Three common polymorphisms in the CYBA gene form a haplotype associated with decreased ROS generation.
NOX enzymes are reactive oxygen species (ROS)-generating NADPH oxidases. Several members of the NOX family depend on the p22(phox) subunit, encoded by the CYBA gene. CYBA is highly polymorphic, and has been widely studied as a potential risk factor for various diseases, with conflicting results. In the present study, we used Epstein-Barr (EBV)-transformed B-lymphocytes from 50 healthy unrelated individuals to analyze their CYBA mRNA sequence and NOX2-dependent ROS generation. Seven single-nucleotide polymorphisms (SNPs) were identified (five previously described, two novel). The combination of these SNPs yielded 11 distinct haplotypes, which could be grouped into seven haplogroups (A-G). Haplogroup C (c.214T>C, c.521T>C, and c.(*)24G>A) showed a significantly lower ROS generation, as compared to the most frequent haplogroup, A. CYBA variants from the seven haplogroups were transduced into p22(phox)-deficient B-lymphocytes. The haplogroup C variant showed significantly lower ROS production. c.214T>C and c.521T>C lead to nonsynonymous codon changes, while c.(*)24G>A lies within the 3'UTR. Using a luciferase/3'UTR construct, we showed that the (*)24A allele led to decreased reporter gene activity. These results help to unravel the complex nature of how genetic variations in CYBA influence NOX2 activity, and indicate that haplotypes, rather than individual SNPs, define the effect on ROS generation.
Bedard
Karen
K
Department of Pathology and Immunology, University of Geneva Medical School and University Hospitals, Geneva, Switzerland.
Attar
Homa
H
Bonnefont
Jérôme
J
Jaquet
Vincent
V
Borel
Christelle
C
Plastre
Olivier
O
Stasia
Marie-José
MJ
Antonarakis
Stylianos E
SE
Krause
Karl-Heinz
KH
D001402:B-Lymphocytes; D001483:Base Sequence; D002461:Cell Line, Transformed; D006239:Haplotypes; D006801:Humans; D008562:Membrane Glycoproteins / Q000378:metabolism*; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases / Q000235:genetics* / Q000378:metabolism*; D011110:Polymorphism, Genetic; D020641:Polymorphism, Single Nucleotide; D012333:RNA, Messenger; D017382:Reactive Oxygen Species / Q000378:metabolism*
D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D017382:Reactive Oxygen Species; C056558:CYBB protein, human; D000074662:NADPH Oxidase 2; D019255:NADPH Oxidases; C086986:CYBA protein, human