scholarly journals Quantitative Proteomic Analyses Identify STO/BBX24 -Related Proteins Induced by UV-B

2020 ◽  
Vol 21 (7) ◽  
pp. 2496 ◽  
Author(s):  
Guizhen Lyu ◽  
Dongbing Li ◽  
Hui Xiong ◽  
Langtao Xiao ◽  
Jianhua Tong ◽  
...  
Keyword(s):  
Regulatory Network ◽  
Negative Regulator ◽  
Photochemical Quenching ◽  
Absolute Quantitation ◽  
Light Harvesting Complex ◽  
Extra Energy ◽  
In The Wild ◽  
Isobaric Tags ◽  
Non Photochemical Quenching ◽  
Related Proteins

Plants use solar radiation for photosynthesis and are inevitably exposed to UV-B. To adapt to UV-B radiation, plants have evolved a sophisticated strategy, but the mechanism is not well understood. We have previously reported that STO (salt tolerance)/BBX24 is a negative regulator of UV-B-induced photomorphogenesis. However, there is limited knowledge of the regulatory network of STO in UV-B signaling. Here, we report the identification of proteins differentially expressed in the wild type (WT) and sto mutant after UV-B radiation by iTRAQ (isobaric tags for relative and absolute quantitation)-based proteomic analysis to explore differential proteins that depend on STO and UV-B signaling. A total of 8212 proteins were successfully identified, 221 of them were STO-dependent proteins in UV-B irradiated plants. The abundances of STO-dependent PSB and LHC (light-harvesting complex) proteins in sto mutants decreased under UV-B radiation, suggesting that STO is necessary to maintain the normal accumulation of photosynthetic system complex under UV-B radiation to facilitate photosynthesis photon capture. The abundance of phenylalanine lyase-1 (PAL1), chalcone synthetase (CHS), and flavonoid synthetase (FLS) increased significantly after UV-B irradiation, suggesting that the accumulation of flavonoids do not require STO, but UV-B is needed. Under UV-B radiation, STO stabilizes the structure of antenna protein complex by maintaining the accumulation of PSBs and LHCs, thereby enhancing the non-photochemical quenching (NPQ) ability, releasing extra energy, protecting photosynthesis, and ultimately promoting the elongation of hypocotyl. The accumulation of flavonoid synthesis key proteins is independent of STO under UV-B radiation. Overall, our results provide a comprehensive regulatory network of STO in UV-B signaling.

scholarly journals Identification of parallel pH- and zeaxanthin-dependent quenching of excess energy in LHCSR3 in Chlamydomonas reinhardtii

2020 ◽  
Author(s):  
Julianne M. Troiano ◽  
Federico Perozeni ◽  
Raymundo Moya ◽  
Luca Zuliani ◽  
Kwangryul Baek ◽  
...  
Keyword(s):  
Chlamydomonas Reinhardtii ◽  
Light Harvesting ◽  
Complex Stress ◽  
Excess Energy ◽  
Photochemical Quenching ◽  
Light Harvesting Complexes ◽  
Light Harvesting Complex ◽  
Non Photochemical Quenching

AbstractUnder high light conditions, oxygenic photosynthetic organisms avoid photodamage by thermally dissipating excess absorbed energy, which is called non-photochemical quenching (NPQ). In green algae, a chlorophyll and carotenoid-binding protein, light-harvesting complex stress-related (LHCSR3), detects excess energy via pH and serves as a quenching site. However, the mechanisms by which LHCSR3 functions have not been determined. Using a combined in vivo and in vitro approach, we identify two parallel yet distinct quenching processes, individually controlled by pH and carotenoid composition, and their likely molecular origin within LHCSR3 from Chlamydomonas reinhardtii. The pH-controlled quenching is removed within a mutant LHCSR3 that lacks the protonable residues responsible for sensing pH. Constitutive quenching in zeaxanthin-enriched systems demonstrates zeaxanthin-controlled quenching, which may be shared with other light-harvesting complexes. We show that both quenching processes prevent the formation of damaging reactive oxygen species, and thus provide distinct timescales and mechanisms of protection in a changing environment.

scholarly journals Comparative Proteomic Analysis of Paulownia fortunei Response to Phytoplasma Infection with Dimethyl Sulfate Treatment

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Zhen Wei ◽  
Zhe Wang ◽  
Xiaoyu Li ◽  
Zhenli Zhao ◽  
Minjie Deng ◽  
...  
Keyword(s):  
Protein Interactions ◽  
Dimethyl Sulfate ◽  
Morphological Characteristics ◽  
Forest Tree ◽  
Protein Protein Interactions ◽  
Absolute Quantitation ◽  
Phytoplasma Infection ◽  
Paulownia Fortunei ◽  
Isobaric Tags ◽  
Related Proteins

