Expression of glucose transporter isoform GLUT-2 and glucokinase genes in human brain |
| |
Authors: | Roncero Isabel Alvarez Elvira Chowen Julie A Sanz Carmen Rábano Alberto Vázquez Patricia Blázquez Enrique |
| |
Affiliation: | Department of Biochemistry and Molecular Biology, Faculty of Medicine, Madrid, Spain. |
| |
Abstract: | The glucose transporter isoform-2 (GLUT-2) and glucokinase are considered to be components of a glucose sensor system controlling several key processes, and hence may modulate feeding behaviour. We have found GLUT-2 and glucokinase mRNAs in several brain regions, including the ventromedial and arcuate nuclei of the hypothalamus. GLUT-2, glucokinase and glucokinase regulatory protein mRNAs and proteins were present in these areas as determined by biochemical approaches. In addition, glucose-phosphorylating activity with a high apparent Km for glucose that displayed no product inhibition by glucose-6-phosphate was observed. Increased glycaemia after meals may be recognized by specific hypothalamic neurones due to the high Km of GLUT-2 and glucokinase. This enzyme is considered to be the true glucose sensor because it catalyses the rate-limiting step of glucose catabolism its activity being regulated by interaction with glucokinase regulatory protein, that functions as a metabolic sensor. |
| |
Keywords: | GLUT-2 glucokinase glucokinase regulatory protein glucose sensing human brain |
本文献已被 PubMed 等数据库收录! |
|