Dataset Information

Lack of glycogenin causes glycogen accumulation andmuscle function impairment

ABSTRACT: Glycogenin is considered essential for glycogen synthesis as it acts as a primer for the initiation of the polysaccharide. In this study, we challenge this notion and demonstrate that glycogen can be synthesized in vivo in the absence of glycogenin. Glycogenin-deficient mice (Gyg KO) accumulate high amounts of the polysaccharide in skeletal and cardiac striated muscles. This glycogen shows no covalently bound protein, thereby indicating that no protein primer is essential for glycogen synthesis. Gyg KO mice show lower resting energy expenditure and lesser resistance when subjected to endurance exercise than control animals, which can be attributed to a switch of oxidative myofibers toward glycolytic metabolism. This switch is caused by the over-accumulation of glycogen, since mice overexpressing glycogen synthase specifically in skeletal muscle show a similar metabolic alteration. These results may explain the muscular defects of GSD XV patients, who show high glycogen accumulation in striated muscles.

INSTRUMENT(S): LTQ FT

ORGANISM(S): Mus Musculus (mouse)

TISSUE(S): Liver

SUBMITTER: Marta Vilaseca

LAB HEAD: Joan J. Guinovart

PROVIDER: PXD006377 | Pride | 2017-07-06

REPOSITORIES: Pride

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Dataset's files

Source:

			Action	DRS
	2124_GT_01_KO_amylase_C18.RAW	Raw
	2124_GT_01_KO_glucosidase_C18.RAW	Raw
	2124_GT_02_KO_amylase_C18.RAW	Raw
	2124_GT_02_KO_glucosidase_C18.RAW	Raw
	2124_GT_04_WT_amylase_C18.RAW	Raw

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Publications

Lack of Glycogenin Causes Glycogen Accumulation and Muscle Function Impairment.

Testoni Giorgia G Duran Jordi J García-Rocha Mar M Vilaplana Francisco F Serrano Antonio L AL Sebastián David D López-Soldado Iliana I Sullivan Mitchell A MA Slebe Felipe F Vilaseca Marta M Muñoz-Cánoves Pura P Guinovart Joan J JJ

Cell metabolism 20170701 1

Glycogenin is considered essential for glycogen synthesis, as it acts as a primer for the initiation of the polysaccharide chain. Against expectations, glycogenin-deficient mice (Gyg KO) accumulate high amounts of glycogen in striated muscle. Furthermore, this glycogen contains no covalently bound protein, thereby demonstrating that a protein primer is not strictly necessary for the synthesis of the polysaccharide in vivo. Strikingly, in spite of the higher glycogen content, Gyg KO mice showed l ...[more]

PMID: 28683291

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