Regulation of gene expression by Set-beta in rat retinal ganglion cells

The goal of this experiment was to investigate the molecular mechanism of how Set-beta regulates neurite growth. Set-betas subcellular localization is regulated by posttranslational modifications. We found that Set-beta suppresses neurite growth of purified postnatal rat retinal ganglion cell (RGC) primary neurons when it is overexpressed in the nucleus, whereas recruiting Set-beta to cellular membrane by fusing myr-tag to its N-terminus promotes neurite growth. Here, we transfected purified by immunopanning postnatal rat RGC with wild-type Set-beta which localizes to the nucleus, myr-Set-beta which is recruited to cellular membranes, and mCherry control, and analyzed with microarrays Set-betas subcellular localization-dependent effects on gene expression. We found that wild-type Set- regulated expression of significantly more genes than myr-Set-, consistent with wild-type Set-s nuclear localization and previously described roles in regulating transcription. These data reveal potential downstream gene effectors regulating neurite growth, and specific candidate genes could be validated and tested in future experiments.

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Trakhtenberg EF, Wang Y, Morkin MI, Fernandez SG, Mlacker GM, Shechter JM, Liu X, Patel KH, Lapins A, Yang S, Dombrowski SM, Goldberg JL