Molecular cloning of murine pig-a, a gene for GPI-anchor biosynthesis, and demonstration of interspecies conservation of its structure, function, and genetic locus.
Many membrane proteins are anchored to the cell membrane by glycosylphosphatidylinositol (GPI). The core structure and biosynthesis of the GPI anchor are well conserved in eukaryote cells. We previously cloned a human PIGA gene that participates in GPI anchor biosynthesis. We have now cloned complementary and genomic DNA of Pig-a, the murine homologue of PIGA, and compared its function and gene structure with those of PIGA. The deduced amino acid sequence of mouse PIG-A is 88% identical with that of human PIG-A. Transfection of Pig-a cDNA complemented the defects of both a PIG-A-deficient murine cell line and a PIG-A-deficient human cell line, demonstrating that functions of mouse and human PIG-A are conserved. Like human PIGA, the chromosomal Pig-a gene has six exons and spans approximately 16 kb. Moreover, Pig-a was mapped to X-F3/4, which is syntenic to human Xp22.1, where PIGA is located. Thus, murine Pig-a provides a good animal model to study paroxysmal nocturnal hemoglobinuria, a disease caused by a somatic mutation of PIGA. Database analysis demonstrated that a yeast gene, SPT14, is homologous to Pig-a and PIGA and that these genes are members of a glycosyltransferase gene family.
Department of Immunoregulation, Osaka University, Japan.
K
K
Kawagoe
J
J
Takeda
Y
Y
Endo
T
T
Kinoshita
D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D002874:Chromosome Mapping; D003001:Cloning, Molecular; D017124:Conserved Sequence; D005091:Exons; D005656:Fungal Proteins / Q000235:genetics; D005816:Genetic Complementation Test; D017261:Glycosylphosphatidylinositols / Q000096:biosynthesis*; D016695:Glycosyltransferases / Q000235:genetics; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D008565:Membrane Proteins / Q000096:biosynthesis / Q000235:genetics*; D051379:Mice / Q000235:genetics*; D008969:Molecular Sequence Data; D015183:Restriction Mapping; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D017386:Sequence Homology, Amino Acid; D015534:Trans-Activators; D014162:Transfection; D014407:Tumor Cells, Cultured; D014960:X Chromosome
D005656:Fungal Proteins; D017261:Glycosylphosphatidylinositols; D008565:Membrane Proteins; C071958:SPT14 protein, S cerevisiae; D029701:Saccharomyces cerevisiae Proteins; D015534:Trans-Activators; C080086:phosphatidylinositol glycan-class A protein; D016695:Glycosyltransferases