Structural basis for synthesis of inflammatory mediators by human leukotriene C4 synthase

Molina, Daniel Martinez; Wetterholm, Anders; Kohl, A.; McCarthy, A.A.; Niegowski, Damian; Ohlson, Eva; Hammarberg, Tove; Eshaghi, Said; Haeggström, Jesper Z.; Nordlund, P.

doi:10.1038/nature06009

Cited by 165 publications

(134 citation statements)

References 25 publications

Supporting

Mentioning

123

Contrasting

Order By: Relevance

“…First, we have shown that all cellular LTC 4 synthase is associated with FLAP (19) and that LTC 4 synthase is likely to be enriched in the outer nuclear membrane (10). Second, structural studies have indicated that both FLAP and LTC 4 synthase must exist as independent homotrimers (16,24,25). When combined with our results, this indicates that LTC 4 synthase and FLAP interact at a site distinct from the site where 5-LO and FLAP interact.…”

Section: Discussionsupporting

confidence: 61%

The nuclear membrane organization of leukotriene synthesis

Mandal

Jones

Bair

et al. 2008

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

View full text Add to dashboard Cite

Leukotrienes (LTs) are signaling molecules derived from arachidonic acid that initiate and amplify innate and adaptive immunity. In turn, how their synthesis is organized on the nuclear envelope of myeloid cells in response to extracellular signals is not understood. We define the supramolecular architecture of LT synthesis by identifying the activation-dependent assembly of novel multiprotein complexes on the outer and inner nuclear membranes of mast cells. These complexes are centered on the integral membrane protein 5-Lipoxygenase-Activating Protein, which we identify as a scaffold protein for 5-Lipoxygenase, the initial enzyme of LT synthesis. We also identify these complexes in mouse neutrophils isolated from inflamed joints. Our studies reveal the macromolecular organization of LT synthesis.inflammation ͉ multiprotein complex ͉ 5-lipoxygenase ͉ 5-lipoxygenase-activating protein L eukotrienes (LTs) are lipid signaling molecules derived from arachidonic acid (AA) that initiate and amplify innate and adaptive immune responses by regulating the recruitment and activation of leukocytes in inflamed tissues (1-3). Cells employ multiple mechanisms to prevent the inappropriate onset of pro-inflammatory signaling while requiring tightly coupled processes to trigger the generation of pro-inflammatory signaling molecules. The interplay of these processes is epitomized by the synthesis of LTB 4 and LTC 4 . In unstimulated myeloid cells, including mast cells, LT formation is held in abeyance by the cytosolic compartmentalization of cytosolic phospholipase A 2 (cPLA 2 ) (4, 5) and the cytosolic/nucleoplasmic localization of 5-lipoxygenase (5-LO) (6). LT formation is initiated by translocation of cPLA 2 to the Golgi and ER/nuclear envelope to release AA (4, 5). In parallel, 5-LO targets to the inner and outer nuclear membranes to initiate LT synthesis by converting AA to 5-HPETE and LTA 4 , a process that requires the integral nuclear envelope protein 5-lipoxygenase-activating protein (FLAP) (7-9). Although we have shown that LTC 4 synthase and FLAP constitutively interact on the nuclear envelope (10), how or whether 5-LO interacts with these proteins on the nuclear envelope in response to cell signaling is unknown.Understanding how cells couple the reorganization of the LT biosynthetic enzymes to efficient AA utilization is central to understanding the signal transduction pathways that control the synthesis of bioactive lipids derived from AA. Scaffold/docking proteins can localize components of biochemical reactions at membrane interfaces; examples include protein kinase A anchoring proteins (11) and the integral membrane proteins caveolins 1-3 (12). The dependence of cellular LT synthesis on FLAP (7, 8) and its membrane localization (9) make it a conceptually appealing candidate for a 5-LO scaffold. However, no interaction of 5-LO with any membrane protein has been detected.A closely related question is: how do different combinations of extracellular signals lead to LT generation? For example, in mast cells, the engage...

show abstract

Section: Discussionsupporting

confidence: 61%

The nuclear membrane organization of leukotriene synthesis

Mandal

Jones

Bair

et al. 2008

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

View full text Add to dashboard Cite

show abstract

“…Initial structural characterization of the MAPEG family was done using electron crystallography and showed that the members contain four transmembrane helices and are organized as trimers (8,9). This was later confirmed by the X-ray crystal structures of FLAP (10) and LTC 4 synthase (11,12). There are also low-resolution 3D electron crystallography structures of MGST1 and mPGES-1 (13,14).…”

mentioning

confidence: 86%

Crystal structure of microsomal prostaglandin E₂synthase provides insight into diversity in the MAPEG superfamily

