Lipin is required for efficient breakdown of the nuclear envelope in Caenorhabditis elegans

The nuclear envelope (NE) is a double lipid bilayer that separates nucleus and cytoplasm. In metazoa, NE breakdown (NEBD) occurs during prophase and NE reformation around segregated chromatids occurs at anaphase-telophase. We identified Caenorhabditis elegans Lipin homologue (called Lpin-1) as an essential factor with roles in endoplasmic reticulum (ER) organization and NEBD. RNAi-mediated downregulation of Lpin-1 had no effect on timely entry into mitosis or on the early steps of NEBD, but Lpin-1 was required for disassembly of the nuclear lamina during late NEBD. This Lpin-1 requirement appears to be separable from the effect of Lpin-1 on the peripheral ER.