Biogenesis of nuclear lipid droplets is regulated by a Sir2-Csa1-Lro1 signaling pathway at the INM.

The Sir2-Csa1-Lro1 signaling pathway at the INM regulates nuclear lipid droplet biogenesis in budding yeast, with Csa1 controlling Lro1 localization and activity.

• Why it matters: Understanding how nuclear lipid droplet formation is controlled is crucial for insights into membrane homeostasis and energy storage, yet the signaling mechanisms remain unclear.
• What they did: The study used budding yeast to investigate the pathway, showing that Csa1 interacts with Ubc4 and is enriched at the n-INM during nutrient depletion, influencing Lro1 stability and localization.
• The result: This pathway's activation depends on Sir2 deacetylase activity, revealing a novel regulatory mechanism at the INM that maintains nuclear membrane homeostasis.