autophosphorylerar

Autophosphorylation is the process by which a protein kinase adds a phosphate group to itself. In protein kinases, this self-phosphorylation typically occurs on serine, threonine, or tyrosine residues and can regulate catalytic activity, substrate recognition, localization, or protein–protein interactions. The term can appear in different languages as autophosphorylerar or similar forms.

Self-phosphorylation can occur in two general modes: cis-autophosphorylation, where the kinase phosphorylates residues within the same molecule, and trans-autophosphorylation, where one kinase molecule phosphorylates a second molecule in a dimer or oligomer. ATP is the usual phosphate donor, and the resulting phosphates can induce conformational changes that increase or decrease activity, alter substrate specificity, or generate binding sites for downstream signaling proteins.

In receptor tyrosine kinases, ligand binding promotes dimerization and trans-autophosphorylation of tyrosine residues within the intracellular kinase domains. These phosphotyrosines serve as docking sites for SH2-, PTB-, and other phospho‑protein domains, facilitating the propagation of signaling cascades such as the MAPK and PI3K pathways.

Autophosphorylation is also a key feature of non-receptor kinases. For example, CaMKII autophosphorylation at a specific site confers autonomous, calcium-independent activity, extending signaling beyond the initial calcium signal.

Bacterial two-component systems employ a related mechanism in which histidine kinases autophosphorylate on histidine and then transfer the phosphate to a response regulator, linking environmental sensing to cellular responses.

Dysregulation of autophosphorylation can contribute to diseases, including cancer, making its regulation and detection important in research and clinical contexts. Detection methods include phospho-specific antibodies and mass spectrometry to identify phosphorylation sites and dynamics.