Читать книгу Essential Endocrinology and Diabetes - Richard I. G. Holt - Страница 61

Phosphorylation of tyrosine kinase receptors can occur through:

 tyrosine kinase that is intrinsic to the cytosolic domain of the receptor and activated after hormone–receptor binding; or

 separate tyrosine kinases that are recruited to the intracellular portion of the receptor after hormone binding (Figure 3.1).

By either mechanism, the conformational change induced by phosphorylation creates ‘docking’ sites for other proteins. Frequently, this occurs via conserved motifs within the target protein, known as ‘SH2’ or ‘SH3’ domains. These domains may be involved in the activation of downstream kinases or they may stabilize other signalling proteins within a phosphorylation cascade.