent understanding of specificity of the cAMP and PKA signaling pathway based on C subunit subcellular targeting as well as evolution of the C subunit structure that may contribute to the dynamic regulation of C subunit activity.
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Affiliation(s)
- Kristoffer Søberg
- Department of Medical Genetics, Oslo University Hospital, Oslo, Norway
| | - Bjørn Steen Skålhegg
- Section for Molecular Nutrition, University of Oslo, Oslo, Norway
- *Correspondence: Bjørn Steen Skålhegg
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Choi KYG, Napper S, Mookherjee N. Human cathelicidin LL-37 and its derivative IG-19 regulate interleukin-32-induced inflammation. Immunology 2014; 143:68-80. [PMID: 24666281 DOI: 10.1111/imm.12291] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 03/20/2014] [Accepted: 03/21/2014] [Indexed: 12/18/2022] Open
Abstract
Human cathelicidin LL-37 protects against infections and endotoxin-induced inflammation. In a recent study we have shown that IG-19, an LL-37-derived peptide, protects in a murine model of arthritis. Cytokine interleukin-32 (IL-32) is elevated and directly associated with the disease severity of inflammatory arthritis. Therefore, in this study we examined the effects of LL-37 and IG-19 on IL-32-induced responses in human peripheral blood-derived mononuclear cells (PBMC) and macrophages. We showed that CD14(+) monocytes are the primary cells that produce pro-inflammatory tumour necrosis factor-α (TNF-α) following stimulation of PBMC with IL-32. We demonstrated that LL-37 and IG-19 significantly suppress IL-32-induced production of pro-inflammatory cytokines, e.g. TNF-α and IL-1β, without altering chemokine production. In contrast, LL-37 and IG-19 enhance the production of the anti-inflammatory cytokine IL-1RA. Further mechanistic studies revealed that LL-37 and IG-19 suppress IL-32-mediated phosphorylation of Fyn (Y420) Src kinase. In contrast, IL-32-mediated phosphorylation of AKT-1 (T308) and MKP-1 (S359) is not suppressed by the peptides. LL-37 and IG-19 alone induce the phosphorylation of MKP-1 (S359), which is a known negative regulator of inflammation. Furthermore, the peptides induce the activity of p44/42 mitogen-activated protein kinase, which is known to phosphorylate MKP-1 (S359). This is the first study to demonstrate the regulation of IL-32-induced inflammation by LL-37 and its derivative peptide IG-19. The mechanistic results from this study suggest that regulation of immune-mediated inflammation by these peptides may be controlled by the dual phosphatase MKP-1. We speculate that LL-37 and its derivatives may contribute to the control of immune-mediated inflammatory diseases.
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Affiliation(s)
- Ka-Yee G Choi
- Department of Internal Medicine, Manitoba Centre for Proteomics and Systems Biology, University of Manitoba, Winnipeg, MB, Canada; Department of Immunology, University of Manitoba, Winnipeg, MB, Canada
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Barallobre-Barreiro J, Chung YL, Mayr M. La proteómica y la metabolómica: los mecanismos de la enfermedad cardiovascular y el descubrimiento de biomarcadores. Rev Esp Cardiol 2013. [DOI: 10.1016/j.recesp.2013.04.010] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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Barallobre-Barreiro J, Chung YL, Mayr M. Proteomics and metabolomics for mechanistic insights and biomarker discovery in cardiovascular disease. REVISTA ESPANOLA DE CARDIOLOGIA (ENGLISH ED.) 2013; 66:657-61. [PMID: 24776335 DOI: 10.1016/j.rec.2013.04.009] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 04/18/2013] [Indexed: 01/24/2023]
Abstract
In the last decade, proteomics and metabolomics have contributed substantially to our understanding of cardiovascular diseases. The unbiased assessment of pathophysiological processes without a priori assumptions complements other molecular biology techniques that are currently used in a reductionist approach. In this review, we highlight some of the "omics" methods used to assess protein and metabolite changes in cardiovascular disease. A discrete biological function is very rarely attributed to a single molecule; more often it is the combined input of many proteins. In contrast to the reductionist approach, in which molecules are studied individually, "omics" platforms allow the study of more complex interactions in biological systems. Combining proteomics and metabolomics to quantify changes in metabolites and their corresponding enzymes will advance our understanding of pathophysiological mechanisms and aid the identification of novel biomarkers for cardiovascular disease.
