Walker-Simmons MK (1998) Protein kinases in seeds. Seed Science Research 7:125-134.

Reversible phosphorylation is catalyzed by protein kinases that transfer the phosphate from ATP to amino acid residues of proteins. The process can be reversed by protein phosphatases. Phosphorylation can dramatically activate or inhibit enzymes and affect protein-protein interaction. Through phosphorylation protein kinases can amplify and propagate cellular signals. In plants and now seeds, protein kinases involved in hormone, defense and environmental stress responses are being identified. Increasingly, these protein kinases are being cloned and characterized, demonstrating the major role of reversible protein phosphorylation in seeds.