Genetic findings and functional studies of human CYP3A5 single nucleotide polymorphisms in different ethnic groups*

Abstract

This study identifies four new potentially defective coding alleles. CYP3A5 F446S is predicted to be more catalytically defective than the splice change alone.

CYP3A5*3Polymorphism and Its Clinical Implications and Pharmacokinetic Role

“…[22] The CYP3A5*8 variant, presenting a substitution of nucleotide C to T, leads to an amino acid change from arginine to cysteine at codon 28. [13] It was first observed in African-American (4%), but the frequencies in other ethnic groups have not yet been revealed. CYP3A5*9 is a SNP in the coding region, resulting from a nucleotide substitution from G to A in exon 10, leading to an amino acid change from alanine to threonine at codon 337.…”

“…It was observed in an Asian population at a frequency of 2%. [13] CYP3A5*10 was identified in one American subject out of a group of 24 diverse Caucasians, with an allelic frequency of 2%. [10] It is a point mutation substituting T to C in exon 12, resulting in an amino acid change at residue 446 from phenylalanine to serine.…”

The discovery of new coding alleles of human CYP26A1 that are potentially defective in the metabolism of all-trans retinoic acid and their assessment in a recombinant cDNA expression system

“…The pcDNA3.1-CYP26A1-FLAG was sequenced and used as a wild-type template for site-directed mutagenesis using a QuickChange kit (Stratagene, La Jolla, CA, USA). PCR primers with N-terminal modification of CYP26A1 cDNA for E.coli expression [15][16][17] were: forward primer, 5'-ggtggtcatatggctctgttattagcagtttttctcctcaccttcgtgctgccg-3' and reverse primer, 5'-gctgccaagctttcagtgatggtgatggtggatttccccatggaaatgg-3'. A second possible shorter CYP26A1 variant predicted in the NCBI (RefSeq NM_057157) was also constructed.…”

“…Initially, CYP26A1 wild-type cDNA was introduced into the pCW vector after N-terminal modification and transfected into E. coli as described previously for CYP3A4 and CYP3A5 [15][16][17]. Although CYP3A4 and CYP3A5 proteins were successfully expressed in the E. coli cDNA expression system as positive controls, no reduced CO-difference spectrum indicative of cytochrome P450 (450nm) was observed for CYP26A1 in more than three separate experiments.…”

“…The identity of at-RA, 9-cis-RA, 13-cis-RA, 4-oxo-RA, 4-OH-RA, 18-OH-RA and 5, 6-epoxy-RA was verified by comparing the retention times and UV spectra with those of the available standard compounds. The elution order and retention times of metabolites were the same as those reported by Marill et al [17]. The time course for metabolite formation was examined in cells transfected with wild-type CYP26A1*1 after 2 min (to allow for cellular uptake), 1 hr, 2 hr, and 3 hr.…”