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Ingelsson, Björn
Publications (8 of 8) Show all publications
Ingelsson, B., Söderberg, D., Strid, T., Söderberg, A., Bergh, A.-C., Loitto, V.-M., . . . Rosén, A. (2018). Lymphocytes eject interferogenic mitochondrial DNA webs in response to CpG and non-CpG oligodeoxynucleotides of class C. Proceedings of the National Academy of Sciences of the United States of America, 115(3), E478-E487
Open this publication in new window or tab >>Lymphocytes eject interferogenic mitochondrial DNA webs in response to CpG and non-CpG oligodeoxynucleotides of class C
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2018 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 115, no 3, p. E478-E487Article in journal (Refereed) Published
Abstract [en]

Circulating mitochondrial DNA (mtDNA) is receiving increasing attention as a danger-associated molecular pattern in conditions such as autoimmunity, cancer, and trauma. We report here that human lymphocytes [B cells, T cells, natural killer (NK) cells], monocytes, and neutrophils derived from healthy blood donors, as well as B cells from chronic lymphocytic leukemia patients, rapidly eject mtDNA as web filament structures upon recognition of CpG and non-CpG oligodeoxynucleotides of class C. The release was quenched by ZnCl2, independent of cell death (apoptosis, necrosis, necroptosis, autophagy), and continued in the presence of TLR9 signaling inhibitors. B-cell mtDNA webs were distinct from neutrophil extracellular traps concerning structure, reactive oxygen species (ROS) dependence, and were devoid of antibacterial proteins. mtDNA webs acted as rapid (within minutes) messengers, priming antiviral type I IFN production. In summary, our findings point at a previously unrecognized role for lymphocytes in antimicrobial defense, utilizing mtDNA webs as signals in synergy with cytokines and natural antibodies, and cast light on the interplay between mitochondria and the immune system.

Place, publisher, year, edition, pages
Washington, DC, United States: National Academy of Sciences, 2018
Keywords
CpG-C, DAMP, immune DNA sensing, lymphocyte signaling, mitochondrial DNA release
National Category
Basic Medicine Immunology in the medical area
Research subject
Economic Information Systems
Identifiers
urn:nbn:se:liu:diva-144187 (URN)10.1073/pnas.1711950115 (DOI)000423091400018 ()29295921 (PubMedID)2-s2.0-85042104216 (Scopus ID)
Funder
Swedish Cancer Society
Note

Funding agencies: Linkoping Medical Society; Linkoping University; ALF grants; Region Ostergotland, Sweden; Linkoping University Cancer; Ingrid Asp Foundation; Swedish Cancer Society

Available from: 2018-01-09 Created: 2018-01-09 Last updated: 2018-09-07Bibliographically approved
Ingelsson, B., Fristedt, R. & Turkina, M. (2015). Phosphorylation stoichiometry determination in plant photosynthetic membranes.. In: Waltraud X. Schulze (Ed.), Plant Phosphoproteomics: Methods and Protocols (pp. 121-134). New York: Springer-Verlag New York
Open this publication in new window or tab >>Phosphorylation stoichiometry determination in plant photosynthetic membranes.
2015 (English)In: Plant Phosphoproteomics: Methods and Protocols / [ed] Waltraud X. Schulze, New York: Springer-Verlag New York, 2015, p. 121-134Chapter in book (Refereed)
Abstract [en]

This chapter describes different strategies for the study of phosphorylation dynamics and stoichiometry in photosynthetic membranes. Detailed procedures for the detection, large-scale identification, and quantification of phosphorylated proteins optimized for plant thylakoid proteins are given.

