Influence of thylakoid membrane lipids on the structure of aggregated light-harvesting complexes of the diatom Thalassiosira pseudonana and the green alga Mantoniella squamata

2017 ◽  
Vol 160 (3) ◽  
pp. 339-358 ◽  
Author(s):  
Susann Schaller-Laudel ◽  
Dariusz Latowski ◽  
Małgorzata Jemioła-Rzemińska ◽  
Kazimierz Strzałka ◽  
Sebastian Daum ◽  
...  
Keyword(s):  
Green Alga ◽  
Thylakoid Membrane ◽  
Light Harvesting ◽  
Membrane Lipids ◽  
Thalassiosira Pseudonana ◽  
Light Harvesting Complexes ◽  
Mantoniella Squamata

scholarly journals Optimization of light harvesting and photoprotection: molecular mechanisms and physiological consequences

2012 ◽  
Vol 367 (1608) ◽  
pp. 3455-3465 ◽  
Author(s):  
Peter Horton
Keyword(s):  
Protein Interactions ◽  
Thylakoid Membrane ◽  
Molecular Mechanisms ◽  
Light Harvesting ◽  
Protein Complexes ◽  
Efficient Energy Transfer ◽  
Light Harvesting Complexes ◽  
Functional Flexibility ◽  
Jan Anderson ◽  
Repulsive Forces

The distinctive lateral organization of the protein complexes in the thylakoid membrane investigated by Jan Anderson and co-workers is dependent on the balance of various attractive and repulsive forces. Modulation of these forces allows critical physiological regulation of photosynthesis that provides efficient light-harvesting in limiting light but dissipation of excess potentially damaging radiation in saturating light. The light-harvesting complexes (LHCII) are central to this regulation, which is achieved by phosphorylation of stromal residues, protonation on the lumen surface and de-epoxidation of bound violaxanthin. The functional flexibility of LHCII derives from a remarkable pigment composition and configuration that not only allow efficient absorption of light and efficient energy transfer either to photosystem II or photosystem I core complexes, but through subtle configurational changes can also exhibit highly efficient dissipative reactions involving chlorophyll–xanthophyll and/or chlorophyll–chlorophyll interactions. These changes in function are determined at a macroscopic level by alterations in protein–protein interactions in the thylakoid membrane. The capacity and dynamics of this regulation are tuned to different physiological scenarios by the exact protein and pigment content of the light-harvesting system. Here, the molecular mechanisms involved will be reviewed, and the optimization of the light-harvesting system in different environmental conditions described.

scholarly journals From isolated light-harvesting complexes to the thylakoid membrane: a single-molecule perspective

Nanophotonics ◽  
2018 ◽  
Vol 7 (1) ◽  
pp. 81-92 ◽  
Author(s):  
J. Michael Gruber ◽  
Pavel Malý ◽  
Tjaart P.J. Krüger ◽  
Rienk van Grondelle
Keyword(s):  
Single Molecule ◽  
Thylakoid Membrane ◽  
Light Harvesting ◽  
Protein Complexes ◽  
Conformational Dynamics ◽  
Physical Models ◽  
Photochemical Quenching ◽  
Light Harvesting Complexes ◽  
Fluorescence Measurements

AbstractThe conversion of solar radiation to chemical energy in plants and green algae takes place in the thylakoid membrane. This amphiphilic environment hosts a complex arrangement of light-harvesting pigment-protein complexes that absorb light and transfer the excitation energy to photochemically active reaction centers. This efficient light-harvesting capacity is moreover tightly regulated by a photoprotective mechanism called non-photochemical quenching to avoid the stress-induced destruction of the catalytic reaction center. In this review we provide an overview of single-molecule fluorescence measurements on plant light-harvesting complexes (LHCs) of varying sizes with the aim of bridging the gap between the smallest isolated complexes, which have been well-characterized, and the native photosystem. The smallest complexes contain only a small number (10–20) of interacting chlorophylls, while the native photosystem contains dozens of protein subunits and many hundreds of connected pigments. We discuss the functional significance of conformational dynamics, the lipid environment, and the structural arrangement of this fascinating nano-machinery. The described experimental results can be utilized to build mathematical-physical models in a bottom-up approach, which can then be tested on larger in vivo systems. The results also clearly showcase the general property of biological systems to utilize the same system properties for different purposes. In this case it is the regulated conformational flexibility that allows LHCs to switch between efficient light-harvesting and a photoprotective function.

