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Lundin, Björn
Publications (9 of 9) Show all publications
Yin, L., Lundin, B., Bertrand, M., Nurmi, M., Solymosi, K., Kangasjarvi, S., . . . Spetea Wiklund, C. (2010). Role of Thylakoid ATP/ADP Carrier in Photoinhibition and Photoprotection of Photosystem II in Arabidopsis. PLANT PHYSIOLOGY, 153(2), 666-677
Open this publication in new window or tab >>Role of Thylakoid ATP/ADP Carrier in Photoinhibition and Photoprotection of Photosystem II in Arabidopsis
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2010 (English)In: PLANT PHYSIOLOGY, ISSN 0032-0889, Vol. 153, no 2, p. 666-677Article in journal (Refereed) Published
Abstract [en]

The chloroplast thylakoid ATP/ADP carrier (TAAC) belongs to the mitochondrial carrier superfamily and supplies the thylakoid lumen with stromal ATP in exchange for ADP. Here, we investigate the physiological consequences of TAAC depletion in Arabidopsis (Arabidopsis thaliana). We show that the deficiency of TAAC in two T-DNA insertion lines does not modify the chloroplast ultrastructure, the relative amounts of photosynthetic proteins, the pigment composition, and the photosynthetic activity. Under growth light conditions, the mutants initially displayed similar shoot weight, but lower when reaching full development, and were less tolerant to high light conditions in comparison with the wild type. These observations prompted us to study in more detail the effects of TAAC depletion on photoinhibition and photoprotection of the photosystem II (PSII) complex. The steady-state phosphorylation levels of PSII proteins were not affected, but the degradation of the reaction center II D1 protein was blocked, and decreased amounts of CP43-less PSII monomers were detected in the mutants. Besides this, the mutant leaves displayed a transiently higher nonphotochemical quenching of chlorophyll fluorescence than the wild-type leaves, especially at low light. This may be attributed to the accumulation in the absence of TAAC of a higher electrochemical H+ gradient in the first minutes of illumination, which more efficiently activates photoprotective xanthophyll cycle-dependent and independent mechanisms. Based on these results, we propose that TAAC plays a critical role in the disassembly steps during PSII repair and in addition may balance the trans-thylakoid electrochemical H+ gradient storage.

Place, publisher, year, edition, pages
American Society of Plant Biologists, 2010
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-57386 (URN)10.1104/pp.110.155804 (DOI)000278340200030 ()
Available from: 2010-06-18 Created: 2010-06-18 Last updated: 2010-06-18
Allahverdiyeva, Y., Mamedov, F., Holmstrom, M., Nurmi, M., Lundin, B., Styring, S., . . . Aro, E.-M. (2009). Comparison of the electron transport properties of the psbo1 and psbo2 mutants of Arabidopsis thaliana. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS, 1787(10), 1230-1237
Open this publication in new window or tab >>Comparison of the electron transport properties of the psbo1 and psbo2 mutants of Arabidopsis thaliana
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2009 (English)In: BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS, ISSN 0005-2728, Vol. 1787, no 10, p. 1230-1237Article in journal (Refereed) Published
Abstract [en]

Genome sequence of Arabidopsis thaliana (Arabidopsis) revealed two psbO genes (At5g66570 and At3g50820) which encode two distinct PsbO isoforms: PsbO1 and PsbO2, respectively. To get insights into the function of the PsbO1 and PsbO2 isoforms in Arabidopsis we have performed systematic and comprehensive investigations of the whole photosynthetic electron transfer chain in the T-DNA insertion mutant lines, psbO1 and psbo2. The absence of the PsbO1 isoform and presence of only the PsbO2 isoform in the psbo1 mutant results in (i) malfunction of both the donor and acceptor sides of Photosystem (PS) 11 and (ii) high sensitivity of PSII centers to photodamage, thus implying the importance of the PsbO1 isoform for proper structure and function of PSII. The presence of only the PsbO2 isoform in the PSII centers has consequences not only to the function of PSII but also to the PSI/PSII ratio in thylakoids. These results in modification of the whole electron transfer chain with higher rate of cyclic electron transfer around PSI, faster induction of NPQ and a larger size of the PQ-pool compared to WT, being in line with apparently increased chlororespiration in the psbo1 mutant plants. The presence of only the PsbO1 isoform in the psbo2 mutant did not induce any significant differences in the performance of PSII under standard growth conditions as compared to WT. Nevertheless, under high light illumination, it seems that the presence of also the PsbO2 isoform becomes favourable for efficient repair of the PSII complex.

