Τίτλος:
Structural Lipids Enable the Formation of Functional Oligomers of the Eukaryotic Purine Symporter UapA
Γλώσσες Τεκμηρίου:
Αγγλικά
Περίληψη:
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. We describe the first in-depth analysis of membrane lipid interactions with a eukaryotic transporter using native mass spectrometry. We demonstrate that the binding of structural lipids is essential to maintain the stability of the functional UapA dimer in both the gas phase and in vivo. © 2018 The Authors
Συγγραφείς:
Pyle, E.
Kalli, A.C.
Amillis, S.
Hall, Z.
Lau, A.M.
Hanyaloglu, A.C.
Diallinas, G.
Byrne, B.
Politis, A.
Περιοδικό:
Cell Chemical Biology
Εκδότης:
Elsevier Ireland Ltd
Λέξεις-κλειδιά:
dimer; membrane lipid; membrane protein; oligomer; phosphatidylcholine; phosphatidylethanolamine; phosphatidylinositol; purine symporter UapA; unclassified drug; carrier protein; fungal protein; phospholipid; UAPA protein, Aspergillus nidulans, Article; Aspergillus nidulans; binding site; controlled study; molecular dynamics; nonhuman; priority journal; protein lipid interaction; chemical structure; chemistry; eukaryote; metabolism, Binding Sites; Eukaryota; Fungal Proteins; Membrane Transport Proteins; Molecular Dynamics Simulation; Molecular Structure; Phospholipids
DOI:
10.1016/j.chembiol.2018.03.011
