TY - JOUR
T1 - trans Arachidonic acid isomers inhibit NADPH-oxidase activity by direct interaction with enzyme components
AU - Souabni, H.
AU - Thoma, V.
AU - Bizouarn, T.
AU - Chatgilialoglu, C.
AU - Siafaka-Kapadai, A.
AU - Baciou, L.
AU - Ferreri, C.
AU - Houée-Levin, C.
AU - Ostuni, M. A.
N1 - Funding Information:
This work was supported by the EDF Grant [no. RB 2011-14 ], the ANRjc [ JCJC06-137200 ] and the ANR-02010-BLAN-1536-01 grants from the French National Agency for Research , and the European COST action CM0603 . We would like to express our grateful thanks to Drs P. Deterre, J-J Lacapere and F. Lederer for their interesting and encouraging discussions.
PY - 2012/9
Y1 - 2012/9
N2 - NADPH-oxidase is an enzyme that represents, when activated, the major source of non-mitochondrial reactive oxygen species. In phagocytes, this production is an indispensable event for the destruction of engulfed pathogens. The functional NADPH-oxidase complex consists of a catalytic membrane flavocytochrome b (Cytb558) and four cytosolic proteins p47 phox, p67phox, Rac and p40phox. The NADPH-oxidase activity is finely regulated spatially and temporally by cellular signaling events that trigger the translocation of the cytosolic subunits to its membrane partner involving post-translational modifications and activation by second messengers such as arachidonic acid (AA). Arachidonic acid in its natural cis-poly unsaturated form (C20:4) has been described to be an efficient activator of the enzyme in vivo and in vitro. In this work, we examined in a cell-free system whether a change of the natural cis geometry to the trans configuration, which could occur either by diet or be produced by the action of free radicals, may have consequences on the functioning of NADPH-oxidase. We showed the inability of mono-trans AA isomers to activate the NADPH-oxidase complex and demonstrated the inhibitory effect on the cis-AA-induced NADPH oxidase activation. The inhibition is mediated by a direct effect of the mono-trans AA which targets both the membrane fraction containing the cytb 558 and the cytosolic p67phox. Our results suggest that the loss of the natural geometric feature (cis-AA) induces substantial structural modifications of p67phox that prevent its translocation to the complex.
AB - NADPH-oxidase is an enzyme that represents, when activated, the major source of non-mitochondrial reactive oxygen species. In phagocytes, this production is an indispensable event for the destruction of engulfed pathogens. The functional NADPH-oxidase complex consists of a catalytic membrane flavocytochrome b (Cytb558) and four cytosolic proteins p47 phox, p67phox, Rac and p40phox. The NADPH-oxidase activity is finely regulated spatially and temporally by cellular signaling events that trigger the translocation of the cytosolic subunits to its membrane partner involving post-translational modifications and activation by second messengers such as arachidonic acid (AA). Arachidonic acid in its natural cis-poly unsaturated form (C20:4) has been described to be an efficient activator of the enzyme in vivo and in vitro. In this work, we examined in a cell-free system whether a change of the natural cis geometry to the trans configuration, which could occur either by diet or be produced by the action of free radicals, may have consequences on the functioning of NADPH-oxidase. We showed the inability of mono-trans AA isomers to activate the NADPH-oxidase complex and demonstrated the inhibitory effect on the cis-AA-induced NADPH oxidase activation. The inhibition is mediated by a direct effect of the mono-trans AA which targets both the membrane fraction containing the cytb 558 and the cytosolic p67phox. Our results suggest that the loss of the natural geometric feature (cis-AA) induces substantial structural modifications of p67phox that prevent its translocation to the complex.
KW - Arachidonic acid
KW - Cell free system
KW - NADPH oxidase
KW - Protein complex assembly
KW - Superoxide production inhibition
KW - trans Fatty acid
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U2 - 10.1016/j.bbamem.2012.04.018
DO - 10.1016/j.bbamem.2012.04.018
M3 - Article
C2 - 22580228
AN - SCOPUS:84861912758
SN - 0005-2736
VL - 1818
SP - 2314
EP - 2324
JO - Biochimica et Biophysica Acta - Biomembranes
JF - Biochimica et Biophysica Acta - Biomembranes
IS - 9
ER -