Submission 2
Adaptation of Golgi-associated molecular machineries upon cell differentiation
PS1-02-Poster Presentation
Presented by: Justine Guguin
Secretion of proteins is an essential mechanism for cell homeostasis, signaling or tissue integrity. Upon cell differentiation, specific secretory requirements are needed to ensure cellular functions. For instance, cardiomyocytes need surface expression of gap junctions and calcium channels for action potential propagation while neurons massively secrete neurotransmitters and associated receptors. At the center of the secretory pathway, the Golgi complex has to ensure correct and precise processing and targeting of the cargos to their destination compartment. However, the question of how this organelle adapts upon cell differentiation to fit specific secretory needs remains to be elucidated, especially when mutations in ubiquitous Golgi proteins have deleterious impact only on some tissues. To investigate that, we analyze the Golgi proteome of three different cell types, using TurboID-based proximity labeling. First, we generated human induced Pluripotent Stem Cells (hiPSC) stably expressing a Golgi-targeted TurboID fusion construct, without altering their pluripotency nor differentiation capacities. These hiPSC were then differentiated into cardiomyocytes and neurons. Second, we performed pull-down using streptavidin-coupled magnetic beads prior to quantitative analysis by mass spectrometry. Our results show a specific and reproducible harvesting of biotinylated proteins from the Golgi apparatus in hiPSC and in differentiated cells. Altogether, our work will lead to the identification of Golgi-associated molecular machineries in differentiated cell types, paving the way to understanding regulation of specific secretory routes.