UNC-45A is a highly conserved member of the UNC-45/CRO1/She4p family of proteins, which act as chaperones for conventional and nonconventional myosins. NMII mediates contractility and actin-based motility, which are fundamental for proper growth cone motility and neurite extension. The presence and role of UNC-45A in neuronal differentiation have been largely unknown. Here we demonstrate that UNC-45A is a novel growth cone--localized, NMII-associated component of the multiprotein complex regulating growth cone dynamics. We show that UNC-45A is dispensable for neuron survival but required for neurite elongation. Mechanistically, loss of UNC-45A results in increased levels of NMII activation. Collectively our results provide novel insights into the molecular mechanisms of neurite growth and define UNC-45A as a novel and master regulator of NMII-mediated cellular processes in neurons.
© 2017 Iizuka, Mooneyham et al. This article is distributed by The American Society for Cell Biology under license from the author(s). Two months after publication it is available to the public under an Attribution–Noncommercial–Share Alike 3.0 Unported Creative Commons License (http://creativecommons.org/licenses/by-nc-sa/3.0).