Sjögren

Nord

et al. 2013

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

139

View full text Add to dashboard Cite

Prostaglandin E 2 (PGE 2 ) is a key mediator in inflammatory response. The main source of inducible PGE 2 , microsomal PGE 2 synthase-1 (mPGES-1), has emerged as an interesting drug target for treatment of pain. To support inhibitor design, we have determined the crystal structure of human mPGES-1 to 1.2 Å resolution. The structure reveals three well-defined active site cavities within the membrane-spanning region in each monomer interface of the trimeric structure. An important determinant of the active site cavity is a small cytosolic domain inserted between transmembrane helices I and II. This extra domain is not observed in other structures of proteins within the MAPEG (MembraneAssociated Proteins involved in Eicosanoid and Glutathione metabolism) superfamily but is likely to be present also in microsomal GST-1 based on sequence similarity. An unexpected feature of the structure is a 16-Å-deep cone-shaped cavity extending from the cytosolic side into the membrane-spanning region. We suggest a potential role for this cavity in substrate access. Based on the structure of the active site, we propose a catalytic mechanism in which serine 127 plays a key role. We have also determined the structure of mPGES-1 in complex with a glutathione-based analog, providing insight into mPGES-1 flexibility and potential for structure-based drug design.membrane protein | X-ray crystallography | enzyme mechanism P rostaglandins are potent lipid messengers and are involved in numerous homeostatic biological functions [for a review of eicosanoid biology, see review by C. D. Funk (1)]. They are enzymatically derived from the essential fatty acid arachidonic acid and the synthesis proceeds via the formation of prostaglandin H 2 (PGH 2 ), a reaction catalyzed by the constitutively active cyclooxygenase COX-1 and the inducible cyclooxygenase COX-2. PGH 2 acts as a substrate for a range of terminal prostaglandin synthases, including the PGE synthases (PGES, EC 5.3.99.3) that convert PGH 2 to PGE 2 .Microsomal prostaglandin E 2 synthase-1 (mPGES-1), colocalized and up-regulated in concert with COX-2, is the major source of inducible PGE 2 and is associated with inflammation and pain (2). Several studies support a role for mPGES-1 also in cancer cell proliferation and tumor growth (3). Because treatment with COX-2 selective inhibitors is associated with elevated cardiovascular risk, safer approaches involving, for example, PGE 2 reduction, are needed (4). Mice deficient in mPGES-1 have shown significantly reduced effect on hypertension, thrombosis, and myocardial damage compared with inhibition or disruption of COX-2, suggesting mPGES-1 to be a potential target for pharmaceutical intervention in various areas of diseases (2, 5).mPGES-1 belongs to a superfamily of Membrane-Associated Proteins involved in Eicosanoid and Glutathione metabolism, the MAPEG family (6). Members of the MAPEG family can be found in prokaryotes and eukaryotes but not in archaea (7). The most closely related MAPEG member is the microsomal glutathione transferase-1...

show abstract

“…8 n-Alkyl-b-D-maltosides (C n G 2 ), which are in the focus of the present study, have been used in many cases as solubilizing agents to achieve membrane protein crystallization. Representative examples of a successful application of C 12 G 2 are photosystem I (PSI) 9 and photosystem II (PSII) [10][11][12] as well as the cytochrome (cyt) b 6 f complex 13 of oxygenic photosynthesis, a bacterial multidrug efflux transporter, 14 a cyt c quinol dehydrogenase, 15 a human leukotriene C 4 synthase, 16,17 and the rotor of V-type Na + -ATPase. 18 The homologous detergent C 11 G 2 was used in the case of the yeast cyt bc 1 complex, 19,20 C 10 G 2 for a glutamate transporter, 21 and C 8 G 2 for a chloride channel.…”

Section: Introductionmentioning

confidence: 99%

The influence of poly(ethylene glycol) on the micelle formation of alkyl maltosides used in membrane protein crystallization

Müh

DiFiore

Zouni

2015

Phys. Chem. Chem. Phys.

View full text Add to dashboard Cite

With the aim of better understanding the phase behavior of alkyl maltosides (n-alkyl-b-D-maltosides, C n G 2 ) under the conditions of membrane protein crystallization, we studied the influence of poly(ethylene glycol) (PEG) 2000, a commonly used precipitating agent, on the critical micelle concentration (CMC) of the alkyl maltosides by systematic variation of the number n of carbon atoms in the alkyl chain (n = 10, 11, and 12) and the concentration of PEG2000 (w) in a buffer suitable for the crystallization of cyanobacterial photosystem II. CMC measurements were based on established fluorescence techniques using pyrene and 8-anilinonaphthalene-1-sulfonate (ANS). We found an increase of the CMC with increasing PEG concentration according to ln(CMC/CMC 0 ) = k P w, where CMC 0 is the CMC in the absence of PEG and k P is a constant that we termed the ''polymer constant''. In parallel, we measured the influence of PEG2000 on the surface tension of detergent-free buffer solutions. At PEG concentrations w 4 1% w/v, the surface pressure p s (w) = g(0) À g(w) was found to depend linearly on the PEG concentration according to p s (w) = kw + p s (0), where g (0) is the surface tension in the absence of PEG. Based on a molecular thermodynamic modeling, CMC shifts and surface pressure due to PEG are related, and it is shown that k P = kc(n) + Z, where c(n) is a detergent-specific constant depending inter alia on the alkyl chain length n and Z is a correction for molarity. Thus, knowledge of the surface pressure in the absence of a detergent allows for the prediction of the CMC shift. The PEG effect on the CMC is discussed concerning its molecular origin and its implications for membrane protein solubilization and crystallization.

show abstract

Structural basis for synthesis of inflammatory mediators by human leukotriene C4 synthase

Cited by 165 publications

References 25 publications

The nuclear membrane organization of leukotriene synthesis

The nuclear membrane organization of leukotriene synthesis

Crystal structure of microsomal prostaglandin E₂synthase provides insight into diversity in the MAPEG superfamily

The influence of poly(ethylene glycol) on the micelle formation of alkyl maltosides used in membrane protein crystallization

Contact Info

Product

Resources

About

Structural basis for synthesis of inflammatory mediators by human leukotriene C4 synthase

Cited by 165 publications

References 25 publications

The nuclear membrane organization of leukotriene synthesis

The nuclear membrane organization of leukotriene synthesis

Crystal structure of microsomal prostaglandin E2synthase provides insight into diversity in the MAPEG superfamily

The influence of poly(ethylene glycol) on the micelle formation of alkyl maltosides used in membrane protein crystallization

Contact Info

Product

Resources

About

Crystal structure of microsomal prostaglandin E₂synthase provides insight into diversity in the MAPEG superfamily