Glycogen metabolism in a Saccharomyces cerevisiae phosphoglucose isomerase (pgi1) disruption mutant

FEBS Letters

Clotet, Josep¹  Boles, Eckhard²  Fernández-Bañares, Isabel¹  Zimmmermann, Friedrich K.²  Corominas, Josep¹  Ariño, Joaquín¹  Guinovart, Joan J.³ 

[1] Department of Bioquímica i Biología Molecular, Facultat de Veterinària, Universitat Autònoma de Barcelona, Bellaterra E-08193, Barcelona, Spain;Institut für Mikrobiologie, T.H. Darmstadt, Darmstadt D-6100, Germany;Department de Bioquímica i Fisiologia, Facultat de Química Fisiologia, Facultat de Química, Universitat de Barcelona, Barcelona E-08028, Spain

关键词: Phosphoglucose isomerase mutant;    Gene disruption;    Glycogen accumulation;    Phosphorylase;    Glycogen synthase;    Saccharomyces cerevisiae;   

DOI  :  10.1016/0014-5793(92)81325-G

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Disruption of the gene pgi1 of Saccharomyces cerevisiae, which codes for phosphoglucose isomerase, results in a dramatic increase in the amount of intracellular glycogen in early exponential cultures. The level or glucose 6-phosphate was much higher in mutant than in wild-type cells. Phosphorylase a activity and the state of activation of glycogen synthase were also investigated. Phosphorylase a activity was rather low along the culture in wild-type cells, whereas it was consistently higher in mutants. Glycogen synthase was mostly in the active form in early-medium exponential cultures in wild-type cells whereas the activation state of this enzyme in mutant cells, although lower at the earlier steps of the culture, did not differ from wild-type cells at later stages. The fact that the intracellular levels of UDP-glucose are markedly increased in mutant cells suggest that the observed accumulation of glycogen results from a rise in substrate availability rather than from the activation of the enzyme responsible for the synthesis of the polysaccharide.

【 授权许可】

Unknown