DAPK interacts with Patronin and the microtubule cytoskeleton in epidermal development and wound repair.

Abstract

Epidermal barrier epithelia form a first line of defense against the environment, protecting animals against infection and repairing physical damage. In <i>C. elegans,</i> death-associated protein kinase (DAPK-1) regulates epidermal morphogenesis, innate immunity and wound repair. Combining genetic suppressor screens and pharmacological tests, we find that DAPK-1 maintains epidermal tissue integrity through regulation of the microtubule (MT) cytoskeleton. <i>dapk-1</i> epidermal phenotypes are suppressed by treatment with microtubule-destabilizing drugs and mimicked or enhanced by microtubule-stabilizing drugs. Loss of function in <i>ptrn-1</i>, the <i>C. elegans</i> member of the Patronin/Nezha/CAMSAP family of MT minus-end binding proteins, suppresses <i>dapk-1</i> epidermal and innate immunity phenotypes. Over-expression of the MT-binding CKK domain of PTRN-1 triggers epidermal and immunity defects resembling those of <i>dapk-1</i> mutants, and PTRN-1 localization is regulated by DAPK-1. DAPK-1 and PTRN-1 physically interact in co-immunoprecipitation experiments, and DAPK-1 itself undergoes MT-dependent transport. Our results uncover an unexpected interdependence of DAPK-1 and the microtubule cytoskeleton in maintenance of epidermal integrity.