摘要：

Growth factor receptors with protein tyrosine kinase activity show similar molecular anatomy and contain closely related structural elements. Hence, their ligand-induced activation is probably mediated by a common mechanism. An allosteric oligomerization model is described for the activation of growth factor receptors by ligand binding. It is proposed that ligand-induced hetero- or homooligomerization is able to regulate receptor kinase activities. Analyses of the properties of various epidermal-growth-factor receptor (EGF-R) mutants indicate that the intrinsic protein tyrosine kinase activity is essential for signal transduction, mitogenesis and normal receptor trafficking. Moreover, autophosphorylation is mediated by intermolecular crossphosphorylation within an oligomeric receptor complex. Thus receptor oligomerization may provide a mechanism for both receptor activation and receptor autophosphorylation.

展开