TY - JOUR A1 - Dauvillee, David A1 - Chochois, Vincent A1 - Steup, Martin A1 - Haebel, Sophie A1 - Eckermann, Nora A1 - Ritte, Gerhard A1 - Ral, Jean-Philippe A1 - Colleoni, Christophe A1 - Hicks, Glenn A1 - Wattebled, Fabrice A1 - Deschamps, Philippe A1 - Lienard, Luc A1 - Cournac, Laurent A1 - Putaux, Jean-Luc A1 - Dupeyre, Danielle A1 - Ball, Steven G. T1 - Plastidial phosphorylase is required for normal starch synthesis in Chlamydomonas reinhardtii JF - The plant journal N2 - Among the three distinct starch phosphorylase activities detected in Chlamydomonas reinhardtii, two distinct plastidial enzymes (PhoA and PhoB) are documented while a single extraplastidial form (PhoC) displays a higher affinity for glycogen as in vascular plants. The two plastidial phosphorylases are shown to function as homodimers containing two 91-kDa (PhoA) subunits and two 110-kDa (PhoB) subunits. Both lack the typical 80-amino-acid insertion found in the higher plant plastidial forms. PhoB is exquisitely sensitive to inhibition by ADP-glucose and has a low affinity for malto-oligosaccharides. PhoA is more similar to the higher plant plastidial phosphorylases: it is moderately sensitive to ADP-glucose inhibition and has a high affinity for unbranched malto-oligosaccharides. Molecular analysis establishes that STA4 encodes PhoB. Chlamydomonas reinhardtii strains carrying mutations at the STA4 locus display a significant decrease in amounts of starch during storage that correlates with the accumulation of abnormally shaped granules containing a modified amylopectin structure and a high amylose content. The wild-type phenotype could be rescued by reintroduction of the cloned wild-type genomic DNA, thereby demonstrating the involvement of phosphorylase in storage starch synthesis. KW - Chlamydomonas KW - starch KW - amylopectin KW - (glycogen) starch phosphorylase Y1 - 2006 U6 - https://doi.org/10.1111/j.1365-313X.2006.02870.x SN - 0960-7412 VL - 48 IS - 2 SP - 274 EP - 285 PB - Blackwell CY - Oxford ER - TY - JOUR A1 - Fettke, Jörg A1 - Malinova, Irina A1 - Eckermann, Nora A1 - Steup, Martin T1 - Cytosolic heteroglycans in photoautotrophic and in heterotrophic plant cells N2 - In plants several 'starch-related' enzymes exist as plastid- and cytosol-specific isoforms and in some cases the extraplastidial isoforms represent the majority of the enzyme activity. Due to the compartmentation of the plant cells, these extraplastidial isozymes have no access to the plastidial starch granules and, therefore, their in vivo function remained enigmatic. Recently, cytosolic heteroglycans have been identified that possess a complex pattern of the monomer composition and glycosidic bonds. The glycans act both as acceptors and donors for cytosolic glucosyl transferases. In autotrophic tissues the heteroglycans are essential for the nocturnal starch-sucrose conversion. In this review we summarize the current knowledge of these glycans, their interaction with glucosyl transferases and their possible cellular functions. We include data on the heteroglycans in heterotrophic plant tissues and discuss their role in intracellular carbon fluxes that originate from externally supplied carbohydrates. Y1 - 2009 UR - http://www.sciencedirect.com/science/journal/00319422 U6 - https://doi.org/10.1016/j.phytochem.2009.03.016 SN - 0031-9422 ER - TY - JOUR A1 - Baumann, Ingrid A1 - Eckermann, Nora A1 - Krause, Udo A1 - Baumann, Guido T1 - Effects of sucrose in the culture medium on cytological characteristics, pigments and photosynthetic activity of green callus cultures of sugar beet Y1 - 1994 ER - TY - JOUR A1 - Baumann, Ingrid A1 - Eckermann, Nora T1 - Ploidy level and chlorophyll content of single plastids and cells from callus cultures during conversion to autotrophic growth Y1 - 1994 ER - TY - JOUR A1 - Baumann, Guido A1 - Eckermann, Nora A1 - Meinel, Thomas T1 - Zur Kohlenstoffassimilation in grünen Zuckerrüben-Kalluskulturen Y1 - 1994 ER - TY - JOUR A1 - Eckermann, Nora A1 - Baumann, Guido T1 - Enzymatic changes in callus cultures of sugar beet during the transition from photoheterotrophic to photoautotrophic growth Y1 - 1995 ER - TY - JOUR A1 - Ritte, Gerhard A1 - Eckermann, Nora A1 - Haebel, Sophie A1 - Lorberth, Ruth A1 - Steup, Martin T1 - Compartmentation of the starch-related R1 protein in higher plants Y1 - 2000 ER - TY - JOUR A1 - Ritte, Gerhard A1 - Lloyd, James R. A1 - Eckermann, Nora A1 - Rottmann, Antje A1 - Kossmann, Jens A1 - Steup, Martin T1 - The starch-related R1 protein is an a-glucan, water dikinase Y1 - 2002 SN - 0027-8424 ER - TY - JOUR A1 - Eckermann, Nora A1 - Fettke, Jörg A1 - Steup, Martin T1 - Identification of polysaccharide binding proteins by affinity electrophoresis in inhomogeneous polyacrylamide gels and subsequent SDS-PAGE/MALDI-TOF analysis Y1 - 2002 ER - TY - JOUR A1 - Usadel, Björn A1 - Kuschinsky, Anja M. A1 - Rosso, Mario G. A1 - Eckermann, Nora A1 - Pauly, Markus T1 - RHM2 is involved in mucilage pectin synthesis and is required for the development of the seed coat in Arabidopsis N2 - Pectins are major components of primary plant cell walls and the seed mucilage of Arabidopsis. Despite progress in the structural elucidation of pectins, only very few enzymes participating in or regulating their synthesis have been identified. A first candidate gene involved-in the synthesis of pectinaceous rhamnogalacturonan I is RHM2, a putative plant ortholog to NDP-rhamnose biosynthetic enzymes in bacteria. Expression studies with a promoter beta-glucuronidase construct and reverse transcription PCR data show that RHM2 is expressed ubiquitously. Rhm2 T-DNA insertion mutant lines were identified using a reverse genetics approach. Analysis of the rhm2 seeds by various staining methods and chemical analysis of the mucilage revealed a strong reduction of rhamnogalacturonan I in the mucilage and a decrease of its molecular weight. In addition, scanning electron microscopy of the seed surface indicated a distorted testa morphology, illustrating not only a structural but also a developmental role for RGI or rhamnose metabolism in proper testa formation Y1 - 2004 ER -