Cookies on this website

We use cookies to ensure that we give you the best experience on our website. If you click 'Accept all cookies' we'll assume that you are happy to receive all cookies and you won't see this message again. If you click 'Reject all non-essential cookies' only necessary cookies providing core functionality such as security, network management, and accessibility will be enabled. Click 'Find out more' for information on how to change your cookie settings.

The receptor-like protein tyrosine phosphatase (RPTP) PTPsigma controls the growth and targeting of retinal axons, both in culture and in ovo. Although the principal actions of PTPsigma have been thought to be cell-autonomous, the possibility that RPTPs related to PTPsigma also have non-cell-autonomous signaling functions during axon development has also been supported genetically. Here we report that a cell culture substrate made from purified PTPsigma ectodomains supports retinal neurite outgrowth in cell culture. We show that a receptor for PTPsigma must exist on retinal axons and that binding of PTPsigma to this receptor does not require the known, heparin binding properties of PTPsigma. The neurite-promoting potential of PTPsigma ectodomains requires a basic amino acid domain, previously demonstrated in vitro as being necessary for ligand binding by PTPsigma. Furthermore, we demonstrate that heparin and oligosaccharide derivatives as short as 8mers, can specifically block neurite outgrowth on the PTPsigma substrate, by competing for binding to this same domain. This is the first direct evidence of a non-cell-autonomous, neurite-promoting function of PTPsigma and of a potential role for heparin-related oligosaccharides in modulating neurite promotion by an RPTP.

Original publication




Journal article


J Neurobiol

Publication Date





59 - 71


Animals, Avian Proteins, Chick Embryo, Chondroitin Sulfates, Drug Interactions, Extracellular Matrix, Heparin, Humans, In Vitro Techniques, Models, Biological, Neurites, Protein Binding, Protein Structure, Tertiary, Protein Tyrosine Phosphatases, Receptor-Like Protein Tyrosine Phosphatases, Class 2, Recombinant Fusion Proteins, Retina, Retinal Ganglion Cells, Time Factors