phosphofructokinase, muscle type. An ubiquitous metabolic enzyme involved in the synthesis and degradation of fructose 2,6-bisphosphate. Key control step of glycolysis. An allosteric enzyme activated by ADP, AMP, or fructose bisphosphate and inhibited by ATP or citrate. Activity: ATP D-fructose 6-phosphate = ADP D-fructose 1,6-bisphosphate. The holoenzyme consists of 4 subunits. The liver and muscle enzymes are homo-tetramers of four liver or muscle isoforms, respectively. The red blood cell enzyme consists hetero-tetramers of the muscle and liver isoforms. A subunit composition with a higher proportion of platelet type subunits is found in platelets, brain and fibroblasts. Defects in PFKM are the cause of glycogen storage disease VII (GSD-VII) also known as Tarui disease. Two alternatively spliced isoforms have been described. Note: This description may include information from UniProtKB.
Protein type: EC 18.104.22.168; Carbohydrate Metabolism - glycolysis and gluconeogenesis; Kinase, other; Carbohydrate Metabolism - fructose and mannose; Carbohydrate Metabolism - pentose phosphate pathway; Carbohydrate Metabolism - galactose
SS: The number of records in which this modification site was determined using site-specific methods. SS methods include amino acid sequencing, site-directed mutagenesis, modification site-specific antibodies, specific MS strategies, etc.