A pseudogene for human glutathione peroxidase.
Glutathione peroxidases (GPx) serve a bioprotective function in the reduction of peroxides to less toxic substances. Both cellular and secreted forms of the protein have been reported, as well a number of distinct cDNA sequences. Previous efforts have described three distinct loci on human chromosomes 3, 21 and X which hybridize to a GPX cDNA and these authors have speculated that only the chromosome 3 locus encodes a functional GPX gene. This conclusion was based on mapping studies showing a precise deletion of intron sequences in the GPX loci on chromosomes 21 and X despite strong conservation among these sequences in both the coding and 3'-untranslated regions. To pursue this issue, we have isolated the chromosome 21 GPX locus by molecular cloning and determined its nucleotide sequence. Consistent with the expectations of McBride et al. [Biofactors 4 (1988) 285-292], the sequence does reveal a highly conserved processed pseudogene. It is suggested that a retrotransposed copy of the GPX gene integrated into chromosome 21 and may have maintained activity prior to the accumulation of inactivating mutations.
Diamond
A M
AM
Department of Radiation and Cellular Oncology, University of Chicago, IL 60637.
Cruz
R
R
Bencsics
C
C
Hatfield
D
D
D001483:Base Sequence; D002891:Chromosomes, Human, Pair 21; D003001:Cloning, Molecular; D004247:DNA; D005979:Glutathione Peroxidase / Q000235:genetics*; D006801:Humans; D008969:Molecular Sequence Data; D011544:Pseudogenes
D004247:DNA; D005979:Glutathione Peroxidase