Lipid of the sphinx : the gate keeper - or - Dynamics of lipid remodelling at trans-Golgi Network (TGN) in protein sorting and cell polarity

RDP seminar by Yohann Boutté from the Laboratoire de Biogenèse Membranaire (Bordeaux, France)

Abstract
Cell polarity is a defining feature of all organisms. Until very recently, it was thought that delivery of proteins to polar domains of root epidermal cells plasma membrane was non-polar, but this view has been re-examined, the delivery is polar but the dynamics, the paths taken and the mechanisms are unknown. We previously characterised an enrichment of Very-Long-Chain-Fatty-Acids (VLCFAs)-containing sphingolipids at the site of secretory vesicles (SVs) sub-domain of the trans-Golgi Network (TGN). Moreover, we identified the role of the length of sphingolipids acyl-chain in secretory sorting of the auxin carrier PIN2 from SVs-associated TGN to apical polar domain of the plasma membrane (PM). Using proteomics of SVs, genetics and pharmacological tools in combination with visualisation of lipid probes we could identify that sphingolipids control the turnover of other lipids at SVs. Our results show that sphingolipids act on phosphoinositides homeostasis establishing a new functional link between these two lipids in plant cells. These results force the reassessment of our view of lipid membranes and highlight the idea that not only proteins display a dynamic behaviour at TGN but also the dynamic remodelling of lipid composition during vesicle maturation and protein sorting plays a prominent role during these processes.

Date : Monday, April 9th
Time : 11am
Location : Salle des Thèses

Selected publications
– Wattelet-Boyer V, Brocard L, Jonsson K, Esnay N, Joubès J, Domergue F, Mongrand S, Raikhel N, Bhalerao RP, Moreau P, Boutté Y*. (2016) Enrichment of hydroxylated C24- and C26-acyl-chain sphingolipids mediates PIN2 apical sorting at trans-Golgi network subdomains. Nat Commun. 29 ;7:12788.
– Boutté Y, Moreau P. (2014) Modulation of endomembranes morphodynamics in the secretory/retrograde pathways depends on lipid diversity. Curr Opin Plant Biol. 22:22-9.
– Boutté Y, Jonsson K, McFarlane HE, Johnson E, Gendre D, Swarup R, Friml J, Samuels L, Robert S, Bhalerao RP. (2013) ECHIDNA-mediated post-Golgi trafficking of auxin carriers for differential cell elongation. Proc Natl Acad Sci U S A. 1 ;110(40):16259-64.
– Boutté Y, Men S, Grebe M. (2011) Fluorescent in situ visualization of sterols in Arabidopsis roots. Nat Protoc. 6(4):446-56.
– Boutté Y, Frescatada-Rosa M, Men S, Chow CM, Ebine K, Gustavsson A, Johansson L, Ueda T, Moore I, Jürgens G, Grebe M. (2010) Endocytosis restricts Arabidopsis KNOLLE syntaxin to the cell division plane during late cytokinesis. EMBO J. 3 ;29(3):546-58.
– Men S, Boutté Y, Ikeda Y, Li X, Palme K, Stierhof YD, Hartmann MA, Moritz T, Grebe M. (2008) Sterol-dependent endocytosis mediates post-cytokinetic acquisition of PIN2 auxin efflux carrier polarity. Nat Cell Biol. 10(2):237-44. 5 Year Impact Factor : 20.001

RDP host : Yvon Jaillais