Peptide Receptor Targeting in Cancer: The Somatostatin Paradigm

Figure 2

Dimerization pattern of somatostatin receptors. Each SST receptor subtype show a different constitutive tendency to dimerize. sst1 exists as a monomer while sst2, 3, 4 and 5 homo-dimerization occurs both constitutively or after somatostatin binding. SST receptors may form heterodimers with other member of SST receptor family, either in resting conditions or upon ligand binding. SST receptors also dimerize with receptors of other GPCR families, (e.g., D2R) or with other receptor families, such as tyrosine kinase receptors (i.e., EGFR), originating heterodimers.