Abstract
Glucose catabolism induces the expression of the L-type pyruvate kinase (L-PK) gene through the glucose response element (GIRE). The metabolic pathway used by glucose after its phosphorylation to glucose 6-phosphate by glucokinase to induce L-PK gene expression in hepatocytes remains unknown. The sugar alcohol xylitol is metabolized to xylulose 5-phosphate, an intermediate of the nonoxidative branch of the pentose phosphate pathway. In this study, we demonstrated that xylitol at low concentration (0.5 mM) induced the expression of the L-PK/CAT construct in glucose-responsive mhAT3F hepatoma cells at the same level as 20 mM glucose, while it did not affect intracellular concentration of glucose 6-phosphate significantly. The effect of xylitol on the induction of the L-PK gene expression was noncumulative with that of glucose since 20 mM glucose plus 5 mM xylitol induced the expression of the L-PK/CAT construct similarly to 20 mM glucose alone. In hepatocytes in primary culture, 5 mM xylitol induced accumulation of the L- PK mRNA even in the absence of insulin. Furthermore, the response to xylitol as well as glucose required the presence of a functional GIRE. It can be assumed from these results that glucose induces the expression of the L-PK gene through the nonoxidative branch of the pentose phosphate pathway. The effect of xylitol at low concentration suggests that the glucose signal to the transcriptional machinery is mediated by xylulose 5-phosphate.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 5321-5324 |
| Number of pages | 4 |
| Journal | Journal of Biological Chemistry |
| Volume | 271 |
| Issue number | 10 |
| DOIs | |
| State | Published - Mar 8 1996 |
| Externally published | Yes |
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ASJC Scopus subject areas
- Biochemistry
Cite this
Transcriptional glucose signaling through the glucose response element is mediated by the pentose phosphate pathway. / Doiron, Bruno; Cuif, Marie Hélène; Chen, Ruihuan; Kahn, Axel.
In: Journal of Biological Chemistry, Vol. 271, No. 10, 08.03.1996, p. 5321-5324.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Transcriptional glucose signaling through the glucose response element is mediated by the pentose phosphate pathway
AU - Doiron, Bruno
AU - Cuif, Marie Hélène
AU - Chen, Ruihuan
AU - Kahn, Axel
PY - 1996/3/8
Y1 - 1996/3/8
N2 - Glucose catabolism induces the expression of the L-type pyruvate kinase (L-PK) gene through the glucose response element (GIRE). The metabolic pathway used by glucose after its phosphorylation to glucose 6-phosphate by glucokinase to induce L-PK gene expression in hepatocytes remains unknown. The sugar alcohol xylitol is metabolized to xylulose 5-phosphate, an intermediate of the nonoxidative branch of the pentose phosphate pathway. In this study, we demonstrated that xylitol at low concentration (0.5 mM) induced the expression of the L-PK/CAT construct in glucose-responsive mhAT3F hepatoma cells at the same level as 20 mM glucose, while it did not affect intracellular concentration of glucose 6-phosphate significantly. The effect of xylitol on the induction of the L-PK gene expression was noncumulative with that of glucose since 20 mM glucose plus 5 mM xylitol induced the expression of the L-PK/CAT construct similarly to 20 mM glucose alone. In hepatocytes in primary culture, 5 mM xylitol induced accumulation of the L- PK mRNA even in the absence of insulin. Furthermore, the response to xylitol as well as glucose required the presence of a functional GIRE. It can be assumed from these results that glucose induces the expression of the L-PK gene through the nonoxidative branch of the pentose phosphate pathway. The effect of xylitol at low concentration suggests that the glucose signal to the transcriptional machinery is mediated by xylulose 5-phosphate.
AB - Glucose catabolism induces the expression of the L-type pyruvate kinase (L-PK) gene through the glucose response element (GIRE). The metabolic pathway used by glucose after its phosphorylation to glucose 6-phosphate by glucokinase to induce L-PK gene expression in hepatocytes remains unknown. The sugar alcohol xylitol is metabolized to xylulose 5-phosphate, an intermediate of the nonoxidative branch of the pentose phosphate pathway. In this study, we demonstrated that xylitol at low concentration (0.5 mM) induced the expression of the L-PK/CAT construct in glucose-responsive mhAT3F hepatoma cells at the same level as 20 mM glucose, while it did not affect intracellular concentration of glucose 6-phosphate significantly. The effect of xylitol on the induction of the L-PK gene expression was noncumulative with that of glucose since 20 mM glucose plus 5 mM xylitol induced the expression of the L-PK/CAT construct similarly to 20 mM glucose alone. In hepatocytes in primary culture, 5 mM xylitol induced accumulation of the L- PK mRNA even in the absence of insulin. Furthermore, the response to xylitol as well as glucose required the presence of a functional GIRE. It can be assumed from these results that glucose induces the expression of the L-PK gene through the nonoxidative branch of the pentose phosphate pathway. The effect of xylitol at low concentration suggests that the glucose signal to the transcriptional machinery is mediated by xylulose 5-phosphate.
UR - http://www.scopus.com/inward/record.url?scp=0029966308&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0029966308&partnerID=8YFLogxK
U2 - 10.1074/jbc.271.10.5321
DO - 10.1074/jbc.271.10.5321
M3 - Article
C2 - 8621383
AN - SCOPUS:0029966308
VL - 271
SP - 5321
EP - 5324
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
SN - 0021-9258
IS - 10
ER -