Human lysosomal acid phosphatase: cloning, expression and chromosomal assignment

A 2112‐bp cDNA clone (lambda CT29) encoding the entire sequence of the human lysosomal acid phosphatase (EC 3.1.3.2) was isolated from a lambda gt11 human placenta cDNA library. The cDNA hybridized with a 2.3‐kb mRNA from human liver and HL‐60 promyelocytes. The gene for lysosomal acid phosphatase was localized to human chromosome 11. The cDNA includes a 12‐bp 5′ non‐coding region, an open reading frame of 1269 bp and an 831‐bp 3′ non‐coding region with a putative polyadenylation signal 25 bp upstream of a 3′ poly(A) tract. The deduced amino acid sequence reveals a putative signal sequence of 30 amino acids followed by a sequence of 393 amino acids that contains eight potential glycosylation sites and a hydrophobic region, which could function as a transmembrane domain. A 60% homology between the known 23 N‐terminal amino acid residues of human prostatic acid phosphatase and the N‐terminal sequence of lysosomal acid phosphatase suggests an evolutionary link between these two phosphatases. Insertion of the cDNA into the expression vector pSVL yielded a construct that encoded enzymatically active acid phosphatase in transfected monkey COS cells.