scholarly journals The lipid head group is the key element for substrate recognition by the P4 ATPase ALA2: a phosphatidylserine flippase

2019 ◽  
Vol 476 (5) ◽  
pp. 783-794 ◽  
Author(s):  
Lisa Theorin ◽  
Kristina Faxén ◽  
Danny Mollerup Sørensen ◽  
Rebekka Migotti ◽  
Gunnar Dittmar ◽  
...  
Keyword(s):  
Enzymatic Activity ◽  
Substrate Recognition ◽  
Hydrolytic Activity ◽  
Head Group ◽  
Structural Element ◽  
Type Iv ◽  
Acyl Chains ◽  
Lipid Head Group ◽  
Phospholipid Transport ◽  
P Type

Abstract Type IV P-type ATPases (P4 ATPases) are lipid flippases that catalyze phospholipid transport from the exoplasmic to the cytoplasmic leaflet of cellular membranes, but the mechanism by which they recognize and transport phospholipids through the lipid bilayer remains unknown. In the present study, we succeeded in purifying recombinant aminophospholipid ATPase 2 (ALA2), a member of the P4 ATPase subfamily in Arabidopsis thaliana, in complex with the ALA-interacting subunit 5 (ALIS5). The ATP hydrolytic activity of the ALA2–ALIS5 complex was stimulated in a highly specific manner by phosphatidylserine. Small changes in the stereochemistry or the functional groups of the phosphatidylserine head group affected enzymatic activity, whereas alteration in the length and composition of the acyl chains only had minor effects. Likewise, the enzymatic activity of the ALA2–ALIS5 complex was stimulated by both mono- and di-acyl phosphatidylserines. Taken together, the results identify the lipid head group as the key structural element for substrate recognition by the P4 ATPase.

scholarly journals Computational Studies of Substrate Transport and Specificity in a Phospholipid Flippase

2020 ◽  
Author(s):  
Yong Wang ◽  
Joseph A Lyons ◽  
Milena Timcenko ◽  
Bert L. de Groot ◽  
Poul Nissen ◽  
...  
Keyword(s):  
Atp Hydrolysis ◽  
Head Group ◽  
Outer Leaflet ◽  
Type Iv ◽  
Lipid Head Group ◽  
Dynamics Simulations ◽  
Phospholipid Distribution ◽  
Phospholipid Transport ◽  
P Type ◽  
Insight Into

AbstractType-IV P-type ATPases are lipid flippases which help maintain asymmetric phospholipid distribution in eukaryotic membranes by using ATP hydrolysis to drive unidirectional translocation of phospholipid substrates. Recent Cryo-EM and crystal structures have provided a detailed view of flippases, and we here use molecular dynamics simulations of the yeast flippase Drs2p:Cdc50p in an outward open conformation to study the first steps of phospholipid transport. Our simulations show phospholipid binding to a groove and subsequent movement towards the centre of the membrane, and reveal a preference for phosphatidylserine lipids. We find that the lipid head group stays solvated in the groove while the lipid tails stay in the membrane during the (half) transport event. The flippase also induces deformation and thinning of the outer leaflet. Together, our simulations provide insight into substrate binding to lipid flippases and suggest that multiple sites and steps in the functional cycle contribute to substrate selectivity.

scholarly journals Cryo-EM structures capture the transport cycle of the P4-ATPase flippase

Science ◽  
2019 ◽  
Vol 365 (6458) ◽  
pp. 1149-1155 ◽  
Author(s):  
Masahiro Hiraizumi ◽  
Keitaro Yamashita ◽  
Tomohiro Nishizawa ◽  
Osamu Nureki
Keyword(s):  
Membrane Trafficking ◽  
Acyl Chain ◽  
Phosphorylation Site ◽  
Head Group ◽  
Transmembrane Helices ◽  
Type Iv ◽  
Adenosine Triphosphatases ◽  
Lipid Environment ◽  
P Type ◽  
Phosphorylation Domain

In eukaryotic membranes, type IV P-type adenosine triphosphatases (P4-ATPases) mediate the translocation of phospholipids from the outer to the inner leaflet and maintain lipid asymmetry, which is critical for membrane trafficking and signaling pathways. Here, we report the cryo–electron microscopy structures of six distinct intermediates of the human ATP8A1-CDC50a heterocomplex at resolutions of 2.6 to 3.3 angstroms, elucidating the lipid translocation cycle of this P4-ATPase. ATP-dependent phosphorylation induces a large rotational movement of the actuator domain around the phosphorylation site in the phosphorylation domain, accompanied by lateral shifts of the first and second transmembrane helices, thereby allowing phosphatidylserine binding. The phospholipid head group passes through the hydrophilic cleft, while the acyl chain is exposed toward the lipid environment. These findings advance our understanding of the flippase mechanism and the disease-associated mutants of P4-ATPases.