Keywords
Arabidopsis thaliana, PsbO, Electron transport, Water oxidizing complex, Photosystem
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-19810 (URN)10.1016/j.bbabio.2009.05.013 (DOI)
Available from: 2009-08-11 Created: 2009-08-10 Last updated: 2009-08-11
Lundin, B., Thuswaldner (Heurtel), S. & Spetea (Wiklund), C. (2008). Arabidopsis PsbOs differ in their GTPase activity. In: John F. Allen, Elisabeth Gantt, John H. Golbeck, Barry Osmond. (Ed.), Photosynthesis: Energy from the Sun: (pp. 729-731). Springer
Open this publication in new window or tab >>Arabidopsis PsbOs differ in their GTPase activity
2008 (English)In: Photosynthesis: Energy from the Sun / [ed] John F. Allen, Elisabeth Gantt, John H. Golbeck, Barry Osmond., Springer , 2008, p. 729-731Chapter in book (Other academic)
Abstract [en]

Crucial for the optimal function of the oxygen-evolving complex (OEC) is the PsbO subunit of the photosystem II (PSII) complex. Previously we reported the ability of PsbO in spinach to bind and hydrolyze GTP. GTP stimulates the dissociation of PsbO from PSII following illumination and induces the degradation of the D1 protein. We have predicted four plant-specific binding motifs for GTP, which are not conserved in the sequences of the cyanobacteria or green algae PsbO proteins. We have proposed a location of the GTP-binding site inside the β-barrel exposed to the lumenal side. Arabidopsis thaliana has two PsbO isoforms encoded by two different genes: psbO1 and psbO2. Here we have measured and compared the GTPase activities of PSII membranes isolated from Arabidopsis knockouts mutants containing T-DNA insertions in one or the other of the psbO genes. The specific GTPase activity of PsbO2 is three fold higher than that of PsbO1. Furthermore, PsbO2 is more efficiently released than PsbO1 from PSII following light treatment. We conclude that PsbO2 is a better GTPase than Psb.

Place, publisher, year, edition, pages
Springer, 2008
Keywords
Photosystem II, PsbO protein, Arabidopsis thaliana, T-DNA insertionO1
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-13006 (URN)10.1007/978-1-4020-6709-9_162 (DOI)978-1-4020-6707-5 (ISBN)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2013-06-14Bibliographically approved
Lundin, B. (2008). Nucleotide-Dependent Processes in the Thylakoid Lumen of Plant Chloroplasts. (Doctoral dissertation). : Institutionen för fysik, kemi och biologi
Open this publication in new window or tab >>Nucleotide-Dependent Processes in the Thylakoid Lumen of Plant Chloroplasts
2008 (English)Doctoral thesis, comprehensive summary (Other academic)
Abstract [en]

Plants, algae and photosynthetic bacteria are able to harvest the sunlight and use its energy to transform water and carbon dioxide to carbohydrate molecules and oxygen, both important to sustain life on Earth. This process is called photosynthesis and is the route by which almost all energy enters the biosphere. As most simple things in life, the process of photosynthesis is easily explained but unfortunately not that easy to reproduce. If we could, we would be living in a much different world with almost unlimited energy. Light energy is harvested by chlorophyll molecules, bound to proteins in the chloroplast thylakoid membrane and drives the oxygen-evolving complex, to extract electrons from water. Electrons are then transferred to NADPH through photosystem II (PSII) to cytochrome b6f and photosystem I, the major photosynthetic protein complexes. The cytochrome b6f complex also transfers protons into the lumenal space of the thylakoid. These protons together with those from water oxidation create an electrochemical gradient across the thylakoid membrane, which fuels the ATP synthase to produce ATP. ATP, NADPH and carbon dioxide are used during the dark reactions to produce sugars in the chloroplast stroma. The thylakoid lumenal space where the water oxidation occurs has until recently been viewed as a proton sink with very few proteins. With the publication of the genome of Arabidopsis thaliana it seems to be a much more complex compartment housing a wide variety of biochemical processes.

