First Author | Monti E | Year | 2000 |
Journal | Biochem J | Volume | 349 |
Issue | Pt 1 | Pages | 343-51 |
PubMed ID | 10861246 | Mgi Jnum | J:63298 |
Mgi Id | MGI:1860728 | Doi | 10.1042/0264-6021:3490343 |
Citation | Monti E, et al. (2000) Identification and expression of NEU3, a novel human sialidase associated to the plasma membrane. Biochem J 349(Pt 1):343-51 |
abstractText | Several mammalian sialidases have been described so far, suggesting the existence of numerous polypeptides with different tissue distributions, subcellular localizations and substrate specificities. Among these enzymes, plasma-membrane-associated sialidase(s) have a pivotal role in modulating the ganglioside content of the lipid bilayer, suggesting their involvement in the complex mechanisms governing cell-surface biological functions. Here we describe the identification and expression of a human plasma-membrane-associated sialidase, NEU3, isolated starting from an expressed sequence tag (EST) clone. The cDNA for this sialidase encodes a 428-residue protein containing a putative transmembrane helix, a YRIP (single-letter amino acid codes) motif and three Asp boxes characteristic of sialidases. The polypeptide shows high sequence identity (78%) with the membrane-associated sialidase recently purified and cloned from Bos taurus. Northern blot analysis showed a wide pattern of expression of the gene, in both adult and fetal human tissues. Transient expression in COS7 cells permitted the detection of a sialidase activity with high activity towards ganglioside substrates at a pH optimum of 3.8. Immunofluorescence staining of the transfected COS7 cells demonstrated the protein's localization in the plasma membrane. |