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Affiliation(s)
| | - Yuen-Li Chung
- Cancer Research UK and EPSRC Cancer Imaging Centre, The Institute of Cancer Research and The Royal Marsden NHS Foundation Trust, Sutton, Surrey, United Kingdom
| | - Manuel Mayr
- King's British Heart Foundation Centre, King's College of London, London, United Kingdom.
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Søberg K, Jahnsen T, Rognes T, Skålhegg BS, Laerdahl JK. Evolutionary paths of the cAMP-dependent protein kinase (PKA) catalytic subunits. PLoS One 2013; 8:e60935. [PMID: 23593352 PMCID: PMC3625193 DOI: 10.1371/journal.pone.0060935] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2012] [Accepted: 03/05/2013] [Indexed: 11/19/2022] Open
Abstract
3',5'-cyclic adenosine monophosphate (cAMP) dependent protein kinase or protein kinase A (PKA) has served as a prototype for the large family of protein kinases that are crucially important for signal transduction in eukaryotic cells. The PKA catalytic subunits Cα and Cβ, encoded by the two genes PRKACA and PRKACB, respectively, are among the best understood and characterized human kinases. Here we have studied the evolution of this gene family in chordates, arthropods, mollusks and other animals employing probabilistic methods and show that Cα and Cβ arose by duplication of an ancestral PKA catalytic subunit in a common ancestor of vertebrates. The two genes have subsequently been duplicated in teleost fishes. The evolution of the PRKACG retroposon in simians was also investigated. Although the degree of sequence conservation in the PKA Cα/Cβ kinase family is exceptionally high, a small set of signature residues defining Cα and Cβ subfamilies were identified. These conserved residues might be important for functions that are unique to the Cα or Cβ clades. This study also provides a good example of a seemingly simple phylogenetic problem which, due to a very high degree of sequence conservation and corresponding weak phylogenetic signals, combined with problematic nonphylogenetic signals, is nontrivial for state-of-the-art probabilistic phylogenetic methods.
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Affiliation(s)
- Kristoffer Søberg
- Department of Nutrition, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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Polacco BJ, Purvine SO, Zink EM, Lavoie SP, Lipton MS, Summers AO, Miller SM. Discovering mercury protein modifications in whole proteomes using natural isotope distributions observed in liquid chromatography-tandem mass spectrometry. Mol Cell Proteomics 2011; 10:M110.004853. [PMID: 21532010 DOI: 10.1074/mcp.m110.004853] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The identification of peptides that result from post-translational modifications is critical for understanding normal pathways of cellular regulation as well as identifying damage from, or exposures to xenobiotics, i.e. the exposome. However, because of their low abundance in proteomes, effective detection of modified peptides by mass spectrometry (MS) typically requires enrichment to eliminate false identifications. We present a new method for confidently identifying peptides with mercury (Hg)-containing adducts that is based on the influence of mercury's seven stable isotopes on peptide isotope distributions detected by high-resolution MS. Using a pure protein and E. coli cultures exposed to phenyl mercuric acetate, we show the pattern of peak heights in isotope distributions from primary MS single scans efficiently identified Hg adducts in data from chromatographic separation coupled with tandem mass spectrometry with sensitivity and specificity greater than 90%. Isotope distributions are independent of peptide identifications based on peptide fragmentation (e.g. by SEQUEST), so both methods can be combined to eliminate false positives. Summing peptide isotope distributions across multiple scans improved specificity to 99.4% and sensitivity above 95%, affording identification of an unexpected Hg modification. We also illustrate the theoretical applicability of the method for detection of several less common elements including the essential element, selenium, as selenocysteine in peptides.
