title: Molecular cloning and expression profile analysis of a novel beta-D-N-acetylhexosaminidase of domestic silkworm (Bombyx mori).
abstract: Lepidoptera such as the domestic silkworm (Bombyx mori) produce proteins modified with unsialylated, mannose-rich moieties known as 'high mannose-type'N-glycans. However, we observed that, under intrinsic acetylglucosaminidase (GlcNAcase)-inhibited conditions, moth cells tend to synthesize different types of glycoform with sialic acid modification. To identify molecules essential to assemble Lepidoptera-specific N-glycans, we performed BLAST analysis on the silkworm genetic database and isolated the entire coding sequence of novel Bombyx GlcNAcase, BmGlcNAcase 2. This enzyme showed weak homology to currently known, lysosome-associated eukaryotic hexosaminidases, but it revealed remarkable similarity with recently reported glycosyl hydrolases of Spodoptera and Bombyx. Interestingly, BmGlcNAcase 2 was found to be expressed in embryos and in certain tissues of molting larvae (i.e. ovary, fat bodies, mid-intestine, skin), but not in pupae, suggesting its unique function in the carbohydrate metabolism of juvenile silkworm.
authors.affiliation: Advanced Biologicals, National Institute of Animal Health, NARO, 3-1-5 Kannondai, Tsukuba, Ibaraki 305-0856, Japan. takehiro@affrc.go.jp
authors.forename: Takehiro
authors.initials: T
authors.lastname: Kokuho
authors.forename: Yuji
authors.initials: Y
authors.lastname: Yasukochi
authors.forename: Satoko
authors.initials: S
authors.lastname: Watanabe
authors.forename: Shigeki
authors.initials: S
authors.lastname: Inumaru
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D012831:Bombyx / Q000201:enzymology* / Q000235:genetics; D003001:Cloning, Molecular; D020869:Gene Expression Profiling; D019476:Insect Proteins / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D007527:Isoenzymes / Q000145:classification / Q000235:genetics* / Q000378:metabolism; D008969:Molecular Sequence Data; D010802:Phylogeny; D016415:Sequence Alignment; D017386:Sequence Homology, Amino Acid; D001619:beta-N-Acetylhexosaminidases / Q000145:classification / Q000235:genetics* / Q000378:metabolism
chemical_list: D019476:Insect Proteins; D007527:Isoenzymes; D001619:beta-N-Acetylhexosaminidases