3
views
0
recommends
+1 Recommend
0 collections
    0
    shares
      • Record: found
      • Abstract: found
      • Article: not found

      Progesterone receptor membrane component 1 modulates human cytochrome p450 activities in an isoform-dependent manner.

      Read this article at

      ScienceOpenPublisherPubMed
      Bookmark
          There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

          Abstract

          Cytochromes P450 (P450s) catalyze the metabolism of a wide spectrum of compounds. Recently, progesterone receptor membrane component 1 (PGRMC1), which shares a key structural motif with cytochrome b(5), has been reported to bind to sterol- or steroid-synthesizing P450s, enhancing their activities. In this study, we investigated whether PGRMC1 affects human drug-metabolizing P450 activities. Using coexpression systems for PGRMC1 and P450s (CYP3A4, CYP2C9, or CYP2E1) in HepG2 cells, we found that PGRMC1 decreased the V(max) values and increased the K(m) values of the CYP3A4 activities, and it decreased the V(max) values but did not affect the K(m) values of the CYP2C9 activities. In contrast, PGRMC1 hardly affected the CYP2E1 activities. These results suggest that PGRMC1 negatively modulates the drug-metabolizing activities of P450, although it was isoform but not substrate dependent. It is worth noting that coimmunoprecipitation analysis using coexpression systems for FLAG-PGRMC1 and Myc-P450s in human embryonic kidney 293 cells revealed that PGRMC1 interacts with all three P450s, although the affinity seemed to vary. In 29 human liver microsomes (HLMs), there was a 5-fold variability in the PGRMC1 protein levels. By the correlation analyses using the P450 activities and the PGRMC1 levels, we could neither observe the contribution of PGRMC1 to the P450 activities in HLMs nor that of the NADPH-cytochrome P450 reductase or cytochrome b(5). In conclusion, in contrast to sterol- or steroid-synthesizing P450s, we found that PGRMC1 negatively modulates the human drug-metabolizing activities of P450 through direct interaction. Further studies are needed to determine the clinical significance of PGRMC1 in the pharmacokinetics of drugs.

          Related collections

          Author and article information

          Journal
          Drug Metab. Dispos.
          Drug metabolism and disposition: the biological fate of chemicals
          American Society for Pharmacology & Experimental Therapeutics (ASPET)
          1521-009X
          0090-9556
          Nov 2011
          : 39
          : 11
          Affiliations
          [1 ] Drug Metabolism and Toxicology, Faculty of Pharmaceutical Sciences, Kanazawa University, Kakuma-machi, Kanazawa 920-1192, Japan.
          Article
          dmd.111.040907
          10.1124/dmd.111.040907
          21825115
          340868d1-70f6-42b3-9dcb-5a926145acc8
          History

          Comments

          Comment on this article