Click here to close Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly. We suggest using a current version of Chrome, FireFox, or Safari.
XB-ART-47831
Biol Open January 1, 2013; 2 (10): 1057-69.

Significant modulation of the hepatic proteome induced by exposure to low temperature in Xenopus laevis.

Nagasawa K , Tanizaki Y , Okui T , Watarai A , Ueda S , Kato T .


Abstract
The African clawed frog, Xenopus laevis, is an ectothermic vertebrate that can survive at low environmental temperatures. To gain insight into the molecular events induced by low body temperature, liver proteins were evaluated at the standard laboratory rearing temperature (22°C, control) and a low environmental temperature (5°C, cold exposure). Using nano-flow liquid chromatography coupled with tandem mass spectrometry, we identified 58 proteins that differed in abundance. A subsequent Gene Ontology analysis revealed that the tyrosine and phenylalanine catabolic processes were modulated by cold exposure, which resulted in decreases in hepatic tyrosine and phenylalanine, respectively. Similarly, levels of pyruvate kinase and enolase, which are involved in glycolysis and glycogen synthesis, were also decreased, whereas levels of glycogen phosphorylase, which participates in glycogenolysis, were increased. Therefore, we measured metabolites in the respective pathways and found that levels of hepatic glycogen and glucose were decreased. Although the liver was under oxidative stress because of iron accumulation caused by hepatic erythrocyte destruction, the hepatic NADPH/NADP ratio was not changed. Thus, glycogen is probably utilized mainly for NADPH supply rather than for energy or glucose production. In conclusion, X. laevis responds to low body temperature by modulating its hepatic proteome, which results in altered carbohydrate metabolism.

PubMed ID: 24167716
PMC ID: PMC3798189
Article link: Biol Open

Genes referenced: acss2.2 agl aldob ces3.7 cs fubp1 g6pd gak gbe1 gck gk gnpda1 gpd1 grhpr.1 gys1 ids pfkm pklr prkg1 pygl tkt tpi1


Article Images: [+] show captions
References [+] :
Aizawa, Expression of erythropoietin receptor-like molecule in Xenopus laevis and erythrocytopenia upon administration of its recombinant soluble form. 2005, Pubmed, Xenbase


Xenbase: The Xenopus laevis and X. tropicalis resource.
Version: 4.13.1
Major funding for Xenbase is provided by grant P41 HD064556