RET is a single transmembrane-spanning receptor tyrosine kinase (RTK) that plays critical roles in the development of vertebrates. Structural analysis indicate that RET contains four consecutive cadherin-like domains (CLD). This entry relates to the first CLD at the N-terminal. Several regions within RET-CLD1 have been shown to be important for ligand-coreceptor binding. CLD1 and CLD2 have a distinctive clamshell shape and CLD1 is essential for CLD2 folding. CLD1 contains 2 sites for GDNF receptor alpha 1 binding [1].

1: RET recognition of GDNF-GFRalpha1 ligand by a composite binding site promotes membrane-proximal self-association. Goodman KM, Kjaer S, Beuron F, Knowles PP, Nawrotek A, Burns EM, Purkiss AG, George R, Santoro M, Morris EP, McDonald NQ; Cell Rep. 2014;8:1894-1904. PMID:25242331