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Affiliation(s)
- Benjamin J Polacco
- Department of Pharmaceutical Chemistry, University of California San Francisco, UCSF MC 2280, San Francisco, CA 94158-2517, USA.
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McInnis B, Mitchell J, Marcus S. Phosphorylation of the protein kinase A catalytic subunit is induced by cyclic AMP deficiency and physiological stresses in the fission yeast, Schizosaccharomyces pombe. Biochem Biophys Res Commun 2010; 399:665-9. [PMID: 20691155 DOI: 10.1016/j.bbrc.2010.07.139] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2010] [Accepted: 07/30/2010] [Indexed: 11/19/2022]
Abstract
In the fission yeast, Schizosaccharomyces pombe, cyclic AMP (cAMP)-dependent protein kinase (PKA) is not essential for viability under normal culturing conditions, making this organism attractive for investigating mechanisms of PKA regulation. Here we show that S. pombe cells carrying a deletion in the adenylate cyclase gene, cyr1, express markedly higher levels of the PKA catalytic subunit, Pka1, than wild type cells. Significantly, in cyr1Delta cells, but not wild type cells, a substantial proportion of Pka1 protein is hyperphosphorylated. Pka1 hyperphosphorylation is strongly induced in cyr1Delta cells, and to varying degrees in wild type cells, by both glucose starvation and stationary phase stresses, which are associated with reduced cAMP-dependent PKA activity, and by KCl stress, the cellular adaptation to which is dependent on PKA activity. Interestingly, hyperphosphorylation of Pka1 was not detected in either cyr1(+) or cyr1Delta S. pombe strains carrying a deletion in the PKA regulatory subunit gene, cgs1, under any of the tested conditions. Our results demonstrate the existence of a cAMP-independent mechanism of PKA catalytic subunit phosphorylation, which we propose could serve as a mechanism for inducing or maintaining specific PKA functions under conditions in which its cAMP-dependent activity is downregulated.
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Affiliation(s)
- Brittney McInnis
- Department of Biological Sciences, The University of Alabama, Tuscaloosa, AL 35487, United States
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Wang W, Han G, Ye M, Shi H, Zou H, Huo K. Mapping of phosphorylation sites in human MSK1 activated by a novel interaction with MRK-beta. Electrophoresis 2010; 31:1283-93. [PMID: 20408143 DOI: 10.1002/elps.200900637] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The desire to map reliable phosphorylation signaling network has motivated the development of high-performance techniques. Targeted biochemical studies and updated methods employing MS techniques are most used in mapping the phosphorylation sites and verifying novel interactions of kinases. Previously, we have established a novel method to efficiently facilitate more comprehensive, accurate phosphorylation site mapping of individual phosphoproteins by using combination of multiple stage MS analysis with target-decoy database search against the much smaller targeted database. In this study, by applying this method, we have identified the phosphorylation sites in human MSK1 mitogen- and stress-activated protein kinase 1, which has been proved to be a multi-phosphorylated kinase that plays key roles in various cell functions, activated by a novel interaction with MRK-beta. The results show that this method can find out not only those previously identified active sites in MSK1, but also some novel phosphorylated sites, which correlates with biochemical evidence that, besides p38 and extracellular signal-regulated kinase, MRK-beta could also activate MSK1 through direct interaction. Hence, we conclude this method is sensitive and reliable as expected and it can be further combined with automated screening and biochemical study in efficiently building up a more comprehensive phosphoprotein network.
