Related Experiment Video
Updated: Aug 9, 2026
13:16
Characterization of Membrane Transporters by Heterologous Expression in E. coli and Production of Membrane Vesicles
Published on: December 31, 2019
[New concepts in anionic and cationic amino acid transport]
E Avila-Chávez1, N Torres-y-Torres, A R Tovar-Palacio
1Departamento de Fisiología de la Nutrición, Instituto Nacional de la Nutrición Salvador Zubirán, México, D.F.
Summary
Mammalian cells utilize specific transporter proteins to move amino acids across membranes. This review details molecular-level insights into anionic and cationic amino acid transport systems, crucial for various cellular functions.
Area of Science:
- Cellular biology
- Molecular biology
- Neuroscience
Background:
- Amino acid uptake in mammalian cells occurs via plasma membrane transport systems.
- Historically, kinetic and competition studies aided characterization, but precise amino acid-system assignments were challenging.
- Molecular biology advances enable identification of specific amino acid transporter proteins.
Purpose of the Study:
- To review anionic and cationic amino acid transport systems at the molecular level.
- To highlight the roles of these transporters in cellular functions and disease.
Main Methods:
- Literature review of studies identifying molecular identities of amino acid transporters.
- Discussion of characterized anionic (XAG-, Xc-) and cationic (y+, y+L, bo,+, Bo,+) transport systems.
- Integration of findings on transporter function in physiological and pathological contexts.
Main Results:
- Anionic amino acids are primarily transported by XAG- (involved in glutamatergic transmission) and Xc- (glutathione synthesis) systems.
- Four XAG- system isoforms in the brain are Na+-dependent amino acid transporters.
- Cationic amino acid transporters also handle zwitterionic substrates, with y+, y+L, bo,+, and Bo,+ being well-characterized.
- Regulation of cationic amino acid uptake impacts nitric oxide, creatine, carnitine, and polyamine biosynthesis.
- Cysteinuria is linked to an inherited defect in the bo,+ system.
Conclusions:
- Molecular identification has clarified amino acid transport mechanisms.
- Specific transporters play vital roles in neurotransmission, biosynthesis, and cellular homeostasis.
- Defects in amino acid transport systems can lead to inherited disorders like cysteinuria.
More Related Videos
09:12Selection of Transporter-Targeted Inhibitory Nanobodies by Solid-Supported-Membrane (SSM)-Based Electrophysiology
Published on: May 3, 2021
04:40Demonstration of Membrane Transport of Histidine using Goat Intestinal Inverted Sacs: An Experiential Pedagogical Tool for Undergraduates
Published on: October 4, 2024
Related Concept Videos
01:55Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme “pump” embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
01:32Secondary Active Transport
One example of how cells use the energy contained in electrochemical gradients is demonstrated by glucose transport into cells. The ion vital to this process is sodium (Na+), which is typically present in higher concentrations extracellularly than in the cytosol. Such a concentration difference is due, in part, to the action of an enzyme "pump" embedded in the cellular membrane that actively expels Na+ from a cell. Importantly, as this pump contributes to the high concentration of...
01:19Drug Absorption Mechanism: Carrier-Mediated Membrane Transport
Certain large, lipid-insoluble drug molecules that resemble amino acids, peptides, or glucose, require specialized carrier proteins to facilitate their diffusion across cell membranes. This transport can occur through either facilitated diffusion, which does not require energy input, or active transport, which does require energy input.
Facilitated diffusion is a passive process that utilizes human Solute Carrier (SLC) transporters. These transporters bind to the drug, undergo structural...
Facilitated diffusion is a passive process that utilizes human Solute Carrier (SLC) transporters. These transporters bind to the drug, undergo structural...
01:17Pore Transport and Ion-Pair Transport
Pore transport and ion-pair formation are critical mechanisms for the absorption and distribution of drugs in the body.
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
Pore transport, also known as convective transport, is a process where small molecules like urea, water, and sugars rapidly cross cell membranes as though there were channels or pores in the membrane. Although direct microscopic evidence is limited but the concept of pores or channels is widely accepted based on physiological evidence. Despite the lack of direct microscopic...
01:06Carrier-Mediated Transport
Carrier-mediated transport is a pivotal process in drug absorption, particularly for lipid-insoluble drugs, and encompasses facilitated diffusion and active transport. Facilitated diffusion allows drugs to move along their concentration gradient without energy expenditure, while active transport utilizes ATP to drive drug movement against this gradient.
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
Active transport involves two types of membrane-spanning transporters: uptake and efflux. Uptake transporters are expressed in the small...
01:14Active Transport
Active transport is a critical biological process that allows cells to move solutes against an electrochemical gradient. This process requires direct energy input and is characterized by its selectivity, saturability, and susceptibility to competitive inhibition.
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...
Primary active transporters, like Na+, K+ and -ATPase, directly utilize ATP to move ions across the membrane. These transporters play significant roles in various physiological processes. For instance, Na+, K+ and -ATPase maintain...