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Christoph Benning - One of the best experts on this subject based on the ideXlab platform.
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ferredoxin dependent glutamate synthase moonlights in plant Sulfolipid biosynthesis by forming a complex with sqd1
Archives of Biochemistry and Biophysics, 2005Co-Authors: Mie Shimojima, Susanne Hoffmannbenning, Michael R Garavito, Christoph BenningAbstract:UDP-sulfoquinovose synthase, SQD1, catalyzes the transfer of sulfite to UDP-glucose giving rise to UDP-sulfoquinovose, which is the head group donor for the biosynthesis of the plant Sulfolipid sulfoquinovosyldiacylglyerol. The native SQD1 enzyme of spinach exists as a 250 kDa heteroprotein complex with much higher affinity for the substrate sulfite than the recombinant SQD1 protein itself. The SQD1 protein co-purified with nine proteins. Likely binding partners included rubisco activase, HSP70, and ferredoxin-dependent glutamate synthase (FdGOGAT). While the first two proteins are known to interact with many other proteins, the identification of FdGOGAT was most intriguing because this 160 kDa protein contains an FMN cofactor known to bind sulfite in vitro. Using different constructs expressing recombinant forms of the multidomain protein FdGOGAT, it was demonstrated that the FMN-binding domain of FdGOGAT is essential for specific binding of the protein to SQD1. A model suggests that FdGOGAT could channel sulfite to SQD1.
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phosphate availability affects the thylakoid lipid composition and the expression of sqd1 a gene required for Sulfolipid biosynthesis in arabidopsis thaliana
Proceedings of the National Academy of Sciences of the United States of America, 1998Co-Authors: Bernd Essigmann, Sinan Guler, Ram Avtar Narang, Dirk Linke, Christoph BenningAbstract:Photosynthetic membranes of higher plants contain specific nonphosphorous lipids like the Sulfolipid sulfoquinovosyl diacylglycerol in addition to the ubiquitous phospholipid phosphatidylglycerol. In bacteria, an environmental factor that drastically affects thylakoid lipid composition appears to be the availability of phosphate. Accordingly, we discovered an increase in the relative amount of Sulfolipid and a concomitant decrease in phosphatidylglycerol in Arabidopsis thaliana grown on medium with reduced amounts of phosphate, as well as in the pho1 mutant of A. thaliana deficient in phosphate transport. To investigate the molecular basis of the observed change in lipid composition, we isolated a cDNA of A. thaliana, designated SQD1, that encodes a protein involved in Sulfolipid biosynthesis as suggested by three lines of evidence. First, the cDNA shows high sequence similarity to bacterial sqdB genes known to be essential for Sulfolipid biosynthesis; second, the SQD1 gene product is imported into chloroplasts where Sulfolipid biosynthesis takes place; and third, transgenic plants expressing SQD1 in antisense orientation show a reduction in Sulfolipid content. In the pho1 mutant as well as in wild-type plants grown under reduced phosphate availability, increased amounts of SQD1 mRNA and SQD1 protein are detected, suggesting that the increase in Sulfolipid content under phosphate limitation is the result of an increased expression of at least one gene required for Sulfolipid biosynthesis in A. thaliana. It is suggested that a certain amount of anionic thylakoid lipid is maintained by substituting Sulfolipid for phosphatidylglycerol under reduced phosphate availability.
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Isolation and genetic complementation of a Sulfolipid-deficient mutant of Rhodobacter sphaeroides.
Journal of bacteriology, 1992Co-Authors: Christoph Benning, Chris SomervilleAbstract:All photosynthetic organisms are thought to contain the Sulfolipid 6-sulfo-alpha-D-quinovosyl diacylglycerol. However, the pathway of Sulfolipid biosynthesis has not been elucidated, and the functional or structural significance of this lipid is not known. Mutants of Rhodobacter sphaeroides deficient in Sulfolipid accumulation were isolated by directly screening for altered Sulfolipid content. The mutants had no apparent phenotype except for the Sulfolipid deficiency. A gene, designated sqdA, which complemented one of the mutations was isolated and characterized. The putative sqdA gene product is a protein with a molecular mass of 33.6 kDa that has no sequence similarity to any enzyme of known function.
