Cloning, characterization and mapping of the mouse trehalase (Treh) gene

Trehalase is the least studied of the membrane-bound alpha- glucosidase enz ymes. Here we report the isolation and characterization of the mouse trehal ase (Treh) gene. Initially. PCR using primers based on published rat cDNA s equence was used to clone a partial mouse cDNA. This allowed design of mous e primers which identified a single positive clone in a bacterial artificia l chromosome (BAC) library of mouse genomic DNA. Analysis of BAC subclones showed that the Treh structural gene spans approximately 13 kb and comprise s 15 exons. Data from genomic Southern blotting were consistent with mouse Treh being a single copy gene. The transcription initiation site was determ ined by both S1 nuclease mapping and 5' rapid amplification of cDNA ends (5 ' RACE) to be located 25 nt upstream of the ATG in exon 1. The mouse Treh e xons were found to have an open reading frame of 1728 nt and the encoded pr otein of 576 amino acids showed 81, 82 and 93% amino acid sequence identity with rabbit, human and rat trehalase, respectively. The trehalase signatur e sequence found at amino acids 162 to 175 had 100% identity with the corre sponding region of rabbit, human and rat and 79% identity with that for yea st trehalase. When a mouse Treh cDNA was used for Northern blot analysis of RNA from 12 mouse tissues, Treh mRNA expression was detected only in kidne y and small intestine. The size of the mRNA in both of these tissues was es timated to be approximately 2.1 kb, furthermore both tissues appear to have the same transcription initiation sire as determined by nuclease protectio n. Using the T31 radiation hybrid panel, mouse Treh was shown to be located on Chromosome 9 in a broad region that is orthologous with human Chromosom e 11q23. The human trehalase gene (TREH) was identified in the latter locat ion via database searching, which also revealed the overall structure of th e human gene as being similar to that of the mouse. (C) 2001 Elsevier Scien ce B.V. All rights reserved.