Partitioning of fatty acids between membrane and storage lipids controls ER membrane expansion.

Biogenesis of membrane-bound organelles involves the synthesis, remodeling, and degradation of their constituent phospholipids. How these pathways regulate organelle size remains poorly understood. Here we demonstrate that a lipid-degradation pathway inhibits expansion of the endoplasmic reticulum (ER) membrane.

Membranes that make fat: roles of membrane lipids as acyl donors for triglyceride synthesis and organelle function.

Triglycerides constitute an inert storage form for fatty acids deposited in lipid droplets and are mobilized to provide metabolic energy or membrane building blocks. The biosynthesis of triglycerides is highly conserved within eukaryotes and normally involves the sequential esterification of activated fatty acids with a glycerol backbone. Some eukaryotes, however, can also use cellular membrane lipids as direct fatty acid donors for triglyceride synthesis.

Oiling the wheels of nuclear division: SUMOylation regulates the expansion of the mitotic nuclear membrane.

Eukaryotic cell division involves the segregation of chromosomes between two daughter cells and must be coordinated with extensive rearrangement of their nuclear envelopes. In this issue, Saik et al. (2023 J.

Nuclear Shape-Shifters: Lipid and Protein Dynamics at the Nuclear Envelope.

The nuclear envelope constitutes a selective barrier that segregates chromatin into the nucleus of eukaryotic cells [...