Structural Basis for Detoxification and Oxidative Stress Protection in Membranes

Holm, Peter; Bhakat, Priyaranjan; Jegerschöld, Caroline; Gyobu, Nobuhiko; Mitsuoka, Kaoru; Fujiyoshi, Yoshinori; Morgenstern, Ralf; Hebert, Hans

doi:10.1016/j.jmb.2006.05.056

Cited by 128 publications

(120 citation statements)

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“…The subunits of MPGES1 form a homotrimer ( Fig. 1) in a similar way as for the other structurally characterized MAPEG members, MGST1 (17), FLAP (18), and LTC4S (19,20) and in agreement with earlier low resolution and hydrodynamic data on MPGES1 (5). Our result thus supports the suggestion that a trimeric arrangement is common to all MAPEG proteins (21).…”

Section: Resultssupporting

confidence: 88%

Structural basis for induced formation of the inflammatory mediator prostaglandin E ₂

Jegerschöld

Pawelzik²,

Purhonen

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

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138

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Prostaglandins (PG) are bioactive lipids produced from arachidonic acid via the action of cyclooxygenases and terminal PG synthases. Microsomal prostaglandin E synthase 1 (MPGES1) constitutes an inducible glutathione-dependent integral membrane protein that catalyzes the oxidoreduction of cyclooxygenase derived PGH 2 into PGE2. MPGES1 has been implicated in a number of human diseases or pathological conditions, such as rheumatoid arthritis, fever, and pain, and is therefore regarded as a primary target for development of novel antiinflammatory drugs. To provide a structural basis for insight in the catalytic mechanism, we determined the structure of MPGES1 in complex with glutathione by electron crystallography from 2D crystals induced in the presence of phospholipids. Together with results from site-directed mutagenesis and activity measurements, we can thereby demonstrate the role of specific amino acid residues. Glutathione is found to bind in a U-shaped conformation at the interface between subunits in the protein trimer. It is exposed to a site facing the lipid bilayer, which forms the specific environment for the oxidoreduction of PGH 2 to PGE 2 after displacement of the cytoplasmic half of the N-terminal transmembrane helix. Hence, insight into the dynamic behavior of MPGES1 and homologous membrane proteins in inflammation and detoxification is provided.electron crystallography ͉ inflammation ͉ MAPEG ͉ membrane protein M icrosomal prostaglandin E synthase 1 (MPGES1) is the key enzyme in pathology related production of PGE 2 from cyclooxygenase (Cox) derived PGH 2 (1). The protein is a member of the MAPEG protein family, which includes 5-lipoxygenase activating protein (FLAP), leukotriene C 4 synthase (LTC4S), microsomal glutathione transferase (MGST)1, MGST2, and MGST3 (2, 3). MPGES1 is the most efficient PGES known and catalyzes the oxidoreduction of prostaglandin endoperoxide H 2 into PGE 2 with an apparent k cat /K m of 310 mM Ϫ1 s Ϫ1 [supporting information (SI) Fig. S1]. The enzyme equally well catalyses the oxidoreduction of endocannabinoids into prostaglandin glycerol esters (4) and PGG 2 into 15-hydroperoxy-PGE 2 (5). In addition, the enzyme confers low glutathione transferase and glutathione-dependent peroxidase activities (5). The biological significance of the latter activities remains unclear but is thought to reflect the close evolutionary distance to MGST1.MPGES1 protein expression levels are in most cases low, and proinflammatory stimuli induce its cellular expression and activity, which is prevented by corticosteroids (1, 6-8). The predominant source of PGH 2 seems derived from Cox-2, although Cox-1 may also contribute (9). Studies, mainly from disruption of the MPGES1 gene in mice, indicate key roles for MPGES1-generated PGE 2 in pathological conditions such as chronic inflammation, pain, fever, anorexia, atherosclerosis, stroke and tumorigenesis (10). Recently, a role for MPGES1 in regulating neonatal respiration was described in ref. 11. MPGES1 has been shown to be overexpressed in rheu...

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Section: Resultssupporting

confidence: 88%

Structural basis for induced formation of the inflammatory mediator prostaglandin E ₂

Jegerschöld

Pawelzik²,

Purhonen

et al. 2008

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

138

204

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“…Recent significant achievements in the understanding of MAPEG protein structure are the determination of MGST1 from rat at 3.2/4.0 Å resolution by electron crystallography (Holm et al 2006), the X-ray crystal structures of human LTC 4 synthase (LTC 4 -S) in its apo and GSH-complexed forms at 2.00 and 2.15 Å (Martinez Molina et al 2007) and 3.3 Å resolution (Ago et al 2007) (Figure 2). Of clinical relevance was the structure of 5-lipoxygenase-activating protein (FLAP) with MK-591 and an iodinated derivative at 4.25 and 4.0 Å resolution (Ferguson et al 2007).…”

Section: Mapegmentioning

confidence: 99%

Glutathione transferases: a structural perspective

Oakley

2011

Drug Metabolism Reviews

316

240

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The glutathione transferases (GSTs) are one of the most important families of detoxifying enzymes in nature. The classic activity of the GSTs is conjugation of compounds with electrophilic centers to the tripeptide glutathione (GSH), but many other activities are now associated with GSTs, including steroid and leukotriene biosynthesis, peroxide degradation, double-bond cis-trans isomerization, dehydroascorbate reduction, Michael addition, and noncatalytic "ligandin" activity (ligand binding and transport). Since the first GST structure was determined in 1991, there has been an explosion in structural data across GSTs of all three families: the cytosolic GSTs, the mitochondrial GSTs, and the membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG family). In this review, the major insights into GST structure and function will be discussed. AbstractThe glutathione transferases (GSTs) are one of the most important families of detoxifying enzymes in nature. The classic activity of the GSTs is conjugation of compounds with electrophilic centers to the tripeptide glutathione (GSH), but many other activities are now associated with GSTs, including steroid and leukotriene biosynthesis, peroxide degradation, double-bond cis-trans isomerization, dehydroascorbate reduction, Michael addition, and non-catalytic "ligandin" activity (ligand binding and transport). Since the first GST structure was determined in 1991, there has been an explosion in structural data across GSTs of all three families: the cytosolic GSTs, the mitochondrial GSTs and the membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG family). In this review, the major insights into GST structure and function will be discussed.

