Human CYP4F12 genetic polymorphism: identification and functional characterization of seven variant allozymes.
The human cytochrome CYP4F12 has been shown to be metabolically active toward inflammatory mediators and exogenous compounds such as antihistaminic drugs. We recently identified a genetic polymorphism within the promoter region, associated with a decreased level of enzyme expression. In the present study, we report the further identification of single nucleotide polymorphisms in the coding sequence of the CYP4F12 gene. A polymerase chain reaction-single strand conformational polymorphism (PCR-SSCP) analysis of DNA samples from 53 unrelated French Caucasians, allowed the identification of ten mutations, comprising seven missense mutations, 31C>T (Leu11Phe), 38C>T (Pro13Leu), 47C>T (Met16Thr), 4759G>A (Asp76Asn), 4801G>A (Val90Leu), 8896C>T (Arg188Cys) and 23545G>A (Gly522Ser). Their functional impact toward ebastine hydroxylation was evaluated using heterologous expression in Saccharomyces cerevisiae cells of site-directed mutated cDNA variants. Five out seven variants did not exhibit any significant difference in CYP4F12 catalytic activity, whereas two variants, Val90Ile and Arg188Cys, displayed significant changes in their Michaelis-Menten (Km, Vm) parameters. These data on CYP4F12 genetic polymorphism provide tools for further studies of association with pathological processes involving an inflammatory component and with variations in anti-histaminic drug response.
Cauffiez
Christelle
C
Equipe d'accueil 2679, Faculté de Médecine de Lille, Pôle Recherche, Lille, France. christelle.cauffiez@caramail.com
Klinzig
Florian
F
Rat
Emmanuel
E
Tournel
Gilles
G
Allorge
Delphine
D
Chevalier
Dany
D
Pottier
Nicolas
N
Lovecchio
Tonio
T
Colombel
Jean-Frédéric
JF
Lhermitte
Michel
M
Lo-Guidice
Jean-Marc
JM
Broly
Franck
F
D001189:Aryl Hydrocarbon Hydroxylases / Q000235:genetics*; D002384:Catalysis; D004252:DNA Mutational Analysis; D015870:Gene Expression; D006801:Humans; D006899:Mixed Function Oxygenases / Q000235:genetics*; D020125:Mutation, Missense; D016133:Polymerase Chain Reaction; D011110:Polymorphism, Genetic; D018807:Polymorphism, Single-Stranded Conformational; D011994:Recombinant Proteins / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000235:genetics
D011994:Recombinant Proteins; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C422180:CYP4F12 protein, human