Coro1A and TRIM67 collaborate in netrin-dependent neuronal morphogenesis.

Neuronal morphogenesis depends on extracellular guidance cues accurately instructing intracellular cytoskeletal remodeling. Here, we describe a novel role of the actin binding protein coronin 1A (Coro1A) in neuronal morphogenesis, where it mediates responses to the axon guidance cue netrin-1. We found that Coro1A localizes to growth cones and filopodial structures and is required for netrin-dependent axon turning, branching, and corpus callosum development. We previously discovered that Coro1A interacts with TRIM67, a brain-enriched E3 ubiquitin ligase that binds the netrin receptor DCC, and is also required for netrin-mediated neuronal morphogenesis. Loss of Coro1A and loss of TRIM67 shared similar phenotypes, suggesting that they may function together in the same netrin pathway. A Coro1A mutant deficient in binding TRIM67 was unable to rescue loss of Coro1A phenotypes, indicating that the interaction between Coro1A and TRIM67 is required for netrin responses. Together, our findings reveal that Coro1A is required for proper neuronal morphogenesis, where it collaborates with TRIM67 downstream of netrin.