Molecular and structural analyses of a novel temperature stress‐induced lipocalin from wheat and <i>Arabidopsis</i>

Charron, Jean; Breton, Ghislaı̀n; Badawi, Mohamed; Sarhan, Fathey

doi:10.1016/s0014-5793(02)02606-6

Cited by 69 publications

(49 citation statements)

References 23 publications

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“…We found the lipocalin-like protein particularly intriguing, because it was not regulated in salt-stressed or osmotically stressed Arabidopsis (Kilian et al, 2007), whereas other members of this gene family are stress responsive, especially under low temperatures (Frenette Charron et al, 2005). Lipocalins are most likely localized in the plasma membrane (Kawamura and Uemura, 2003), bind small hydrophobic ligands, act as transporters, and protect plants from oxidative stress (Frenette Charron et al, 2002;Charron et al, 2008). We used loss-of-function mutants of Arabidopsis to test the involvement of TIL and SIS, a salt-regulated unknown gene in salt tolerance.…”

Section: Stress Acclimation Involves a Redirection Of Protein Metabolmentioning

confidence: 96%

Linking the Salt Transcriptome with Physiological Responses of a Salt-Resistant Populus Species as a Strategy to Identify Genes Important for Stress Acclimation

et al. 2010

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To investigate early salt acclimation mechanisms in a salt-tolerant poplar species (Populus euphratica), the kinetics of molecular, metabolic, and physiological changes during a 24-h salt exposure were measured. Three distinct phases of salt stress were identified by analyses of the osmotic pressure and the shoot water potential: dehydration, salt accumulation, and osmotic restoration associated with ionic stress. The duration and intensity of these phases differed between leaves and roots. Transcriptome analysis using P. euphratica-specific microarrays revealed clusters of coexpressed genes in these phases, with only 3% overlapping salt-responsive genes in leaves and roots. Acclimation of cellular metabolism to high salt concentrations involved remodeling of amino acid and protein biosynthesis and increased expression of molecular chaperones (dehydrins, osmotin). Leaves suffered initially from dehydration, which resulted in changes in transcript levels of mitochondrial and photosynthetic genes, indicating adjustment of energy metabolism. Initially, decreases in stress-related genes were found, whereas increases occurred only when leaves had restored the osmotic balance by salt accumulation. Comparative in silico analysis of the poplar stress regulon with Arabidopsis (Arabidopsis thaliana) orthologs was used as a strategy to reduce the number of candidate genes for functional analysis. Analysis of Arabidopsis knockout lines identified a lipocalin-like gene (AtTIL) and a gene encoding a protein with previously unknown functions (AtSIS) to play roles in salt tolerance. In conclusion, by dissecting the stress transcriptome of tolerant species, novel genes important for salt endurance can be identified.

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Section: Stress Acclimation Involves a Redirection Of Protein Metabolmentioning

confidence: 96%

Linking the Salt Transcriptome with Physiological Responses of a Salt-Resistant Populus Species as a Strategy to Identify Genes Important for Stress Acclimation

et al. 2010

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“…LCNP belongs to the group of true lipocalins, as it contains three SCRs (Figure 3). In the Arabidopsis genome (or other land plants), there is another true lipocalin, TIL (for temperatureinduced lipocalin; Frenette Charron et al, 2002), which locates to different cell membranes and organelles (but not the chloroplast), depending on growth conditions (Charron et al, 2005;Hernández-Gras and Boronat, 2015). TIL and LCNP play a role during abiotic stress and have overlapping functions in protecting against lipid peroxidation (Boca et al, 2014), but their mechanism of action is unknown.…”