Place, publisher, year, edition, pages
New York: Springer-Verlag New York, 2015
Series
Methods in Molecular Biology, ISSN 1064-3745 ; 1306
Keywords
Protein phosphorylation, Immunological detection, Phosphorylation stoichiometry, Mass spectrometry
National Category
Biochemistry and Molecular Biology
Identifiers
urn:nbn:se:liu:diva-125278 (URN)10.1007/978-1-4939-2648-0_9 (DOI)978-1-4939-2647-3 (ISBN)978-1-4939-2648-0 (ISBN)
Available from: 2016-02-19 Created: 2016-02-19 Last updated: 2016-03-01Bibliographically approved
Samol, I., Shapiguzov, A., Ingelsson, B., Fucile, G., Crèvecoeur, M., Vener, A. V., . . . Goldschmidt-Clermont, M. (2012). Identification of a Photosystem II Phosphatase Involved in Light Acclimation in Arabidopsis. The Plant Cell, 24(6), 2596-2609
Open this publication in new window or tab >>Identification of a Photosystem II Phosphatase Involved in Light Acclimation in Arabidopsis
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2012 (English)In: The Plant Cell, ISSN 1040-4651, E-ISSN 1532-298X, Vol. 24, no 6, p. 2596-2609Article in journal (Refereed) Published
Abstract [en]

Reversible protein phosphorylation plays a major role in the rapid acclimation of the photosynthetic apparatus to changes in light. Two paralogous kinases phosphorylate subsets of thylakoid membrane proteins. STN7 phosphorylates LHCII, the light harvesting antenna of photosystem II (PSII), to balance the activity of the two photosystems through state transitions. STN8 which is mainly involved in phosphorylation of PSII influences folding of the thylakoid membranes and repair of PSII after photo-damage. The rapid reversibility of these acclimatory responses requires the action of protein phosphatases.

In a reverse genetic screen we have identified the chloroplast PP2C phosphatase, PBCP (PHOTOSYSTEM II CORE PHOSPHATASE), which is required for efficient dephosphorylation of PSII. Its targets identified by immunoblotting and mass spectrometry largely coincide with those of the kinase STN8. The recombinant phosphatase is active in vitro on a synthetic substrate or on isolated thylakoids. Thylakoid folding and degradation of D1 after photo-damage are affected in the absence of PBCP, while its over-expression alters the kinetics of state transitions. PBCP and STN8 form an antagonistic kinase and phosphatase pair whose substrate specificity and physiological function are distinct from those of STN7 and the counteracting phosphatase PPH1 (TAP38), but their activities may overlap to some degree.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-76725 (URN)10.3410/f.717847818.793153384 (DOI)000306919300027 ()
Note

On the day of the defence date the title of the article was The role of PHOTOSYSTEM II CORE PHOSPHATASE in light acclimation of photosynthesis in Arabidopsis.

Funding agencies|SystemsX.ch (RTD Plant Growth in a Changing Environment)||Swiss National Foundation|3100AO-11771231003A_133089/1|FP7 Marie-Curie Initial Training Network (ITN) COSI|ITN 2008 GA 215-174|EMBO postdoctoral fellowship||Swedish Research Council|2008-5490|

Available from: 2012-04-18 Created: 2012-04-18 Last updated: 2017-12-07Bibliographically approved
Ingelsson, B. & Vener, A. (2012). Phosphoproteomics of Arabidopsis chloroplasts reveals involvement of the STN7 kinase in phosphorylation of nucleoid protein pTAC16. FEBS Letters, 586(9), 1265-1271
Open this publication in new window or tab >>Phosphoproteomics of Arabidopsis chloroplasts reveals involvement of the STN7 kinase in phosphorylation of nucleoid protein pTAC16
2012 (English)In: FEBS Letters, ISSN 0014-5793, E-ISSN 1873-3468, Vol. 586, no 9, p. 1265-1271Article in journal (Refereed) Published
Abstract [en]

