Molecular Mechanisms of Insect Immunity
Grant-in-Aid for Scientific Research (C)
|Allocation Type||Single-year Grants|
|Research Institution||Tottori University|
MORISHIMA Isao Faculty of Agriculture, Tottori University, Professor, 農学部, 教授 (30032296)
YAMANO Yoshiaki Faculty of Agriculture, Tottori University, Associate Professor, 農学部, 助教授 (00182593)
|Project Period (FY)
1997 – 1999
Completed(Fiscal Year 1999)
|Budget Amount *help
¥3,300,000 (Direct Cost : ¥3,300,000)
Fiscal Year 1999 : ¥700,000 (Direct Cost : ¥700,000)
Fiscal Year 1998 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1997 : ¥1,700,000 (Direct Cost : ¥1,700,000)
|Keywords||antibacterial protein / cecropin / lysozyme / attacin / peptidoglycan / insect immunity / silkworm / Eri-silkworm / 生体防御|
(1)Minimum structure of peptidoglycan required for the induction of antibacterial proteins.
Peptidoglycan fragments which differ in their peptide bridge structure or the chain length were prepared and tested for the inducing ability of antibacterial activity in the silkworm, Bombyx mori. The results indicated the silkworm recognized some definite structure of peptidoglycan, and the minimum structure was determined.
(2)Isolation and characterization of peptidoglycan recognition protein.
A peptidoglycan binding protein was isolated from immunized hemolymph of the silkworm larvae. The protein had a molecular weight of 37kd, and the N-terminal amino acid sequence so far determined had no homology to known proteins. The binding specificities and other characteristics of the protein showed the protein was the most possible for the candidate of the peptidoglycan recognition protein involved in the induction of antibacterial protein genes.
(3)Signal transduction system involved in the induction of
antibacterial protein genes.
Testing various inhibitors of the signal transduction for the effect on the induction of antibacterial genes by peptidoglycan, eicosanoids were found to be involved in the induction of the genes.
(4)Cloning and analysis of the promoter of cecropin genes.
Two cecropin A gene were cloned by screening the silkworm genome. A NF-κB binding motif was found in the promoter region of the two genes. The protein which specifically bound to the motif was detected only in the nuclear extract from immunized fat body.
(5)Detection and cloning of the gene induced by bacterial infection in the Eri-silkworm.
By means of differential display method, several bacteria-induced genes including cecropin and lysozyme were isolated from immunized fat body of the Eri-silkworm, Samia cynthia ricini.
(6)Protein isolation and cloning of attacin cDNA from Eri-silkworm.
Attacin, an antibacterial protein, was isolated from immunized hemolymph of the Eri-silkworm. The DNA fragment synthesized according to the N-terminal amino acid sequence of attacin was used as a probe, and the cDNA was cloned and sequenced. The sequence had high homology to the attacin from cecropia silkmoth. Less
Research Output (13results)