title: Characterization of nucleotide pyrophosphatase-5 as an oligomannosidic glycoprotein in rat brain.
abstract: Membrane glycoproteins of neural cells play crucial roles in axon guidance, synaptogenesis, and neuronal transmission. We have here characterized membrane glycoproteins containing terminal alpha-mannose residues in rat brain membranes. Affinity purification using Galanthus nivalis agglutinin, that is highly specific for terminal alpha-mannose residues, revealed a 50-kDa protein as well as 80-kDa SHPS-1 and 45-kDa beta2 subunit of Na,K-ATPase in rat brain membranes. Combination of N-terminal peptide sequencing and mass spectrometry indicated that the 50-kDa protein was rat nucleotide pyrophosphatase-5 (NPP-5). In contrast to other NPPs, NPP-5 was a type-I transmembrane protein. Northern blot analysis showed that NPP-5 was highly expressed in brain, but also expressed in other peripheral tissues. However, we could not detect either the NPP activity or the lysophospholipase D activity in the immunoprecipitates with antibodies to NPP-5 from rat brain membranes. These data, therefore, suggest that NPP-5 is a neural oligomannosidic glycoprotein that may participate in neural cell communications.
authors.affiliation: Biosignal Research Center, Institute for Molecular and Cellular Regulation, Gunma University, 3-39-15 Showa-Machi, Maebashi, Gunma 371-8512, Japan.
authors.forename: Yoshihide
authors.initials: Y
authors.lastname: Ohe
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Ohnishi
authors.forename: Hideki
authors.initials: H
authors.lastname: Okazawa
authors.forename: Kyoko
authors.initials: K
authors.lastname: Tomizawa
authors.forename: Hisae
authors.initials: H
authors.lastname: Kobayashi
authors.forename: Katsuya
authors.initials: K
authors.lastname: Okawa
authors.forename: Takashi
authors.initials: T
authors.lastname: Matozaki
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism; D002448:Cell Adhesion; D002450:Cell Communication; D002462:Cell Membrane / Q000378:metabolism*; D018076:DNA, Complementary / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D019281:Dimerization; D005982:Glutathione Transferase / Q000378:metabolism; D006023:Glycoproteins / Q000737:chemistry*; D006031:Glycosylation; D015151:Immunoblotting; D013058:Mass Spectrometry; D051379:Mice; D008969:Molecular Sequence Data; D009474:Neurons / Q000378:metabolism; D017830:Octoxynol / Q000494:pharmacology; D010455:Peptides; D010727:Phosphoric Diester Hydrolases / Q000737:chemistry; D011233:Precipitin Tests; D017434:Protein Structure, Tertiary; D011755:Pyrophosphatases / Q000737:chemistry* / Q000502:physiology*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D016622:Silver Staining; D000254:Sodium-Potassium-Exchanging ATPase / Q000737:chemistry; D014018:Tissue Distribution; D000099189:Lysophospholipase D
chemical_list: D018076:DNA, Complementary; D003902:Detergents; D005982:Glutathione Transferase; D006023:Glycoproteins; D017830:Octoxynol; D010455:Peptides; D010727:Phosphoric Diester Hydrolases; D011755:Pyrophosphatases; D011993:Recombinant Fusion Proteins; D000254:Sodium-Potassium-Exchanging ATPase; D000099189:Lysophospholipase D; C021899:nucleotide pyrophosphatase