The entire genomic sequence and cDNA expression of mouse α-galactosidase A

The full-length cDNA and genomic sequences encoding mouse α- galactosidase A (α-Gal A; EC 3.2.1.22), a lysosomal galactohydrolase, were isolated and characterized. The cDNA's open reading frame encoded 419 amino acids and had 82% nucleotide (nt) and 78% amino acid identity with the human sequence, although the carboxy terminus of the mouse α-Gal A polypeptide was 10 amino acids shorter. The functional integrity of the mouse cDNA was demonstrated by transient expression in COS-1 cells. Northern analysis revealed two mRNA species of about 1.6 and 3.4 kb due to alternative polyadenylation signals. The entire 14.4-kb mouse genomic sequence was determined; each of its seven exons was interrupted by intronic sequence at the identical positions as the exons in the human gene. The mouse 5' flanking region (250 nt) had one Sp1 site, five CAAT boxes, and no TATA box and had 67% identity with the human promoter region. The gene contained 18 complete or partial Alu-repetitive elements (13 type 1 and 5 type 2 repeats), and three putative functional AATAAA consensus polyadenylation signals were identified 72, 1668, and 1682 nt after the TAA termination codon. Use of the 72-nt site and the 1688 and/or 1662 sites were consistent with the shorter and longer transcripts. The availability of the full-length cDNA and genomic sequence encoding mouse α-Gal A should facilitate structure/function studies of this lysosomal glycosidase and the construction of α-Gal A-deficient mice by targeted gene disruption.