Alternative titles; symbols
HGNC Approved Gene Symbol: CYP2G1P
Cytogenetic location: 19q13.2 Genomic coordinates (GRCh38): 19:40,890,826-40,900,508 (from NCBI)
CYP2G1P is a nearly intact pseudogene of the cytochrome P450 family (Nelson et al., 2004). It appears to be transcribed in nasal mucosa (Sheng and Ding, 1996).
Cyp2g1 is an enzyme expressed abundantly and uniquely in the olfactory mucosa of mammalian species, where it is believed to have physiologic functions important for the olfactory chemosensory system. The primary structure of rabbit and rat Cyp2g1 was determined by cDNA cloning. Nef et al. (1990) determined the gene structure for rat Cyp2g1. Sheng and Ding (1996) used PCR primers based on conserved sequences between rabbit and rat Cyp2g1 cDNAs to analyze human genomic DNA. Genomic Southern blot analysis with cloned human DNA probes suggested that there may be more than 1 CYP2G-related gene in the human genome. Transcripts from 1 of the genes designated CYP2G1 were detected in nasal mucosa.
Sheng et al. (2000) found that there are 2 different human CYP2G genes, which they designated CYP2GP1 and CYP2GP2. They identified numerous loss-of-function mutations in PCR-based genotyping of more than 200 individuals. A deletion of exons 4-6 in CYP2GP1 was detected in 94% of subjects (either homozygous or heterozygous), and an allele that did not contain this deletion was detected in 11.6% of individuals. A nonsense mutation in CYP2GP2 exon 3 was detected in 86% of individuals (either homozygous or heterozygous); however, a potentially functional CYP2GP2 allele based on the absence of the nonsense mutation in exon 3 was also detected in 31% of individuals. The results indicated that a functional CYP2G allele is rare in humans. Analysis of the allelic distribution in different ethnic groups suggested that a functional CYP2G allele, if present, is most likely to be present in black and Hispanic subjects.
Sheng et al. (2000) found that both CYP2GP1 and CYP2GP2 localized to human chromosome 19. Southern blot analysis of human genomic DNA did not detect any additional copies of the CYP2G gene.
By sequence analysis, Nelson et al. (2004) mapped the CYP2G1P and CYP2G2P pseudogenes to chromosome 19q13.2.
Nef, P., Larabee, T. M., Kagimoto, K., Meyer, U. A. Olfactory-specific cytochrome P-450 (P-450olf1; IIG1): gene structure and developmental regulation. J. Biol. Chem. 265: 2903-2907, 1990. [PubMed: 2406242]
Nelson, D. R., Zeldin, D. C., Hoffman, S. M. G., Maltais, L. J., Wain, H. M., Nebert, D. W. Comparison of cytochrome P450 (CYP) genes from the mouse and human genomes, including nomenclature recommendations for genes, pseudogenes and alternative-splice variants. Pharmacogenetics 14: 1-18, 2004. [PubMed: 15128046] [Full Text: https://doi.org/10.1097/00008571-200401000-00001]
Sheng, J., Ding, X. Identification of human genes related to olfactory-specific CYP2G1. Biochem. Biophys. Res. Commun. 218: 570-574, 1996. [PubMed: 8561797] [Full Text: https://doi.org/10.1006/bbrc.1996.0101]
Sheng, J., Guo, J., Hua, Z., Caggana, M., Ding, X. Characterization of human CYP2G genes: widespread loss-of-function mutations and genetic polymorphism. Pharmacogenetics 10: 667-678, 2000. [PubMed: 11186129] [Full Text: https://doi.org/10.1097/00008571-200011000-00001]