Title of article :
AMP-activated protein kinase and metabolic regulation in cold-hardy insects
Author/Authors :
Rider، نويسنده , , Mark H. and Hussain، نويسنده , , Nusrat and Dilworth، نويسنده , , Stephen M. and Storey، نويسنده , , Janet M. and Storey، نويسنده , , Kenneth B.، نويسنده ,
Issue Information :
روزنامه با شماره پیاپی سال 2011
Pages :
10
From page :
1453
To page :
1462
Abstract :
Winter survival for many insects depends on cold hardiness adaptations as well as entry into a hypometabolic diapause state that minimizes energy expenditure. We investigated whether AMP-activated protein kinase (AMPK) could be involved in this adaptation in larvae of two cold-hardy insects, Eurosta solidaginis that is freeze tolerant and Epiblema scudderiana that uses a freeze avoidance strategy. AMPK activity was almost 2-fold higher in winter larvae (February) compared with animals collected in September. Immunoblotting revealed that phosphorylation of AMPK in the activation loop and phosphorylation of acetyl-CoA carboxylase (ACC), a key target of AMPK, were higher in Epiblema during midwinter whereas no seasonal change was seen in Eurosta. Immunoblotting also revealed a significant increase in ribosomal protein S6 phosphorylation in overwintering Epiblema larvae, and in both Eurosta and Epiblema, phosphorylation of eukaryotic initiation factor 4E-binding protein-1 dramatically increased in the winter. Pyruvate dehydrogenase (PDH) E1α subunit site 1 phosphorylation was 2-fold higher in extracts of Eurosta larvae collected in February versus September while PDH activity decreased by about 50% in Eurosta and 80% in February Eurosta larvae compared with animals collected in September. Glycogen phosphorylase phosphorylation was 3-fold higher in Epiblema larvae collected in February compared with September and also in these animals, triglyceride lipase activity increased by 70% during winter. Overall, our study suggests a re-sculpting of metabolism during insect diapause, which shifted to a more catabolic poise in freeze-avoiding overwintering Epiblema larvae, possibly involving AMPK.
Keywords :
Protein synthesis , Metabolic rate depression , AMPK , PDH , Glycogen phosphorylase , 4E-BP1 , Triglyceride lipase , rpS6
Journal title :
Journal of Insect Physiology
Serial Year :
2011
Journal title :
Journal of Insect Physiology
Record number :
1416507
Link To Document :
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