The aim of this work was to study whether changes in fructose 2,6-bisphosphate concentration are correlated with variations of the glycolytic flux in the isolated working rat heart. Glycolysis was stimulated to different extents by increasing the concentration of glucose, increasing the workload, or by the addition of insulin. The glycolytic flux was measured by the rate of detritiation of [2-3H]- and [3-3H]glucose. Under all the conditions tested, an increase in fructose 2,6-bisphosphate content was observed. The glucose- or insulin-induced increase in fructose 2,6-bisphosphate content was related to an increase in the concentration of fructose 6-phosphate, the substrate of 6-phosphofructo-2-kinase. An increase in the workload correlated with a 50% decrease in the Km of 6-phosphofructo-2-kinase for fructose 6-phosphate. Similar changes in Km have been observed when purified heart 6-phosphofructo-2-kinase was phosphorylated in vitro by the cyclic AMP-dependent protein kinase or by the calcium/calmodulin-dependent protein kinase. Since the concentration of cyclic AMP was not affected by increasing the workload, it is possible that the change in Km of 6-phosphofructo-2-kinase, which was found in hearts submitted to a high load, resulted from phosphorylation by calcium/calmodulin protein kinase; other possibilities are not excluded. Anoxia decreased the external work developed by the heart, stimulated glycolysis and glycogenolysis, but did not increase fructose 2,6-bisphosphate.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
A vacuolar invertase gene modulates sugar metabolism and postharvest fruit quality and stress resistance in tomato.
Hortic Res
January 2025
Key Laboratory of Bio-Resource and Eco-Environment of Ministry of Education, College of Life Sciences, Sichuan University, Chengdu 610065, Sichuan, China.
Sugars act as signaling molecules to modulate various growth processes and enhance plant tolerance to various abiotic and biotic stresses. Moreover, sugars contribute to the postharvest flavor in fleshy fruit crops. To date, the regulation of sugar metabolism and its effect in plant growth, fruit ripening, postharvest quality, and stress resistance remains not fully understood.
View Article and Find Full Text PDFStrawberry plant growth enhancement: Effects of artificial light and methyl jasmonate-salicylic acid treatments on physiology and metabolism.
Heliyon
January 2025
Department of Agronomy and Horticulture, Faculty of Agriculture, IPB University, Bogor, Indonesia.
Strawberries, known for their antioxidant properties, exhibit changes in physiology and metabolite profiles based on cultivation techniques. In Indonesia, strawberries are typically grown in highland regions, but climate change has necessitated adjustments in cultivation practices to enhance production and quality. This study investigates the adaptation of strawberry plants in lowland environments using light-emitting diodes (LEDs) and the exogenous application of methyl jasmonate (MeJA) and methyl salicylic acid (MeSA).
View Article and Find Full Text PDFPutative Transformation Mechanism of γ-l-Glutamyl-S-Allyl-l-Cysteine during the Processing of Black Garlic.
J Agric Food Chem
January 2025
Institute of Quality Standard and Testing Technology for Agro-Products, Shandong Academy of Agricultural Sciences, Jinan 250100, Shandong, China.
γ-l-Glutamyl-S-allyl-l-cysteine (GSAC) is renowned for its flavor-modifying effects and beneficial biological activities. However, the level of GSAC decreases significantly during the processing of black garlic, and the pathways and degradation products resulting from this decline remain unclear. To investigate the potential transformation mechanisms of GSAC in black garlic, simulation systems for thermal decomposition, Maillard reactions, and enzymatic hydrolysis were established.
View Article and Find Full Text PDFA Dive Into Yeast's Sugar Diet-Comparing the Metabolic Response of Glucose, Fructose, Sucrose, and Maltose Under Dynamic Feast/Famine Conditions.
Biotechnol Bioeng
January 2025
Department of Biotechnology, Faculty of Applied Sciences, Delft University of Technology, Delft, The Netherlands.
Microbes experience dynamic conditions in natural habitats as well as in engineered environments, such as large-scale bioreactors, which exhibit increased mixing times and inhomogeneities. While single perturbations have been studied for several organisms and substrates, the impact of recurring short-term perturbations remains largely unknown. In this study, we investigated the response of Saccharomyces cerevisiae to repetitive gradients of four different sugars: glucose, fructose, sucrose, and maltose.
View Article and Find Full Text PDFRepression of PFKFB3 sensitizes ovarian cancer to PARP inhibitors by impairing homologous recombination repair.
Cell Commun Signal
January 2025
Department of Obstetrics and Gynecology, Peking University Third Hospital, Beijing, 100191, China.
Background: Ovarian cancer (OC), particularly high-grade serous ovarian carcinoma (HGSOC), is the leading cause of mortality from gynecological malignancies worldwide. Despite the initial effectiveness of treatment, acquired resistance to poly(ADP-ribose) polymerase inhibitors (PARPis) represents a major challenge for the clinical management of HGSOC, highlighting the necessity for the development of novel therapeutic strategies. This study investigated the role of 6-phosphofructo-2-kinase/fructose-2,6-bisphosphatase 3 (PFKFB3), a pivotal regulator of glycolysis, in PARPi resistance and explored its potential as a therapeutic target to overcome PARPi resistance.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!