| Autor: |
McKnight GL; ZymoGenetics, Inc., Seattle, Washington 98105., Mudri SL, Mathewes SL, Traxinger RR, Marshall S, Sheppard PO, O'Hara PJ |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of biological chemistry [J Biol Chem] 1992 Dec 15; Vol. 267 (35), pp. 25208-12. |
| Abstrakt: |
Glutamine:fructose-6-phosphate amidotransferase (GFAT) has recently been shown to be an insulin-regulated enzyme that plays a key role in the induction of insulin resistance in cultured cells. As a first step in understanding the molecular regulation of this enzyme the human form of this enzyme has been cloned and the functional protein has been expressed in Escherichia coli. A 3.1-kilobase cDNA was isolated which contains the complete coding region of 681 amino acids. Expression of the cDNA in E. coli produced a protein of approximately 77 kDa and increased GFAT activity 4.5-fold over endogenous bacterial levels. Recombinant GFAT activity was inhibited 51% by UDP-GlcNAc whereas bacterial GFAT activity was insensitive to inhibition by UDP-GlcNAc. On the basis of these results we conclude that: 1) functional human GFAT protein was expressed, and 2) the cloned human cDNA encodes both the catalytic and regulatory domains of GFAT since the recombinant GFAT was sensitive to UDP-GlcNAc. Overall, the development of cloned GFAT molecular probes should provide new insights into the development of insulin resistance by allowing quantitation of GFAT mRNA levels in pathophysiological states such as non-insulin-dependent diabetes mellitus and obesity. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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