cDNA cloning of the murine PEX gene implicated in X-linked hypophosphatemia and evidence for expression in bone

Journal Article · Thu Aug 15 00:00:00 EDT 1996 · Genomics

DOI:https://doi.org/10.1006/geno.1996.0421· OSTI ID:484321

Du, L; Desbarats, M; Viel, J ^[1]

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1. McGill Univ., Montreal, Quebec (Canada); and others

The recently identified human PEX g ene apparently encodes for a neutral endopeptidase that is mutated in patients with X-linked hypophosphatemia. The 3{prime} and 5{prime} ends of the coding region of PEX have not been cloned, nor has the tissue expression of the gene been identified. Here we report the isolation and characterization of the complete open reading frame of the mouse Pex gene and the demonstration of its expression in bone. Mouse Pex cDNA is predicted to encode a protein of 749 amino acids with 95% identity to the available human PEX sequence and significant homology to members of the membrane-bound metalloendopeptidase family. Northern blot analysis revealed a 6.6-kb transcript in bone and in cultured osteoblasts from normal mice that was not detectable in samples from the Hyp mouse, the murine homolog of human X-linked hypophosphatemia. Pex transcripts were, however, detectable in Hyp bone by RT-PCR amplification. Of particular interest, a cDNA clone from rat incisor shows 93% sequence identity to the 5{prime} end of Pex cDNA, suggesting that Pex may be expressed in another calcified tissue, the tooth. The association of impaired mineralization of bone and teeth and disturbed renal phosphate reabsorption with altered expression of Pex suggests that the Pex gene product may play a critical role in these processes. 47 refs., 2 figs., 1 tab.

• OSTI ID: 484321
• Journal Information: Genomics, Vol. 36, Issue 1; Other Information: PBD: 15 Aug 1996
• Country of Publication: United States
• Language: English

Related Subjects

55 BIOLOGY AND MEDICINE
BASIC STUDIES
GENES
GENETIC MAPPING
DNA-CLONING
GENE REGULATION
TISSUE DISTRIBUTION
STRUCTURE-ACTIVITY RELATIONSHIPS
DNA SEQUENCING
TRANSCRIPTION
GENE MUTATIONS
MICE
HEREDITARY DISEASES
RICKETS
X CHROMOSOME
SKELETON
MINERALIZATION
TEETH
PHOSPHATES
UPTAKE
AMINO ACIDS
POLYMERASE CHAIN REACTION
NUCLEOTIDES