Probing into the function of the gene product responsible for glycogen storage disease type Ib

FEBS Letters

Xie, Wensheng²  Berteloot, Alfred¹  van de Werve, Gérald² 

[1] Groupe de Recherche en Transport Membranaire, Montréal, QC, Canada H3C 3J7;Laboratoire d'Endocrinologie Métabolique, Départements de Nutrition et de Biochimie, Centre de Recherche du CHUM, Montréal, QC, Canada H3C 3J7

关键词: Glucose 6-phosphatase system;    Transport kinetics;    Glucose 6-phosphate transport;    Vectorial transport;    Rat liver microsome;    FSRFA;    fast-sampling;    rapid-filtration apparatus;    G6P;    glucose 6-phosphate;    G6Pase;    glucose 6-phosphatase;    GSD;    glycogen storage disease;    Pi;    inorganic phosphate;    p36;    catalytic unit of G6Pase;    p46;    GSD-Ib gene product;    the putative G6P transport protein;    S.E.M.;    standard error of the mean;    S.E.R.;    standard error of regression;    UhpT;    upper hexose phosphate transporter;   

DOI  :  10.1016/S0014-5793(01)02758-2

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

This study aimed at directly assessing glucose 6-phosphate (G6P) transport by intact rat liver microsomes. Tracer uptake from labeled G6P occurred with T _1/2 values that proved insensitive to unlabeled G6P or 100 μM vanadate, and could not be activated over background levels by intravesicular phosphate in the complete absence of G6P hydrolysis. [³²P]Phosphate efflux was similarly unaffected by G6P or phosphate in the incubation medium. We conclude that the gene product responsible for glycogen storage disease type Ib is functionally distinct from the bacterial hexose phosphate transporter, which operates as an obligatory phosphate:phosphate or G6P:phosphate exchanger.

【 授权许可】

Unknown