ATP is a nucleotide and the major energy currency, but there are also other nucleotides such as AMP, ADP, GMP, GDP and GTP. Chloroplast metabolism has mostly been associated with ATP, but GTP has been shown to have a role in integration of light harversting complexes into the thylakoid. In this work, we have demonstrated the occurrence of nucleotide-dependent processes in the lumenal space of spinach by bringing evidence first for nucleotide (ATP) transport across the thylakoid membrane, second for nucleotide inter-conversion (ATP to GTP) by a nucleoside diphosphate kinase, and third the discovery that the PsbO extrinsic subunit of PSII complex can bind and hydrolyse GTP to GDP. The active PSII complex functions as a dimer but following light-induced damage, it is monomerised allowing for repair of its reaction center D1 protein. PsbO is ubiquitous in all oxygenic photosynthetic organisms and together with other extrinsic proteins stabilises the oxygen-evolving complex. We have modelled the GTP-binding site in the PsbO structure and showed that the GTPase activity of spinach PsbO induces changes in the protein structure, dissociation from the complex and stimulates the degradation of the D1 protein, possibly by inducing momerisation of damaged PSII complexes. As compared to spinach, Arabidopsis has two isoforms of PsbO, PsbO1 and PsbO2, expressed in a 4:1 ratio. A T-DNA insertion knockout mutant of PsbO1 showed a retarded growth rate, pale green leaves and a decrease in the oxygen evolution while a PsbO2 knockout mutant did not show any visual phenotype as compared to wild type. Unexpectedly, during growth under high light conditions the turnover rate of the D1 protein was impaired in the PsbO2 knockout, whereas it occurred faster in the PsbO1 knockout as compared to wild type. We concluded that the PsbO1 protein mainly functions in stabilizing the oxygen evolving complex, whereas the PsbO2 protein regulates the turnover of the D1 protein. The two PsbO proteins also differ in their GTPase-activity (PsbO2 >> PsbO1). Although their amino acid sequences are 90% identical, they differ in the GTP-binding region which could explain the difference in their GTPase activity. Based on these data, we propose that the GTPase activity of PsbO(2) leads to structural changes in interacting loops and plays a role in the initial steps of D1 turnover such as the PSII monomerisation step.

The nucleotide-dependent processes we discovered in the thylakoid lumen raise questions of transporters to facilitate these processes. As stated earlier, we provided biochemical evidence of an ATP thylakoid transporter, and most recently have identified a transporter that may be important for the export of lumenal phosphate back to the stroma. More transporters for GDP, metal ions and others solutes have still to be identified.

Place, publisher, year, edition, pages
Institutionen för fysik, kemi och biologi, 2008
Series
Linköping Studies in Science and Technology. Dissertations, ISSN 0345-7524 ; 1165
Keywords
plant, chloroplast, thylakoid, nucleotide, PSII, PsbO
National Category
Biological Sciences
Identifiers
urn:nbn:se:liu:diva-11244 (URN)978-91-7393-965-2 (ISBN)
Public defence
2008-04-04, Linden, Hus 421, Ingång 65; HU, Campus US, Linköpings universitet, Linköping, 09:30 (English)
Opponent
Supervisors
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2009-05-07
Spetea Wiklund, C., Ruiz Pavón, L., Thuswaldner, S., Lundin, B., Lundh, F., Persson, B., . . . Adamska, I. (2008). Screening for solute transporters in plant photosynthetic membranes. In: Photosynthesis 2007: Energy from the sun,2007 (pp. 1067-1070). Springer Publisher
Open this publication in new window or tab >>Screening for solute transporters in plant photosynthetic membranes
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2008 (English)In: Photosynthesis 2007: Energy from the sun,2007, Springer Publisher , 2008, p. 1067-1070Conference paper, Published paper (Other academic)
Place, publisher, year, edition, pages
Springer Publisher, 2008
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-44417 (URN)76586 (Local ID)76586 (Archive number)76586 (OAI)
Available from: 2009-10-10 Created: 2009-10-10
Lundin, B., Nurmi, M., Rojas-Stuetz, M., Aro, E.-M., Adamska, I. & Spetea Wiklund , C. (2008). Towards understanding the functional difference between the two PsbO isoforms in Arabidopsis thaliana-insights from phenotypic analyses of psbo knockout mutants. Photosynthesis Research, 98(1-3), 405-414
Open this publication in new window or tab >>Towards understanding the functional difference between the two PsbO isoforms in Arabidopsis thaliana-insights from phenotypic analyses of psbo knockout mutants
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2008 (English)In: Photosynthesis Research, ISSN 0166-8595, E-ISSN 1573-5079, Vol. 98, no 1-3, p. 405-414Article in journal (Refereed) Published
Abstract [en]

