@article{YuKoflerHaeusleretal.2001, author = {Yu, Tien-Shin and Kofler, Heike and H{\"a}usler, Rainer E. and Hille, Diana and Fl{\"u}gge, Ulf-Ingo and Zeeman, Samuel C. and Smith, Alison M. and Kossmann, Jens and Lloyd, James R. and Ritte, Gerhard and Steup, Martin and Lue, Wei-Ling and Chen, Jychian and Weber, Andreas P. M.}, title = {The Arabidopsis sex1 mutant is defective in the R1 protein, a general regulator of starch degradation in plants, and not in the chloroplast hexose transporter}, issn = {1040-4651}, year = {2001}, language = {en} } @article{WernerBehrsingScharteetal.2002, author = {Werner, Deljana and Behrsing, Olaf and Scharte, Gudrun and Woller, Jochen and Steup, Martin and Micheel, Burkhard}, title = {Monoclonal anti-diuron antibodies prevent inhibition of photosynthesis by diuron}, year = {2002}, language = {en} } @article{TenenboimSmirnovaWillmitzeretal.2014, author = {Tenenboim, Hezi and Smirnova, Julia and Willmitzer, Lothar and Steup, Martin and Brotman, Yariv}, title = {VMP1-deficient Chlamydomonas exhibits severely aberrant cell morphology and disrupted cytokinesies}, series = {BMC plant biology}, volume = {14}, journal = {BMC plant biology}, publisher = {BioMed Central}, address = {London}, issn = {1471-2229}, doi = {10.1186/1471-2229-14-121}, pages = {13}, year = {2014}, abstract = {Background: The versatile Vacuole Membrane Protein 1 (VMP1) has been previously investigated in six species. It has been shown to be essential in macroautophagy, where it takes part in autophagy initiation. In addition, VMP1 has been implicated in organellar biogenesis; endo-, exo- and phagocytosis, and protein secretion; apoptosis; and cell adhesion. These roles underly its proven involvement in pancreatitis, diabetes and cancer in humans. Results: In this study we analyzed a VMP1 homologue from the green alga Chlamydomonas reinhardtii. CrVMP1 knockdown lines showed severe phenotypes, mainly affecting cell division as well as the morphology of cells and organelles. We also provide several pieces of evidence for its involvement in macroautophagy.}, language = {en} } @article{Steup2015, author = {Steup, Martin}, title = {Raum und Zahl in der Pflanzenphysiologie}, series = {Raum und Zahl}, journal = {Raum und Zahl}, publisher = {Trafo}, address = {Berlin}, isbn = {978-3-86464-082-7}, pages = {77 -- 109}, year = {2015}, language = {de} } @article{SteinfathStrehmelPetersetal.2010, author = {Steinfath, Matthias and Strehmel, Nadine and Peters, Rolf and Schauer, Nicolas and Groth, Detlef and Hummel, Jan and Steup, Martin and Selbig, Joachim and Kopka, Joachim and Geigenberger, Peter and Dongen, Joost T. van}, title = {Discovering plant metabolic biomarkers for phenotype prediction using an untargeted approach}, issn = {1467-7644}, doi = {10.1111/j.1467-7652.2010.00516.x}, year = {2010}, abstract = {Biomarkers are used to predict phenotypical properties before these features become apparent and, therefore, are valuable tools for both fundamental and applied research. Diagnostic biomarkers have been discovered in medicine many decades ago and are now commonly applied. While this is routine in the field of medicine, it is of surprise that in agriculture this approach has never been investigated. Up to now, the prediction of phenotypes in plants was based on growing plants and assaying the organs of interest in a time intensive process. For the first time, we demonstrate in this study the application of metabolomics to predict agronomic important phenotypes of a crop plant that was grown in different environments. Our procedure consists of established techniques to screen untargeted for a large amount of metabolites in parallel, in combination with machine learning methods. By using this combination of metabolomics and biomathematical tools metabolites were identified that can be used as biomarkers to improve the prediction of traits. The predictive metabolites can be selected and used subsequently to develop fast, targeted and low-cost diagnostic biomarker assays that can be implemented in breeding programs or quality assessment analysis. The identified metabolic biomarkers allow for the prediction of crop product quality. Furthermore, marker-assisted selection can benefit from the discovery of metabolic biomarkers when other molecular markers come to its limitation. The described marker selection method was developed for potato tubers, but is generally applicable to any crop and trait as it functions independently of genomic information.