دورية أكاديمية
Phosphofructokinase isozymes in pancreatic islets and clonal beta-cells (INS-1).
| العنوان: | Phosphofructokinase isozymes in pancreatic islets and clonal beta-cells (INS-1). |
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| المؤلفون: | Yaney GC; Evans Department of Medicine, Boston University School of Medicine, Massachusetts 02118, USA., Schultz V, Cunningham BA, Dunaway GA, Corkey BE, Tornheim K |
| المصدر: | Diabetes [Diabetes] 1995 Nov; Vol. 44 (11), pp. 1285-9. |
| نوع المنشور: | Journal Article; Research Support, Non-U.S. Gov't; Research Support, U.S. Gov't, P.H.S. |
| اللغة: | English |
| بيانات الدورية: | Publisher: American Diabetes Association Country of Publication: United States NLM ID: 0372763 Publication Model: Print Cited Medium: Print ISSN: 0012-1797 (Print) Linking ISSN: 00121797 NLM ISO Abbreviation: Diabetes Subsets: MEDLINE |
| أسماء مطبوعة: | Publication: Alexandria, VA : American Diabetes Association Original Publication: [New York, American Diabetes Association] |
| مواضيع طبية MeSH: | Insulin/*metabolism , Islets of Langerhans/*enzymology , Islets of Langerhans/*metabolism , Isoenzymes/*metabolism , Phosphofructokinase-1/*metabolism, Adenosine Monophosphate/pharmacology ; Adenosine Triphosphate/pharmacology ; Animals ; Blotting, Western ; Clone Cells ; Enzyme Activation ; Fructosediphosphates/pharmacology ; Fructosephosphates/pharmacology ; Glucose/pharmacology ; In Vitro Techniques ; Insulin Secretion ; Islets of Langerhans/drug effects ; Isoenzymes/isolation & purification ; Kinetics ; Macromolecular Substances ; Male ; Oscillometry ; Phosphofructokinase-1/isolation & purification ; Rats ; Rats, Sprague-Dawley ; Time Factors |
| مستخلص: | Normal insulin secretion is oscillatory in vivo, and the oscillations are impaired in type II diabetes. We and others have shown oscillations in insulin secretion from isolated perifused islets stimulated with glucose, and in this study we show oscillations in insulin secretion from the glucose-sensitive clonal beta-cell line INS-1. We have proposed that the oscillatory insulin secretion may be caused by spontaneous oscillations of glycolysis and the ATP:ADP ratio in the beta-cell, analogous to those seen in glycolyzing muscle extracts. The mechanism of the latter involves autocatalytic activation of the key regulatory enzyme, phosphofructokinase (PFK), by its product fructose 1,6-bisphosphate (F16BP). However, of the three PFK subunit isoforms (M-[muscle], L-[liver], and C-type, predominant in fibroblasts), only M-type is activated by micromolar F16BP at near-physiological conditions. We therefore studied PFK isoforms in the beta-cell. Western analysis of PFK subunits in isolated rat islets and INS-1 cells showed the presence of M-type, as well as C-type and perhaps lesser amounts of L-type. Kinetic studies of PFK activity in INS-1 cell extracts showed strong activation by micromolar concentrations of F16BP at near-physiological concentrations of ATP (several millimolar) and AMP and fructose 6-phosphate (micromolar), indicative of the M-type isoform. Activation by submicromolar concentrations of fructose 2,6-bisphosphate (F26BP) and potent inhibition by citrate were also observed. The F16BP-stimulatable activity was about one-half of the F26BP-stimulatable activity.(ABSTRACT TRUNCATED AT 250 WORDS) |
| معلومات مُعتمدة: | DK-31559 United States DK NIDDK NIH HHS; DK-35914 United States DK NIDDK NIH HHS; DK-46200 United States DK NIDDK NIH HHS; etc. |
| المشرفين على المادة: | 0 (Fructosediphosphates) 0 (Fructosephosphates) 0 (Insulin) 0 (Isoenzymes) 0 (Macromolecular Substances) 415SHH325A (Adenosine Monophosphate) 6814-87-5 (fructose-6-phosphate) 8L70Q75FXE (Adenosine Triphosphate) EC 2.7.1.11 (Phosphofructokinase-1) IY9XDZ35W2 (Glucose) M7522JYX1H (fructose-1,6-diphosphate) |
| تواريخ الأحداث: | Date Created: 19951101 Date Completed: 19951129 Latest Revision: 20190515 |
| رمز التحديث: | 20231215 |
| DOI: | 10.2337/diab.44.11.1285 |
| PMID: | 7589825 |
| قاعدة البيانات: | MEDLINE |
| تدمد: | 0012-1797 |
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| DOI: | 10.2337/diab.44.11.1285 |