Updated project metadata. In neurons, mRNAs and associated RNA-binding proteins assemble into ribonucleoprotein (RNP) granules essential to regulate mRNA trafficking, local translation, and turnover. Dysregulation of RNA-protein condensation can disturb synaptic plasticity. We report that the novel lncRNA mimi is a constitutive and essential component of large cytoplasmic condensates (RNP granules) in fly neurons that are biochemically enriched by differential centrifugation. Here, employing relative iBAQ quantification we carry out a differential proteomic analysis of cytoplasmic RNP granules in wild-type versus delta-mimi mutant fly brains. Brain lysates from wild-type and mutant flies serve as a general proteome input control.