}, language = {en} } @article{StahlThurlZengetal.1994, author = {Stahl, Bernd and Thurl, Stephan and Zeng, Jianru and Karas, Michael and Hillenkamp, Franz and Steup, Martin and Sawatzki, G{\"u}nther}, title = {Oligosaccharides from human milk as revealed by matrix-assisted laser desorption : ionization mass spectrometry}, year = {1994}, language = {en} } @article{StahlLinosKarasetal.1997, author = {Stahl, Bernd and Linos, Alexandros and Karas, Michael and Hillenkamp, Franz and Steup, Martin}, title = {Analysis of fructans from higher plants by matrix-assisted laser desorption/ionization mass spectrometry}, year = {1997}, language = {en} } @article{StahlKlabundeWitzeletal.1994, author = {Stahl, Bernd and Klabunde, Thomas and Witzel, Herbert and Krebs, Bernt and Steup, Martin and Karas, Michael and Hillenkamp, Franz}, title = {The oligosaccharides of the Fe(III)-Zn(II) purple acid phosphatase of the red kidney bean : determination of the structure by a combination of matrix-assisted laser desorption-ionization mass spectrometry and selective enzymic degradation}, year = {1994}, language = {en} } @article{SonnewaldBasnerGreveetal.1995, author = {Sonnewald, Uwe and Basner, Astrid and Greve, Burkhard and Steup, Martin}, title = {A second L-type isozyme of potato glucan phosphorylase : cloning, antisense inhibition and expression analysis}, year = {1995}, language = {en} } @article{SmirnovaFernieSpahnetal.2017, author = {Smirnova, Julia and Fernie, Alisdair R. and Spahn, Christian M. T. and Steup, Martin}, title = {Photometric assay of maltose and maltose-forming enzyme activity by using 4-alpha-glucanotransferase (DPE2) from higher plants}, series = {Analytical biochemistry : methods in the biological sciences}, volume = {532}, journal = {Analytical biochemistry : methods in the biological sciences}, publisher = {Elsevier}, address = {San Diego}, issn = {0003-2697}, doi = {10.1016/j.ab.2017.05.026}, pages = {72 -- 82}, year = {2017}, abstract = {Maltose frequently occurs as intermediate of the central carbon metabolism of prokaryotic and eukaryotic cells. Various mutants possess elevated maltose levels. Maltose exists as two anomers, (alpha- and beta-form) which are rapidly interconverted without requiring enzyme-mediated catalysis. As maltose is often abundant together with other oligoglucans, selective quantification is essential. In this communication, we present a photometric maltose assay using 4-alpha-glucanotransferase (AtDPE2) from Arabidopsis thaliana. Under in vitro conditions, AtDPE2 utilizes maltose as glucosyl donor and glycogen as acceptor releasing the other hexosyl unit as free glucose which is photometrically quantified following enzymatic phosphorylation and oxidation. Under the conditions used, DPE2 does not noticeably react with other di- or oligosaccharides. Selectivity compares favorably with that of maltase frequently used in maltose assays. Reducing end interconversion of the two maltose anomers is in rapid equilibrium and, therefore, the novel assay measures total maltose contents. Furthermore, an AtDPE2-based continuous photometric assay is presented which allows to quantify beta-amylase activity and was found to be superior to a conventional test. Finally, the AtDPE2-based maltose assay was used to quantify leaf maltose contents of both Arabidopsis wild type and AtDPE2-deficient plants throughout the light-dark cycle. These data are presented together with assimilatory starch levels. (C) 2017 Published by Elsevier Inc.