Mouse Beta-Mannosidase: cDNA Cloning, Expression, and Chromosomal Localization

β-mannosidase is an exoglycosidase involved in the degradation of N-linked oligosacharides moieties of glycoproteins. Lack of β-mannosidase activity leads to the lysosomal disorder β-mannosidosis (MIM 248510). We have isolated and sequenced the gene encoding the mouse β-mannosidase. Comparison of the deduced amino acid sequence of mouse, human, bovine, and goat β-mannosidase showed 64% identity, reflecting a high degree of evolutionary conservation. Analysis of a multiple tissue northern blotting revealed a major transcript of about 3.7 kb in all tissues examined. The northern analysis also demonstrates that there is differential tissue mRNA expression. The mouse β-mannosidase gene (Bmn) was mapped to the distal end of Chromosome (Chr) 3, in a region that is homologous with a segment of human Chr 4 containing the orthologous human gene.