PKCδ is essential for Dishevelled function in a noncanonical Wnt pathway that regulates Xenopus convergent extension movements

Protein kinase C (PKC) has been implicated in the Wnt signaling pathway; however, its molecular role is poorly understood. We identified novel genes encoding delta-type PKC in the Xenopus EST databases. Loss of PKCdelta function revealed that it was essential for convergent extension during gastrulation. We then examined the relationship between PKCdelta and the Wnt pathway. PKCdelta was translocated to the plasma membrane in response to Frizzled signaling. In addition, loss of PKCdelta function inhibited the translocation of Dishevelled and the activation of c-Jun N-terminal kinase (INK) by Frizzled. Furthermore, PKCdelta formed a complex with Dishevelled, and the activation of PKCdelta by phorbol ester was sufficient for Dishevelled translocation and INK activation. Thus, PKCdelta plays an essential role in the Wnt/JNK pathway by regulating the localization and activity of Dishevelled.