FIGURE 1.

Anaplastic lymphoma kinase (ALK) receptor domains, pathways, inhibitors, and homologies. Amino acid positions flanking different domains in ALK are shown. Small molecule kinase inhibitors and antibodies are indicated as is the ALK translocation breakpoint. The amino acid sequence overlap and homology of the ECD of LTK is shown. Also, the homology with the closest related kinases is indicated for the kinase domain. Mutations discussed in the text and also in (Wellstein and Toretsky, 2011). The LBD was identified by phage display of a brain cDNA library against immobilized PTN (Stoica et al., 2001). The LBD is within an MAM domain that is frequently found in the ECDs of a diverse family of transmembrane proteins (Prosite data base PDOC 00604). SigP, signal peptide; LBD, ligand binding domain; ECD, extracellular domain; ICD, intracellular domain; TM, transmembrane domain; PTN, pleiotrophin; MK, midkine; LTK, leukocyte tyrosine kinase; IGF1R, insulin-like growth factor 1 receptor; InsR, insulin receptor.