Functionally Important Amino Acids in the <i>Arabidopsis</i> Thylakoid Phosphate Transporter: Homology Modeling and Site-Directed Mutagenesis

Ruiz-Pavón, Lorena; Karlsson, Patrik; Carlsson, Jonas; Samyn, Dieter R.; Persson, Bengt L.; Spetea, Cornelia

doi:10.1021/bi100239j

Cited by 14 publications

(11 citation statements)

References 43 publications

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“…PHT4;1 belongs to the PHT4 family of Pi symporters and was localized to the thylakoid membrane and to the chloroplast envelope (Pavon et al 2008, Ferro et al 2010. Yeast complementation experiments revealed a H + -dependent mechanism of Pi transport (Guo et al 2008), however, assays in E. coli indicated PHT4;1 as a high-affinity Na + -dependent Pi transporter (Pavon et al 2008, Ruiz-Pavon et al 2010. More recently, the envelope PHT4;4 transporter was found to preferentially function in ascorbate rather than Pi transport based on uptake assays in proteoliposomes (Miyaji et al 2015).…”

Section: Ion Transportersmentioning

confidence: 99%

An update on the regulation of photosynthesis by thylakoid ion channels and transporters in Arabidopsis

Spetea

Herdean

Allorent

et al. 2017

Physiologia Plantarum

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In natural, variable environments, plants rapidly adjust photosynthesis for optimal balance between light absorption and utilization. There is increasing evidence suggesting that ion fluxes across the chloroplast thylakoid membrane play an important role in this regulation by affecting the proton motive force and consequently photosynthesis and thylakoid membrane ultrastructure. This article presents an update on the thylakoid ion channels and transporters characterized in Arabidopsis thaliana as being involved in these processes, as well as an outlook at the evolutionary conservation of their functions in other photosynthetic organisms. This is a contribution to shed light on the thylakoid network of ion fluxes and how they help plants to adjust photosynthesis in variable light environments.

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Section: Ion Transportersmentioning

confidence: 99%

An update on the regulation of photosynthesis by thylakoid ion channels and transporters in Arabidopsis

Spetea

Herdean

Allorent

et al. 2017

Physiologia Plantarum

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“…Channels/porins K + channel (SynK) Synechocystis slr0498 K + Photosynthesis: regulation of the electric component of proton motive force[46, 51] Two-pore K + channel 3 (TPK3) Arabidopsis At4g18160 K + ?Not determined[46, 47, 128] Chloride channel e (CLCe) Arabidopsis At4g35440 Cl − , NO 2 − Photosynthesis, nitrate homeostasis[57, 58] Tonoplast intrinsic protein 2;1 (TIP2;1) Arabidopsis At3g16240 H 2 O, H 2 O 2 , NH 3 , ureaNot determined[34, 35, 61] TC #2. Secondary transporters Phosphate transporter 4;1 (PHT4;1) Arabidopsis At2g29650 PiPSII repair and photoprotection[66, 67, 71] Thylakoid ATP/ADP carrier (TAAC) Arabidopsis At5g01500 ATP, ADP, PAPS, PAPThylakoid biogenesis, PSII repair and photoprotection, sulfur metabolism, retrograde signaling[78, 79, 82, 84] Na + /H + antiporter NhaS3 Synechocystis sll0689 Na + , H + Essential gene. Balance of Na + /K + ratio.…”

Section: The Photosynthetic Machinery Requires Thylakoid Channels Andmentioning

confidence: 99%

Function and evolution of channels and transporters in photosynthetic membranes

Pfeil

Schoefs

Spetea

2013

Cell. Mol. Life Sci.

