Akt and its downstream targets play key roles in mediating dormancy in land snails.
Comp Biochem Physiol B Biochem Mol Biol
; 148(3): 245-55, 2007 Nov.
Article
em En
| MEDLINE
| ID: mdl-17611133
ABSTRACT
Estivation, a state of aerobic dormancy, facilitates survival during adverse environmental conditions and is characterized at the molecular level by regulatory protein phosphorylation. The Akt (protein kinase B) signaling pathway regulates diverse responses in cells and the present study analyzes its role in the estivating desert snail Otala lactea. Kinetic analysis (maximal velocity, substrate affinities) determined that Akt was activated in tissues of estivating snails and Western blotting and in vitro incubations promoting changes to Akt phosphorylation state both confirmed that higher amounts of active (phosphorylated Ser473) Akt were present during estivation. Akt protein stability was also enhanced during estivation as assessed from urea denaturation studies. Multiple downstream targets of Akt were differentially regulated during estivation. Estivating animals showed elevated levels of phosphorylated FOXO3a (Ser253) and BAD (Ser136), no change in mTOR (Ser2481 and Ser2448), and reduced amounts of phosphorylated glycogen synthase kinase-3 (GSK-3) beta subunit (Ser9). Kinetic analysis of GSK-3 showed 1.5-1.7 fold higher activities in estivating snails coupled with increased GSK-3 substrate affinities in hepatopancreas. The data suggest an active role for Akt signaling during estivation emphasizing anti-apoptotic actions but uncoupling growth/proliferation actions to help achieve life extension on a limited energy budget.
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Base de dados:
MEDLINE
Assunto principal:
Caramujos
/
Proteínas Proto-Oncogênicas c-akt
Limite:
Animals
Idioma:
En
Revista:
Comp Biochem Physiol B Biochem Mol Biol
Assunto da revista:
BIOLOGIA MOLECULAR
/
BIOQUIMICA
Ano de publicação:
2007
Tipo de documento:
Article
País de afiliação:
Estados Unidos