RRC ID 3579
著者 Gutternigg M, Kretschmer-Lubich D, Paschinger K, Rendić D, Hader J, Geier P, Ranftl R, Jantsch V, Lochnit G, Wilson IB.
タイトル Biosynthesis of truncated N-linked oligosaccharides results from non-orthologous hexosaminidase-mediated mechanisms in nematodes, plants, and insects.
ジャーナル J Biol Chem
Abstract In many invertebrates and plants, the N-glycosylation profile is dominated by truncated paucimannosidic N-glycans, i.e. glycans consisting of a simple trimannosylchitobiosyl core often modified by core fucose residues. Even though they lack antennal N-acetylglucosamine residues, the biosynthesis of these glycans requires the sequential action of GlcNAc transferase I, Golgi mannosidase II, and, finally, beta-N-acetylglucosaminidases. In Drosophila, the recently characterized enzyme encoded by the fused lobes (fdl) gene specifically removes the non-reducing N-acetylglucosamine residue from the alpha1,3-antenna of N-glycans. In the present study, we examined the products of five beta-N-acetylhexosaminidase genes from Caenorhabditis elegans (hex-1 to hex-5, corresponding to reading frames T14F9.3, C14C11.3, Y39A1C.4, Y51F10.5, and Y70D2A.2) in addition to three from Arabidopsis thaliana (AtHEX1, AtHEX2, and AtHEX3, corresponding to reading frames At1g65590, At3g55260, and At1g05590). Based on homology, the Caenorhabditis HEX-1 and all three Arabidopsis enzymes are members of the same sub-family as the aforementioned Drosophila fused lobes enzyme but either act as chitotriosidases or non-specifically remove N-acetylglucosamine from both N-glycan antennae. The other four Caenorhabditis enzymes are members of a distinct sub-family; nevertheless, two of these enzymes displayed the same alpha1,3-antennal specificity as the fused lobes enzyme. Furthermore, a deletion of part of the Caenorhabditis hex-2 gene drastically reduces the native N-glycan-specific hexosaminidase activity in mutant worm extracts and results in a shift in the N-glycan profile, which is a demonstration of its in vivo enzymatic relevance. Based on these data, it is hypothesized that the genetic origin of paucimannosidic glycans in nematodes, plants, and insects involves highly divergent members of the same hexosaminidase gene family.
巻・号 282(38)
ページ 27825-40
公開日 2007-9-21
DOI 10.1074/jbc.M704235200
PII S0021-9258(20)58678-X
PMID 17636254
PMC PMC2850174
MeSH Amino Acid Sequence Animals Arabidopsis / metabolism Caenorhabditis elegans Carbohydrate Conformation Drosophila Hexosaminidases / chemistry Hydrogen-Ion Concentration Insecta Molecular Sequence Data Nematoda Oligosaccharides / chemistry* Plant Proteins / chemistry Plants / metabolism Sequence Homology, Amino Acid
IF 4.238
引用数 61
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY
リソース情報
線虫 tm2350 tm1992 tm2725