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Chloroplasts from land plants and algae originated from an endosymbiotic event, most likely involving an ancestral photoautotrophic prokaryote related to cyanobacteria. Both chloroplasts and cyanobacteria have thylakoid membranes, harboring pigment-protein complexes that perform the light-dependent reactions of oxygenic photosynthesis. The composition, function and regulation of these complexes have thus far been the major topics in thylakoid membrane research. For many decades, we have also accumulated biochemical and electrophysiological evidence for the existence of solute transthylakoid transport activities that affect photosynthesis. However, research dedicated to molecular identification of the responsible proteins has only recently emerged with the explosion of genomic information. Here we review the current knowledge about channels and transporters from the thylakoid membrane of Arabidopsis thaliana and of the cyanobacterium Synechocystis sp. PCC 6803. No homologues of these proteins have been characterized in algae, although similar sequences could be recognized in many of the available sequenced genomes. Based on phylogenetic analyses, we hypothesize a host origin for most of the so far identified Arabidopsis thylakoid channels and transporters. Additionally, the shift from a non-thylakoid to a thylakoid location appears to have occurred at different times for different transport proteins. We propose that closer control of and provision for the thylakoid by products of the host genome has been an ongoing process, rather than a one-step event. Some of the proteins recruited to serve in the thylakoid may have been the result of the increased specialization of its pigment-protein composition and organization in green plants.Electronic supplementary materialThe online version of this article (doi:10.1007/s00018-013-1412-3) contains supplementary material, which is available to authorized users.

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“…() observed H + ‐dependent Pi transport when it was expressed in Saccharomyces cerevisiae . Several residues that are important for Pi transport and its Na + dependence were identified using homology modeling, site‐directed mutagenesis and functional characterization in Escherichia coli (Ruiz‐Pavon et al ., ). It was suggested that the direction of transport across thylakoids depends on the electrochemical gradient of Pi, and that H + , Na + or K + ion gradients could drive the transport (Guo et al ., ; Pavon et al ., ).…”

Section: Introductionmentioning

confidence: 97%

The Arabidopsis thylakoid transporter PHT4;1 influences phosphate availability for ATP synthesis and plant growth

et al. 2015

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SUMMARYThe Arabidopsis phosphate transporter PHT4;1 was previously localized to the chloroplast thylakoid membrane. Here we investigated the physiological consequences of the absence of PHT4;1 for photosynthesis and plant growth. In standard growth conditions, two independent Arabidopsis knockout mutant lines displayed significantly reduced leaf size and biomass but normal phosphorus content. When mutants were grown in high-phosphate conditions, the leaf phosphorus levels increased and the growth phenotype was suppressed. Photosynthetic measurements indicated that in the absence of PHT4;1 stromal phosphate was reduced to levels that limited ATP synthase activity. This resulted in reduced CO 2 fixation and accumulation of soluble sugars, limiting plant growth. The mutants also displayed faster induction of non-photochemical quenching than the wild type, in line with the increased contribution of DpH to the proton-motive force across thylakoids. Small-angle neutron scattering showed a smaller lamellar repeat distance, whereas circular dichroism spectroscopy indicated a perturbed long-range order of photosystem II (PSII) complexes in the mutant thylakoids. The absence of PHT4;1 did not alter the PSII repair cycle, as indicated by wild-type levels of phosphorylation of PSII proteins, inactivation and D1 protein degradation. Interestingly, the expression of genes for several thylakoid proteins was downregulated in the mutants, but the relative levels of the corresponding proteins were either not affected or could not be discerned. Based on these data, we propose that PHT4;1 plays an important role in chloroplast phosphate compartmentation and ATP synthesis, which affect plant growth. It also maintains the ionic environment of thylakoids, which affects the macro-organization of complexes and induction of photoprotective mechanisms.

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Functionally Important Amino Acids in the Arabidopsis Thylakoid Phosphate Transporter: Homology Modeling and Site-Directed Mutagenesis

Cited by 14 publications

References 43 publications

An update on the regulation of photosynthesis by thylakoid ion channels and transporters in Arabidopsis

An update on the regulation of photosynthesis by thylakoid ion channels and transporters in Arabidopsis

Function and evolution of channels and transporters in photosynthetic membranes

The Arabidopsis thylakoid transporter PHT4;1 influences phosphate availability for ATP synthesis and plant growth

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