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Studies on the molecular mechanisms of dehydration tolerance have been largely limited to plants and invertebrates. Currently, research in whole body dehydration of complex animals is limited to cognitive and behavioral effects in humans, leaving the molecular mechanisms of vertebrate dehydration relatively unexplored. The present review summarizes studies to date on the African clawed frog (Xenopus laevis) and examines whole-body dehydration on physiological, cellular and molecular levels. This aquatic frog is exposed to seasonal droughts in its native habitat and can endure a loss of over 30% of its total body water. When coping with dehydration, osmoregulatory processes prioritize water retention in skeletal tissues and vital organs over plasma volume. Although systemic blood circulation is maintained in the vital organs and even elevated in the brain during dehydration, it is done so at the expense of reduced circulation to the skeletal muscles. Increased hemoglobin affinity for oxygen helps to counteract impaired blood circulation and metabolic enzymes show altered kinetic and regulatory parameters that support the use of anaerobic glycolysis. Recent studies with X. laevis also show that pro-survival pathways such as antioxidant defenses and heat shock proteins are activated in an organ-specific manner during dehydration. These pathways are tightly coordinated at the post-transcriptional level by non-coding RNAs, and at the post-translational level by reversible protein phosphorylation. Paired with ongoing research on the X. laevis genome, the African clawed frog is poised to be an ideal animal model with which to investigate the molecular adaptations for dehydration tolerance much more deeply.
6793 Natural Sciences and Engineering Research Council of Canada, Post-graduate scholarship Natural Sciences and Engineering Research Council of Canada, Molecular Physiology Canada Research Chairs, Ontario Graduate Scholarship Government of Ontario
Ali,
Isolation and characterization of a cDNA encoding a Xenopus 70-kDa heat shock cognate protein, Hsc70.I.
1996, Pubmed,
Xenbase
Ali,
Isolation and characterization of a cDNA encoding a Xenopus 70-kDa heat shock cognate protein, Hsc70.I.
1996,
Pubmed
,
Xenbase Balinsky,
Amino acid metabolism and urea synthesis in naturally aestivating Xenopus laevis.
1967,
Pubmed
,
Xenbase Bhattacharya,
STAT3-mediated transcription of Bcl-2, Mcl-1 and c-IAP2 prevents apoptosis in polyamine-depleted cells.
2005,
Pubmed Biggar,
Identification of a novel dehydration responsive gene, drp10, from the African clawed frog, Xenopus laevis.
2015,
Pubmed
,
Xenbase Bruey,
Hsp27 negatively regulates cell death by interacting with cytochrome c.
2000,
Pubmed Cajo,
The role of the DIF motif of the DnaJ (Hsp40) co-chaperone in the regulation of the DnaK (Hsp70) chaperone cycle.
2006,
Pubmed Childers,
Post-translational Regulation of Hexokinase Function and Protein Stability in the Aestivating Frog Xenopus laevis.
2016,
Pubmed
,
Xenbase Chung,
STAT3 serine phosphorylation by ERK-dependent and -independent pathways negatively modulates its tyrosine phosphorylation.
1997,
Pubmed Cowan,
Mitogen-activated protein kinases: new signaling pathways functioning in cellular responses to environmental stress.
2003,
Pubmed Feder,
Heat-shock proteins, molecular chaperones, and the stress response: evolutionary and ecological physiology.
1999,
Pubmed Gao,
Inhibition of miR-15a Promotes BDNF Expression and Rescues Dendritic Maturation Deficits in MeCP2-Deficient Neurons.
2015,
Pubmed Goldfarb,
Differential effects of Hsc70 and Hsp70 on the intracellular trafficking and functional expression of epithelial sodium channels.
2006,
Pubmed
,
Xenbase Jung,
Identification of aldo-keto reductases as NRF2-target marker genes in human cells.
2013,
Pubmed Kampinga,
The HSP70 chaperone machinery: J proteins as drivers of functional specificity.
2010,
Pubmed Katzenback,
Purification and characterization of a urea sensitive lactate dehydrogenase from the liver of the African clawed frog, Xenopus laevis.
2014,
Pubmed
,
Xenbase Lu,
Heat shock protein 70 interacts with aquaporin-2 and regulates its trafficking.
2007,
Pubmed Malik,
Transcriptional regulation of antioxidant enzymes by FoxO1 under dehydration stress.
2011,
Pubmed
,
Xenbase Malik,
Activation of antioxidant defense during dehydration stress in the African clawed frog.
2009,
Pubmed
,
Xenbase Moberg,
Site of action of endotoxins on hypothalamic-pituitary-adrenal axis.
1971,
Pubmed Moon,
Inhibition of microRNA-181 reduces forebrain ischemia-induced neuronal loss.
2013,
Pubmed Moreira,
Current Trends and Research Challenges Regarding "Preparation for Oxidative Stress".
2017,
Pubmed Session,
Genome evolution in the allotetraploid frog Xenopus laevis.
2016,
Pubmed
,
Xenbase Storey,
Stress response and adaptation: a new molecular toolkit for the 21st century.
2013,
Pubmed Storey,
Life in the slow lane: molecular mechanisms of estivation.
2002,
Pubmed Wu,
Regulation of the insulin-Akt signaling pathway and glycolysis during dehydration stress in the African clawed frog Xenopus laevis.
2017,
Pubmed
,
Xenbase Xu,
Post-stroke treatment with miR-181 antagomir reduces injury and improves long-term behavioral recovery in mice after focal cerebral ischemia.
2015,
Pubmed Yin,
Peroxisome proliferator-activated receptor delta regulation of miR-15a in ischemia-induced cerebral vascular endothelial injury.
2010,
Pubmed Zhang,
FoxO4 activity is regulated by phosphorylation and the cellular environment during dehydration in the African clawed frog, Xenopus laevis.
2018,
Pubmed
,
Xenbase Zhu,
Role of Nrf2 signaling in regulation of antioxidants and phase 2 enzymes in cardiac fibroblasts: protection against reactive oxygen and nitrogen species-induced cell injury.
2005,
Pubmed Zou,
Repression of heat shock transcription factor HSF1 activation by HSP90 (HSP90 complex) that forms a stress-sensitive complex with HSF1.
1998,
Pubmed
