Enrichment of hydroxylated C24-and C26-acyl-chain sphingolipids mediates PIN2 apical sorting at trans-Golgi network subdomains

Valérie Wattelet-Boyer (1, 2, 3) , Lysiane Brocard (4, 5, 6) , Kristoffer Jonsson (7) , Nicolas Esnay (8, 1, 5, 3) , Jérôme Joubes (8, 1, 5, 3) , Frédéric Domergue (8, 1, 2, 3) , Sébastien Mongrand (8, 1, 2, 3) , Natasha Raikhel (9) , Rishikesh P. Bhalerao (10, 7) , Patrick Moreau (11, 1, 2, 3, 4, 6) , Yohann Boutté (1, 2, 3)

1 LBM - Laboratoire de biogenèse membranaire
2 UB - Université de Bordeaux
3 INRA - Institut National de la Recherche Agronomique
4 BIC - Bordeaux Imaging Center
5 CNRS - Centre National de la Recherche Scientifique
6 INSERM - Institut National de la Santé et de la Recherche Médicale
7 UPSC - Umea Plant Science Center
8 BVI - Biologie végétale intégrative
9 Center for Plant Cell Biology - Department of Botany and Plant Sciences
10 College of Science [Swansea]
11 BFP - Biologie du fruit et pathologie

The post-Golgi compartment trans-Golgi Network (TGN) is a central hub divided into multiple subdomains hosting distinct trafficking pathways, including polar delivery to apical membrane. Lipids such as sphingolipids and sterols have been implicated in polar trafficking from the TGN but the underlying mechanisms linking lipid composition to functional polar sorting at TGN subdomains remain unknown. Here we demonstrate that sphingolipids with alpha-hydroxylated acyl-chains of at least 24 carbon atoms are enriched in secretory vesicle subdomains of the TGN and are critical for de novo polar secretory sorting of the auxin carrier PIN2 to apical membrane of Arabidopsis root epithelial cells. We show that sphingolipid acyl-chain length influences the morphology and interconnections of TGN-associated secretory vesicles. Our results uncover that the sphingolipids acyl-chain length links lipid composition of TGN subdomains with polar secretory trafficking of PIN2 to apical membrane of polarized epithelial cells.

Domaines: Sciences du Vivant [q-bio]

Valérie Wattelet-Boyer, Lysiane Brocard, Kristoffer Jonsson, Nicolas Esnay, Jérôme Joubes, et al.. Enrichment of hydroxylated C24-and C26-acyl-chain sphingolipids mediates PIN2 apical sorting at trans-Golgi network subdomains. Nature Communications, 2016, 7, pp.1-15. ⟨10.1038/ncomms12788⟩. ⟨hal-01608825⟩