What Is Phosphorylation?

Phosphorylation is the process of adding phosphate groups to intermediate metabolites or to proteins. The enzyme in which the phosphate group is removed is called a phosphatase. Protein phosphorylation can occur on many types of amino acids (the main unit of protein), most of which are serine, followed by threonine.

Phosphorylation

Addition or removal of phosphate group (

Distribution process (3 photos)

Phosphorylation (English: Phosphorylation ), or phosphorylation, refers to the addition of a phosphate (PO4) group to a protein or other type of molecule. It can also be defined as "introducing a phosphate group into an organic molecule." This role plays an important role in biochemistry. Protein phosphorylation can occur on many types of amino acids (the main unit of protein), most of which are serine, followed by threonine. Tyrosine is relatively less phosphorylated. However, since tyrosine after phosphorylation is easier to be purified by antibodies, the position of tyrosine phosphorylation is also widely known.

In addition to proteins, the formation of some nucleotides, such as adenosine triphosphate (ATP) or guanosine triphosphate (GTP), also occurs through the phosphorylation of adenosine diphosphate and guanosine diphosphate. This process is called oxidative phosphorylation. In addition, in the biochemical reactions of many sugars (such as glycolysis), there are some steps where oxidative phosphorylation occurs.

Role in signalling:

(1) Signaling proteins in cells are mainly divided into two categories: one is phosphorylated under the action of protein kinases and covalently binds the phosphate group provided by ATP; the other is bound to GTP under the action of signals, usually by GTP replaces GDP.

(2) The common feature of these two intracellular signaling proteins is that they are activated by obtaining one or several phosphate groups when the signal is reached, and they can be removed when the signal is weakened, thereby losing activity. In a signal relay network, phosphorylation of a signal protein usually causes downstream proteins to phosphorylate in sequence, forming a phosphorylation cascade.

(3) The phosphorylation of proteins is mainly concentrated on the tyrosine, serine, and threonine residues in the peptide chain. These residues have free hydroxyl groups and are not charged. When phosphorylation occurs, the protein will Having a charge, so that the structure changes, and further changes in protein activity, which is also the significance of protein phosphorylation.