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Affiliation(s)
- Wei Wang
- State Key Laboratory of Genetic Engineering, School of Life Sciences, Fudan University, Shanghai, P. R. China
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Analysis of autophosphorylation sites in the recombinant catalytic subunit alpha of cAMP-dependent kinase by nano-UPLC–ESI–MS/MS. Anal Bioanal Chem 2009; 395:1713-20. [DOI: 10.1007/s00216-009-2932-4] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2009] [Revised: 05/26/2009] [Accepted: 06/22/2009] [Indexed: 12/14/2022]
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Schlüter S, Franz CMAP, Gesellchen F, Bertinetti O, Herberg FW, Schmidt FRJ. The High Biofilm-Encoding Bee Locus: A Second Pilus Gene Cluster in Enterococcus faecalis? Curr Microbiol 2009; 59:206-11. [DOI: 10.1007/s00284-009-9422-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2009] [Revised: 04/17/2009] [Accepted: 04/23/2009] [Indexed: 11/27/2022]
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Top D, Barry C, Racine T, Ellis CL, Duncan R. Enhanced fusion pore expansion mediated by the trans-acting Endodomain of the reovirus FAST proteins. PLoS Pathog 2009; 5:e1000331. [PMID: 19266079 PMCID: PMC2646142 DOI: 10.1371/journal.ppat.1000331] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Accepted: 02/06/2009] [Indexed: 02/07/2023] Open
Abstract
The reovirus fusion-associated small transmembrane (FAST) proteins are virus-encoded membrane fusion proteins that function as dedicated cell–cell fusogens. The topology of these small, single-pass membrane proteins orients the majority of the protein on the distal side of the membrane (i.e., inside the cell). We now show that ectopic expression of the endodomains of the p10, p14, and p15 FAST proteins enhances syncytiogenesis induced by the full-length FAST proteins, both homotypically and heterotypically. Results further indicate that the 68-residue cytoplasmic endodomain of the p14 FAST protein (1) is endogenously generated from full-length p14 protein expressed in virus-infected or transfected cells; (2) enhances syncytiogenesis subsequent to stable pore formation; (3) increases the syncytiogenic activity of heterologous fusion proteins, including the differentiation-dependent fusion of murine myoblasts; (4) exerts its enhancing activity from the cytosol, independent of direct interactions with either the fusogen or the membranes being fused; and (5) contains several regions with protein–protein interaction motifs that influence enhancing activity. We propose that the unique evolution of the FAST proteins as virus-encoded cellular fusogens has allowed them to generate a trans-acting, soluble endodomain peptide to harness a cellular pathway or process involved in the poorly understood process that facilitates the transition from microfusion pores to macrofusion and syncytiogenesis. The reovirus FAST proteins are the only known examples of nonenveloped virus membrane fusion proteins. Functioning as virus-encoded cellular fusogens, they mediate cell–cell membrane fusion and syncytium formation rather than virus–cell fusion. The FAST proteins are also the smallest protein fusogens and assume an unusual membrane topology, positioning the majority of their mass within or internal to the membrane in which they reside. We have been interested in reconciling the donor membrane-biased structural features of the FAST proteins with their ability to orchestrate the multi-step cell–cell membrane fusion process that leads to syncytium formation. We now show that the FAST proteins generate a soluble endodomain fragment that functions in trans from the cytosol, enhancing the capacity of diverse viral and cellular fusogens to drive the conversion of fusion pores into syncytia. The FAST proteins may therefore function in a similar manner as membrane receptors whose signalling activity requires regulated intramembrane proteolysis to generate a soluble signalling peptide. The endodomain signalling peptide of the FAST proteins provides a novel approach to identify cellular effectors involved in the fusion pore expansion stage of biological cell–cell membrane fusion.
