scholarly journals Demyristoylation of the Cytoplasmic Redox Protein Trx-h2 Is Critical for Inducing a Rapid Cold Stress Response in Plants

Antioxidants ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1287
Author(s):  
Eun Seon Lee ◽  
Joung Hun Park ◽  
Seong Dong Wi ◽  
Ho Byoung Chae ◽  
Seol Ki Paeng ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Cold Stress ◽  
Nuclear Translocation ◽  
Transgenic Arabidopsis ◽  
Wild Type ◽  
Warm Temperature ◽  
Acid Modification ◽  
Redox Protein ◽  
Cold Snap ◽  
Cor Genes

In Arabidopsis, the cytosolic redox protein thioredoxin h2 (Trx-h2) is anchored to the cytoplasmic endomembrane through the myristoylated second glycine residue (Gly2). However, under cold stress, the cytosolic Trx-h2 is rapidly translocated to the nucleus, where it interacts with and reduces the cold-responsive C-repeat-binding factors (CBFs), thus activating cold-responsive (COR) genes. In this study, we investigated the significance of fatty acid modification of Trx-h2 under cold conditions by generating transgenic Arabidopsis lines in the trx-h2 mutant background, overexpressing Trx-h2 (Trx-h2OE/trx-h2) and its point mutation variant Trx-h2(G/A) [Trx-h2(G/A)OE/trx-h2], in which the Gly2 was replaced by alanine (Ala). Due to the lack of Gly2, Trx-h2(G/A) was incapable of myristoylation, and a part of Trx-h2(G/A) localized to the nucleus even under warm temperature. As no time is spent on the demyristoylation and subsequent nuclear translocation of Trx-h2(G/A) under a cold snap, the ability of Trx-h2(G/A) to protect plants from cold stress was greater than that of Trx-h2. Additionally, COR genes were up-regulated earlier in Trx-h2(G/A)2OE/trx-h2 plants than in Trx-h2OE/trx-h2 plants under cold stress. Consequently, Trx-h2(G/A)2OE/trx-h2 plants showed greater cold tolerance than Col-0 (wild type) and Trx-h2OE/trx-h2 plants. Overall, our results clearly demonstrate the significance of the demyristoylation of Trx-h2 in enhancing plant cold/freezing tolerance.

scholarly journals Arabidopsis Disulfide Reductase, Trx-h2, Functions as an RNA Chaperone under Cold Stress

2021 ◽  
Vol 11 (15) ◽  
pp. 6865
Author(s):  
Eun Seon Lee ◽  
Joung Hun Park ◽  
Seong Dong Wi ◽  
Ho Byoung Chae ◽  
Seol Ki Paeng ◽  
...  
Keyword(s):  
Cold Stress ◽  
Wild Type ◽  
Rna Chaperone ◽  
E Coli ◽  
Cold Sensitive ◽  
Thioredoxin H ◽  
Functional Rnas

The thioredoxin-h (Trx-h) family of Arabidopsis thaliana comprises cytosolic disulfide reductases. However, the physiological function of Trx-h2, which contains an additional 19 amino acids at its N-terminus, remains unclear. In this study, we investigated the molecular function of Trx-h2 both in vitro and in vivo and found that Arabidopsis Trx-h2 overexpression (Trx-h2OE) lines showed significantly longer roots than wild-type plants under cold stress. Therefore, we further investigated the role of Trx-h2 under cold stress. Our results revealed that Trx-h2 functions as an RNA chaperone by melting misfolded and non-functional RNAs, and by facilitating their correct folding into active forms with native conformation. We showed that Trx-h2 binds to and efficiently melts nucleic acids (ssDNA, dsDNA, and RNA), and facilitates the export of mRNAs from the nucleus to the cytoplasm under cold stress. Moreover, overexpression of Trx-h2 increased the survival rate of the cold-sensitive E. coli BX04 cells under low temperature. Thus, our data show that Trx-h2 performs function as an RNA chaperone under cold stress, thus increasing plant cold tolerance.

scholarly journals Degradation of trinitrotoluene by transgenic nitroreductase in Arabidopsis plants

