RESEARCH: MEMBRANE TRANSPORT
FOLDING PROJECT #15004 PROFILE

This project explores how LAX3, a unique protein, moves substances across cell membranes using only proton power. Unlike similar proteins that rely on sodium or chloride, LAX3's shape and movement change depending on whether it has a proton attached, which helps drive the transport process. Studying this will help us understand how cells use protons to move important things in and out.

Note: This TLDR is a simplication and may not be 100% accurate.

Understanding Unique Mechanisms of Membrane Transport
Membrane transporters are an integral part of the cell and serve many roles across their involvement in the transport of ions, nutrients, neurotransmitters, and many drugs across cellular membranes.

There are three major classes of membrane transport proteins that facilitate the transport of various solutes.

These classes are Uniporters, which transport one solute across the membrane in one direction, Symporters, which transport two solutes across the membrane in the same direction, and Antiporters, which transfer two solutes in opposite directions across the membrane.

These classes follow different mechanisms of transport to move their solute(s) across the membrane.
This project will study a powerful mode of transport; proton driven.

LAX3 is the protein of interest, notable also for its characteristic LeuT fold, the same present in neuronal trasporters SERT, DAT, and NET.

Unlike these, however, it seems to not be driven by sodium or chloride gradients, only protons.

This force is difficult to study in full scale systems given the lack of change in covalent bonds used in molecular dynamics simulations.

This project will break down motion in the protonated, and unprotonated state to compare how the differences drive transport.

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Membrane Transporter

A protein embedded in the cell membrane that facilitates the movement of substances across it.

Membrane transporters are essential proteins found in cell membranes. They act like tiny gateways, allowing specific molecules like ions, nutrients, and drugs to pass through the membrane. This is crucial for various cellular functions, including nutrient uptake, waste removal, and signal transmission.

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Uniporters

A type of membrane transporter protein that moves one molecule across the cell membrane in one direction.

Uniporters are membrane proteins that transport single molecules across the cell membrane. They work like a one-way door, allowing substances to move in only one direction. Examples include glucose transporters, which facilitate the uptake of sugar into cells.

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Symporters

A type of membrane transporter protein that moves two molecules across the cell membrane in the same direction.

Symporters are membrane proteins that transport two different molecules simultaneously across the cell membrane. They work together, moving both substances in the same direction. An example is the sodium-glucose symporter, which brings glucose into cells along with sodium ions.

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Antiporters

A type of membrane transporter protein that moves two molecules across the cell membrane in opposite directions.

Antiporters are membrane proteins that transport two different molecules in opposite directions across the cell membrane. They act like a swap system, exchanging one substance for another. An example is the sodium-potassium pump, which pumps sodium ions out of the cell and potassium ions into the cell.

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Proton

A subatomic particle with a positive charge, found in the nucleus of an atom.

Protons are tiny particles that reside in the nucleus of every atom. They carry a positive electrical charge and contribute to the overall mass of an atom. Protons play a crucial role in chemical reactions and cellular processes.

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LAX3

A membrane transporter protein that is a focus of research due to its unique proton-driven transport mechanism.

LAX3 is a membrane protein being studied for its unique ability to transport substances using proton gradients instead of sodium or chloride ions. Its structure and function provide insights into cellular transport processes and potential drug delivery mechanisms.

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LeuT Fold

A common structural motif found in many membrane transporter proteins, including LAX3.

The LeuT fold is a characteristic three-dimensional shape observed in numerous membrane transporter proteins. This conserved structure suggests a shared mechanism for transporting molecules across cell membranes.

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SERT

Serotonin Transporter

The serotonin transporter (SERT) is a membrane protein that removes serotonin from the synaptic cleft, regulating mood and other brain functions. It is a target for antidepressants.

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DAT

Dopamine Transporter

The dopamine transporter (DAT) removes dopamine from the synaptic cleft, playing a crucial role in reward and movement. It is targeted by drugs like cocaine.

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NET

Norepinephrine Transporter

The norepinephrine transporter (NET) removes norepinephrine from the synaptic cleft, influencing alertness and mood. It is a target for some antidepressants.