scholarly journals Slow desiccation improves dehydration tolerance and accumulation of compatible osmolytes in earthworm cocoons (Dendrobaena octaedra Savigny)

2008 ◽  
Vol 211 (12) ◽  
pp. 1903-1910 ◽  
Author(s):  
C. R. Petersen ◽  
M. Holmstrup ◽  
A. Malmendal ◽  
M. Bayley ◽  
J. Overgaard
2001 ◽  
Vol 280 (2) ◽  
pp. C248-C253 ◽  
Author(s):  
Stephen C. Dahl ◽  
Joseph S. Handler ◽  
H. Moo Kwon

The accumulation of compatible osmolytes during osmotic stress is observed in virtually all organisms. In mammals, the hypertonicity-induced expression of osmolyte transporters and synthetic enzymes is conferred by the presence of upstream tonicity-responsive enhancer (TonE) sequences. Recently, we described the cloning and initial characterization of TonE-binding protein (TonEBP), a transcription factor that translocates to the nucleus and associates with TonE sequences in a tonicity-dependent manner. We now report that hypertonicity induces an increase in TonEBP phosphorylation that temporally correlates with increased nuclear localization of the molecule. TonEBP phosphorylation is not affected by a number of kinase inhibitors, including the p38 inhibitor SB-203580. In addition, in vitro binding assays show that the association of TonEBP with TonE sequences is not affected by phosphorylation. Thus TonEBP phosphorylation is an early step in the response of cells to hypertonicity and may be required for nuclear import or retention.


2015 ◽  
Vol 67 (3) ◽  
pp. 849-860
Author(s):  
Kyung Lee ◽  
Doo Moon ◽  
Sang Kang

Trehalose is a disaccharide molecule that serves as a natural osmotic regulator in halophilic microorganisms and plants but not in mammals. We observed that human HaCaT cells supplied with trehalose improved cell proliferation and extended viability under dehydration. In HaCaT cells, in response to increasing concentrations of exogenous trehalose, the levels of heat shock protein (HSP) 70 increased and matrix metalloproteinase (MMP) 1 decreased. Proteome analysis of trehalose-treated HaCaT cells revealed remarkable increases in the levels of proteins involved in cell signaling and the cell cycle, including p21 activated kinase I, Sec I family domain protein and elongation factor G. Moreover, the proteins for cell stress resistance, tryptophan hydroxylase, serine/cysteine proteinase inhibitors and vitamin D receptors were also increased. In addition, the proteins responsible for the maintenance of the cytoskeleton and cellular structures including procollagen-lysine dioxygenase, vinculin and ezrin were increased. Proteomic data revealed that trehalose affected HaCaT cells by inducing the proteins involved in cell proliferation. These results suggest that trehalose improves the proliferation and dehydration tolerance of HaCaT cells by inducing proteins involved in cell growth and dehydration protection.


2001 ◽  
Vol 204 (13) ◽  
pp. 2331-2338 ◽  
Author(s):  
Allen G. Gibbs ◽  
Luciano M. Matzkin

SUMMARYFruit flies of the genus Drosophila have independently invaded deserts around the world on numerous occasions. To understand the physiological mechanisms allowing these small organisms to survive and thrive in arid environments, we performed a phylogenetic analysis of water balance in Drosophila species from different habitats. Desert (cactophilic) species were more resistant to desiccation than mesic ones. This resistance could be accomplished in three ways: by increasing the amount of water in the body, by reducing rates of water loss or by tolerating the loss of a greater percentage of body water (dehydration tolerance). Cactophilic Drosophila lost water less rapidly and appeared to be more tolerant of low water content, although males actually contained less water than their mesic congeners. However, when the phylogenetic relationships between the species were taken into account, greater dehydration tolerance was not correlated with increased desiccation resistance. Therefore, only one of the three expected adaptive mechanisms, lower rates of water loss, has actually evolved in desert Drosophila, and the other apparently adaptive difference between arid and mesic species (increased dehydration tolerance) instead reflects phylogenetic history.


2018 ◽  
Vol 122 (2) ◽  
pp. 325-336 ◽  
Author(s):  
Florence Volaire ◽  
Frederic Lens ◽  
Hervé Cochard ◽  
Hueng Xu ◽  
Larissa Chacon-Doria ◽  
...  

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