Overexpression of Thalassiosira pseudonana violaxanthin de-epoxidase-like 2 (VDL2) increases fucoxanthin while stoichiometrically reducing diadinoxanthin cycle pigment abundance

2020 ◽  
Author(s):  
Olga Gaidarenko ◽  
Dylan W. Mills ◽  
Maria Vernet ◽  
Mark Hildebrand
Keyword(s):  
Light Harvesting ◽  
Photosynthetic Pigment ◽  
Carotenoid Biosynthesis ◽  
Thalassiosira Pseudonana ◽  
Physiological Data ◽  
Biosynthesis Pathway ◽  
Chloroplast Targeting ◽  
Light Harvesting Complexes ◽  
Carotenoid Biosynthesis Pathway ◽  
Transcriptomic Responses

ABSTRACTDespite the ubiquity and ecological importance of diatoms, much remains to be understood about their physiology and metabolism, including their carotenoid biosynthesis pathway. Early carotenoid biosynthesis steps are well-conserved, while the identity of the enzymes that catalyze the later steps and their order remain unclear. Those steps lead to the biosynthesis of the final pathway products: the main accessory light-harvesting pigment fucoxanthin (Fx) and the main photoprotective pigment pool comprised of diadinoxanthin (Ddx) and its reversibly de-epoxidized form diatoxanthin (Dtx). We used sequence comparison to known carotenoid biosynthesis enzymes to identify novel candidates in the diatom Thalassiosira pseudonana. Microarray and RNA-seq data was used to select candidates with transcriptomic responses similar to known carotenoid biosynthesis genes and to create full-length gene models, and we focused on those that encode proteins predicted to be chloroplast-localized. We identified a violaxanthin de-epoxidase-like gene (Thaps3_11707, VDL2) that when overexpressed results in increased Fx abundance while stoichiometrically reducing Ddx+Dtx. Based on transcriptomics, we hypothesize that Thaps3_10233 may also contribute to Fx biosynthesis, in addition to VDL2. Separately using antisense RNA to target VDL2, VDL1, and both LUT1-like copies (hypothesized to catalyze an earlier step in the pathway) simultaneously, reduced the overall cellular photosynthetic pigment content, including chlorophylls, suggesting destabilization of light-harvesting complexes by Fx deficiency. Based on transcriptomic and physiological data, we hypothesize that the two predicted T. pseudonana zeaxanthin epoxidases have distinct functions and that different copies of phytoene synthase and phytoene desaturase may serve to initiate carotenoid biosynthesis in response to different cellular needs. Finally, nine carotene cis/trans isomerase (CRTISO) candidates identified based on sequence identity to known CRTISO proteins were narrowed to two most likely to be part of the T. pseudonana carotenoid biosynthesis pathway based on transcriptomic responses and predicted chloroplast targeting.

scholarly journals Revealing the architecture of the photosynthetic apparatus in the diatom Thalassiosira pseudonana

2021 ◽  
Author(s):  
Rameez Arshad ◽  
Claudio Calvaruso ◽  
Egbert J Boekema ◽  
Claudia Büchel ◽  
Roman Kouřil
Keyword(s):  
Carbon Fixation ◽  
Light Harvesting ◽  
Electron Tomography ◽  
Three Dimensional ◽  
Photosynthetic Apparatus ◽  
Volume Averaging ◽  
Adaptation Strategy ◽  
Thalassiosira Pseudonana ◽  
Diatom Species ◽  
Light Harvesting Complexes

Abstract Diatoms are a large group of marine algae that are responsible for about one-quarter of global carbon fixation. Light-harvesting complexes of diatoms are formed by the fucoxanthin chlorophyll a/c proteins and their overall organization around core complexes of photosystem (PS) I and II is unique in the plant kingdom. Using cryo-electron tomography, we have elucidated the structural organization of PSII and PSI supercomplexes and their spatial segregation in the thylakoid membrane of the model diatom species Thalassiosira pseudonana. Three-dimensional sub-volume averaging revealed that the PSII supercomplex of Thalassiosira pseudonana incorporates a trimeric form of light-harvesting antenna, which differs from the tetrameric antenna observed previously in another diatom, Chaetoceros gracilis. Surprisingly, the organization of the PSI supercomplex is conserved in both diatom species. These results strongly suggest that different diatom classes have various architectures of PSII as an adaptation strategy, whilst a convergent evolution occurred concerning PSI and the overall plastid structure.

Assembly Apparatus of Light-Harvesting Complexes; Identification of Alb3.1-cpSRP-LHCP Complexes in the Green Alga Chlamydomonas reinhardtii

2021 ◽  
Author(s):  
Mithun Kumar Rathod ◽  
Nellaipalli Sreedhar ◽  
Shin-ichiro Ozawa ◽  
Hiroshi Kuroda ◽  
Natsumi Kodama ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Green Alga ◽  
Light Harvesting ◽  
Affinity Purification ◽  
Signal Recognition Particle ◽  
Thylakoid Membranes ◽  
Signal Recognition ◽  
Light Harvesting Complexes ◽  
C Terminus ◽  
Unicellular Green Alga

