title: Glutathione s-transferase omega 1-1 is a target of cytokine release inhibitory drugs and may be responsible for their effect on interleukin-1beta posttranslational processing.
abstract: Stimulus-induced posttranslational processing of human monocyte interleukin-1beta (IL-1beta) is accompanied by major changes to the intracellular ionic environment, activation of caspase-1, and cell death. Certain diarylsulfonylureas inhibit this response, and are designated cytokine release inhibitory drugs (CRIDs). CRIDs arrest activated monocytes so that caspase-1 remains inactive and plasma membrane latency is preserved. Affinity labeling with [(14)C]CRIDs and affinity chromatography on immobilized CRID were used in seeking potential protein targets of their action. Following treatment of intact human monocytes with an epoxide-bearing [(14)C]CRID, glutathione S-transferase (GST) Omega 1-1 was identified as a preferred target. Moreover, labeling of this polypeptide correlated with irreversible inhibition of ATP-induced IL-1beta posttranslational processing. When extracts of human monocytic cells were chromatographed on a CRID affinity column, GST Omega 1-1 bound selectively to the affinity matrix and was eluted by soluble CRID. Recombinant GST Omega 1-1 readily incorporated [(14)C]CRID epoxides, but labeling was negated by co-incubation with S-substituted glutathiones or by mutagenesis of the catalytic center Cys(32) to alanine. Peptide mapping by high performance liquid chromatography-mass spectrometry also demonstrated that Cys(32) was the site of modification. Although S-alkylglutathiones did not arrest ATP-induced IL-1beta posttranslational processing or inhibit [(14)C]CRID incorporation into cell-associated GST Omega 1-1, a glutathione-CRID adduct effectively demonstrated these attributes. Therefore, the ability of CRIDs to arrest stimulus-induced IL-1beta posttranslational processing may be attributable to their interaction with GST Omega 1-1.
authors.affiliation: Department of Antibacterials, Pfizer Global Research and Development, Pfizer, Inc., Groton, Connecticut 06340, USA.
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Laliberte
authors.forename: David G
authors.initials: DG
authors.lastname: Perregaux
authors.forename: Lise R
authors.initials: LR
authors.lastname: Hoth
authors.forename: Philip J
authors.initials: PJ
authors.lastname: Rosner
authors.forename: Crystal K
authors.initials: CK
authors.lastname: Jordan
authors.forename: Kevin M
authors.initials: KM
authors.lastname: Peese
authors.forename: James F
authors.initials: JF
authors.lastname: Eggler
authors.forename: Mark A
authors.initials: MA
authors.lastname: Dombroski
authors.forename: Kieran F
authors.initials: KF
authors.lastname: Geoghegan
authors.forename: Christopher A
authors.initials: CA
authors.lastname: Gabel
mesh_terms: D000255:Adenosine Triphosphate / Q000494:pharmacology; D000595:Amino Acid Sequence; D001665:Binding Sites / Q000235:genetics; D002478:Cells, Cultured; D003545:Cysteine; D005982:Glutathione Transferase / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D007375:Interleukin-1 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D008969:Molecular Sequence Data; D009000:Monocytes / Q000378:metabolism*; D016297:Mutagenesis, Site-Directed; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D007375:Interleukin-1; D011994:Recombinant Proteins; D000255:Adenosine Triphosphate; D005982:Glutathione Transferase; D003545:Cysteine