Premium
cDNA cloning, characterization and gene expression of nitric oxide synthase from the silkworm, Bombyx mori
Author(s) -
Imamura M.,
Yang J.,
Yamakawa M.
Publication year - 2002
Publication title -
insect molecular biology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.955
H-Index - 93
eISSN - 1365-2583
pISSN - 0962-1075
DOI - 10.1046/j.1365-2583.2002.00333.x
Subject(s) - biology , bombyx mori , complementary dna , scylla paramamosain , manduca sexta , microbiology and biotechnology , drosophila melanogaster , malpighian tubule system , nitric oxide synthase , gene expression , molecular cloning , bombyx , gene , biochemistry , midgut , insect , enzyme , ecology , botany , larva
Molecular cloning and nucleotide sequencing of cDNA encoding Bombyx mori nitric oxide synthase (BmNOS) was conducted to analyse its possible role in insect immunity. The amino acid sequence deduced from the BmNOS cDNA showed 84%, 54% and 53% identity with those of NOSs from Manduca sexta , Drosophila melanogaster and Rhodonius prolixus . Recombinant BmNOS produced in insect cells using baculovirus was found to require NADPH, Ca 2+ , calmodulin and tetrahydrobiopterin (BH 4 ) for its activity. The BmNOS gene was constitutively expressed at a low level in the larval fat body, haemocyte, Malpighian tubule and midgut, and adult antenna, and induced strongly in the fat body by lipopolysaccharide (LPS), suggesting that the BmNOS gene plays different physiological roles in different tissues. Injection of NO donors that produce NO in vivo induced the gene expression of an antibacterial peptide, cecropin B, strongly suggesting that NO produced by BmNOS following LPS stimulation is involved in signal transduction as a signalling molecule for immune gene expression.