Light-regulated protein kinases STN7 and STN8 phosphorylate thylakoid membrane proteins and also affect expression of several chloroplast proteins via yet unknown mechanisms. Comparative phosphoproteomics of acetic acid protein extracts of chloroplasts from Arabidopsis thaliana wild type, stn7, stn8 and stn7stn8 mutants yielded two previously unknown findings: (i) neither STN7 nor STN8 kinase was required for phosphorylation of Ser-48 in Lhcb1.1–1.3 proteins; and (ii) phosphorylation of Thr-451 in pTAC16 protein was STN7-dependent. pTAC16 was found distributed between thylakoids and nucleoid. Its knockout did not affect the nucleoid protein composition and the Thr-451 phosphorylated protein was excluded from the nucleoid. Thr-451 of pTAC16 is conserved in all studied plants and its phosphorylation may regulate membrane-anchoring functions of the nucleoid.

Place, publisher, year, edition, pages
Elsevier, 2012
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-76726 (URN)10.1016/j.febslet.2012.03.061 (DOI)000303434200003 ()
Available from: 2012-04-18 Created: 2012-04-18 Last updated: 2017-12-07Bibliographically approved
Ingelsson, B. (2012). Reversible modifications of chloroplast proteins and assessment of their functions. (Doctoral dissertation). Linköping: Linköping University Electronic Press
Open this publication in new window or tab >>Reversible modifications of chloroplast proteins and assessment of their functions
2012 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Oxygenic photosynthesis is the process of solar energy conversion into chemical energy in the form of carbohydrates. This event is carried out by plants, algae and cyanobacteria and represents the starting point of the food chain in which most organisms are fed. Due to never-ending changes in the surrounding environment, these photoautotrophic organisms have evolved different acclimatizing strategies to optimize photosynthesis. Many of these fine-tuning mechanisms are dependent on reversible modifications of proteins on a post-translational level. In my research I have been focused on such reversible modifications of proteins in the organelle where photosynthesis takes place – the chloroplast – using the model plant Arabidopsis thaliana.

Within chloroplasts, light-driven reactions of photosynthesis are catalyzed by several multi-subunit protein complexes in the thylakoid membrane. Proteins need to be folded properly in order to function correctly. A rate-limiting step of protein folding is the isomerization of the peptide bond around proline, a step that is catalyzed by enzymes possessing peptidyl-prolyl cis-trans isomerase (PPIase) activity. Within the thylakoid lumen, only two proteins have been found to possess PPIase activity, FKBP13 and CYP20-2. Both these enzymes belong to a protein superfamily called immunophilins - ubiquitous proteins attributed with several different functions. By characterization of Arabidopsis mutants lacking FKBP13 and CYP20-2 I found that PPIase activity is a dispensable function of immunophilins in the thylakoid lumen.

A common post-translational modification of chloroplast proteins is phosphorylation. Protein phosphorylation alters protein functions and is a reversible mechanism utilized by plants for rapid acclimation to changes in the incident light. These events require the action of kinases and phosphatases that either add or remove phosphate groups on proteins, respectively. I have characterized mutants deficient in protein phosphatases responsible for dephosphorylation of thylakoid proteins. These phosphatases, PPH1 and PBCP, represent key players in acclimation of the photosynthetic machinery to changes in light quality/quantity. In addition, I discovered that phosphorylation of pTAC16, a protein associated with the chloroplast gene-expression machinery, depends on the presence of STN7; a light-regulated protein kinase located in the thylakoid membrane. This finding could provide a link between the redox state of the photosynthetic apparatus and chloroplast gene expression.

