Search research articles

ABOUT JoVE

Overview Leadership Blog JoVE Help Center

AUTHORS

Publishing Process Editorial Board Scope & Policies Peer Review FAQ Submit

LIBRARIANS

Testimonials Subscriptions Access Resources Library Advisory Board FAQ

RESEARCH

JoVE Journal Methods Collections JoVE Encyclopedia of Experiments Archive

EDUCATION

JoVE Core JoVE Business JoVE Science Education JoVE Lab Manual Faculty Resource Center Faculty Site

Terms & Conditions of Use

Related Concept Videos

Membrane Asymmetry Regulating Transporters

Membrane Asymmetry Regulating Transporters

Enzymes like flippase, floppase, and scramblase transfer phospholipids from one layer to another in the membrane, thereby affecting membrane asymmetry.
Flippase
Eukaryotic flippases are type-IV P-type ATPases or P4-ATPases belonging to P-type ATPase family proteins that are membrane-bound pumps involved in the ATP-mediated transport of ions and molecules across the membrane. Flippases flip specific phospholipids from the outer to the inner leaflet of a membrane. All P4-ATPases have one...

Assembly of the Lipid Bilayer in the ER

Assembly of the Lipid Bilayer in the ER

Biological membranes are more than just a barrier separating cell cytoplasm from the outside environment. They are highly dynamic and help maintain the integrity and physiological stability of the cells as well as membrane-bound organelles. Membranes also play vital roles in cell-to-cell and intracellular communication.
A large chunk of any biological membrane is composed of phospholipids. These lipids have a heterogeneous distribution across different subcellular organelles and even between...

Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)

Olefin Metathesis Polymerization: Ring-Opening Metathesis Polymerization (ROMP)

Ring-opening metathesis polymerization or ROMP involves strained cycloalkenes as starting materials. The mechanism of ROMP proceeds by reacting cycloalkene with Grubbs catalyst to give metallacyclobutane intermediate which undergoes a ring-opening reaction to form new carbene. The new carbene reacts with another molecule of cycloalkene. Repetition of these steps leads to the formation of an unsaturated open-chain polymer product. All these steps are reversible, however, relieving the ring...

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by

Same author

A single-vesicle fluorescence microscopy platform to quantify phospholipid scrambling.

Nature structural & molecular biology·2026

Same author

Fronto-insular circuit mechanisms of accelerated intermittent theta burst stimulation.

Cell·2026

Same author

Fronto-insular circuit mechanisms of accelerated intermittent theta burst stimulation.

Cell·2026

Same author

TrkB/mGluR5 cross-talk underlies a synaptic metaplasticity mechanism of ketamine.

Science advances·2026

Same author

Mechanism-guided identification of antidepressant G protein-coupled receptor drug targets.

Cell·2026

Same author

Structures of partially occupied hetero-tetramers provide insight into kainate receptor activation and desensitization.

Nature communications·2026

Same journal

Correction: A method for supervoxel-wise association studies of age and other non-imaging variables from coronary computed tomography angiograms.

Scientific reports·2026

Same journal

Poly(bromophenol blue)/CoSn(OH)<sub>6</sub> cubic particles modified pencil graphite electrode for electrochemical determination of diphenhydramine.

Scientific reports·2026

Same journal

Dietary Chlorella, Spirulina, and acidifier modulate jejunal cytokine-related gene expression in broiler chickens.

Scientific reports·2026

Same journal

Perceived physical activity barriers in university students: associations with fatigue and eating behaviours.

Scientific reports·2026

Same journal

Refuge limitation structures habitat use in agricultural landscapes: evidence from Sunda pangolins.

Scientific reports·2026

Same journal

Lightweight stateless transaction verification with outsourced witness updates for UTXO blockchains.

Scientific reports·2026

See all related articles

Search research articles

Related Experiment Video

Updated: Feb 17, 2026

A Fluorescence-based Assay of Phospholipid Scramblase Activity

A Fluorescence-based Assay of Phospholipid Scramblase Activity

Published on: September 20, 2016

An engineered opsin monomer scrambles phospholipids.

Kalpana Pandey¹, Birgit Ploier¹, Michael A Goren¹

¹Department of Biochemistry, Weill Cornell Medical College, 1300 York Avenue, New York, NY, 10065, USA.

Scientific Reports

|December 3, 2017

Summary

This summary is machine-generated.

Engineered opsin monomers can scramble phospholipids, challenging the idea that protein dimerization is required for this lipid transport. This finding suggests the lipid-exposed face of transmembrane helix 4 is not essential for opsin

More Related Videos

Author Spotlight: Photo Switchable Protein Recruitment for Reversible Patterning in Artificial Cellular Systems

Author Spotlight: Photo Switchable Protein Recruitment for Reversible Patterning in Artificial Cellular Systems

Published on: February 23, 2024

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

Published on: August 24, 2016

Related Experiment Videos

Last Updated: Feb 17, 2026

A Fluorescence-based Assay of Phospholipid Scramblase Activity

A Fluorescence-based Assay of Phospholipid Scramblase Activity

Published on: September 20, 2016

Author Spotlight: Photo Switchable Protein Recruitment for Reversible Patterning in Artificial Cellular Systems

Author Spotlight: Photo Switchable Protein Recruitment for Reversible Patterning in Artificial Cellular Systems

Published on: February 23, 2024

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

SNARE-mediated Fusion of Single Proteoliposomes with Tethered Supported Bilayers in a Microfluidic Flow Cell Monitored by Polarized TIRF Microscopy

Published on: August 24, 2016

Area of Science:

Membrane biophysics
Protein structure and function
Lipid transport mechanisms

Background:

G protein-coupled receptor opsin acts as a phospholipid scramblase, facilitating lipid exchange across membranes.
The precise mechanism of opsin-mediated lipid scrambling remains unclear.
A hypothesis suggests lipid translocation occurs at protein-protein interfaces within opsin dimers.

Purpose of the Study:

To investigate the role of opsin dimerization in phospholipid scrambling.
To determine if opsin monomers can exhibit scramblase activity.
To elucidate the contribution of transmembrane helix 4 to opsin's function.

Main Methods:

Rational engineering of QUAD opsin by tryptophan substitution in transmembrane helix 4 (TM4).
Atomistic molecular dynamics simulations and continuum modeling to assess dimerization propensity.
Purification of thermostable wild-type and QUAD opsins with SNAP tags.
Single-molecule fluorescence and activity assays to evaluate protein state and scramblase function.

Main Results:

Engineered QUAD opsin exhibits reduced dimerization propensity due to optimized hydrophobic mismatch.
Both wild-type and QUAD opsins were purified as monomers.
QUAD opsin demonstrates full phospholipid scramblase activity as a monomer.
Unlike wild-type opsin, QUAD opsin reconstitutes as a monomer in phospholipid vesicles.

Conclusions:

Opsin monomers are capable of phospholipid scrambling, independent of dimerization.
The lipid-exposed face of TM4 is not critical for transbilayer phospholipid exchange.
This study reframes the understanding of opsin's mechanism of action in lipid transport.