A filter at the entrance of the Golgi that selects vesicles according to size and bulk lipid composition

Maud Magdeleine,Pierre Gounon,Romain Gautier,Stefano Vanni,Bruno Antonny,Hélène Barelli

doi:10.7554/elife.16988

Abstract

When small phosphatidylcholine liposomes are added to perforated cells, they bind preferentially to the Golgi suggesting an exceptional avidity of this organelle for curved membranes without stereospecific interactions. We show that the cis golgin GMAP-210 accounts for this property. First, the liposome tethering properties of the Golgi resembles that of the amphipathic lipid-packing sensor (ALPS) motif of GMAP-210: both preferred small (radius < 40 nm) liposomes made of monounsaturated but not saturated lipids. Second, reducing GMAP-210 levels or redirecting its ALPS motif to mitochondria decreased liposome capture by the Golgi. Extensive mutagenesis analysis suggests that GMAP-210 tethers authentic transport vesicles via the same mechanism whereby the ALPS motif senses lipid-packing defects at the vesicle surface through its regularly spaced hydrophobic residues. We conclude that the Golgi uses GMAP-210 as a filter to select transport vesicles according to their size and bulk lipid composition.

Highlights

Exchange of material between organelles is largely mediated by transport vesicles, which bud from the surface of a donor compartment through the mechanical action of protein coats and fuse with an acceptor compartment through the action of SNARE proteins (Bonifacino and Glick, 2004)
The Kobayashi and Pagano experiment was remarkable in its simplicity – mixing liposomes with perforated cells – and in its outcomes: the Golgi has an exceptional liposome tethering capacity, which is accompanied by size filtration (Kobayashi and Pagano, 1988)
By connecting these pioneering observations with the molecular and cellular properties of the golgin GMAP-210 (Drin et al, 2008; Wong and Munro, 2014; Sato et al, 2015; Roboti et al, 2015), our study suggests that the amphipathic lipid-packing sensor (ALPS)

Summary

Introduction

Exchange of material between organelles is largely mediated by transport vesicles, which bud from the surface of a donor compartment through the mechanical action of protein coats and fuse with an acceptor compartment through the action of SNARE proteins (Bonifacino and Glick, 2004). Between these two elementary steps, various protein machineries control the fate of transport vesicles.

Methods

Results

Conclusion