The extrinsic PsbO subunit of the water-oxidizing photosystem II (PSII) complex is represented by two isoforms in Arabidopsis thaliana, namely PsbO1 and PsbO2. Recent analyses of psbo1 and psbo2 knockout mutants have brought insights into their roles in photosynthesis and light stress. Here we analyzed the two psbo mutants in terms of PsbOs expression pattern, organization of PSII complexes and GTPase activity. Both PsbOs are present in wild-type plants, and their expression is mutually controlled in the mutants. Almost all PSII complexes are in the monomeric form not only in the psbo1 but also in the psbo2 mutant grown under high-light conditions. This results either from an enhanced susceptibility of PSII to photoinactivation or from malfunction of the repair cycle. Notably, the psbo1 mutant displays such problems even under growth-light conditions. These results together with the finding that PsbO2 has a threefold higher GTPase activity than PsbO1 have significance for the turnover of the PSII D1 subunit in Arabidopsis.

Keywords
Arabidopsis thaliana, Blue Native gel electrophoresis, D1 protein turnover, GTPase, High-light stress, Photosystem II organization, PsbO protein
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-16241 (URN)10.1007/s11120-008-9325-y (DOI)
Available from: 2009-01-12 Created: 2009-01-09 Last updated: 2017-12-14
Lundin, B., Hansson, M., Schoefs, B., Vener, A. V. & Spetea (Wiklund), C. (2007). Arabidopsis PsbO2 protein regulates dephosphorylation and turnover of the photosystem II reaction centre D1 protein. The Plant Journal, 49(3), 528-539
Open this publication in new window or tab >>Arabidopsis PsbO2 protein regulates dephosphorylation and turnover of the photosystem II reaction centre D1 protein
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2007 (English)In: The Plant Journal, ISSN 0960-7412, Vol. 49, no 3, p. 528-539Article in journal (Refereed) Published
Abstract [en]

The extrinsic photosystem II (PSII) protein of 33 kDa (PsbO), which stabilizes the water-oxidizing complex, is represented in Arabidopsis thaliana (Arabidopsis) by two isoforms. Two T-DNA insertion mutant lines deficient in either the PsbO1 or the PsbO2 protein were retarded in growth in comparison with the wild type, while differing from each other phenotypically. Both PsbO proteins were able to support the oxygen evolution activity of PSII, although PsbO2 was less efficient than PsbO1 under photoinhibitory conditions. Prolonged high light stress led to reduced growth and fitness of the mutant lacking PsbO2 as compared with the wild type and the mutant lacking PsbO1. During a short period of treatment of detached leaves or isolated thylakoids at high light levels, inactivation of PSII electron transport in the PsbO2-deficient mutant was slowed down, and the subsequent degradation of the D1 protein was totally inhibited. The steady-state levels of in vivo phosphorylation of the PSII reaction centre proteins D1 and D2 were specifically reduced in the mutant containing only PsbO2, in comparison with the mutant containing only PsbO1 or with wild-type plants. Phosphorylation of PSII proteins in vitro proceeded similarly in thylakoid membranes from both mutants and wild-type plants. However, dephosphorylation of the D1 protein occurred much faster in the thylakoids containing only PsbO2. We conclude that the function of PsbO1 in Arabidopsis is mostly in support of PSII activity, whereas the interaction of PsbO2 with PSII regulates the turnover of the D1 protein, increasing its accessibility to the phosphatases and proteases involved in its degradation.