}, language = {en} } @article{SchwarteWegnerHavensteinetal.2015, author = {Schwarte, Sandra and Wegner, Fanny and Havenstein, Katja and Groth, Detlef and Steup, Martin and Tiedemann, Ralph}, title = {Sequence variation, differential expression, and divergent evolution in starch-related genes among accessions of Arabidopsis thaliana}, series = {Plant molecular biology : an international journal of fundamental research and genetic engineering}, volume = {87}, journal = {Plant molecular biology : an international journal of fundamental research and genetic engineering}, number = {4-5}, publisher = {Springer}, address = {Dordrecht}, issn = {0167-4412}, doi = {10.1007/s11103-015-0293-2}, pages = {489 -- 519}, year = {2015}, abstract = {Transitory starch metabolism is a nonlinear and highly regulated process. It originated very early in the evolution of chloroplast-containing cells and is largely based on a mosaic of genes derived from either the eukaryotic host cell or the prokaryotic endosymbiont. Initially located in the cytoplasm, starch metabolism was rewired into plastids in Chloroplastida. Relocation was accompanied by gene duplications that occurred in most starch-related gene families and resulted in subfunctionalization of the respective gene products. Starch-related isozymes were then evolutionary conserved by constraints such as internal starch structure, posttranslational protein import into plastids and interactions with other starch-related proteins. 25 starch-related genes in 26 accessions of Arabidopsis thaliana were sequenced to assess intraspecific diversity, phylogenetic relationships, and modes of selection. Furthermore, sequences derived from additional 80 accessions that are publicly available were analyzed. Diversity varies significantly among the starch-related genes. Starch synthases and phosphorylases exhibit highest nucleotide diversities, while pyrophosphatases and debranching enzymes are most conserved. The gene trees are most compatible with a scenario of extensive recombination, perhaps in a Pleistocene refugium. Most genes are under purifying selection, but disruptive selection was inferred for a few genes/substitutiones. To study transcript levels, leaves were harvested throughout the light period. By quantifying the transcript levels and by analyzing the sequence of the respective accessions, we were able to estimate whether transcript levels are mainly determined by genetic (i.e., accession dependent) or physiological (i.e., time dependent) parameters. We also identified polymorphic sites that putatively affect pattern or the level of transcripts.}, language = {en} } @article{SchwarteBrustSteupetal.2013, author = {Schwarte, Sandra and Brust, Henrike and Steup, Martin and Tiedemann, Ralph}, title = {Intraspecific sequence variation and differential expression in starch synthase genes of Arabidopsis thaliana}, doi = {10.1186/1756-0500-6-84}, year = {2013}, language = {en} } @article{SchmiederNitschkeSteupetal.2013, author = {Schmieder, Peter and Nitschke, Felix and Steup, Martin and Mallow, Keven and Specker, Edgar}, title = {Determination of glucan phosphorylation using heteronuclear H-1,C-13 double and H-1,C-13,P-31 triple-resonance NMR spectra}, series = {Magnetic resonance in chemistry}, volume = {51}, journal = {Magnetic resonance in chemistry}, number = {10}, publisher = {Wiley-Blackwell}, address = {Hoboken}, issn = {0749-1581}, doi = {10.1002/mrc.3996}, pages = {655 -- 661}, year = {2013}, abstract = {Phosphorylation and dephosphorylation of starch and glycogen are important for their physicochemical properties and also their physiological functions. It is therefore desirable to reliably determine the phosphorylation sites. Heteronuclear multidimensional NMR-spectroscopy is in principle a straightforward analytical approach even for complex carbohydrate molecules. With heterogeneous samples from natural sources, however, the task becomes more difficult because a full assignment of the resonances of the carbohydrates is impossible to obtain. Here, we show that the combination of heteronuclear H-1,C-13 and H-1,C-13,P-31 techniques and information derived from spectra of a set of reference compounds can lead to an unambiguous determination of the phosphorylation sites even in heterogeneous samples.