fosforila

Fosforila (phosphorylation) is the process of introducing a phosphate group into a molecule, typically via transfer from an activated donor such as ATP. In biology, the most common form is protein phosphorylation, in which a kinase transfers a phosphate group to a substrate, usually a protein. The reaction converts ATP to ADP and inorganic phosphate, often requiring divalent metal ions such as Mg2+. The addition of a negatively charged phosphate alters the substrate’s charge, conformation, activity, localization, or interactions.

In cells, phosphorylation is a central mechanism of regulation and signal transduction. Proteins are commonly phosphorylated on serine, threonine, or tyrosine residues by serine/threonine kinases or tyrosine kinases. Phosphorylation is reversible: phosphatases remove phosphate groups, allowing rapid and dynamic control of cellular processes. Beyond proteins, phosphorylation also modifies lipids (such as phosphoinositides) and carbohydrate metabolism (e.g., glucose phosphorylation by hexokinase).

Dysregulation of phosphorylation pathways is linked to many diseases, including cancer, diabetes, and neurodegenerative disorders. The study of phosphorylation in biology and medicine employs techniques such as phospho-specific antibodies, mass spectrometry, kinase assays, and radiolabeling with 32P to identify phosphorylation sites and measure activity.

In summary, phosphorylation is a fundamental post-translational modification and metabolic mechanism that modulates protein function, signaling networks, and cellular metabolism through reversible phosphate transfer.