Format

Send to

Choose Destination
See comment in PubMed Commons below
Cell Metab. 2011 Mar 2;13(3):274-82. doi: 10.1016/j.cmet.2011.01.017.

Phosphate incorporation during glycogen synthesis and Lafora disease.

Author information

1
Department of Biochemistry and Molecular Biology, Indiana University School of Medicine, Indianapolis, IN 46202, USA.

Abstract

Glycogen is a branched polymer of glucose that serves as an energy store. Phosphate, a trace constituent of glycogen, has profound effects on glycogen structure, and phosphate hyperaccumulation is linked to Lafora disease, a fatal progressive myoclonus epilepsy that can be caused by mutations of laforin, a glycogen phosphatase. However, little is known about the metabolism of glycogen phosphate. We demonstrate here that the biosynthetic enzyme glycogen synthase, which normally adds glucose residues to glycogen, is capable of incorporating the β-phosphate of its substrate UDP-glucose at a rate of one phosphate per approximately 10,000 glucoses, in what may be considered a catalytic error. We show that the phosphate in glycogen is present as C2 and C3 phosphomonoesters. Since hyperphosphorylation of glycogen causes Lafora disease, phosphate removal by laforin may thus be considered a repair or damage control mechanism.

PMID:
21356517
PMCID:
PMC3124772
DOI:
10.1016/j.cmet.2011.01.017
[Indexed for MEDLINE]
Free PMC Article
PubMed Commons home

PubMed Commons

0 comments
How to join PubMed Commons

    Supplemental Content

    Full text links

    Icon for Elsevier Science Icon for PubMed Central
    Loading ...
    Support Center