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Isolation and genetic complementation of a Sulfolipid-deficient mutant of Rhodobacter sphaeroides
1992Co-Authors: Christoph Benning, C R SomervilleAbstract:sphaeroides. Sulfolipid-deficient mutant of Rhodobacter Isolation and genetic complementation of
Sonya T Dyhrman - One of the best experts on this subject based on the ideXlab platform.
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proteome changes driven by phosphorus deficiency and recovery in the brown tide forming alga aureococcus anophagefferens
PLOS ONE, 2011Co-Authors: Louie L Wurch, Erin M Bertrand, Mak A Saito, Benjamin A S Van Mooy, Sonya T DyhrmanAbstract:Shotgun mass spectrometry was used to detect proteins in the harmful alga, Aureococcus anophagefferens, and monitor their relative abundance across nutrient replete (control), phosphate-deficient (2P) and 2P refed with phosphate (P-refed) conditions. Spectral counting techniques identified differentially abundant proteins and demonstrated that under phosphate deficiency, A. anophagefferens increases proteins involved in both inorganic and organic phosphorus (P) scavenging, including a phosphate transporter, 59-nucleotidase, and alkaline phosphatase. Additionally, an increase in abundance of a Sulfolipid biosynthesis protein was detected in 2P and P-refed conditions. Analysis of the polar membrane lipids showed that cellular concentrations of the Sulfolipid sulphoquinovosyldiacylglycerol (SQDG) were nearly two-fold greater in the 2P condition versus the control condition, while cellular phospholipids were approximately 8-fold less. Transcript and protein abundances were more tightly coupled for gene products involved in P metabolism compared to those involved in a range of other metabolic functions. Comparison of protein abundances between the 2P and P-refed conditions identified differences in the timing of protein degradation and turnover. This suggests that culture studies examining nutrient starvation responses will be valuable in interpreting protein abundance patterns for cellular nutritional status and history in metaproteomic datasets.
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Proteome Changes Driven by Phosphorus Deficiency and Recovery in the Brown Tide-Forming Alga Aureococcus anophagefferens
2011Co-Authors: Louie L Wurch, Mak A Saito, Benjamin A S Van Mooy, Erin M. Bertr, Sonya T DyhrmanAbstract:Shotgun mass spectrometry was used to detect proteins in the harmful alga, Aureococcus anophagefferens, and monitor their relative abundance across nutrient replete (control), phosphate-deficient (2P) and 2P refed with phosphate (P-refed) conditions. Spectral counting techniques identified differentially abundant proteins and demonstrated that under phosphate deficiency, A. anophagefferens increases proteins involved in both inorganic and organic phosphorus (P) scavenging, including a phosphate transporter, 59-nucleotidase, and alkaline phosphatase. Additionally, an increase in abundance of a Sulfolipid biosynthesis protein was detected in 2P and P-refed conditions. Analysis of the polar membrane lipids showed that cellular concentrations of the Sulfolipid sulphoquinovosyldiacylglycerol (SQDG) were nearly two-fold greater in the 2P condition versus the control condition, while cellular phospholipids were approximately 8-fold less. Transcript and protein abundances were more tightly coupled for gene products involved in P metabolism compared to those involved in a range of other metabolic functions. Comparison of protein abundances between the 2P and P-refed conditions identified differences in the timing of protein degradation and turnover. This suggests that culture studies examining nutrient starvation responses will be valuable in interpreting protein abundance patterns for cellular nutritiona
Ikuya Yano - One of the best experts on this subject based on the ideXlab platform.
