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Identification and characterisation of a new human glucose‐6‐phosphatase isoform
Author(s) -
Guionie Olivier,
Clottes Eric,
Stafford Kirsten,
Burchell Ann
Publication year - 2003
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(03)00903-7
Subject(s) - glucose 6 phosphatase , biochemistry , glycogenolysis , gluconeogenesis , glucose 6 phosphate , hydrolysis , phosphatase , chemistry , gene isoform , phosphate , chinese hamster ovary cell , biology , enzyme , glycogen , gene , receptor
The liver endoplasmic reticulum glucose‐6‐phosphatase catalytic subunit (G6PC1) catalyses glucose 6‐phosphate hydrolysis during gluconeogenesis and glycogenolysis. The highest glucose‐6‐phosphatase activities are found in the liver and the kidney; there have been many reports of glucose 6‐phosphate hydrolysis in other tissues. We cloned a new G6Pase isoform (G6PC3) from human brain encoded by a six‐exon gene (chromosome 17q21). G6PC3 protein was able to hydrolyse glucose 6‐phosphate in transfected Chinese hamster ovary cells. The optimal pH for glucose 6‐phosphate hydrolysis was lower and the K m higher relative to G6PC1. G6PC3 preferentially hydrolyzed other substrates including pNPP and 2‐deoxy‐glucose‐6‐phosphate compared to the liver enzyme.