}, language = {en} } @article{SchmalzlinvanDongenKlimantetal.2005, author = {Schmalzlin, E. and van Dongen, J. T. and Klimant, I. and Marmodee, Bettina and Steup, Martin and Fisahn, Joachim and Geigenberger, Peter Ludwig and L{\"o}hmannsr{\"o}ben, Hans-Gerd}, title = {An optical multifrequency phase-modulation method using microbeads for measuring intracellular oxygen concentrations in plants}, issn = {0006-3495}, year = {2005}, abstract = {A technique has been developed to measure absolute intracellular oxygen concentrations in green plants. Oxygen- sensitive phosphorescent microbeads were injected into the cells and an optical multifrequency phase-modulation technique was used to discriminate the sensor signal from the strong auto fluorescence of the plant tissue. The method was established using photosynthesis- competent cells of the giant algae Chara corallina L., and was validated by application to various cell types of other plant species}, language = {en} } @article{RuzanskiSmirnovaRejzeketal.2013, author = {Ruzanski, Christian and Smirnova, Julia and Rejzek, Martin and Cockburn, Darrell and Pedersen, Henriette L. and Pike, Marilyn and Willats, William G. T. and Svensson, Birte and Steup, Martin and Ebenh{\"o}h, Oliver and Smith, Alison M. and Field, Robert A.}, title = {A bacterial glucanotransferase can replace the complex maltose metabolism required for starch to sucrose conversion in leaves at night}, series = {The journal of biological chemistry}, volume = {288}, journal = {The journal of biological chemistry}, number = {40}, publisher = {American Society for Biochemistry and Molecular Biology}, address = {Bethesda}, issn = {0021-9258}, doi = {10.1074/jbc.M113.497867}, pages = {28581 -- 28598}, year = {2013}, abstract = {Controlled conversion of leaf starch to sucrose at night is essential for the normal growth of Arabidopsis. The conversion involves the cytosolic metabolism of maltose to hexose phosphates via an unusual, multidomain protein with 4-glucanotransferase activity, DPE2, believed to transfer glucosyl moieties to a complex heteroglycan prior to their conversion to hexose phosphate via a cytosolic phosphorylase. The significance of this complex pathway is unclear; conversion of maltose to hexose phosphate in bacteria proceeds via a more typical 4-glucanotransferase that does not require a heteroglycan acceptor. It has recently been suggested that DPE2 generates a heterogeneous series of terminal glucan chains on the heteroglycan that acts as a glucosyl buffer to ensure a constant rate of sucrose synthesis in the leaf at night. Alternatively, DPE2 and/or the heteroglycan may have specific properties important for their function in the plant. To distinguish between these ideas, we compared the properties of DPE2 with those of the Escherichia coli glucanotransferase MalQ. We found that MalQ cannot use the plant heteroglycan as an acceptor for glucosyl transfer. However, experimental and modeling approaches suggested that it can potentially generate a glucosyl buffer between maltose and hexose phosphate because, unlike DPE2, it can generate polydisperse malto-oligosaccharides from maltose. Consistent with this suggestion, MalQ is capable of restoring an essentially wild-type phenotype when expressed in mutant Arabidopsis plants lacking DPE2. In light of these findings, we discuss the possible evolutionary origins of the complex DPE2-heteroglycan pathway.}, language = {en} } @article{RitteSteupKossmannetal.2003, author = {Ritte, Gerhard and Steup, Martin and Kossmann, Jens and Lloyd, James R.