The Kinetochore Protein KNL-1 Regulates the Actin Cytoskeleton to Control Dendrite Branching

Abstract

ABSTRACTThe function of the nervous system is intimately linked to its complex and highly inter-connected architecture. Precise control of dendritic branching in individual neurons is central to building the complex structure of the nervous system. Here we show that the kinetochore protein KNL-1 and its associated KMN (Knl1/Mis12/Ndc80 complex) network partners, typically known for their role in chromosome-microtubule coupling during mitosis, regulate dendrite branching in theC. elegansmechanosensory PVD neuron. KNL-1 restrains excess dendritic branching and promotes contact-dependent repulsion events, ensuring robust sensory behaviour and protecting against age-dependent neuron degeneration. Surprisingly, KNL-1 does not act via modulating the microtubule cytoskeleton in dendrites. Instead, KNL-1 controls the actin cytoskeleton to ensure proper dendrite architecture. These findings establish that the post-mitotic neuronal KMN network acts to shape the developing nervous system by regulating the actin cytoskeleton and provide new insight into the mechanisms controlling dendrite architecture.