Systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes

<p>One of the deepest branches in the tree of life separates the Archaea from the Bacteria. These prokaryotic groups have distinct cellular systems including fundamentally different phospholipid membrane bilayers. This dichotomy has been termed the lipid divide and possibly bestows different b...

Full description

Bibliographic Details
Main Authors: Łapińska, U, Glover, G, Kahveci, Z, Irwin, NAT, Milner, DS, Tourte, M, Albers, S-V, Santoro, AE, Richards, TA, Pagliara, S
Format: Journal article
Language:English
Published: Public Library of Science 2023
_version_ 1797110393664962560
author Łapińska, U
Glover, G
Kahveci, Z
Irwin, NAT
Milner, DS
Tourte, M
Albers, S-V
Santoro, AE
Richards, TA
Pagliara, S
author_facet Łapińska, U
Glover, G
Kahveci, Z
Irwin, NAT
Milner, DS
Tourte, M
Albers, S-V
Santoro, AE
Richards, TA
Pagliara, S
author_sort Łapińska, U
collection OXFORD
description <p>One of the deepest branches in the tree of life separates the Archaea from the Bacteria. These prokaryotic groups have distinct cellular systems including fundamentally different phospholipid membrane bilayers. This dichotomy has been termed the lipid divide and possibly bestows different biophysical and biochemical characteristics on each cell type. Classic experiments suggest that bacterial membranes (formed from lipids extracted from&nbsp;<em>Escherichia coli</em>, for example) show permeability to key metabolites comparable to archaeal membranes (formed from lipids extracted from&nbsp;<em>Halobacterium salinarum</em>), yet systematic analyses based on direct measurements of membrane permeability are absent. Here, we develop a new approach for assessing the membrane permeability of approximately 10 &mu;m unilamellar vesicles, consisting of an aqueous medium enclosed by a single lipid bilayer. Comparing the permeability of 18 metabolites demonstrates that diether glycerol-1-phosphate lipids with methyl branches, often the most abundant membrane lipids of sampled archaea, are permeable to a wide range of compounds useful for core metabolic networks, including amino acids, sugars, and nucleobases. Permeability is significantly lower in diester glycerol-3-phosphate lipids without methyl branches, the common building block of bacterial membranes. To identify the membrane characteristics that determine permeability, we use this experimental platform to test a variety of lipid forms bearing a diversity of intermediate characteristics. We found that increased membrane permeability is dependent on both the methyl branches on the lipid tails and the ether bond between the tails and the head group, both of which are present on the archaeal phospholipids. These permeability differences must have had profound effects on the cell physiology and proteome evolution of early prokaryotic forms. To explore this further, we compare the abundance and distribution of transmembrane transporter-encoding protein families present on genomes sampled from across the prokaryotic tree of life. These data demonstrate that archaea tend to have a reduced repertoire of transporter gene families, consistent with increased membrane permeation. These results demonstrate that the lipid divide demarcates a clear difference in permeability function with implications for understanding some of the earliest transitions in cell origins and evolution.</p>
first_indexed 2024-03-07T07:54:22Z
format Journal article
id oxford-uuid:5041482e-4d05-4e21-b4bd-9918628d7a7c
institution University of Oxford
language English
last_indexed 2024-03-07T07:54:22Z
publishDate 2023
publisher Public Library of Science
record_format dspace
spelling oxford-uuid:5041482e-4d05-4e21-b4bd-9918628d7a7c2023-08-07T07:12:42ZSystematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranesJournal articlehttp://purl.org/coar/resource_type/c_dcae04bcuuid:5041482e-4d05-4e21-b4bd-9918628d7a7cEnglishSymplectic ElementsPublic Library of Science2023Łapińska, UGlover, GKahveci, ZIrwin, NATMilner, DSTourte, MAlbers, S-VSantoro, AERichards, TAPagliara, S<p>One of the deepest branches in the tree of life separates the Archaea from the Bacteria. These prokaryotic groups have distinct cellular systems including fundamentally different phospholipid membrane bilayers. This dichotomy has been termed the lipid divide and possibly bestows different biophysical and biochemical characteristics on each cell type. Classic experiments suggest that bacterial membranes (formed from lipids extracted from&nbsp;<em>Escherichia coli</em>, for example) show permeability to key metabolites comparable to archaeal membranes (formed from lipids extracted from&nbsp;<em>Halobacterium salinarum</em>), yet systematic analyses based on direct measurements of membrane permeability are absent. Here, we develop a new approach for assessing the membrane permeability of approximately 10 &mu;m unilamellar vesicles, consisting of an aqueous medium enclosed by a single lipid bilayer. Comparing the permeability of 18 metabolites demonstrates that diether glycerol-1-phosphate lipids with methyl branches, often the most abundant membrane lipids of sampled archaea, are permeable to a wide range of compounds useful for core metabolic networks, including amino acids, sugars, and nucleobases. Permeability is significantly lower in diester glycerol-3-phosphate lipids without methyl branches, the common building block of bacterial membranes. To identify the membrane characteristics that determine permeability, we use this experimental platform to test a variety of lipid forms bearing a diversity of intermediate characteristics. We found that increased membrane permeability is dependent on both the methyl branches on the lipid tails and the ether bond between the tails and the head group, both of which are present on the archaeal phospholipids. These permeability differences must have had profound effects on the cell physiology and proteome evolution of early prokaryotic forms. To explore this further, we compare the abundance and distribution of transmembrane transporter-encoding protein families present on genomes sampled from across the prokaryotic tree of life. These data demonstrate that archaea tend to have a reduced repertoire of transporter gene families, consistent with increased membrane permeation. These results demonstrate that the lipid divide demarcates a clear difference in permeability function with implications for understanding some of the earliest transitions in cell origins and evolution.</p>
spellingShingle Łapińska, U
Glover, G
Kahveci, Z
Irwin, NAT
Milner, DS
Tourte, M
Albers, S-V
Santoro, AE
Richards, TA
Pagliara, S
Systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes
title Systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes
title_full Systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes
title_fullStr Systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes
title_full_unstemmed Systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes
title_short Systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes
title_sort systematic comparison of unilamellar vesicles reveals that archaeal core lipid membranes are more permeable than bacterial membranes
work_keys_str_mv AT łapinskau systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes
AT gloverg systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes
AT kahveciz systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes
AT irwinnat systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes
AT milnerds systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes
AT tourtem systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes
AT alberssv systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes
AT santoroae systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes
AT richardsta systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes
AT pagliaras systematiccomparisonofunilamellarvesiclesrevealsthatarchaealcorelipidmembranesaremorepermeablethanbacterialmembranes