Physicochemical Factors Controlling the Activity and Energy Coupling of an Ionic Strength-gated ATP-binding Cassette (ABC) Transporter

Karasawa, Akira; Swier, Lotteke J Y M; Stuart, Marc C. A.; Brouwers, Jos F.; Helms, Bernd; Poolman, Berend

doi:10.1074/jbc.m113.499327

Cited by 42 publications

(61 citation statements)

References 50 publications

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“…34,47 BetP activity correlates with the luminal K + concentration in proteoliposomes, reaching a half-maximal level at 0.22 M K + in proteoliposomes comprised of E. coli lipid. 48 Each of these systems differs from ProP in showing cation specificity: Na + did not activate Na + symporter BetP, while Rb + and Cs + inhibited OpuA.…”

Section: Discussionmentioning

confidence: 94%

Contributions of Coulombic and Hofmeister Effects to the Osmotic Activation of Escherichia coli Transporter ProP

et al. 2016

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Osmosensing transporters mediate osmolyte accumulation to forestall cellular dehydration as the extracellular osmolality increases. ProP is a bacterial osmolyte-H+ symporter, a major facilitator superfamily member, and a paradigm for osmosensing. ProP activity is a sigmoid function of the osmolality. It is determined by the osmolality, not the magnitude or direction of the osmotic shift, in cells and salt-loaded proteoliposomes. The activation threshold varies directly with the proportion of anionic phospholipid in cells and proteoliposomes. The osmosensory mechanism was probed by varying the salt composition and concentration outside and inside proteoliposomes. Data analysis was based on the hypothesis that the fraction of maximal transporter activity at a particular luminal salt concentration reflects the proportion of ProP molecules in an active conformation. ProP attained the same activity at the same osmolality when diverse, membrane-impermeant salts were added to the external medium. Contributions of Coulombic and/or Hofmeister salt effects to ProP activation were examined by varying the luminal salt cation (K+ and Na+) and anion (chloride, phosphate, and sulfate) composition and then systematically increasing the luminal salt concentration by increasing the external osmolality. ProP activity increased with the sixth power of the univalent cation concentration, independent of the type of anion. This indicates that salt activation of ProP is a Coulombic, cation effect resulting from salt cation accumulation and not site-specific cation binding. Possible origins of this Coulombic effect include folding or assembly of anionic cytoplasmic ProP domains, an increase in local membrane surface charge density, and/or the juxtaposition of anionic protein and membrane surfaces during activation.

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Section: Discussionmentioning

confidence: 94%

Contributions of Coulombic and Hofmeister Effects to the Osmotic Activation of Escherichia coli Transporter ProP

et al. 2016

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“…A substantial gap in our knowledge base exists on how the lipid matrix in thylakoid membranes interacts with LHCII (and other proteins) and modulates light-harvesting. For non-photosynthetic membrane protein complexes, like mechanosensitive channels and membrane transporters, strong evidence exists that the composition and physicochemical properties of the lipid bilayer has significant impact on the conformation and functionality of these proteins (12)(13)(14)(15)(16)(17). A concept that bridges physicochemical lipid bilayer properties with structural and functional alterations of membrane proteins is the lateral membrane pressure (LMP) hypothesis (12,18) also known as force-from-lipid principle (17).…”

Section: Introductionmentioning

confidence: 99%

A proteoliposome-based system reveals how lipids control photosynthetic light harvesting

Tietz

Leuenberger

Höhner

et al. 2020

Journal of Biological Chemistry

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Integral membrane proteins are exposed to a complex and dynamic lipid environment modulated by nonbilayer lipids that can influence protein functions by lipid-protein interactions. The nonbilayer lipid monogalactosyldiacylglycerol (MGDG) is the most abundant lipid in plant photosynthetic thylakoid membranes, but its impact on the functionality of energy-converting membrane protein complexes is unknown. Here, we optimized a detergent-based reconstitution protocol to develop a proteoliposome technique that incorporates the major light-harvesting complex II (LHCII) into compositionally well-defined large unilamellar lipid bilayer vesicles to study the impact of MGDG on light harvesting by LHCII. Using steady-state fluorescence spectroscopy, CD spectroscopy, and time-correlated single-photon counting, we found that both chlorophyll fluorescence quantum yields and fluorescence lifetimes clearly indicate that the presence of MGDG in lipid bilayers switches LHCII from a light-harvesting to a more energy-quenching mode that dissipates harvested light into heat. It is hypothesized that in the in vitro system developed here, MGDG controls light harvesting of LHCII by modulating the hydrostatic lateral membrane pressure profile in the lipid bilayer sensed by LHCII-bound peripheral pigments.

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“…The observed 3-5 mol% of ergosterol in SMALP-Lyp1 is more in line with a high transport activity. Detailed analysis of the effects of lipids on the activity and regulation of membrane transport is limited to studies on bacterial transporters such as the lactose-proton symporter LacY(47), a leucine-proton symporter(48), the ATP-driven betaine transporter OpuA(49) and other membrane-associated proteins(50, 51). Each of these systems requires anionic (PG) and non-bilayer (PE) lipids, and function optimally in lipids with dioleoyl chains.…”

Section: Discussionmentioning

confidence: 99%

Periprotein membrane lipidomics and the role of lipids in transporter function in yeast

Cheng

et al. 2020

Preprint

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Impact statementMembrane protein-specific lipidomics provides information on the organization of the yeast plasma membrane and the functioning of solute transporters 2 Abstract 21 22The yeast plasma membrane is segregated into domains: the Micro-Compartment-of-Can1 (MCC) 23and Pma1 (MCP) have a different protein composition, but their lipid composition is largely 24 unknown. We extracted proteins residing in these microdomains via stoichiometric capture of lipids 25and proteins in styrene-maleic-acid-lipid-particles (SMALPs). We purified SMALPs by affinity 26 chromatography and quantitatively analyzed the lipids by mass spectrometry and their role in 27 transporter function. We found that phospholipid and sterol concentrations are similar for MCC and 28MCP, but sphingolipids are enriched in MCP. Ergosterol is depleted from the periprotein lipidome, 29whereas phosphatidylserine is enriched relative to the bulk of the plasma membrane. 30Phosphatidylserine, non-bilayer lipids and ergosterol are essential for activity of Lyp1; the 31 transporter also requires a balance of saturated/unsaturated fatty acids. We propose that proteins 32can function in the yeast plasma membrane by the disordered state of surrounded lipids and diffuse 33 slowly in domains of high lipid order. 34 35

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Physicochemical Factors Controlling the Activity and Energy Coupling of an Ionic Strength-gated ATP-binding Cassette (ABC) Transporter

Cited by 42 publications

References 50 publications

Contributions of Coulombic and Hofmeister Effects to the Osmotic Activation of Escherichia coli Transporter ProP

Contributions of Coulombic and Hofmeister Effects to the Osmotic Activation of Escherichia coli Transporter ProP

A proteoliposome-based system reveals how lipids control photosynthetic light harvesting

Periprotein membrane lipidomics and the role of lipids in transporter function in yeast

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