Interactions of the Antimicrobial Peptide Maculatin 1.1 and Analogues with Phospholipid Bilayers

2011 ◽  
Vol 64 (6) ◽  
pp. 798 ◽  
Author(s):  
David I. Fernandez ◽  
Marc-Antoine Sani ◽  
Frances Separovic
Keyword(s):  
Antimicrobial Peptide ◽  
Solid State Nmr ◽  
Acyl Chain ◽  
Head Group ◽  
Group Interactions ◽  
Bacterial Membranes ◽  
Helical Content ◽  
Lipid System ◽  
Acyl Chains ◽  
Mixed Bilayer

The interactions of the antimicrobial peptide, maculatin 1.1 (GLFGVLAKVAAHVVPAIAEHF-NH2) and two analogues, with model phospholipid membranes have been studied using solid-state NMR and circular dichroism spectroscopy. Maculatin 1.1 and the P15G and P15A analogues displayed minimal secondary structure in water, but with zwitterionic dimyristoylphosphatidylcholine (DMPC) vesicles displayed a significant increase in α-helical content. In mixed phospholipid vesicles of DMPC and anionic dimyristoylphosphatidylglycerol (DMPG), each peptide was highly structured with ~80% α-helical content. In DMPC vesicles, the native peptide displayed moderate head group interaction and significant perturbation of the lipid acyl chains. In DMPC/DMPG vesicles, maculatin 1.1 promoted formation of a DMPG-enriched phase and moderately increased disorder towards acyl chain ends of DMPC in the mixed bilayer. Both analogues showed reduced phospholipid head group interactions with DMPC but displayed significant interactions with the mixed lipid system. These effects support the preferential activity of these antimicrobial peptides for bacterial membranes.

scholarly journals Correction: Effect of lipid head group interactions on membrane properties and membrane-induced cationic β-hairpin folding

2016 ◽  
Vol 18 (38) ◽  
pp. 26998-26998
Author(s):  
Sai J. Ganesan ◽  
Hongcheng Xu ◽  
Silvina Matysiak
Keyword(s):  
Chem Phys ◽  
Membrane Properties ◽  
Head Group ◽  
Group Interactions ◽  
Correction Effect ◽  
Lipid Head Group ◽  
Phys Chem Chem Phys

Correction for ‘Effect of lipid head group interactions on membrane properties and membrane-induced cationic β-hairpin folding’ by Sai J. Ganesan et al., Phys. Chem. Chem. Phys., 2016, 18, 17836–17850.

scholarly journals Structural basis of substrate recognition and translocation by human ABCD1

2021 ◽  
Author(s):  
Zhipeng Chen ◽  
Da Xu ◽  
Liang Wang ◽  
Cong-Zhao Zhou ◽  
Wen-Tao Hou ◽  
...  
Keyword(s):  
Genetic Disorder ◽  
Substrate Recognition ◽  
Acyl Chain ◽  
Chain Fatty Acid ◽  
Structural Basis ◽  
Long Chain Fatty Acid ◽  
Lateral Entry ◽  
Binding Domains ◽  
Acyl Chains ◽  
Functional States

Human ATP-binding cassette (ABC) subfamily D transporter ABCD1 can transport CoA esters of saturated/monounsaturated long/very long chain fatty acid into the peroxisome for β-oxidation. Dysfunction of human ABCD1 causes X-linked adrenoleukodystrophy, which is a severe progressive genetic disorder affecting the nervous system. Nevertheless, the mechanistic details of substrate recognition and translocation by ABCD1 remains obscure. Here, we present three cryo-EM structures of human ABCD1 in distinct functional states. In the apo-form structure of 3.53 Å resolution, ABCD1 exhibits an inward-facing conformation, allowing the lateral entry of substrate from the lipid bilayer. In the 3.59 Å structure of substrate-bound ABCD1, two molecules of C22:0-CoA, the physiological substrate of ABCD1, is symmetrically bound in two transmembrane domains (TMDs). Each C22:0-CoA adopts a L-shape, with its CoA portion and acyl chain components bound to two TMDs respectively, resembling a pair of strings that pull the TMDs closer, resultantly generating a narrower outward-facing conformation. In the 2.79 Å ATP-bound ABCD1 structure, the two nucleotide-binding domains dimerize, leading to an outward-facing conformation, which opens the translocation cavity exit towards the peroxisome matrix side and releases the substrates. Our study provides a molecular basis to understand the mechanism of ABCD1-mediated substrate recognition and translocation, and suggests a unique binding pattern for amphipathic molecules with long acyl chains.

scholarly journals The P5A ATPase Spf1p is stimulated by phosphatidylinositol 4-phosphate and influences cellular sterol homeostasis

