PKDCC (also known as vertebrate lonesome kinase, VLK) is a secreted tyrosine kinase that mediates phosphorylation of extracellular proteins and endogenous proteins in the secretory pathway, which is essential for patterning at organogenesis stages []. It contains an N-terminal signal sequence and a divergent C-terminal catalytic protein kinase-like domain that replaces the canonical kinase 'DFG' and 'HRD' motifs with alternate, yet functional residues []. It has been shown to interact with Gli3 to regulate chondrocyte differentiation during mouse long bone development [].In Xenopus, there are two members of the PKDCC family, Pkdcc1 and Pkdcc2. They are involved in the regulation of JNK dependent Wnt/PCP signaling pathway [].
