Phosphoprotein

A phosphoprotein is a protein that is posttranslationally modified by the attachment of either a single phosphate group, or a complex molecule such as 5'-phospho-DNA, through a phosphate group. The target amino acid is most often serine, threonine, or tyrosine residues (mostly in eukaryotes), or aspartic acid or histidine residues (mostly in prokaryotes).^[1]

Serine in an amino acid chain, before and after phosphorylation.

Biological function

The phosphorylation of proteins is a major regulatory mechanism in cells.^[2][3]

Clinical significance

Phosphoproteins have been proposed as biomarkers for breast cancer.^[4][2]

See also

• Protein phosphorylation
• Phosphoserine