SLAM-seq ML-792

Tight control of gene expression networks involved in adipose tissue formation and plasticity is required to adapt to energy needs and environmental cues. However, little is known about the mechanisms that orchestrate the dramatic transcriptional changes leading to adipocyte differentiation. We investigated the regulation of nascent transcription by SUMO during adipocyte differentiation using SLAMseq and ChIPseq. We discovered that SUMO has a dual function in differentiation; it supports the initial downregulation of pre-adipocyte-specific genes, while it promotes the establishment of the mature adipocyte transcriptional program. By characterizing sumoylome dynamics in differentiating adipocytes by mass spectrometry, we found that sumoylation of chromatin modifiers and specific transcription factors like PPARg/RXR promotes the transcription of adipogenic genes. Our data demonstrate that the sumoylation pathway coordinates the rewiring of transcriptional networks required for formation of functional adipocytes. Analysis of the nascant transcriptome of differentiating 3T3-L1 cells