Keywords
Arabidopsis, photosystem II, PsbO, oxygen evolution, D1 protein degradation, high light stress
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-13005 (URN)10.1111/j.1365-313X.2006.02976.x (DOI)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2009-05-07
Lundin, B., Thuswaldner (Heurtel), S., Shutova, T., Eshaghi, S., Samuelsson, G., Barber, J., . . . Spetea (Wiklund), C. (2007). Subsequent events to GTP binding by the plant PsbO protein: structural changes, GTP hydrolysis and dissociation from the photosystem II complex. Biochimica et Biophysica Acta - Bioenergetics, 1767(6), 500-508
Open this publication in new window or tab >>Subsequent events to GTP binding by the plant PsbO protein: structural changes, GTP hydrolysis and dissociation from the photosystem II complex
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2007 (English)In: Biochimica et Biophysica Acta - Bioenergetics, ISSN 0005-2728, E-ISSN 1879-2650, Vol. 1767, no 6, p. 500-508Article in journal (Refereed) Published
Abstract [en]

Besides an essential role in optimizing water oxidation in photosystem II (PSII), it has been reported that the spinach PsbO protein binds GTP [C. Spetea, T. Hundal, B. Lundin, M. Heddad, I. Adamska, B. Andersson, Proc. Natl. Acad. Sci. U.S.A. 101 (2004) 1409–1414]. Here we predict four GTP-binding domains in the structure of spinach PsbO, all localized in the β-barrel domain of the protein, as judged from comparison with the 3D-structure of the cyanobacterial counterpart. These domains are not conserved in the sequences of the cyanobacterial or green algae PsbO proteins. MgGTP induces specific changes in the structure of the PsbO protein in solution, as detected by circular dichroism and intrinsic fluorescence spectroscopy. Spinach PsbO has a low intrinsic GTPase activity, which is enhanced fifteen-fold when the protein is associated with the PSII complex in its dimeric form. GTP stimulates the dissociation of PsbO from PSII under light conditions known to also release Mn2+ and Ca2+ ions from the oxygen-evolving complex and to induce degradation of the PSII reaction centre D1 protein. We propose the occurrence in higher plants of a PsbO-mediated GTPase activity associated with PSII, which has consequences for the function of the oxygen-evolving complex and D1 protein turnover.

Keywords
Photosystem II, PsbO protein, GTPase, Oxygen-evolving complex, D1 protein
National Category
Medical and Health Sciences
Identifiers
urn:nbn:se:liu:diva-13004 (URN)10.1016/j.bbabio.2006.10.009 (DOI)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2017-12-13Bibliographically approved
Spetea Wiklund, C., Hundal, T., Lundin, B., Heddad, M., Adamska, I. & Andersson, B. (2004). Multiple evidence for nucleotide metabolism in the chloroplast thylakoid lumen. Proceedings of the National Academy of Science, 101(5), 1409-1414
Open this publication in new window or tab >>Multiple evidence for nucleotide metabolism in the chloroplast thylakoid lumen
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2004 (English)In: Proceedings of the National Academy of Science, ISSN 0027-8424, Vol. 101, no 5, p. 1409-1414Article in journal (Refereed) Published
Abstract [en]

The apparatus of photosynthetic energy conversion in chloroplasts is quite well characterized with respect to structure and function. Light-driven electron transport in the thylakoid membrane is coupled to synthesis of ATP, used to drive energy-dependent metabolic processes in the stroma and the outer surface of the thylakoid membrane. The role of the inner (luminal) compartment of the thylakoids has, however, remained largely unknown although recent proteomic analyses have revealed the presence of up to 80 different proteins. Further, there are no reports concerning the presence of nucleotides in the thylakoid lumen. Here, we bring three lines of experimental evidence for nucleotide-dependent processes in this chloroplast compartment. (i) The thylakoid lumen contains a protein of 17.2 kDa, catalyzing the transfer of the γ-phosphate group from ATP to GDP, proposed to correspond to the nucleoside diphosphate kinase III. (ii) The 33-kDa subunit of photosystem II, bound to the luminal side of the thylakoid membrane and associated with the water-splitting process, can bind GTP. (iii) The thylakoid membrane contains a nucleotide transport system that is suggested to be associated with a 36.5-kDa nucleotide-binding protein. Our results imply, against current dogmas, that the thylakoid lumen contains nucleotides, thereby providing unexpected aspects on this chloroplast compartment from a metabolic and regulatory perspective and expanding its functional significance beyond a pure bioenergetic function.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-13003 (URN)10.1073/pnas.0308164100 (DOI)
Available from: 2008-03-20 Created: 2008-03-20 Last updated: 2010-01-26
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