Question

Which of the following glycolytic enzymes is regulated by both allosteric regulation and reversible phosphorylation?

Group of answer choices

phosphoglyceromutase

pyruvate kinase

glyceraldehyde-3-phosphate dehydrogenase

phosphoglycerate kinase

cyclic AMP-dependent protein kinase

Answer 1

Answer: Pyruvate kinase

Pyruvate kinase is used in the last step of glycolysis and its regulation is important while making pyruvate. They are regulated by both by allosteric regulation and reversible although its function is affected or regulated by various minor factors one important effector factor is FBP or fructose 1,6 bisphosphate which works allosterically to regulate the enzyme.

While there are various isozymes for PK one of the form is M2 which exists in both dimer and tetramer form. The tetramer form acts as the active enzyme but it can be regulated reverse phosphorylating it into dimer and making it inactive.