Place, publisher, year, edition, pages
Linköping: Linköping University Electronic Press, 2012. p. 67
Series
Linköping University Medical Dissertations, ISSN 0345-0082 ; 1296
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-76727 (URN)9789175199528 (ISBN)
Public defence
2012-05-16, Eken, Hälsouniversitetet, Campus US, Linköpings universitet, Linköping, 09:00 (English)
Opponent
Supervisors
Available from: 2012-04-18 Created: 2012-04-18 Last updated: 2017-12-18Bibliographically approved
Shapiguzov, A., Ingelsson, B., Samol, I., Andres, C., Kessler, F., Rochaix, J.-D., . . . Goldschmidt-Clermont, M. (2010). The PPH1 phosphatase is specifically involved in LHCII dephosphorylation and state transitions in Arabidopsis. Proceedings of the National Academy of Sciences of the United States of America, 107(10), 4782-4787
Open this publication in new window or tab >>The PPH1 phosphatase is specifically involved in LHCII dephosphorylation and state transitions in Arabidopsis
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2010 (English)In: Proceedings of the National Academy of Sciences of the United States of America, ISSN 0027-8424, E-ISSN 1091-6490, Vol. 107, no 10, p. 4782-4787Article in journal (Refereed) Published
Abstract [en]

The ability of plants to adapt to changing light conditions depends on a protein kinase network in the chloroplast that leads to the reversible phosphorylation of key proteins in the photosynthetic membrane. Phosphorylation regulates, in a process called state transition, a profound reorganization of the electron transfer chain and remodeling of the thylakoid membranes. Phosphorylation governs the association of the mobile part of the light-harvesting antenna LHCII with either photosystem I or photosystem II. Recent work has identified the redox-regulated protein kinase STN7 as a major actor in state transitions, but the nature of the corresponding phosphatases remained unknown. Here we identify a phosphatase of Arabidopsis thaliana, called PPH1, which is specifically required for the dephosphorylation of light-harvesting complex II (LHCII). We show that this single phosphatase is largely responsible for the dephosphorylation of Lhcb1 and Lhcb2 but not of the photosystem II core proteins. PPH1, which belongs to the family of monomeric PP2C type phosphatases, is a chloroplast protein and is mainly associated with the stroma lamellae of the thylakoid membranes. We demonstrate that loss of PPH1 leads to an increase in the antenna size of photosystem I and to a strong impairment of state transitions. Thus phosphorylation and dephosphorylation of LHCII appear tobe specifically mediated by the kinase/phosphatase pair STN7 and PPH1. These two proteins emerge as key players in the adaptation of the photosynthetic apparatus to changes in light quality and quantity.

Keywords
Photosynthesis, PP2C phosphatases, thylakoid, plastid
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-54602 (URN)10.1073/pnas.0913810107 (DOI)000275368400053 ()
Available from: 2010-03-26 Created: 2010-03-26 Last updated: 2017-12-12Bibliographically approved
Strid, T., Svartz, J., Franck, N., Hallin, E., Ingelsson, B., Söderström, M. & Hammarström, S. (2009). Distinct parts of leukotriene C-4 synthase interact with 5-lipoxygenase and 5-lipoxygenase activating protein. Biochemical and Biophysical Research Communications - BBRC, 381(4), 518-522
Open this publication in new window or tab >>Distinct parts of leukotriene C-4 synthase interact with 5-lipoxygenase and 5-lipoxygenase activating protein
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2009 (English)In: Biochemical and Biophysical Research Communications - BBRC, ISSN 0006-291X, E-ISSN 1090-2104, Vol. 381, no 4, p. 518-522Article in journal (Refereed) Published
Abstract [en]

Leukotriene C-4 is a potent inflammatory mediator formed from arachidonic acid and glutathione. 5-Lipoxygenase (5-LO), 5-lipoxygenase activating protein (FLAP) and leukotriene C-4 synthase (LTC4S) participate in its biosynthesis. We report evidence that LTC4S interacts in vitro with both FLAP and 5-LO and that these interactions involve distinct parts of LTC4S. FLAP bound to the N-terminal part/first hydrophobic region of LTC4S. This part did not bind 5-LO which bound to the second hydrophilic loop of LTC4S. Fluorescent FLAP- and LTC4S-fusion proteins co-localized at the nuclear envelope. Furthermore, GFP-FLAP and GFP-LTC4S co-localized with a fluorescent ER marker. In testing HEK293/T or COS-7 cells GFP-5-LO was found mainly in the nuclear matrix. Upon stimulation with calcium ionophore, GFP-5-LO translocated to the nuclear envelope allowing it to interact with FLAP and LTC4S. Direct interaction of 5-LO and LTC4S in ionophore-stimulated (but not un-stimulated) cells was demonstrated by BRET using GFP-5-LO and Rluc-LTC4S.

