title: Cloning and characterization of a β-N-acetylglucosaminidase (BmFDL) from silkworm Bombyx mori.
abstract: In insects, β-N-acetylglucosaminidase (GlcNAcase) participates in critical physiological processes such as fertilization, metamorphosis, and glycoconjugate degradation. Insects produce glycoproteins carrying paucimannosidic-type N-glycans, the terminal GlcNAc residue of which is cleaved by a GlcNAc-linkage specific GlcNAcase, also known as the fused lobes (FDL) protein. To obtain information on the structure of GlcNAcases and insight into their contribution to physiological processes, we cloned Bombyx mori FDL (BmFDL) from silkworm larvae. The full-length cDNA (1.9 kb) encoded a protein of 633 amino acids with 42% amino acid sequence identity to Drosophila melanogaster FDL (DmFDL). Recombinant BmFDL cleaved only β-1,2-linked GlcNAc residues from the α-1,3 branch of biantennary N-glycan. This substrate specificity was similar to that of DmFDL. Microsomal FDL activity was inhibited by anti-BmFDL antibodies. Taken together, our results suggest that BmFDL is a N-glycan-processing GlcNAcase in B. mori.
authors.affiliation: Research Institute of Biological Science, Katakura industries CO., LTD., 1548 Simo-okutomi, Sayama, Saitama 350-1332, Japan. t.nomura@katakura.co.jp
authors.forename: Tsuyoshi
authors.initials: T
authors.lastname: Nomura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Ikeda
authors.forename: Seiji
authors.initials: S
authors.lastname: Ishiyama
authors.forename: Kazuhide
authors.initials: K
authors.lastname: Mita
authors.forename: Toshiki
authors.initials: T
authors.lastname: Tamura
authors.forename: Takahiro
authors.initials: T
authors.lastname: Okada
authors.forename: Kazuhito
authors.initials: K
authors.lastname: Fujiyama
authors.forename: Akihiro
authors.initials: A
authors.lastname: Usami
mesh_terms: D000118:Acetylglucosaminidase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D001483:Base Sequence; D012831:Bombyx / Q000201:enzymology*; D002240:Carbohydrate Sequence; D002851:Chromatography, High Pressure Liquid; D003001:Cloning, Molecular; D017931:DNA Primers; D018076:DNA, Complementary; D004591:Electrophoresis, Polyacrylamide Gel; D008969:Molecular Sequence Data; D011994:Recombinant Proteins / Q000737:chemistry / Q000235:genetics / Q000378:metabolism
chemical_list: D017931:DNA Primers; D018076:DNA, Complementary; D011994:Recombinant Proteins; D000118:Acetylglucosaminidase