Seipin involved in lipid droplet (LD) assembly; controls lipid particle morphology, number, and size; promotes initiation of LD formation on the ER; ensures that LDs bud from the ER towards the cytosolic side of the membrane; stabilizes ER-LD contact sites in complex with Ldb16p; regulates phosphatidic acid and diacylglycerol homeostasis at the inner nuclear membrane to preserve nuclear envelope integrity; BSCL2, human homolog implicated in congenital lipodystrophy, complements yeast null mutant