Abstract The unicellular green alga, Chlamydomonas reinhardtii, contains many light-harvesting complexes (LHCs) associating chlorophylls a/b and carotenoids; the major light-harvesting complexes, LHCIIs (types I, II, III, and IV), and minor light-harvesting complexes, CP26 and CP29, for photosystem II, as well as nine light-harvesting complexes, LHCIs (LHCA1-9), for photosystem I. A pale green mutant BF4 exhibited impaired accumulation of LHCs due to deficiency in Alb3.1 gene which encodes the insertase involved in insertion, folding and assembly of LHC proteins in the thylakoid membranes. To elucidate the molecular mechanism by which ALB3.1 assists LHC assembly, we complemented BF4 to express ALB3.1 fused with no, single, or triple HA tag at its C-terminus (cAlb3.1, cAlb3.1-HA, or cAlb3.1-3HA). The resulting complemented strains accumulated most LHC proteins comparable to wild-type levels. The affinity purification of Alb3.1-HA and Alb3.1-3HA preparations showed that ALB3.1 interacts with cpSRP43 and cpSRP54 proteins of chloroplast signal recognition particle cpSRP and several LHC proteins; two major LHCII proteins (types I and III), two minor LHCII proteins (CP26 and CP29), and eight LHCI proteins (LHCA1, 2, 3, 4, 5, 6, 8, and 9). Pulse-chase labeling experiments revealed that the newly synthesized major LHCII proteins were transiently bound to the Alb3.1 complex. We propose that Alb3.1 interacts with cpSRP43 and cpSRP54 to form an assembly apparatus for most LHCs in the thylakoid membranes. Interestingly, PSI proteins were also detected in the Alb3.1 preparations, suggesting that the integration of LHCIs to a PSI core complex to form a PSI-LHCI subcomplex occurs before assembled LHCIs dissociate from the Alb3.1-cpSRP complex.

scholarly journals Functional and mutational analysis of the light-harvesting chlorophyll a/b protein of thylakoid membranes.

1986 ◽  
Vol 102 (3) ◽  
pp. 972-981 ◽  
Author(s):  
B D Kohorn ◽  
E Harel ◽  
P R Chitnis ◽  
J P Thornber ◽  
E M Tobin
Keyword(s):  
Chlorophyll A ◽  
Thylakoid Membrane ◽  
Mutational Analysis ◽  
Light Harvesting ◽  
Chlorophyll Biosynthesis ◽  
Thylakoid Membranes ◽  
Stable Complex ◽  
Coding Region ◽  
Light Harvesting Complexes ◽  
Lhc Ii

The precursor for a Lemna light-harvesting chlorophyll a/b protein (pLHCP) has been synthesized in vitro from a single member of the nuclear LHCP multigene family. We report the sequence of this gene. When incubated with Lemna chloroplasts, the pLHCP is imported and processed into several polypeptides, and the mature form is assembled into the light-harvesting complex of photosystem II (LHC II). The accumulation of the processed LHCP is enhanced by the addition to the chloroplasts of a precursor and a co-factor for chlorophyll biosynthesis. Using a model for the arrangement of the mature polypeptide in the thylakoid membrane as a guide, we have created mutations that lie within the mature coding region. We have studied the processing, the integration into thylakoid membranes, and the assembly into light-harvesting complexes of six of these deletions. Four different mutant LHCPs are found as processed proteins in the thylakoid membrane, but only one appears to have an orientation in the membrane that is similar to that of the wild type. No mutant LHCP appears in LHC II. The other two mutant LHCPs cannot be detected within the chloroplasts. We conclude that stable complex formation is not required for the processing and insertion of altered LHCPs into the thylakoid membrane. We discuss the results in light of our model.

Reconstitution of Light-Harvesting Complexes from Chlorella fusca (Chlorophyceae) and Mantoniella squamata (Prasinophyceae)

1993 ◽  
Vol 48 (5-6) ◽  
pp. 461-473 ◽  
Author(s):  
Monika Meyer ◽  
Christian Wilhelm
Keyword(s):  
Light Harvesting ◽  
Higher Plants ◽  
Binding Capacity ◽  
High Specificity ◽  
Chlorella Fusca ◽  
Light Harvesting Complexes ◽  
Modified Method ◽  
Green Alga Chlorella ◽  
High Flexibility ◽  
Mantoniella Squamata

Abstract Reconstitution experiments of light-harvesting complexes were performed with the green alga Chlorella fusca and the chlorophyll c-containing prasinophyte Mantoniella squamata using a modified method according to Plumley and Schmidt [Proc. N atl. Acad. Sei. U .S.A . 84, 146 -150 (1987)]. Changing the pigment supply quantitatively or qualitatively in the reconsti­tution mixture homologous and heterologous reconstitutes were obtained. In contrast to higher plants, light-harvesting polypeptides from green algae are able to bind the chlorophylls as well as the xanthophylls in different stoichiometries. Heterologous reconstitutes of M . squamata polypeptides give further evidence for a rather high flexibility of pigment recog­nition and binding. This is the first report of successful reconstitution of a chlorophyll c-binding protein. Contrary to chlorophyll c-less light-harvesting complexes, the reconstitution of M . squamata is strongly pH-controlled. In summary, the results give evidence for a high specificity of porphyrin ring recognition and variability in xanthophyll binding capacity. Therefore, it is suggested that at least in algal light-harvesting proteins chlorophyll organiza­tion may be determined by other mechanisms than xanthophyll binding.

Sign in / Sign up

Export Citation Format

Share Document