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in vivo administration of mycobacterial cord factor trehalose 6 6 dimycolate can induce lung and liver granulomas and thymic atrophy in rabbits
Infection and Immunity, 2000Co-Authors: Naoko Hamasaki, Takayuki Matsumoto, Tetsuo Arakawa, Koichi Isowa, Kohachi Kamada, Yoshitake Terano, Kazuo Kobayashi, Ikuya YanoAbstract:Trehalose 6,6′-dimycolate (TDM) is a cell surface molecule of Mycobacterium tuberculosis. TDM induced a loss of body weight and prominent granulomas in the liver and lungs by the intravenous injection of TDM into rabbits. TDM also induced atrophy of the thymus and spleen due to apoptosis. By contrast, Sulfolipid (2,3,6,6′-tetraacyl trehalose 2′-sulfate) induced neither toxicity, nor granuloma formation, nor atrophy of the thymus and spleen. In rabbits the histopathological changes were more dramatic than in mice. The rabbit model may be more sensitive and may provide more information on the beneficial or pathological effects of TDM.
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induction of hypersensitivity to endotoxin lethality in mice by treatment with trehalose 6 6 dimycolate but not with 2 3 6 6 tetraacyl trehalose 2 sulfate
Journal of Endotoxin Research, 1999Co-Authors: Kenji Watanabe, Nagatoshi Fujiwara, Yoshio Kumazawa, Ryoichi Hasunuma, Tomoko Horikoshi, Hironobu Yamana, Hiroko Maruyama, Ikuya YanoAbstract:The mechanism by which priming with trehalose 6,6′-dimycolate (TDM, cord factor) induced hypersensitivity to endotoxin lethality was investigated. C57BL/6 and BALB/c mice primed with TDM succumbed to endotoxin shock, but BALB/c IFN-γ knock-out (IFN-γ —/—) mice showed resistance to LPS lethality. The levels of serum IFN-γ peaked on day 4 after priming with TDM and kept significant levels, indicating that IFN-γ plays a critical role for inducing hypersensitivity to LPS lethality. After challenge with LPS, TDM-primed mice produced higher amounts of serum TNFα and soluble CD14. A Sulfolipid (SL, 2,3,6,6′-tetraacyl trehalose 2′-sulfate) did not induce the hypersensitivity and, conversely, suppressed the activity of TDM when administered together. Administration of TDM induced infiltration of mononuclear cells in liver, and apoptosis of cells present in the liver sinus was observed after LPS challenge. These results suggest that the hypersensitivity to LPS lethality is due to overproduction of cytokines and oth...
Louie L Wurch - One of the best experts on this subject based on the ideXlab platform.
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proteome changes driven by phosphorus deficiency and recovery in the brown tide forming alga aureococcus anophagefferens
PLOS ONE, 2011Co-Authors: Louie L Wurch, Erin M Bertrand, Mak A Saito, Benjamin A S Van Mooy, Sonya T DyhrmanAbstract:Shotgun mass spectrometry was used to detect proteins in the harmful alga, Aureococcus anophagefferens, and monitor their relative abundance across nutrient replete (control), phosphate-deficient (2P) and 2P refed with phosphate (P-refed) conditions. Spectral counting techniques identified differentially abundant proteins and demonstrated that under phosphate deficiency, A. anophagefferens increases proteins involved in both inorganic and organic phosphorus (P) scavenging, including a phosphate transporter, 59-nucleotidase, and alkaline phosphatase. Additionally, an increase in abundance of a Sulfolipid biosynthesis protein was detected in 2P and P-refed conditions. Analysis of the polar membrane lipids showed that cellular concentrations of the Sulfolipid sulphoquinovosyldiacylglycerol (SQDG) were nearly two-fold greater in the 2P condition versus the control condition, while cellular phospholipids were approximately 8-fold less. Transcript and protein abundances were more tightly coupled for gene products involved in P metabolism compared to those involved in a range of other metabolic functions. Comparison of protein abundances between the 2P and P-refed conditions identified differences in the timing of protein degradation and turnover. This suggests that culture studies examining nutrient starvation responses will be valuable in interpreting protein abundance patterns for cellular nutritional status and history in metaproteomic datasets.
