Glycogen hyperaccumulation in Saccharomyces cerevisiae ras2 mutant A biochemical study

FEBS Letters

Ariño, Joaquin¹  Clotet, Josep¹  Fernández-Bañares, Isabel¹  Guinovart, Joan J.² 

[1] Departament de Bioquímica i Biologia Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra E-08193, Barcelona, Spain;Departament de Bioquímica i Fisiologia, Facultat de Química, Universitat de Barcelona, Barcelona E-08028, Spain

关键词: cAMP;    ras2 Mutants;    Glycogen;    Glycogen synthase;    Glycogen phosphorylase;    Yeast;    Saccharomyces cerevisiae;    fructose-2;    6;    -P2;    fructose 2;    6-bisphosphate;    glucose 6-P;    glucose 6-phosphate;    PFK-2;    6-phosphofructo-2-kinase;   

DOI  :  10.1016/0014-5793(91)81220-3

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

The mechanism by which yeast ras2 mutant hyperaccumulates glycogen has been investigated. Total glycogen synthase activity was between and 1.3 times higher in the ras2 mutant than in an isogenic strain. In addition, while in the normal strain the glycogen synthase activation state decreased along the exponential phase, in the mutant strain the opposite behaviour was observed: glycogen synthase activation state rose continuously reaching full activation at the beginning of the stationary phase. Glycogen phosphorylase a activity was up to 40 times higher in the mutant than in the normal strain. Glucose 6-phosphate and fructose 2,6-bisphosphate levels were slightly more elevated in the mutants. The increase in total glycogen synthase and, particularly, the full activation of this enzyme may explain glycogen hyperaccumulation in the ras2 mutant even in the presence of elevated levels of glycogen phosphorylase a.

【 授权许可】

Unknown