Related Experiment Video
Updated: Jul 20, 2026
05:28
Demonstration of Heterologous Complexes formed by Golgi-Resident Type III Membrane Proteins using Split Luciferase Complementation Assay
Published on: September 10, 2020
Nucleotide-sugar transporters: structure, function and roles in vivo
M Handford1, C Rodriguez-Furlán, A Orellana
1Department of Biology, Faculty of Science, University of Chile, Santiago, Chile.
Summary
Nucleotide-sugar transporters (NSTs) move essential sugars into cellular compartments for glycosylation. Mutations in these crucial transporters cause developmental and health issues, highlighting their specific, non-redundant roles.
Area of Science:
- Cell Biology
- Biochemistry
- Genetics
Background:
- Glycosylation and polysaccharide biosynthesis rely on nucleotide-sugars, substrates for glycosyltransferases.
- Key glycosyltransferases reside in the Golgi apparatus and endoplasmic reticulum lumen.
- Nucleotide-sugars are primarily synthesized in the cytosol, necessitating transport mechanisms.
Purpose of the Study:
- To investigate the role and characterization of nucleotide-sugar transporters (NSTs).
- To understand the substrate specificity and functional significance of NSTs.
- To explore the consequences of NST gene mutations in various organisms.
Main Methods:
- Identification of NST-encoding sequences through genome and expressed sequence tag sequencing.
- Biochemical assays and mutant complementation for initial NST identification.
- Functional characterization of identified NST genes.
Main Results:
- Multiple NSTs were identified across different organisms, varying in substrate specificity.
- Mutations in NST genes impact development in model organisms (Drosophila, C. elegans) and parasite infectivity (Leishmania).
- Human mutations in a GDP-fucose transporter lead to immune deficiencies and growth retardation.
Conclusions:
- NSTs are essential for targeted nucleotide-sugar delivery, critical for cellular functions.
- Despite a considerable number of NST genes, they exhibit specific functions and are not redundant.
- NSTs play vital, distinct roles in glycosylation pathways, impacting development and health.
Related Concept Videos
01:27Glucose Transporters
Glucose transporters facilitate the transport of glucose across the cell membrane. In addition to glucose, some glucose transporters can also aid the movement of other hexoses such as fructose, mannose, and galactose.
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
Facilitated diffusion-glucose transporters (GLUTs) are encoded by the solute-linked carrier (SLC) family 2, subfamily A gene family, or SLC2A. The 14 GLUT protein members are distributed into three classes:
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...
01:32Secondary 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...
01:31Membrane Transporters
Transporters are essential membrane transport proteins with functions related to cell nutrition, homeostasis, communication, etc. Approximately 7% of all genes in the human genome code for transporters or transporter-related proteins.
Transporters are mainly composed of alpha-helices, built from bundles of ten or more helices traversing the plasma membrane. The solute-binding sites are located midway, where some of the helices are broken or distorted, making space for the binding site through...
Transporters are mainly composed of alpha-helices, built from bundles of ten or more helices traversing the plasma membrane. The solute-binding sites are located midway, where some of the helices are broken or distorted, making space for the binding site through...
01:30Membrane Proteins
Plasma membranes have integral transmembrane proteins involved in facilitated transport. These proteins are collectively referred to as transport proteins, and they function as either channels for the material or as carriers themselves. Channel proteins have hydrophilic domains exposed to the intracellular and extracellular fluids and a hydrophilic channel through their core that provides a hydrated opening for solutes to pass through the membrane layers. Passage through the channel allows...