Phosphofructokinase-1 (PFK-1) is one of the most important regulatory enzymes of glycolysis. It is an allosteric enzyme made of 4 subunits and controlled by many activators and inhibitors. PFK-1 catalyzes the important "committed" step of glycolysis, the conversion of fructose 6-phosphate and ATP to fructose 1,6-bisphosphate and ADP. Glycolysis is the foundation for respiration, both anaerobic and aerobic. Because phosphofructokinase (PFK) catalyzes the ATP-dependent phosphorylation to convert fructose-6-phosphate into fructose 1,6-bisphosphate and ADP, it is one of the key regulatory steps of glycolysis. PFK is able to regulate glycolysis through allosteric inhibition, and in this way, the cell can increase or decrease the rate of glycolysis in response to the cell's energy requirements. For example, a high ratio of ATP to ADP will inhibit PFK and glycolysis. The key difference between the regulation of PFK in eukaryotes and prokaryotes is that in eukaryotes PFK is activated by fructose 2,6-bisphosphate. The purpose of fructose 2,6-bisphosphate is to supersede ATP inhibition, thus allowing eukaryotes to have greater sensitivity to regulation by hormones like glucagon and insulin.
Aldolase A, also known as fructose-bisphosphate aldolase, is an enzyme that in humans is encoded by the ALDOA gene on chromosome 16.
Phosphofructokinase-2 (6-phosphofructo-2-kinase, PFK-2) or fructose bisphosphatase-2 (FBPase-2), is an enzyme indirectly responsible for regulating the rates of glycolysis and gluconeogenesis in cells. It catalyzes formation and degradation of a significant allosteric regulator, fructose-2,6-bisphosphate (Fru-2,6-P2) from substrate fructose-6-phosphate. Fru-2,6-P2 contributes to the rate-determining step of glycolysis as it activates enzyme phosphofructokinase 1 in the glycolysis pathway, and inhibits fructose-1,6-bisphosphatase 1 in gluconeogenesis. Since Fru-2,6-P2 differentially regulates glycolysis and gluconeogenesis, it can act as a key signal to switch between the opposing pathways. Because PFK-2 produces Fru-2,6-P2 in response to hormonal signaling, metabolism can be more sensitively and efficiently controlled to align with the organism's glycolytic needs. This enzyme participates in fructose and mannose metabolism. The enzyme is important in the regulation of hepatic carbohydrate metabolism and is found in greatest quantities in the liver, kidney and heart. In mammals, several genes often encode different isoforms, each of which differs in its tissue distribution and enzymatic activity. The family described here bears a resemblance to the ATP-driven phospho-fructokinases, however, they share little sequence similarity, although a few residues seem key to their interaction with fructose 6-phosphate.
Hippocalcin is a protein that in humans is encoded by the HPCA gene.
Fructose 2,6-bisphosphate, abbreviated Fru-2,6-P2, is a metabolite that allosterically affects the activity of the enzymes phosphofructokinase 1 (PFK-1) and fructose 1,6-bisphosphatase (FBPase-1) to regulate glycolysis and gluconeogenesis. Fru-2,6-P2 itself is synthesized and broken down in either direction by the integrated bifunctional enzyme phosphofructokinase 2 (PFK-2/FBPase-2), which also contains a phosphatase domain and is also known as fructose-2,6-bisphosphatase. Whether the kinase and phosphatase domains of PFK-2/FBPase-2 are active or inactive depends on the phosphorylation state of the enzyme.
Phosphofructokinase (PFK) is a kinase enzyme that phosphorylates fructose 6-phosphate in glycolysis.
14-3-3 protein beta/alpha is a protein that in humans is encoded by the YWHAB gene.
14-3-3 protein theta is a protein that in humans is encoded by the YWHAQ gene.
PFKFB3 is a gene that encodes the 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 enzyme in humans. It is one of 4 tissue-specific PFKFB isoenzymes identified currently (PFKFB1-4).
Phosphorylase b kinase gamma catalytic chain, skeletal muscle isoform is an enzyme that in humans is encoded by the PHKG1 gene.
Mitogen-activated protein kinase kinase kinase 4 is an enzyme that in humans is encoded by the MAP3K4 gene.
Phosphofructokinase, platelet, also known as PFKP is an enzyme which in humans is encoded by the PFKP gene.
Serine/threonine-protein kinase PLK2 is an enzyme that in humans is encoded by the PLK2 gene.
Protein phosphatase 1 regulatory subunit 12B is an enzyme that in humans is encoded by the PPP1R12B gene.
6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 1 is an enzyme that in humans is encoded by the PFKFB1 gene.
Dual specificity tyrosine-phosphorylation-regulated kinase 2 is an enzyme, in particular a dual-specificity kinase, that in humans is encoded by the DYRK2 gene.
Twinfilin-2 is a protein that in humans is encoded by the TWF2 gene.
6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 4 also known as PFKFB4 is an enzyme which in humans is encoded by the PFKFB4 gene.
The TP53-inducible glycolysis and apoptosis regulator (TIGAR) also known as fructose-2,6-bisphosphatase TIGAR is an enzyme that in humans is encoded by the C12orf5 gene.
Fructose-bisphosphatase 2 is an enzyme that in humans is encoded by the FBP2 gene.