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“…31,32) Although the implications of the presence of an SRCR domain in hepsin have not been clarified, it is suggested that the hepsin SRCR domain may play such role of mediating interactions with soluble or cell surface proteins. MGST1 has four transmembrane regions and 2 cytosolic domains 33,34) in which Lys 41 and Cys 49 are in the cytosolic domain. MGST1 is activated by modulation of Cys 49 through disulfide-linked dimer formation or protein-glutathione disulfide formation (a mixed disulfide bond) 6,7,35) and by proteolytic degradation at Lys 41.…”

Section: Discussionmentioning

confidence: 99%

Activation of Rat Liver Microsomal Glutathione Transferase by Hepsin

Nakama

Oshiro

Aniya

2010

Biological & Pharmaceutical Bulletin

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Glutathione transferases (GST) catalyze the conjugation of various electrophiles including antitumor drugs with reduced glutathione and distribute in cytosol, microsomes, and mitochondria.1-3) Rat liver microsomal glutathione transferase (MGST1) is a homotrimer that contains a sole thiol (Cys49) per each subunit protein and is activated through a modification of the thiol such as alkylation, thiol/disulfide exchange, or oxidation to sulfenic acid. [4][5][6][7][8][9] MGST1 is also activated by limited proteolysis at lysine 41 with trypsin 10) and oxidatively modified MGST1 becomes sensitive to the proteolytic activation.11) It is of great interest whether protease is capable of activating MGST1 in the liver.Recently we purified a serine protease, hepsin, from rat liver microsomes and found that when purified MGST1 was incubated with hepsin for 3-6 d at 4°C, MGST1 activity was increased and a disulfide-linked dimer of MGST1 was observed, 12) suggesting that hepsin stimulates MGST1 dimer formation. However, the activation mechanism of MGST1 by hepsin has not been clarified.Hepsin is a cell surface-expressed type II transmembrane serine protease found in plasma membrane and microsomes. 13,14) Hepsin zymogen is activated autocatalytically by cleavage at 14) forming a heterodimeric enzyme. Many lines of evidence have shown that hepsin contributes to activation of coagulation factor VII 15) and growth promoting and suppressing activities [16][17][18] and is increased in ovarian 19) and prostate cancer. 20,21) Hepsin is a 417 amino acid polypeptide containing a short N-terminal cytoplasmic tail, a transmembrane region, and an extracellular domain (Arg45-Leu417) composed of the scavenger receptor cysteine-rich (SRCR) domain and protease domain. 22) Since intra-or inter-domain disulfide bonds are involved in hepsin, it is suggested that hepsin may activate MGST1 via thiol/disulfide exchange. To confirm the activation mechanism of MGST1 by hepsin, we investigated the possibility of thiol/disulfide exchange between MGST1 and hepsin molecules. MATERIALS AND METHODSChemicals Reduced glutathione (GSH), Triton X-100, and CM Sepharose CL 6B were purchased from Sigma Chemicals (St. Louis, MO, U.S.A.). Lubrol PX, benzamidine hydrochloride, and sodium cholate were from Nacalai Tesque (Kyoto, Japan). 1-Chloro-2,4-dinitrobenzene (CDNB) and glycerol were obtained from Wako Pure Chemicals (Osaka, Japan). Hydroxyapatite, silver stain kit, gout anti-rabbit immunoglobulin G (IgG) (HϩL), and horseradish peroxidase conjugate substrate kit were from Bio-Rad Laboratories (Richmond, CA, U.S.A.). Benzamidine-Sepharose 6B and synthetic protease substrate t-butyloxycarbonyl (Boc)-GlnArg-Arg-4-methylcoumaryl-7-amide (MCA) were from Pharmacia-LKB Biotechnology Inc. (Tokyo, Japan) and Peptide Institute Inc. (Osaka, Japan), respectively. Anti-hepsin antibody was prepared against C-terminal 17 peptide as described previously.12) Anti-MGST1 antibody was prepared in our laboratory as described previously.23) All other reagents were of analytical grade.P...

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Structural Basis for Detoxification and Oxidative Stress Protection in Membranes

Cited by 128 publications

References 49 publications

Structural basis for induced formation of the inflammatory mediator prostaglandin E ₂

Structural basis for induced formation of the inflammatory mediator prostaglandin E ₂

Glutathione transferases: a structural perspective

Activation of Rat Liver Microsomal Glutathione Transferase by Hepsin

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Structural Basis for Detoxification and Oxidative Stress Protection in Membranes

Cited by 128 publications

References 49 publications

Structural basis for induced formation of the inflammatory mediator prostaglandin E 2

Structural basis for induced formation of the inflammatory mediator prostaglandin E 2

Glutathione transferases: a structural perspective

Activation of Rat Liver Microsomal Glutathione Transferase by Hepsin

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Product

Resources

About

Structural basis for induced formation of the inflammatory mediator prostaglandin E ₂

Structural basis for induced formation of the inflammatory mediator prostaglandin E ₂