Differences in regulatory properties between human and rat glucokinase regulatory protein.
The inhibition of glucokinase by rat and Xenopus GKRPs (glucokinase regulatory protein) is well documented. We report a comparison of the effects of human and rat GKRPs on glucokinase activity. Human GKRP is a more potent inhibitor of glucokinase than rat GKRP in the absence of fructose 6-phosphate or sorbitol 6-phosphate, and has a higher affinity for these ligands. However, human and rat GKRPs have similar affinities for fructose 1-phosphate and chloride. Residues that are not conserved between the rodent and human proteins affect both the affinity for fructose 6-phosphate and sorbitol 6-phosphate and the inhibitory potency of GKRP on glucokinase in the absence of these ligands.
Brocklehurst
Katy J
KJ
Cardiovascular and Gastrointestinal Department, AstraZeneca, Macclesfield, Cheshire SK10 4TG, UK.
Davies
Rick A
RA
Agius
Loranne
L
D048868:Adaptor Proteins, Signal Transducing; D000818:Animals; D002352:Carrier Proteins / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D002712:Chlorides / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000302:isolation & purification / Q000378:metabolism / Q000494:pharmacology*; D005636:Fructosephosphates / Q000378:metabolism / Q000494:pharmacology; D005941:Glucokinase / Q000378:metabolism*; D005947:Glucose / Q000494:pharmacology; D006600:Hexosephosphates / Q000378:metabolism / Q000494:pharmacology; D006801:Humans; D047908:Intracellular Signaling Peptides and Proteins; D007700:Kinetics; D008024:Ligands; D051381:Rats; D013045:Species Specificity
D048868:Adaptor Proteins, Signal Transducing; D002352:Carrier Proteins; D002712:Chlorides; D004791:Enzyme Inhibitors; D005636:Fructosephosphates; C485100:GCKR protein, human; C499484:Gckr protein, rat; D006600:Hexosephosphates; D047908:Intracellular Signaling Peptides and Proteins; D008024:Ligands; C080906:glucokinase regulatory protein; C032284:fructose-1-phosphate; C035752:sorbitol 6-phosphate; C027618:fructose-6-phosphate; D005941:Glucokinase; D005947:Glucose