Proteoglycan-specific molecular switch for RPTPσ clustering and neuronal extension.

Journal article

Heparan and chondroitin sulfate proteoglycans (HSPGs and CSPGs, respectively) regulate numerous cell surface signaling events, with typically opposite effects on cell function. CSPGs inhibit nerve regeneration through receptor protein tyrosine phosphatase sigma (RPTPσ). Here we report that RPTPσ acts bimodally in sensory neuron extension, mediating CSPG inhibition and HSPG growth promotion. Crystallographic analyses of a shared HSPG-CSPG binding site reveal a conformational plasticity that can accommodate diverse glycosaminoglycans with comparable affinities. Heparan sulfate and analogs induced RPTPσ ectodomain oligomerization in solution, which was inhibited by chondroitin sulfate. RPTPσ and HSPGs colocalize in puncta on sensory neurons in culture, whereas CSPGs occupy the extracellular matrix. These results lead to a model where proteoglycans can exert opposing effects on neuronal extension by competing to control the oligomerization of a common receptor.

Authors: Coles, C; Shen, Y; Tenney, A; Siebold, C; Sutton, G

• Publication status: Published
• Journal: Science (New York, N.Y.)
• Volume: 332
• Issue: 6028
• Pages: 484-488
• Publication date: 2011-04-01
• DOI: 10.1126/science.1200840
• EISSN: 1095-9203
• ISSN: 0036-8075
• Language: English
• Keywords: Protein Multimerization; Sensory Receptor Cells; Binding Sites; Models, Molecular; Amino Acid Sequence; Crystallography, X-Ray; Receptor-Like Protein Tyrosine Phosphatases, Class 2; Models, Biological; Protein Conformation; Cells, Cultured; Growth Cones; Humans; Glypicans; Protein Structure, Tertiary; Extracellular Matrix; Ganglia, Spinal; Neurites; Mice; Chondroitin Sulfate Proteoglycans; Animals; Neurocan; Chondroitin Sulfates; Molecular Sequence Data; Heparan Sulfate Proteoglycans; Cell Membrane; Heparitin Sulfate; Axons