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Physical interaction between CYP1A2 and CYP2B4 causes a disruption of inhibitory CYP1A2 complexes (LB592)
Author(s) -
Connick John,
Reed James,
Backes Wayne
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.lb592
Subject(s) - cyp1a2 , chemistry , homomeric , biochemistry , biophysics , metabolism , biology , cytochrome p450 , gene , protein subunit
Previous reports showed that CYP1A2 and CYP2B4 can affect each other’s activity when present in the same vesicles with subsaturating NADPH‐P450 reductase (CPR). Specifically, systems containing both P450s exhibited increased CYP1A2 and decreased CYP2B4 activities when compared with those containing each P450 alone. These effects were consistent with the formation of CYP1A2•CYP2B4 complexes that affected the affinity of each P450 for CPR, and were corroborated in living cells using bioluminescence resonance energy transfer (BRET). Previous results also showed that CYP1A2 forms homomeric complexes whose presence was correlated with inhibition of CYP1A2 activity at subsaturating CPR. The goal of this study was to determine if homomeric P450 complexes were disrupted by the presence of another P450 using BRET. First, the potential for CYP2B4•CYP2B4 complexes was examined. Unlike with CYP1A2, we were unable to detect specific CYP2B4•CYP2B4 complexes. Next, we examined the potential for CYP2B4 to disrupt the inhibitory CYP1A2•CYP1A2 complexes, and facilitate the CPR:CYP1A2 interaction. To do this, we cotransfected HEK293T cells with plasmids encoding both CYP1A2‐GFP and CYP1A2‐Rluc in the absence and presence of unlabeled CYP2B4. The data showed a significant decrease in the maximum CYP1A2•CYP1A2 BRET signal when CYP2B4 was present, indicating that CYP2B4 is capable of disrupting these complexes. Grant Funding Source : Supported by R01 ES004344