Ubiquitinated proteome of E15.5 murine cortical neurons

TRIM9 and TRIM67 are neuronally-enriched E3 ubiquitin ligases essential for neuronal morphogenesis and responses to the axon guidance cue netrin-1. Deletion of either gene in the mouse results in subtle neuroanatomical anomalies yet overt deficits in spatial learning and memory. The identify of few TRIM9 or TRIM67 substrates are known. Here we performed ubiquitin remnant profiling approach (Xu et al., 2010)in cultured cortical neurons from murine wildtype, Trim9-/-, Trim67-/-, and Trim9-/-:Trim67-/- embryos cultured with or without netrin-1 supplementation to attempt to identify proteins with altered ubiquitination. Although batch variability hindered our ability to identify differential protein ubiquitination, the results delineate the neuronal ubiquitionome during neurite outgrowth, axon specification, and axon branching.