2019 ◽  
Vol 30 (9) ◽  
pp. 1069-1084 ◽  
Author(s):  
Danny Mollerup Sørensen ◽  
Henrik Waldal Holen ◽  
Jesper Torbøl Pedersen ◽  
Helle Juel Martens ◽  
Daniele Silvestro ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Endoplasmic Reticulum ◽  
Marked Change ◽  
Hydrolytic Activity ◽  
Genetic Interactions ◽  
Eukaryotic Cells ◽  
Lipid Bodies ◽  
Increased Sensitivity ◽  
Phosphatidylinositol 4 ◽  
P Type

P5A ATPases are expressed in the endoplasmic reticulum (ER) of all eukaryotic cells, and their disruption results in severe ER stress. However, the function of these ubiquitous membrane proteins, which belong to the P-type ATPase superfamily, is unknown. We purified a functional tagged version of the Saccharomyces cerevisiae P5A ATPase Spf1p and observed that the ATP hydrolytic activity of the protein is stimulated by phosphatidylinositol 4-phosphate (PI4P). Furthermore, SPF1 exhibited negative genetic interactions with SAC1, encoding a PI4P phosphatase, and with OSH1 to OSH6, encoding Osh proteins, which, when energized by a PI4P gradient, drive export of sterols and lipids from the ER. Deletion of SPF1 resulted in increased sensitivity to inhibitors of sterol production, a marked change in the ergosterol/lanosterol ratio, accumulation of sterols in the plasma membrane, and cytosolic accumulation of lipid bodies. We propose that Spf1p maintains cellular sterol homeostasis by influencing the PI4P-induced and Osh-mediated export of sterols from the ER.

scholarly journals How Transmembrane Model Peptides Affect Lipid Head Group Orientation: An Application of 14N NMR

2011 ◽  
Vol 100 (3) ◽  
pp. 638a-639a ◽  
Author(s):  
Jacques P.F. Doux ◽  
Benjamin A. Hall ◽  
J. Antoinette Killian
Keyword(s):  
Head Group ◽  
Group Orientation ◽  
Lipid Head Group ◽  
14N Nmr ◽  
Model Peptides

scholarly journals Internalization of Phospholipids from the Plasma Membrane of Human Osteoblasts Depends on the Lipid Head Group

1999 ◽  
Vol 14 (5) ◽  
pp. 690-699 ◽  
Author(s):  
Jeanette Libera ◽  
Thomas Pomorski ◽  
Oliviera Josimović-Alasević ◽  
Karl-Gerd Fritsch ◽  
Andreas Herrmann
Keyword(s):  
Plasma Membrane ◽  
Head Group ◽  
Human Osteoblasts ◽  
Lipid Head Group

scholarly journals Infrared Spectroscopic Studies on the Dipalmitoyl Phosphatidylcholine Bilayer Interactions with Calcium Phosphate: Effect of Vitamin D2

2002 ◽  
Vol 16 (3-4) ◽  
pp. 399-408 ◽  
Author(s):  
Neslihan Toyran ◽  
Feride Severcan
Keyword(s):  
Vitamin D ◽  
Calcium Phosphate ◽  
Liquid Crystalline ◽  
Spectroscopic Studies ◽  
The Body ◽  
Head Group ◽  
Dipalmitoyl Phosphatidylcholine ◽  
Major Structural Component ◽  
Ftir Spectral Analysis ◽  
Acyl Chains

In the present work, the interaction of calcium-phosphate with DPPC (dipalmitoyl phosphatidylcholine) model membranes has been studied in the presence and absence of vitamin D2by using Fourier Transform Infrared (FTIR) spectroscopy. Calcium and phosphorus are the most abundant elements in the body. They combine in the form of calcium phosphate salt, called hydroxyapatite. Hydroxyapatite is the major structural component of the bone. Calcium phosphate assists with the digestion and absorption of food and is vitally important for the building of sturdy bone and body structures and a robust constitution. Phosphorus is extracted from foods and its use is controlled by vitamin D and calcium. FTIR spectral analysis results suggested that, calcium–phosphate complex, which is the major component of the bones, decreases the phase transition temperature to lower values, causes a loss in cooperativity of the acyl chains, decreases the order of the membrane in both phases and decreases the dynamics of the membrane in the liquid crystalline phase, increases the flexibility of the chains in the center of the bilayer in both phases, and increases the mobility of the head group of DPPC in the gel phase. The effect of calcium-phosphate on DPPC liposomes diminishes with the addition of vitamin D2into the liposomes. Our results suggest how calcium-phosphate and/or vitamin D2, which have indispensable role for the functioning of the bone tissue, affect the thermal behaviour of DPPC liposomes at molecular level.

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