@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}
}
@article{NitschkeWangSchmiederetal.2013,
  author    = {Nitschke, Felix and Wang, Peixiang and Schmieder, Peter and Girard, Jean-Marie and Awrey, Donald E. and Wang, Tony and Israelian, Johan and Zhao, XiaoChu and Turnbull, Julie and Heydenreich, Matthias and Kleinpeter, Erich and Steup, Martin and Minassian, Berge A.},
  title     = {Hyperphosphorylation of glucosyl C6 carbons and altered structure of glycogen in the neurodegenerative epilepsy lafora disease},
  series = {Cell metabolism},
  volume    = {17},
  journal   = {Cell metabolism},
  number    = {5},
  publisher = {Cell Press},
  address   = {Cambridge},
  issn      = {1550-4131},
  doi       = {10.1016/j.cmet.2013.04.006},
  pages     = {756 -- 767},
  year      = {2013},
  abstract  = {Laforin or malin deficiency causes Lafora disease, characterized by altered glycogen metabolism and teenage-onset neurodegeneration with intractable and invariably fatal epilepsy. Plant starches possess small amounts of metabolically essential monophosphate esters. Glycogen contains similar phosphate amounts, which are thought to originate from a glycogen synthase error side reaction and therefore lack any specific function. Glycogen is also believed to lack monophosphates at glucosyl carbon C6, an essential phosphorylation site in plant starch metabolism. We now show that glycogen phosphorylation is not due to a glycogen synthase side reaction, that C6 is a major glycogen phosphorylation site, and that C6 monophosphates predominate near centers of glycogen molecules and positively correlate with glycogen chain lengths. Laforin or malin deficiency causes C6 hyperphosphorylation, which results in malformed long-chained glycogen that accumulates in many tissues, causing neurodegeneration in brain. Our work advances the understanding of Lafora disease pathogenesis and suggests that glycogen phosphorylation has important metabolic function.},
  language  = {en}
}