Paulownia fortunei is a widely cultivated economic forest tree species that is susceptible to infection with phytoplasma, resulting in Paulownia witches’ broom (PaWB) disease. Diseased P. fortunei is characterized by stunted growth, witches’ broom, shortened internodes, and etiolated and smaller leaves. To understand the molecular mechanism of its pathogenesis, we applied isobaric tags for relative and absolute quantitation (iTRAQ) and liquid chromatography coupled with tandem mass spectrometry approaches to study changes in the proteomes of healthy P. fortunei, PaWB-infected P. fortunei, and PaWB-infected P. fortunei treated with 15 mg·L−1 or 75 mg·L−1 dimethyl sulfate. We identified 2969 proteins and 104 and 32 differentially abundant proteins that were phytoplasma infection responsive and dimethyl sulfate responsive, respectively. Based on our analysis of the different proteomes, 27 PaWB-related proteins were identified. The protein-protein interactions of these 27 proteins were analyzed and classified into four groups (photosynthesis-related, energy-related, ribosome-related, and individual proteins). These PaWB-related proteins may help in developing a deeper understanding of how PaWB affects the morphological characteristics of P. fortunei and further establish the mechanisms involved in the response of P. fortunei to phytoplasma.

scholarly journals Cell-free soluble expression of the membrane protein PsbS

2018 ◽  
Author(s):  
M. Krishnan ◽  
T.J.J.F. de Leeuw ◽  
A. Pandit
Keyword(s):  
Membrane Protein ◽  
Conformational Changes ◽  
Activation Mechanism ◽  
Spin Labels ◽  
Photochemical Quenching ◽  
Exchange Method ◽  
Light Harvesting Complex ◽  
Natural Amino Acids ◽  
Non Photochemical Quenching

AbstractPhotosystem II subunit S (PsbS) is a membrane protein that plays an exclusive role in non-photochemical quenching for photoprotection of plants under high-light conditions. The activation mechanism of PsbS and its pH-induced conformational changes are currently unknown. For structural investigation of PsbS, effective synthesis of PsbS with selective isotope or electron-spin labels or non-natural amino acids incorporated would be a great asset. This communication presents cell-free expression as a successful method for in vitro production of PsbS that would allow such incorporation. We have optimized the cell-free method to yield soluble PsbS of ~500 ng/µl using a continuous-exchange method at 30°C, along with a successful purification and refolding of PsbS in n-Dodecyl β-D-maltoside (β-DM) detergent. We expect that the presented protocols are transferrable for in vitro expression of other membrane proteins of the Light-Harvesting Complex family.

Proteomics Profiling of Plasma Exosomes in VKH Patients

2020 ◽  
Vol 20 ◽  
Author(s):  
Hao Zheng ◽  
Fuhua Yang ◽  
Vicki Ea ◽  
Lei Zhou ◽  
Lingzi Wu ◽  
...  
Keyword(s):  
Carbonic Anhydrase ◽  
Stationary Phase ◽  
Related Protein ◽  
Active Stage ◽  
Absolute Quantitation ◽  
Associated Proteins ◽  
Isobaric Tags ◽  
Pathway Analyses ◽  
Active Inflammation ◽  
Related Proteins

Objectives: Vogt-Koyanagi-Harada syndrome is a common autoimmune uveitis that can cause blindness. Recent studies have shown that plasma exosomes carry disease-related proteins that may serve as biomarkers. Here, we aimed to find candidate biomarkers of Vogt-Koyanagi-Harada disease using proteomic analysis of plasma exosomes. Methods: Exosomes were isolated from the plasma of normal controls and Vogt-Koyanagi-Harada patients in the following groups: a) initial inflammatory attack (active stage), b) remission after one month of treatment (unstable stage), and c) stationary phase after three months of treatment (stable stage). Groups were analyzed by mass spectrometry using isobaric tags for relative and absolute quantitation. After functional analysis, proteins of interest were verified by ELISA. Results: 463 proteins were identified in the exosomes. Forty-three were upregulated at the active inflammation stage, including inflammation-associated proteins. Thirty-one were downregulated. Gene ontology and pathway analyses revealed differential proteins related to cell adhesion, cell phagocytosis, cytoskeleton movement, leukocyte migration across endothelial cells, and platelet activation. By ELISA, Carbonic anhydrase 2 and Ras-related protein Rap-1b were verified as more plentiful at the active stage compared to the normal control and stationary phase in exosomes, but not, however, in microvesicles or plasma. Conclusion: Plasma exosomes of Vogt-Koyanagi-Harada patients contain many proteins related to the degree of inflammation. The levels of Carbonic anhydrase 2 and Ras-related protein Rap-1b in exosomes can be used as biomarkers for active inflammation in Vogt-Koyanagi-Harada disease. Further investigation could help study the pathogenesis of Vogt-KoyanagiHarada disease and identify therapeutic targets.

