TY  - GEN
T1  - Lack of evidence for condensin or cohesin sequestration on lipid droplets with packing defects
AU  - Mura, Anaïs
AU  - Moriel-Carretero, María
DO  - 10.17912/micropub.biology.000497
UR  - http://beta.micropublication.org/journals/biology/micropub-biology-000497/
AB  - Lipid droplets (LD) are organelles that form around neutral lipids that coalesce within the two leaflets of the endoplasmic reticulum (ER) membrane, more frequently the cytoplasmic one, and pop out towards the cytoplasm (Pol et al. 2014; Wilfling et al. 2014). They are the only organelle of the cell delimited by a monolayer of phospholipids and are present in virtually all species (Beller et al. 2010). LD act as an energy reservoir mostly in the shape of triacylglycerols (TAGs) and steryl esters, shelter lipids from unscheduled oxidation and protect the cell from lipotoxicity (Garbarino et al. 2009; Bailey et al. 2015). Mutations exist that modify the surface and the physico-chemical properties of the LD monolayer. For example, the absence of Cds1p, crucial for phosphatidylcholine synthesis (Klig et al. 1988), decreases the availability of phospholipids and, as a consequence, super-sized LD form to spare membrane by increasing the volume-to-surface area ratio (Fei et al. 2011a). Further, the monolayers of these LD bear discontinuities, named “packing defects”, that expose their hydrophobic contents to the surrounding water environment. The same defects can occur in mutants lacking Ino2p (Fei et al. 2011a), a transcription factor essential for the induction of multiple genes necessary for phospholipid and inositol synthesis (Carman and Henry 2007). Of note, not all mutations giving rise to giant LD are accompanied by packing defects. For example, mutations such as the lack of seipin (Fld1p), which give rise to the severe Berardinelli–Seip lipodystrophy congenital syndrome, support an aberrant flow of TAGs into forming LD, which become super-sized, yet are normally packed (Fei et al. 2011a; Wang et al. 2014; Wolinski et al. 2015). Importantly, the LD surface is covered by a rich proteome under constant evolution (Cermelli et al. 2006; Kory et al. 2016; Bersuker et al. 2018). Part of this proteome supports the function of the LD itself, while the rest constitutes a selective reservoir for other proteins that, this way, can be made available elsewhere in the cell in a regulated manner (Welte 2015).
PY  - 2021
JO  - microPublication Biology
ER  -