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Glucokinase regulatory protein is associated with mitochondria in hepatocytes
Author(s) -
Arden Catherine,
Baltrusch Simone,
Agius Loranne
Publication year - 2006
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/j.febslet.2006.03.009
Subject(s) - glucokinase , glycolysis , mitochondrion , hexokinase , biology , phosphofructokinase , percoll , biochemistry , gluconeogenesis , hepatocyte , microbiology and biotechnology , metabolism , enzyme , centrifugation , in vitro
The association of glucokinase with liver mitochondria has been reported [Danial et al. (2003) BAD and glucokinase reside in a mitochondrial complex that integrates glycolysis and apoptosis. Nature 424, 952–956]. We confirmed association of glucokinase immunoreactivity with rat liver mitochondria using Percoll gradient centrifugation and demonstrated its association with the 68 kDa regulatory protein (GKRP) but not with the binding protein phosphofructokinase‐2/fructose bisphosphatase‐2. Substrates and glucagon induced adaptive changes in the mitochondrial glucokinase/GKRP ratio suggesting a regulatory role for GKRP. Combined with previous observations that GKRP overexpression partially inhibits glycolysis [de la Iglesia et al. (2000) The role of the regulatory protein of glucokinase in the glucose sensory mechanism of the hepatocyte. J. Biol. Chem. 275, 10597–10603] these findings suggest that there may be distinct glycolytic pools of glucokinase.