Section: Function Of Lcnp In Npqmentioning

confidence: 99%

The Plastid Lipocalin LCNP Is Required for Sustained Photoprotective Energy Dissipation in Arabidopsis

et al. 2017

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Light utilization is finely tuned in photosynthetic organisms to prevent cellular damage. The dissipation of excess absorbed light energy, a process termed nonphotochemical quenching (NPQ), plays an important role in photoprotection. Little is known about the sustained or slowly reversible form(s) of NPQ and whether they are photoprotective, in part due to the lack of mutants. The Arabidopsis thaliana suppressor of quenching1 (soq1) mutant exhibits enhanced sustained NPQ, which we term qH. To identify molecular players involved in qH, we screened for suppressors of soq1 and isolated mutants affecting either chlorophyllide a oxygenase or the chloroplastic lipocalin, now renamed plastid lipocalin (LCNP). Analysis of the mutants confirmed that qH is localized to the peripheral antenna (LHCII) of photosystem II and demonstrated that LCNP is required for qH, either directly (by forming NPQ sites) or indirectly (by modifying the LHCII membrane environment). qH operates under stress conditions such as cold and high light and is photoprotective, as it reduces lipid peroxidation levels. We propose that, under stress conditions, LCNP protects the thylakoid membrane by enabling sustained NPQ in LHCII, thereby preventing singlet oxygen stress.

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“…TaTIL transcripts and proteins are upregulated during stresses out a 4-day in vitro culture period, following cryopreservation of hepatocytes. such as cold and heat shock, which are known to induce membrane damage (8,15). Thus, TaTIL is likely to protect…”

Section: +mentioning

confidence: 99%

Wheat Proteins Enhance Stability and Function of Adhesion Molecules in Cryopreserved Hepatocytes

et al. 2009

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Cryopreserved hepatocytes with good hepatospecific functions upon thawing are important for clinical transplantation and for in vitro drug toxicity testing. However, cryopreservation reduces viability and certain hepatospecific functions, but the most pronounced change is diminished attachment efficiency of hepatocytes. Adhesion of cells to the extracellular matrix and cell-cell contacts are crucial for many aspects of cellular function. These processes are partly mediated and controlled by cellular adhesion molecules. The mechanisms responsible for reduced attachment efficiency of cryopreserved hepatocytes are not well understood. To address this question, we investigated the effect of a new cryopreservation procedure, using wheat proteins (WPs) or mixtures of recombinant forms of wheat freezing tolerance-associated proteins, on the stability of three important adhesion molecules (β1-integrin, E-cadherin, and β-catenin). Immunoblot analyses revealed that the levels of β1-integrin, E-cadherin, and β-catenin were much lower in cryopreserved rat hepatocytes, when compared to fresh cells. Protein expression of the adhesion molecules was generally lower in cells cryopreserved with DMSO, compared to WPs. Moreover, the stability of the adhesion molecules was not affected by cryopreservation to the same degree, with more pronounced decreases occurring for β1-integrin (62-74%) > β-catenin (51-58%) > E-cadherin (21-37%). However, when hepatocytes were cryopreserved with partially purified WPs (SulWPE, AcWPE) or with mixtures of recombinant wheat proteins, there was a clear protective effect against the loss of protein expression of β1-integrin, E-cadherin, and β-catenin. Protein expression was only 10-20% lower than that observed in fresh hepatocytes. These findings clearly demonstrate that WPs, and more particularly, partially purified WPs and recombinant wheat proteins, were more efficient for cryopreservation of rat hepatocytes by maintaining good expression of these adhesion molecules. These promising results could lead to a new and improved cryopreservation technology for applications such as clinical transplantation of hepatocytes.

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Molecular and structural analyses of a novel temperature stress‐induced lipocalin from wheat and Arabidopsis

Abstract: Two cDNAs corresponding to a novel lipocalin were identified from wheat and Arabidopsis. The two cDNAs designated Tatil

Cited by 69 publications

References 23 publications

Linking the Salt Transcriptome with Physiological Responses of a Salt-Resistant Populus Species as a Strategy to Identify Genes Important for Stress Acclimation

Linking the Salt Transcriptome with Physiological Responses of a Salt-Resistant Populus Species as a Strategy to Identify Genes Important for Stress Acclimation

The Plastid Lipocalin LCNP Is Required for Sustained Photoprotective Energy Dissipation in Arabidopsis

Wheat Proteins Enhance Stability and Function of Adhesion Molecules in Cryopreserved Hepatocytes

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