Diabetes, Vol 45, Issue 12 1670-1677, Copyright © 1996 by American Diabetes Association

ARTICLES

Heterologous expression and characterization of rat liver glucokinase regulatory protein

KA Mookhtiar, SS Kalinowski, KS Brown, YH Tsay, C Smith-Monroy and GW Robinson
Department of Metabolic Diseases, Bristol-Myers Squibb Pharmaceutical Research Institute, Princeton, New Jersey 08543, USA.

Glucokinase is a critical component of the physiological glucose sensor found in cell types that are responsive to changes in plasma glucose levels. The acute regulation of glucokinase activity has been shown to occur via a regulatory protein found in liver parenchymal cells (Van Schaftingen E, Detheux M, Da Cunha MV. Faseb J 8:414-419, 1994). The action of this protein is modulated by phosphate esters of fructose. In the presence of fructose-6-phosphate, the protein inhibits glucokinase in an allosteric competitive manner, while fructose-1-phosphate reverses this inhibition. A cDNA potentially encoding the rat liver regulatory protein has been cloned, but its identity is uncertain because of the small amounts of soluble protein obtained by expression in bacteria. We report the heterologous expression of the regulatory protein in Escherichia coli and its purification to homogeneity and high specific activity in a single chromatographic step. The properties of this recombinant protein are very similar to those of the liver protein. Direct demonstration of the binding of the recombinant protein to glucokinase has been obtained in vitro using coprecipitation experiments and in vivo, using the yeast two-hybrid system. These studies establish that the protein encoded by the cDNA is identical to the glucokinase regulatory protein and also validate tools with which to carry out structure-function studies on the interaction of the regulatory protein with glucokinase.
CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				V. V. Heredia, T. J. Carlson, E. Garcia, and S. Sun Biochemical Basis of Glucokinase Activation and the Regulation by Glucokinase Regulatory Protein in Naturally Occurring Mutations J. Biol. Chem., December 29, 2006; 281(52): 40201 - 40207. [Abstract] [Full Text] [PDF]

				M. Futamura, H. Hosaka, A. Kadotani, H. Shimazaki, K. Sasaki, S. Ohyama, T. Nishimura, J.-i. Eiki, and Y. Nagata An Allosteric Activator of Glucokinase Impairs the Interaction of Glucokinase and Glucokinase Regulatory Protein and Regulates Glucose Metabolism J. Biol. Chem., December 8, 2006; 281(49): 37668 - 37674. [Abstract] [Full Text] [PDF]

				M A. Zulet, A. Barber, H. Garcin, P. Higueret, and J. A. Martinez Alterations in Carbohydrate and Lipid Metabolism Induced by a Diet Rich in Coconut Oil and Cholesterol in a Rat Model J. Am. Coll. Nutr., February 1, 1999; 18(1): 36 - 42. [Abstract] [Full Text] [PDF]