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Affiliation(s)
- Deniz Top
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Chris Barry
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Trina Racine
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Chelsey Louise Ellis
- Department of Microbiology & Immunology, Dalhousie University, Halifax, Nova Scotia, Canada
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Bertinetti D, Schweinsberg S, Hanke SE, Schwede F, Bertinetti O, Drewianka S, Genieser HG, Herberg FW. Chemical tools selectively target components of the PKA system. BMC CHEMICAL BIOLOGY 2009; 9:3. [PMID: 19216744 PMCID: PMC2660902 DOI: 10.1186/1472-6769-9-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/10/2008] [Accepted: 02/12/2009] [Indexed: 11/23/2022]
Abstract
Background In the eukaryotic cell the cAMP-dependent protein kinase (PKA) is a key enzyme in signal transduction and represents the main target of the second messenger cAMP. Here we describe the design, synthesis and characterisation of specifically tailored cAMP analogs which can be utilised as a tool for affinity enrichment and purification as well as for proteomics based analyses of cAMP binding proteins. Results Two sets of chemical binders were developed based on the phosphorothioate derivatives of cAMP, Sp-cAMPS and Rp-cAMPS acting as cAMP-agonists and -antagonists, respectively. These compounds were tested via direct surface plasmon resonance (SPR) analyses for their binding properties to PKA R-subunits and holoenzyme. Furthermore, these analogs were used in an affinity purification approach to analyse their binding and elution properties for the enrichment and improvement of cAMP binding proteins exemplified by the PKA R-subunits. As determined by SPR, all tested Sp-analogs provide valuable tools for affinity chromatography. However, Sp-8-AEA-cAMPS displayed (i) superior enrichment properties while maintaining low unspecific binding to other proteins in crude cell lysates, (ii) allowing mild elution conditions and (iii) providing the capability to efficiently purify all four isoforms of active PKA R-subunit in milligram quantities within 8 h. In a chemical proteomics approach both sets of binders, Rp- and Sp-cAMPS derivatives, can be employed. Whereas Sp-8-AEA-cAMPS preferentially binds free R-subunit, Rp-AHDAA-cAMPS, displaying antagonist properties, not only binds to the free PKA R-subunits but also to the intact PKA holoenzyme both from recombinant and endogenous sources. Conclusion In summary, all tested cAMP analogs were useful for their respective application as an affinity reagent which can enhance purification of cAMP binding proteins. Sp-8-AEA-cAMPS was considered the most efficient analog since Sp-8-AHA-cAMPS and Sp-2-AHA-cAMPS, demonstrated incomplete elution from the matrix, as well as retaining notable amounts of bound protein contaminants. Furthermore it could be demonstrated that an affinity resin based on Rp-8-AHDAA-cAMPS provides a valuable tool for chemical proteomics approaches.
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Affiliation(s)
- Daniela Bertinetti
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Sonja Schweinsberg
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Susanne E Hanke
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | - Frank Schwede
- Biolog Life Science Institute, Flughafendamm 9a, P.O. Box 107125, Bremen, Germany
| | - Oliver Bertinetti
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
| | | | | | - Friedrich W Herberg
- Department of Biochemistry, University of Kassel, Heinrich-Plett-Str. 40, 34132 Kassel, Germany
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Amoresano A, Carpentieri A, Giangrande C, Palmese A, Chiappetta G, Marino G, Pucci P. Technical advances in proteomics mass spectrometry: identification of post-translational modifications. Clin Chem Lab Med 2009; 47:647-65. [DOI: 10.1515/cclm.2009.154] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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15
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Regulation of the subcellular localization of cyclic AMP-dependent protein kinase in response to physiological stresses and sexual differentiation in the fission yeast Schizosaccharomyces pombe. EUKARYOTIC CELL 2008; 7:1450-9. [PMID: 18621924 DOI: 10.1128/ec.00168-08] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
