ALKALs are in vivo ligands for ALK family receptor tyrosine kinases in the neural crest and derived cells

作者：Fadeev Andrey; Mendoza Garcia Patricia; Irion Uwe; Guan Jikui; Pfeifer Kathrin; Wiessner Stephanie; Serluca Fabrizio; Singh Ajeet Pratap; Nuesslein Volhard Christiane; Palmer Ruth H^*

来源：Proceedings of the National Academy of Sciences, 2018, 115(4): E630-E638.

DOI：10.1073/pnas.1719137115

• ALK
• ALKAL
• FAM150
• Ltk
• iridophore

Mutations in anaplastic lymphoma kinase (ALK) are implicated in somatic and familial neuroblastoma, a pediatric tumor of neural crest-derived tissues. Recently, biochemical analyses have identified secreted small ALKAL proteins (FAM150, AUG) as potential ligands for human ALK and the related leukocyte tyrosine kinase (LTK). In the zebrafish Danio rerio, DrLtk, which is similar to human ALK in sequence and domain structure, controls the development of iridophores, neural crest-derived pigment cells. Hence, the zebrafish system allows studying Alk/Ltk and Alkals involvement in neural crest regulation in vivo. Using zebrafish pigment pattern formation, Drosophila eye patterning, and cell culture-based assays, we show that zebrafish Alkals potently activate zebrafish Ltk and human ALK driving downstream signaling events. Overexpression of the three DrAlkals cause ectopic iridophore development, whereas loss-of-function alleles lead to spatially distinct patterns of iridophore loss in zebrafish larvae and adults. alkal loss-of-function triple mutants completely lack iridophores and are larval lethal as is the case for ltk null mutants. Our results provide in vivo evidence of (i) activation of ALK/LTK family receptors by ALKALs and (ii) an involvement of these ligand-receptor complexes in neural crest development.

• 出版日期2018-1-23