Structural lipids enable the formation of Functional oligomers of the eukaryotic purine symporter UapA
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
The role of membrane lipids in modulating eukaryotic transporter assembly and function remains unclear. We investigated the effect of membrane lipids in the structure and transport activity of the purine transporter UapA from Aspergillus nidulans. We found that UapA exists mainly as a dimer and that two lipid molecules bind per UapA dimer. We identified three phospholipid classes that co-purified with UapA: phosphatidylcholine, phosphatidylethanolamine (PE), and phosphatidylinositol (PI). UapA delipidation caused dissociation of the dimer into monomers. Subsequent addition of PI or PE rescued the UapA dimer and allowed recovery of bound lipids, suggesting a central role of these lipids in stabilizing the dimer. Molecular dynamics simulations predicted a lipid binding site near the UapA dimer interface. Mutational analyses established that lipid binding at this site is essential for formation of functional UapA dimers. We propose that structural lipids have a central role in the formation of functional, dimeric UapA.
Date Issued
2018-07-19
Date Acceptance
2018-03-22
Citation
Cell Chemical Biology, 2018, 25 (7), pp.840-848.e4
ISSN
2451-9456
Publisher
Elsevier
Start Page
840
End Page
848.e4
Journal / Book Title
Cell Chemical Biology
Volume
25
Issue
7
Copyright Statement
© 2018 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Sponsor
Biotechnology and Biological Sciences Research Council (BBSRC)
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/29681524
PII: S2451-9456(18)30113-2
Grant Number
BB/K017292/1
Subjects
UapA
eukaryotic membrane protein
in vivo mutational analyses
ion-mobility mass spectrometry
lipidomics
liquid chromatography-mass spectrometry
membrane protein oligomerization
molecular dynamics simulations
native mass spectrometry
protein-lipid interactions
Publication Status
Published
Coverage Spatial
United States
Date Publish Online
2018-04-19