Related Experiment Video
Updated: Jul 3, 2026
14:06
Mapping Bacterial Functional Networks and Pathways in Escherichia Coli using Synthetic Genetic Arrays
Published on: November 12, 2012
Genome-scale identification of UDP-GlcNAc-dependent pathways
Ken S Lau1, Sofia Khan, James W Dennis
1Samuel Lunenfeld Research Institute, Mount Sinai Hospital, ON, Canada.
Proteomics
|July 23, 2008
Summary
Supplementing cells with N-acetylglucosamine (GlcNAc) optimizes proliferation and endocytosis by altering N-glycan branching. Specific genes influenced by GlcNAc impact these cellular processes, highlighting novel therapeutic targets.
Area of Science:
- Cell Biology
- Glycobiology
- Molecular Biology
Background:
- Cellular sensitivity to external signals depends on glycoprotein receptor and transporter localization.
- N-glycan biosynthesis, regulated by UDP-N-acetylglucosamine (UDP-GlcNAc) flux, influences this surface residency.
- GlcNAc salvage impacts UDP-GlcNAc levels and N-glycan branching.
Purpose of the Study:
- To investigate the global gene expression changes induced by varying GlcNAc concentrations.
- To identify genes and pathways affected by GlcNAc supplementation.
- To determine the functional roles of specific GlcNAc-modulated genes in cellular phenotypes.
Main Methods:
- Global gene expression profiling of epithelial cells cultured in low and high GlcNAc conditions.
- Transfection of cells with small interfering RNA (siRNA) targeting specific genes.
- Phenotypic analysis of cell proliferation, bulk endocytosis, and N-glycan branching.
Main Results:
- High GlcNAc upregulated genes in EGF and TGF-beta signaling pathways and cell cycle checkpoints.
- Downregulated genes under high GlcNAc conditions indicated reduced metabolic activity.
- siRNA-mediated knockdown of LGALS3, WBSCR17, PHF3, SDC2, and CTNNAL1 partially reversed GlcNAc-induced changes in proliferation, endocytosis, and N-glycan branching.
Conclusions:
- GlcNAc supplementation optimizes cell proliferation and endocytosis through modulation of N-glycan branching.
- Specific genes, including LGALS3, are implicated in mediating GlcNAc's effects on cellular phenotypes.
- Findings suggest potential roles for galectin-3/N-glycans, proteoglycans, O-glycans, and cell adhesion in GlcNAc-regulated cellular functions.
More Related Videos
Related Concept Videos
01:26Biosynthesis of Polysaccharides
Polysaccharides such as glycogen and starch are synthesized from nucleoside diphosphate sugars, primarily uridine diphosphate glucose (UDPG) and adenosine diphosphate glucose (ADPG). These activated glucose donors act as key intermediates in carbohydrate metabolism and biosynthesis. UDPG primarily involves glycogen synthesis in animals and many bacteria, while ADPG plays a fundamental role in starch synthesis in plants and certain bacteria.UDPG is formed when glucose-1-phosphate reacts with...
01:24Other Glycolytic Pathways
The pentose phosphate pathway (PPP) operates in parallel with glycolysis, facilitating the metabolism of both pentoses and glucose. This pathway consists of two distinct phases: the oxidative and non-oxidative phases. While it does not directly generate ATP, the intermediates formed during the process can integrate into glycolysis, contributing to cellular energy metabolism when required.Oxidative Phase: NADPH ProductionThe oxidative phase of the pentose phosphate pathway is primarily...
01:28Global Regulatory Systems
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
01:22Inorganic Nitrogen Assimilation
Nitrogen is an essential element in biological systems, forming a crucial component of proteins, nucleic acids, and other cellular constituents. Many bacteria and archaea acquire nitrogen in the form of nitrate (NO₃⁻) or ammonia (NH₃), which are then assimilated into biomolecules through specific enzymatic pathways.Assimilatory Nitrate ReductionWhen nitrate enters the cell, it undergoes a two-step reduction process known as assimilatory nitrate reduction. Initially, the enzyme nitrate reductase...
01:29Amino Acid Biosynthetic Pathways
Amino acid biosynthesis is essential for cell growth, protein synthesis, and metabolic regulation. Cells generate essential and non-essential amino acids from metabolic intermediates to sustain vital biological functions. These intermediates originate from key metabolic pathways: glycolysis, the tricarboxylic acid (TCA) cycle, and the pentose phosphate pathway. Important precursors include α-ketoglutarate, pyruvate, oxaloacetate, phosphoenolpyruvate, and erythrose-4-phosphate, which provide...
01:11IP3/DAG Signaling Pathway
Membrane lipids such as phosphatidylinositol (PI) are precursors for several membrane-bound and soluble second messengers. Specific kinases phosphorylate PI and produce phosphorylated inositol phospholipids. One such inositol phospholipids are the phosphatidylinositol-4,5 bisphosphate [PI(4,5)P2], present in the inner half of the lipid bilayer. Upon ligand binding, GPCR stimulates Gq proteins to turn on phospholipase Cꞵ. Activated phospholipase Cꞵ cleaves PI(4,5)P2 and produces two-second...