scholarly journals Genetic manipulation of carotenoid biosynthesis and photoprotection

2000 ◽  
Vol 355 (1402) ◽  
pp. 1395-1403 ◽  
Author(s):  
Barry J. Pogson ◽  
Heather M. Rissler
Keyword(s):  
Xanthophyll Cycle ◽  
Genetic Manipulation ◽  
Carotenoid Biosynthesis ◽  
Photochemical Quenching ◽  
Light Harvesting Complex ◽  
Photooxidative Damage ◽  
Lutein Content ◽  
Genetically Manipulated ◽  
Non Photochemical Quenching ◽  
Β Carotene

There are multiple complementary and redundant mechanisms to provide protection against photooxidative damage, including non–photochemical quenching (NPQ). NPQ dissipates excess excitation energy as heat by using xanthophylls in combination with changes to the light–harvesting complex (LHC) antenna. The xanthophylls are oxygenated carotenoids that in addition to contributing to NPQ can quench singlet or triplet chlorophyll and are necessary for the assembly and stability of the antenna. We have genetically manipulated the expression of the ε–cyclase and β–carotene hydroxylase carotenoid biosynthetic enzymes in Arabidopsis thaliana . The ε–cyclase overexpression confirmed that lut2 (lutein deficient) is a mutation in the ε–cyclase gene and demonstrated that lutein content can be altered at the level of mRNA abundance with levels ranging from 0 to 180% of wild–type. Also, it is clear that lutein affects the induction and extent of NPQ. The deleterious effects of lutein deficiency on NPQ in Arabidopsis and Chlamydomonas are additive, no matter what the genetic background, whether npq1 (zeaxanthin deficient), aba1 or antisense β–hydroxylase (xanthophyll cycle pool decreased). Additionally, increasing lutein content causes a marginal, but significant, increase in the rate of induction of NPQ despite a reduction in the xanthophyll cycle pool size.

scholarly journals The photo-inhibition of camphor leaves (Cinnamomum camphora L.) by NaCl stress based on physiological, chloroplast structure and comparative proteomic analysis

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9443
Author(s):  
Jiammin Yue ◽  
Dawei Shi ◽  
Liang Zhang ◽  
Zihan Zhang ◽  
Zhiyuan Fu ◽  
...  
Keyword(s):  
Eastern China ◽  
Nacl Stress ◽  
Photochemical Quenching ◽  
Cinnamomum Camphora ◽  
Absolute Quantitation ◽  
Photosynthetic Inhibition ◽  
Relative Quantum ◽  
Psii Photochemistry ◽  
Chlorophyll Protein ◽  
Isobaric Tags

Background The distribution and use of camphor (Cinnamomum camphora L.) trees are constrained by increasing soil salinity in south-eastern China along the Yangtze River. However, the response mechanism of this species to salinity, especially in team of photosynthesis, are unknown. Methods Here, we analysed themorphological, physiological, ultrastructural, and proteomic traits of camphor seedlings under NaCl (103.45 mM) treatment in pot experiments for 80 days. Results The growth was limited because of photosynthetic inhibition, with the most significant disturbance occurring within 50 days. Salinity caused severe reductions in the leaf photosynthetic rate (An), stomatal conductance (gs), maximal chlorophyll fluorescence (Fm), maximum quantum yield of PSII (Fv/Fm), non-photochemical quenching (NPQ), relative quantum efficiency of PSII photochemistry (ΦPSII), photochemical quenching coefficient (qP) and photo-pigment contents (chlorophyll a (Cha), chlorophyll b (Chb), total chlorophyll (Chl)); weakened the antioxidant effects, including those of malondialdehyde (MDA), superoxide dismutase (SOD) and peroxidase (POD); and injured chloroplasts. The physiologicalresults indicated that the main reason for photo-inhibition was oxidative factors induced by NaCl. The proteomic results based on isobaric tags for relative and absolute quantitation (iTRAQ) further confirmedthat photosynthesis was the most significant disrupted process by salinity (P < 0.01) and there were 30 downregulated differentially expression proteins (DEPs) and one upregulated DEP related to restraint of the photosynthetic system, which affected photosystem I, photosystem II, the Cytochrome b6/f complex, ATP synthase and the light-harvesting chlorophyll protein complex. In addition, 57 DEPs were related to photo-inhibition by redox effect and 6 downregulated DEPs, including O2 evolving complex 33kD family protein (gi—224094610) and five other predicted proteins (gi—743921083, gi—743840443, gi—743885735, gi—743810316 and gi—743881832) were directly affected. This study provides new proteomic information and explains the possible mechanisms of photo-inhibition caused by salinity on C. camphor.

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