GCKR
Domain
Fructose 1-phosphate and fructose 6-phosphate compete for the same binding site.
Function
Regulates glucokinase (GCK) by forming an inactive complex with this enzyme (PubMed:23621087, PubMed:23733961). Acts by promoting GCK recruitment to the nucleus, possibly to provide a reserve of GCK that can be quickly released in the cytoplasm after a meal (PubMed:10456334). The affinity of GCKR for GCK is modulated by fructose metabolites: GCKR with bound fructose 6-phosphate has increased affinity for GCK, while GCKR with bound fructose 1-phosphate has strongly decreased affinity for GCK and does not inhibit GCK activity (PubMed:23621087, PubMed:23733961).
Sequence Similarities
Belongs to the GCKR family.
Tissue Specificity
Found in liver and pancreas. Not detected in muscle, brain, heart, thymus, intestine, uterus, adipose tissue, kidney, adrenal, lung or spleen.
Cellular localization
- Cytoplasm
- Nucleus
- Mitochondrion
- Under low glucose concentrations, GCKR associates with GCK and the inactive complex is recruited to the hepatocyte nucleus.
Alternative names
Glucokinase regulatory protein, GKRP, Glucokinase regulator, GCKR