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Muscle Disorders
Published in Philip B. Gorelick, Fernando D. Testai, Graeme J. Hankey, Joanna M. Wardlaw, Hankey's Clinical Neurology, 2020
Kourosh Rezania, Peter Pytel, Betty Soliven
Autosomal recessive disorder due to phosphofructokinase (PFK) deficiency. PFK gene is mapped to chromosome 12. PFK catalyzes the conversion of fructose-6-phosphate to fructose-1, 6-diphosphate in muscle, which is the rate-limiting step in the glycolytic pathway.
The Bioenergetics of Mammalian Sperm Motility
Published in Claude Gagnon, Controls of Sperm Motility, 2020
About 50% of the fructose 1,6-bisphosphate produced by phosphofructokinase is recycled to fructose 6-phosphate and this is nearly independent of glycolytic flux. At low glycolytic flux, substrate cycling consumes all or nearly all the ATP produced by the conversion of glucose to lactate and the pathway probably serves as source of pyruvate for mitochondrial respiration. Futile substrate cycling also occurs in boar and rat spermatozoa. In the boar, increased cycling of hexose phosphates accounts for a large part of the decrease in net glycolytic flux when pyruvate and lactate are added to the incubation.6
Specific Nature of Training on Skeletal Muscles
Published in Atko Viru, Adaptation in Sports Training, 2017
Phosphofructokinase activity is controlled by AMP, ADP, ATP, citrate, ammonium, and fructose biphosphate.173 The enzyme is also sensitive to decrease in pH.174 The enzyme concentration itself may also modulate the activity: a cell with a high concentration of the enzyme will exhibit a higher activity than could be expected from the simple linear relationship between enzyme concentration and activity.175 It may be speculated that training-induced increase in the enzyme concentration sensitizes the enzyme activity to stimulatory factors. This explanation implies that the enzyme sensitivity to inhibitory factors is also increased. Thus, despite the elevated number of enzyme molecules, the activity was reduced in resting conditions. Final conclusion of the obtained results points to an enhanced effectiveness of the regulation of phosphofructokinase activity in the organism trained by interval or continuous exercises.
PFKFB3 downregulation aggravates Angiotensin II-induced podocyte detachment
Published in Renal Failure, 2023
Xiaoxiao Huang, Zhaowei Chen, Zilv Luo, Yiqun Hao, Jun Feng, Zijing Zhu, Xueyan Yang, Zongwei Zhang, Jijia Hu, Wei Liang, Guohua Ding
The homodimeric and bifunctional enzyme family of phosphofructokinase-2/Fructose-2,6-bisphosphatase (PFK-2/PFKFB) promotes glycolysis by increasing levels of fructose-2,6-bisphosphate (F2,6P2), which in turn activates the key rate-limiting enzyme 6-phosphofructo-1-kinase (PFK-1) and enhances the conversion of fructose-6-phosphate (F6P) to fructose-1,6-bisphosphate (F1,6P2) in the glycolytic pathway. This causes increased glycolytic flux and increased ATP and NADH production [16]. Among the PFKFB family of four enzymes (PFKFB1-4), PFKFB3 has the highest ratio of kinase to phosphatase activity, which ensures a high glycolytic rate [17]. Recent findings have indicated that PFKFB3 exerts protective effects on the kidneys [18] and promotes the activation of cyclin-dependent kinase-1(cdk1) [19], which promotes talin1 phosphorylation [20]. Excessive talin1 phosphorylation promotes integrin beta1 subunit (ITGB1) activity on the cell surface [21]. Active ITGB1 is an important adhesion molecule on the surface of podocytes, and its activation enhances podocyte adhesion capacity [22–25]. Inhibiting PFKFB3 significantly reduces the expression of cell adhesion molecules, resulting in diminished cell adhesion [26–29]. Therefore, we speculated that Ang II could inhibit talin1 phosphorylation and ITGB1 activation through downregulating PFKFB3 expression. Therefore, we investigated the role of PFKFB3 in Ang II-induced podocyte injury and identified a novel target for CKD treatment.
Glucose metabolism inhibitor PFK-015 combined with immune checkpoint inhibitor is an effective treatment regimen in cancer
Published in OncoImmunology, 2022
Jia Bo Zheng, Chau Wei Wong, Jia Liu, Xiao-Jing Luo, Wei-Yi Zhou, Yan-Xing Chen, Hui-Yan Luo, Zhao-Lei Zeng, Chao Ren, Xiao-Ming Xie, De-Shen Wang
Glycolysis intensity is regulated by the activity of three physiologically reversible enzymes: hexokinase, phosphofructokinase-1 (PFK-1), and pyruvate kinase. PFK-1 is the main rate-limiting enzyme of glycolysis and the activity of PFK-1 is regulated by metabolic products such as adenosine triphosphate (ATP), adenosine diphosphate (ADP), and fructose 2–6 biphosphate.4 Of these compounds, F-2-6-BP is a reaction product catalyzed by 6-phosphofructose 2-kinase/fructose-2,6-biphosphatase (PFK-2/FBPase-2/PFKFB), which is also the most potent positive allosteric effector of PFK-1.4,5 PFKFB is a bifunctional enzyme responsible for the catalyzation of both the synthesis and degradation of F-2,6-BP mediated through its N-terminal domain (2-kase) and C-terminal domain (2-pase) respectively. Of note, the active site of the 2-kase domain has 2 distinct key areas (the F-6-P binding loop and the ATP-binding loop) which are essential for PFKFB to function.6
Research progress of nanocarriers for gene therapy targeting abnormal glucose and lipid metabolism in tumors
Published in Drug Delivery, 2021
Xianhu Zeng, Zhipeng Li, Chunrong Zhu, Lisa Xu, Yong Sun, Shangcong Han
At present, studies (Shlomai et al. 2016; Wojciechowska et al. 2016; Miao et al. 2017) have found that patients with diabetes have a higher incidence of related tumor diseases than normal people. Research data show that the risk of colorectal cancer in diabetic patients is 27% higher than that of normal people (Gonzalez et al. 2017). Thus, researchers have concluded that the occurrence of tumors is related to abnormal glucose and lipid metabolism. In the process of glucose and lipid metabolism, hexokinase and phosphofructokinase play an important role in the glycolysis process (Tao et al. 2017), and Katagiri et al. (Katagiri et al. 2017) found that the high expression level of type II hexokinase is related to the size of tumors. The degree of invasion and the nature of metastasis are significantly related to the increase in tumor recurrence rate and the overall mortality of patients.