Identification of Bombyx mori Akt and its phosphorylation by bombyxin stimulation.

Abstract

Akt, a Ser/Thr protein kinase involved in insulin signaling, was identified from the silkworm, Bombyx mori. Bombyx Akt (BomAkt) is composed of 493 amino acid residues including regions conserved in other Akts: the Pleckstrin homology and kinase domains, and a dual phosphorylation site essential for kinase activation. Commercially available antibodies against mammalian Akt and phosphoAkt were able to recognize BomAkt and phosphorylated BomAkt in HEK293 cells expressing BomAkt. Additionally, phosphorylation of BomAkt was detectable in insulin-like growth factor (IGF)-I stimulated-HEK293 cells expressing BomAkt. RT-PCR and immunoblotting analyses revealed that BomAkt is expressed ubiquitously in Bombyx larvae. Phosphorylation of BomAkt was observed both in the isolated fat body after exposure to bombyxin, an endogenous insulin-like peptide, and in the larval fat body by refeeding a diet after starvation. These results suggest that dietary intake may activate the insulin signaling pathway, including Akt, through bombyxin action in B. mori.

• Authors: Shinji Nagata, Fumihiko Hakuno, Shin-Ichiro Takahashi, Hiromichi Nagasawa
• Journal: Comparative biochemistry and physiology. Part B, Biochemistry & molecular biology (Comp Biochem Physiol B Biochem Mol Biol) Vol. 151 Issue 3 Pg. 355-60 (Nov 2008) ISSN: 1096-4959 [Print] England
• PMID: 18760376 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Proto-Oncogene Proteins c-akt

Topics

• Amino Acid Sequence
• Animals
• Bombyx (metabolism)
• Cell Line
• Fat Body (metabolism)
• Humans
• Larva (metabolism)
• Molecular Sequence Data
• Phosphorylation
• Proto-Oncogene Proteins c-akt (genetics, metabolism)
• Signal Transduction