}, title = {Determination of the starch phosphorylating enzyme activity in plant extracts}, year = {2003}, language = {en} } @article{RitteScharfEckermannetal.2004, author = {Ritte, Gerhard and Scharf, Anke and Eckermann, Nora and Haebel, Sophie and Steup, Martin}, title = {Phosphorylation of transitory starch is increased during degradation}, year = {2004}, abstract = {The starch excess phenotype of Arabidopsis mutants defective in the starch phosphorylating enzyme glucan, water dikinase (EC 2.7.9.4) indicates that phosphorylation of starch is required for its degradation. However, the underlying mechanism has not yet been elucidated. In this study, two in vivo systems have been established that allow the analysis of phosphorylation of transitory starch during both biosynthesis in the light and degradation in darkness. First, a photoautotrophic culture of the unicellular green alga Chlamydomonas reinhardtii was used to monitor the incorporation of exogenously supplied P-32 orthophosphate into starch. Illuminated cells incorporated P-32 into starch with a constant rate during 2 h. By contrast, starch phosphorylation in darkened cells exceeded that in illuminated cells within the first 30 min, but subsequently phosphate incorporation declined. Pulse-chase experiments performed with P-32/P-31 orthophosphate revealed a high turnover of the starch-bound phosphate esters in darkened cells but no detectable turnover in illuminated cells. Secondly, leaf starch granules were isolated from potato (Solanum tuberosum) plants grown under controlled conditions and glucan chains from the outer granule layer were released by isoamylase. Phosphorylated chains were purified and analyzed using high performance anion-exchange chromatography and matrix-assisted laser desorption/ionization mass spectrometry. Glucans released from the surface of starch granules that had been isolated from darkened leaves possessed a considerably higher degree of phosphorylation than those prepared from leaves harvested during the light period. Thus, in the unicellular alga as well as in potato leaves, net starch degradation is accompanied with an increased phosphorylation of starch}, language = {en} } @article{RitteRuthSteup2000, author = {Ritte, Gerhard and Ruth, Lorberth and Steup, Martin}, title = {Reversible binding of the starch-related R1 protein to the surface of transitory starch granules}, year = {2000}, language = {en} } @article{RitteLloydEckermannetal.2002, author = {Ritte, Gerhard and Lloyd, James R. and Eckermann, Nora and Rottmann, Antje and Kossmann, Jens and Steup, Martin}, title = {The starch-related R1 protein is an a-glucan, water dikinase}, issn = {0027-8424}, year = {2002}, language = {en} } @article{RitteHeydenreichMahlowetal.2006, author = {Ritte, Gerhard and Heydenreich, Matthias and Mahlow, Sebastian and Haebel, Sophie and Koetting, Oliver and Steup, Martin}, title = {Phosphorylation of C6- and C3-positions of glucosyl residues in starch is catalysed by distinct dikinases}, series = {FEBS letters : the journal for rapid publication of short reports in molecular biosciences}, volume = {580}, journal = {FEBS letters : the journal for rapid publication of short reports in molecular biosciences}, number = {20}, publisher = {Elsevier}, address = {Amsterdam}, issn = {0014-5793}, doi = {10.1016/j.febslet.2006.07.085}, pages = {4872 -- 4876}, year = {2006}, abstract = {Glucan, water dikinase (GWD) and phosphoglucan, water dikinase (PWD) are required for normal starch metabolism. We analysed starch phosphorylation in Arabidopsis wildtype plants and mutants lacking either GWD or PWD using P-31 NMR. Phosphorylation at both C6- and C3-positions of glucose moieties in starch was drastically decreased in GWD-deficient mutants. In starch from PWD-deficient plants C3-bound phosphate was reduced to levels close to the detection limit. The latter result contrasts with previous reports according to which GWD phosphorylates both C6- and C3-positions. In these studies, phosphorylation had been analysed by HPLC of acid-hydrolysed glucans. We now show that maltose-6-phosphate, a product of incomplete starch hydrolysis, co-eluted with glucose-3-phosphate under the chromatographic conditions applied. Re-examination of the specificity of the dikinases using an improved method demonstrates that C6- and C3-phosphorylation is selectively catalysed by GWD and PWD, respectively.}, language = {en} }