title: Molecular cloning and structural organization of the gene encoding the mouse lysosomal di-N-acetylchitobiase (ctbs).
abstract: The lysosomal enzyme di-N-acetylchitobiase hydrolyzes N-acetylglucosamine from the reducing-end of the N,N' diacetylchitobiose core of N-linked-oligosaccharides. The presence of chitobiase in the tissues of different species is probably responsible for differences in the structure of oligosaccharides accumulated in the lysosomal storage disease beta-mannosidosis. The disease has so far been described in humans, cats, cattle and goats. Low chitobiase activity has been observed in the tissues of ruminants and it has been hypothesized that in cattle this low level of expression is due to evolutionary changes in the promoter region. A cDNA encoding the mouse chitobiase has been isolated, sequenced and its identity confirmed by expression in COS-7 cells. Comparison of the mouse genomic sequence with the cDNA sequence revealed the presence of seven exons within the chitobiase gene. The gene spans about 15 kb and a single transcription initiation site was determined by 5'RACE. Chitobiase is differentially and ubiquitously expressed in mouse tissues as demonstrated by qRT-PCR analysis. Chitobiase is differentially expressed at lower levels in bovine tissues. In two bovine tissues (heart and muscle) mRNA was not detectable. Mouse and bovine promoters have been isolated and sequenced and their activities compared. The activity of the bovine promoter is very low and might explain the low activity of chitobiase observed in cattle.
authors.affiliation: Dipartimento di Medicina Interna, Università degli Studi di Perugia, Via del Giochetto 06126 Perugia, Italy.
authors.forename: Chiara
authors.initials: C
authors.lastname: Balducci
authors.forename: Lucia
authors.initials: L
authors.lastname: Bibi
authors.forename: Thomas
authors.initials: T
authors.lastname: Berg
authors.forename: Emanuele
authors.initials: E
authors.lastname: Persichetti
authors.forename: Roberto
authors.initials: R
authors.lastname: Tiribuzi
authors.forename: Sabata
authors.initials: S
authors.lastname: Martino
authors.forename: Silvia
authors.initials: S
authors.lastname: Paciotti
authors.forename: Rita
authors.initials: R
authors.lastname: Roberti
authors.forename: Aldo
authors.initials: A
authors.lastname: Orlacchio
authors.forename: Tommaso
authors.initials: T
authors.lastname: Beccari
mesh_terms: D000118:Acetylglucosaminidase / Q000235:genetics*; D000818:Animals; D001483:Base Sequence; D019556:COS Cells; D002417:Cattle; D002522:Chlorocebus aethiops; D003001:Cloning, Molecular; D008247:Lysosomes / Q000201:enzymology*; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D014162:Transfection
chemical_list: C530409:Ctbs protein, mouse; D000118:Acetylglucosaminidase