We describe regulation of the subcellular localization of cyclic AMP (cAMP)-dependent protein kinase (PKA) regulatory (Cgs1p) and catalytic (Pka1p) subunits in the fission yeast Schizosaccharomyces pombe in response to physiological stresses and during sexual differentiation as determined by fluorescence microscopy of the Cgs1-green fluorescent protein (GFP) and Pka1-GFP fusion proteins, respectively. In wild-type S. pombe cells cultured to log phase under normal growth conditions, Cgs1p and Pka1p are concentrated in the nucleus and more diffusely present in the cytoplasm. Nuclear localization of both proteins is dependent on cAMP, since in cells lacking adenylate cyclase they are detectable only in the cytoplasm. In cells lacking Cgs1p or both Cgs1p and adenylate cyclase, Pka1p is concentrated in the nucleus, demonstrating a role for Cgs1p in the nuclear exclusion of Pka1p. Nuclear-cytoplasmic redistribution of Cgs1p and Pka1p is triggered by growth in glucose-limited or hyperosmotic media and in response to stationary-phase growth. In addition, both proteins are excluded from the nucleus in mating cells undergoing karyogamy and subsequently concentrated in postmeiotic spores. Cgs1p is required for subcellular redistribution of Pka1p induced by growth in glucose-limited and hyperosmotic media and during karyogamy but is not required for Pka1p redistribution triggered by stationary-phase growth or for the enrichment of Pka1p in spores. Our results demonstrate that PKA localization is regulated by cAMP and regulatory subunit-dependent and -independent mechanisms in S. pombe.
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Scholten A, Aye TT, Heck AJR. A multi-angular mass spectrometric view at cyclic nucleotide dependent protein kinases: in vivo characterization and structure/function relationships. MASS SPECTROMETRY REVIEWS 2008; 27:331-353. [PMID: 18381623 DOI: 10.1002/mas.20166] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
Abstract
Mass spectrometry has evolved in recent years to a well-accepted and increasingly important complementary technique in molecular and structural biology. Here we review the many contributions mass spectrometry based studies have made in recent years in our understanding of the important cyclic nucleotide activated protein kinase A (PKA) and protein kinase G (PKG). We both describe the characterization of kinase isozymes, substrate phosphorylation, binding partners and post-translational modifications by proteomics based methodologies as well as their structural and functional properties as revealed by native mass spectrometry, H/D exchange MS and ion mobility. Combining all these mass spectrometry based data with other biophysical and biochemical data has been of great help to unravel the intricate regulation of kinase function in the cell in all its magnificent complexity.
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Affiliation(s)
- Arjen Scholten
- Biomolecular Mass Spectrometry & Proteomics Group, Utrecht Institute of Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Sorbonnelaan 16, 3584CA, Utrecht, The Netherlands
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Yang W, Steen H, Freeman MR. Proteomic approaches to the analysis of multiprotein signaling complexes. Proteomics 2008; 8:832-51. [PMID: 18297654 DOI: 10.1002/pmic.200700650] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Signal transduction is one of the most active fields in modern biomedical research. Increasing evidence has shown that signaling proteins associate with each other in characteristic ways to form large signaling complexes. These diverse structures operate to boost signaling efficiency, ensure specificity and increase sensitivity of the biochemical circuitry. Traditional methods of protein analysis are inadequate to fully characterize and understand these structures, which are intricate, contain many components and are highly dynamic. Instead, proteomics technologies are currently being applied to investigate the nature and composition of multimeric signaling complexes. This review presents commonly used and potential proteomic methods of analyzing diverse protein complexes along with a discussion and a brief evaluation of alternative approaches. Challenges associated with proteomic analysis of signaling complexes are also discussed.
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Affiliation(s)
- Wei Yang
- The Urological Diseases Research Center, Department of Urology, Children's Hospital Boston, Boston, MA 02115, USA
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Meng Y, Liu XH, Ma X, Shen Y, Fan L, Leng J, Liu JY, Sha JH. The protein profile of mouse mature cumulus–oocyte complex. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2007; 1774:1477-90. [DOI: 10.1016/j.bbapap.2007.08.026] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/24/2007] [Revised: 08/19/2007] [Accepted: 08/20/2007] [Indexed: 10/22/2022]
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