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Proteome Changes Driven by Phosphorus Deficiency and Recovery in the Brown Tide-Forming Alga Aureococcus anophagefferens
2011Co-Authors: Louie L Wurch, Mak A Saito, Benjamin A S Van Mooy, Erin M. Bertr, Sonya T DyhrmanAbstract:Shotgun mass spectrometry was used to detect proteins in the harmful alga, Aureococcus anophagefferens, and monitor their relative abundance across nutrient replete (control), phosphate-deficient (2P) and 2P refed with phosphate (P-refed) conditions. Spectral counting techniques identified differentially abundant proteins and demonstrated that under phosphate deficiency, A. anophagefferens increases proteins involved in both inorganic and organic phosphorus (P) scavenging, including a phosphate transporter, 59-nucleotidase, and alkaline phosphatase. Additionally, an increase in abundance of a Sulfolipid biosynthesis protein was detected in 2P and P-refed conditions. Analysis of the polar membrane lipids showed that cellular concentrations of the Sulfolipid sulphoquinovosyldiacylglycerol (SQDG) were nearly two-fold greater in the 2P condition versus the control condition, while cellular phospholipids were approximately 8-fold less. Transcript and protein abundances were more tightly coupled for gene products involved in P metabolism compared to those involved in a range of other metabolic functions. Comparison of protein abundances between the 2P and P-refed conditions identified differences in the timing of protein degradation and turnover. This suggests that culture studies examining nutrient starvation responses will be valuable in interpreting protein abundance patterns for cellular nutritiona
Hiroki Yoshida - One of the best experts on this subject based on the ideXlab platform.
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characterization of entamoeba histolytica adenosine 5 phosphosulfate aps kinase validation as a target and provision of leads for the development of new drugs against amoebiasis
PLOS Neglected Tropical Diseases, 2019Co-Authors: Fumika Miichi, Takeshi Ishikawa, Vo Kha Tam, Sharmina Deloer, Shinjiro Hamano, Tsuyoshi Hamada, Hiroki YoshidaAbstract:Background Amoebiasis, caused by Entamoeba histolytica infection, is a global public health problem. However, available drugs to treat amoebiasis are currently limited, and no effective vaccine exists. Therefore, development of new preventive measures against amoebiasis is urgently needed. Methodology/Principal findings Here, to develop new drugs against amoebiasis, we focused on E. histolytica adenosine 5′-phosphosulfate kinase (EhAPSK), an essential enzyme in Entamoeba Sulfolipid metabolism. Fatty alcohol disulfates and cholesteryl sulfate, Sulfolipids synthesized in Entamoeba, play important roles in trophozoite proliferation and cyst formation. These processes are closely associated with clinical manifestation and severe pathogenesis of amoebiasis and with disease transmission, respectively. We validated a combination approach of in silico molecular docking analysis and an in vitro enzyme activity assay for large scale screening. Docking simulation ranked the binding free energy between a homology modeling structure of EhAPSK and 400 compounds. The 400 compounds were also screened by a 96-well plate-based in vitro APSK activity assay. Among fifteen compounds identified as EhAPSK inhibitors by the in vitro system, six were ranked by the in silico analysis as having high affinity toward EhAPSK. Furthermore, 2-(3-fluorophenoxy)-N-[4-(2-pyridyl)thiazol-2-yl]-acetamide, 3-phenyl-N-[4-(2-pyridyl)thiazol-2-yl]-imidazole-4-carboxamide, and auranofin, which were identified as EhAPSK inhibitors by both in silico and in vitro analyses, halted not only Entamoeba trophozoite proliferation but also cyst formation. These three compounds also dose-dependently impaired the synthesis of Sulfolipids in E. histolytica. Conclusions/Significance Hence, the combined approach of in silico and in vitro-based EhAPSK analyses identified compounds that can be evaluated for their effects on Entamoeba. This can provide leads for the development of new anti-amoebic and amoebiasis transmission-blocking drugs. This strategy can also be applied to identify specific APSK inhibitors, which will benefit research into sulfur metabolism and the ubiquitous pathway terminally synthesizing essential sulfur-containing biomolecules.
