THE HUMAN GLUCOSAMINE-6-PHOSPHATE DEAMINASE GENE - CDNA CLONING AND EXPRESSION, GENOMIC ORGANIZATION AND CHROMOSOMAL LOCALIZATION

When mammalian eggs are fertilized by sperm, a distinct series of calc ium oscillations are generated which serve as the essential trigger fo r egg activation and early embryo development. The identification of a soluble hamster sperm 33-kDa protein that co-migrated with calcium os cillation-inducing activity was recently described by Parrington et al . (Parrington, J., Swann, K., Shevchenko, V.I., Sesay, A.K. and Lai, F .A., 1996. Calcium oscillations in mammalian eggs triggered by a solub le sperm protein. Nature 379, 364-368). The hamster sperm 33 kDa prote in was termed oscillin because it correlated with calcium oscillation- inducing activity in mammalian eggs. Sequence analysis of the hamster sperm 33 kDa protein indicated no similarity to any known cell signall ing molecule, however, it displayed extensive homology with a bacteria l glucosamine-6-phosphate deaminase. We have isolated the correspondin g human testis homologue of the hamster sperm 33 kDa cDNA. Nucleotide sequence analysis reveals a high level of sequence identity between th e hamster and human genes. The deduced protein sequence of the human g ene also shares extensive amino acid identity with the bacterial gluco samine-6-phosphate deaminase enzyme. Heterologous expression of the hu man testis 33 kDa protein produced a glucosamine-6-phosphate deaminase activity. The genomic structure of the human glucosamine-6-phosphate deaminase has been mapped and the gene was localized by fluorescence i n situ hybridization (FISH) to chromosome 5q31. (C) 1998 Elsevier Scie nce B.V. All rights reserved.