2018 ◽  
Vol 64 (No. 8) ◽  
pp. 379-385 ◽  
Author(s):  
Zhu Bo ◽  
Han Hongjuan ◽  
Fu Xiaoyan ◽  
Li Zhenjun ◽  
Gao Jianjie ◽  
...  
Keyword(s):  
Transgenic Plants ◽  
Transgenic Arabidopsis ◽  
Environmental Pollutant ◽  
Specific Rate ◽  
Wild Type Plant ◽  
Wild Type ◽  
Fresh Weight ◽  
Human Carcinogen ◽  
Specific Rate Constant ◽  
Nitroreductase Activity

The explosive 2,4,6-trinitrotoluene (TNT) is a highly toxic and persistent environmental pollutant. TNT is toxic to many organisms, it is known to be a potential human carcinogen, and is persistent in the environment. This study presents a system of phytoremediation by Arabidopsis plants developed on the basis of overexpression of NAD(P)H-flavin nitroreductase (NFSB) from the Sulfurimonas denitrificans DSM1251. The resulting transgenic Arabidopsis plants demonstrated significantly enhanced TNT tolerance and a strikingly higher capacity to remove TNT from their media. The highest specific rate constant of TNT disappearance rate was 1.219 and 2.297 mL/g fresh weight/h for wild type and transgenic plants, respectively. Meanwhile, the nitroreductase activity in transgenic plant was higher than wild type plant. All this indicates that transgenic plants show significantly enhanced tolerances to TNT; transgenic plants also exhibit strikingly higher capabilities of removing TNT from their media and high efficiencies of transformation.

scholarly journals Effects of Conjugated Linoleic Acid. 1. Fatty Acid Modification of Yolks and Neonatal Fatty Acid Metabolism

2000 ◽  
Vol 79 (6) ◽  
pp. 817-821 ◽  
Author(s):  
M.A. Latour ◽  
A.A. Devitt ◽  
R.A. Meunier ◽  
J.J. Stewart ◽  
B.A. Watkins
Keyword(s):  
Fatty Acid ◽  
Linoleic Acid ◽  
Conjugated Linoleic Acid ◽  
Fatty Acid Metabolism ◽  
Acid Metabolism ◽  
Acid Modification ◽  
Fatty Acid Modification

scholarly journals Spindle dynamics and cell cycle regulation of dynein in the budding yeast, Saccharomyces cerevisiae.

1995 ◽  
Vol 130 (3) ◽  
pp. 687-700 ◽  
Author(s):  
E Yeh ◽  
R V Skibbens ◽  
J W Cheng ◽  
E D Salmon ◽  
K Bloom
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Nuclear Translocation ◽  
Spindle Pole ◽  
Cell Cortex ◽  
Wild Type ◽  
Immunofluorescent Localization ◽  
Yeast Saccharomyces Cerevisiae ◽  
Spindle Dynamics ◽  
Spindle Elongation ◽  
Anaphase B

We have used time-lapse digital- and video-enhanced differential interference contrast (DE-DIC, VE-DIC) microscopy to study the role of dynein in spindle and nuclear dynamics in the yeast Saccharomyces cerevisiae. The real-time analysis reveals six stages in the spindle cycle. Anaphase B onset appears marked by a rapid phase of spindle elongation, simultaneous with nuclear migration into the daughter cell. The onset and kinetics of rapid spindle elongation are identical in wild type and dynein mutants. In the absence of dynein the nucleus does not migrate as close to the neck as in wild-type cells and initial spindle elongation is confined primarily to the mother cell. Rapid oscillations of the elongating spindle between the mother and bud are observed in wild-type cells, followed by a slower growth phase until the spindle reaches its maximal length. This stage is protracted in the dynein mutants and devoid of oscillatory motion. Thus dynein is required for rapid penetration of the nucleus into the bud and anaphase B spindle dynamics. Genetic analysis reveals that in the absence of a functional central spindle (ndcl), dynein is essential for chromosome movement into the bud. Immunofluorescent localization of dynein-beta-galactosidase fusion proteins reveals that dynein is associated with spindle pole bodies and the cell cortex: with spindle pole body localization dependent on intact microtubules. A kinetic analysis of nuclear movement also revealed that cytokinesis is delayed until nuclear translocation is completed, indicative of a surveillance pathway monitoring nuclear transit into the bud.

