Related Experiment Video
Updated: Jul 19, 2026

Modeling the Endothelial Glycocalyx Post-Pneumonectomy in a 3D Fluidic Chip - An Approach to Fabricating a Vascular-based Organ-on-Chip System
Published on: September 16, 2025
Cell-surface heparan sulfate proteoglycans are essential components of the unconventional export machinery of FGF-2
Christoph Zehe1, André Engling, Sabine Wegehingel
1Heidelberg University Biochemistry Center (BZH), Im Neuenheimer Feld 328, 69120 Heidelberg, Germany.
Abstract:
FGF-2 is an unconventionally secreted lectin that transmits proangiogenic signals through a ternary complex with high-affinity FGF receptors and heparan sulfate proteoglycans (HSPGs). Although FGF-2 signal transduction is understood in great detail, its mechanism of release from cells, which is independent of the classical secretory pathway, remains elusive. To test the hypothesis that FGF-2 secretion is linked to its cell-surface ligands, we studied FGF-2 release using mutants defective for HSPG binding and cells with impaired HSPG biosynthesis. Here, we report that a functional interaction between FGF-2 and HSPGs is required for net export of FGF-2 from mammalian cells. FGF-2 release requires extracellular, membrane-proximal HSPGs. We propose that extracellular HSPGs form a molecular trap that drives FGF-2 translocation across the plasma membrane.
Related Concept Videos
Matrix Proteoglycans and Glycoproteins
Proteoglycans
Glycosaminoglycans
GAGS are found in the extracellular matrix of vertebrates, invertebrates, and bacteria. Due to their polar nature they attract water, and serve as excellent lubricants or shock absorbers in an animal body.
Hyaluronic...
Fibronectins Connect Cells with ECM
Both proteoglycans and collagen are attached to fibronectin proteins, which, in turn, are attached to integrin proteins. These integrin proteins interact with transmembrane...
Glycocalyx and its Functions
Components of...
Coat Assembly and GTPases
Coat assembly depends on the local availability of phosphatidylinositol phosphates or PIPs and GTP-binding proteins. Adaptor proteins, which link the coat proteins to the membrane, bind to these PIPs and play a crucial role in controlling...