Keywords
BRET, Confocal fluorescence microscopy, Eicosanoids, Fusion proteins, GFP, GST pull-down assay, Nuclear envelope
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-17904 (URN)10.1016/j.bbrc.2009.02.074 (DOI)000264929400013 ()
Note

Original Publication: Tobias Strid, Jesper Svartz, Niclas Franck, Elisabeth Hallin, Björn Ingelsson, Mats Söderström and Sven Hammarström, Distinct parts of leukotriene C-4 synthase interact with 5-lipoxygenase and 5-lipoxygenase activating protein, 2009, BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS, (381), 4, 518-522. http://dx.doi.org/10.1016/j.bbrc.2009.02.074 Copyright: Elsevier Science B.V., Amsterdam http://www.elsevier.com/

Available from: 2009-04-30 Created: 2009-04-24 Last updated: 2017-12-13Bibliographically approved
Ingelsson, B., Shapiguzov, A., Kieselbach, T. & Vener, A. (2009). PeptidylProlyl Isomerase Activity in Chloroplast Thylakoid Lumen is a Dispensable Function of Immunophilins in Arabidopsis thaliana. Plant and Cell Physiology, 50(10), 1801-1814
Open this publication in new window or tab >>PeptidylProlyl Isomerase Activity in Chloroplast Thylakoid Lumen is a Dispensable Function of Immunophilins in Arabidopsis thaliana
2009 (English)In: Plant and Cell Physiology, ISSN 0032-0781, E-ISSN 1471-9053, Vol. 50, no 10, p. 1801-1814Article in journal (Refereed) Published
Abstract [en]

Chloroplast thylakoid lumen of Arabidopsis thaliana contains 16 immunophilins, five cyclophilins and 11 FK506-binding proteins (FKBPs), which are considered protein folding catalysts, although only two of them, AtFKBP13 and AtCYP20-2, possess peptidylprolyl cis/trans isomerase (PPIase) activity. To address the question of the physiological significance of this activity, we obtained and characterized Arabidopsis mutants deficient in the most active PPIase, AtFKBP13, and a double mutant deficient in both AtFKBP13 and AtCYP20-2. Two-dimensional gel electrophoresis of isolated thylakoid lumen, as well as immunoblotting analyses of major photosynthetic membrane protein complexes did not reveal differences in protein composition between the mutants and the wild type. No changes in the relative content of photosynthetic proteins were found by differential stable isotope labeling and liquid chromatographymass spectrometry (LC-MS) analyses. PPIase activity was measured in vitro in isolated thylakoid lumen samples using two different synthetic peptide substrates. Depending on the peptide substrate used for the assay, the PPIase activity in the thylakoid lumen of the mutants lacking either AtFKBP13 or both AtFKBP13 and AtCYP20-2 was as low as 10 or 2 of that in the wild type. Residual PPIase activity detected in the double mutant originated from AtCYP20-3, a cyclophilin from chloroplast stroma contaminating thylakoid lumen preparations. None of the mutants differed from the wild-type plants when grown under normal, cold stress or high light conditions. It is concluded that cellular functions of immunophilins in the thylakoid lumen of chloroplasts are not related to their PPIase capacity and should be investigated beyond this enzymatic activity.

Keywords
Arabidopsis thaliana, Chloroplast thylakoid lumen, Cyclophilin, FKBP, Immunophilin, Peptidyl-prolyl isomerase activity
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-51383 (URN)10.1093/pcp/pcp122 (DOI)
Available from: 2009-10-30 Created: 2009-10-30 Last updated: 2017-12-12Bibliographically approved
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