scholarly journals Cellular retinol-binding protein type III is a PPARγ target gene and plays a role in lipid metabolism

2008 ◽  
Vol 295 (6) ◽  
pp. E1358-E1368 ◽  
Author(s):  
Cynthia F. Zizola ◽  
Gary J. Schwartz ◽  
Silke Vogel
Keyword(s):  
Adipose Tissue ◽  
Fatty Acid ◽  
Lipid Metabolism ◽  
Free Fatty Acid ◽  
Target Gene ◽  
Binding Protein ◽  
Retinol Binding Protein ◽  
Wild Type ◽  
Type Iii ◽  
Cellular Retinol Binding Protein

Cellular retinol-binding protein (CRBP) type III (CRBP-III) belongs to the family of intracellular lipid-binding proteins, which includes the adipocyte-binding protein aP2. In the cytosol, CRBP-III binds retinol, the precursor of retinyl ester and the active metabolite retinoic acid. The goal of the present work is to understand the regulation of CRBP-III expression and its role in lipid metabolism. Using EMSAs, luciferase reporter assays, and chromatin immunoprecipitation assays, we found that CRBP-III is a direct target of peroxisome proliferator-activated receptor-γ (PPARγ). Moreover, CRBP-III expression was induced in adipose tissue of mice after treatment with the PPARγ agonist rosiglitazone. To examine a potential role of CRBP-III in regulating lipid metabolism in vivo, CRBP-III-deficient (C-III-KO) mice were maintained on a high-fat diet (HFD). Hepatic steatosis was decreased in HFD-fed C-III-KO compared with HFD-fed wild-type mice. These differences were partly explained by decreased serum free fatty acid levels and decreased free fatty acid efflux from adipose tissue of C-III-KO mice. In addition, the lack of CRBP-III was associated with reduced food intake, increased respiratory energy ratio, and altered body composition, with decreased adiposity and increased lean body mass. Furthermore, expression of genes involved in mitochondrial fatty acid oxidation in brown adipose tissue was increased in C-III-KO mice, and C-III-KO mice were more cold tolerant than wild-type mice fed an HFD. In summary, we demonstrate that CRBP-III is a PPARγ target gene and plays a role in lipid and whole body energy metabolism.

Two native types of phytochrome A, phyAʹ and phyAʺ, differ by the state of phosphorylation at the N-terminus as revealed by fluorescence investigations of the Ser/Ala mutant of rice phyA expressed in transgenic Arabidopsis

2018 ◽  
Vol 45 (2) ◽  
pp. 150 ◽  
Author(s):  
Vitaly A. Sineshchekov ◽  
Larissa A. Koppel ◽  
Cordelia Bolle
Keyword(s):  
Transgenic Arabidopsis ◽  
Emission Spectra ◽  
Total Content ◽  
The State ◽  
Serine Phosphorylation ◽  
Phytochrome A ◽  
Wild Type ◽  
Etiolated Seedlings ◽  
Pre Treatment

Phytochrome A (phyA) mediates different photoresponses what may be connected with the existence of its two types, phyAʹ and phyAʹʹ, differing by spectroscopic, photochemical and functional properties. We investigated a role of phyA phosphorylation in their formation turning to transgenic Arabidopsis thaliana (L. Heynh.) phyA or phyAphyB mutants overexpressing rice wild-type phyA (phyA WT) or mutant phyA (phyA SA) with the first 10 serines substituted by alanines. This prevents phyA phosphorylation at these sites and modifies photoresponses. Etiolated seedlings were employed and phyA parameters were evaluated with the use of low temperature fluorescence spectroscopy and photochemistry. Germination of seeds was induced by white light (WL) pre-treatment for 15 min or 3 h. Emission spectra of rice phyA WT and phyA SA were similar and their total content was comparable. However, the phyAʹ/phyAʹʹ proportion in phyA WT was high and varied with the duration of the WL pre-treatment, whereas in phyA SA it was substantially shifted towards phyAʹʹ and did not depend on the pre-illumination. This suggests that phyA SA comprises primarily or exclusively the phyAʹʹ pool and supports the notion that the two phyA types differ by the state of serine phosphorylation. phyAʹʹ was also found to be much more effective in the germination induction than phyAʹ.

Sign in / Sign up

Export Citation Format

Share Document