A CRISPR-based genome-wide screen for adipogenesis reveals new insights into mitotic expansion and lipogenesis

In response to excess nutrients, white adipose tissue expands by both generating new adipocytes and by upregulating lipogenesis in existing adipocytes. Here, we performed a genome-wide functional genomics screen to identify regulators of adipogenesis in the mouse 3T3-L1 cell model. The pooled screening strategy utilized FACS to isolate populations based on lipid content by gating for fluorescence intensity of the lipophilic, green fluorescent BODIPY 493/503 dye. Additionally, this approach categorized if genes functioned during mitotic expansion or lipogenesis. Cellular mechanisms regulating the rates of protein translation and protein stability were found to be critical for adipogenesis and lipogenesis. These mechanisms were further supported by proteomic analyses, which demonstrated that many changes in protein abundance during 3T3-L1 adipogenesis were not driven by transcription. Within these themes, we illustrate that hypusination is critical for translating adipogenic inducers of mitotic expansion and that the neddylation/ubiquitin pathway modulates insulin sensitivity to regulate lipogenesis.