Abstract
Class 1 and 3 semaphorins repulse axons but bind to different cell surface proteins. We find that the two known semaphorin-binding proteins, plexin 1 (Plex 1) and neuropilin-1 (NP-1), form a stable complex. Plex 1 alone does not bind semaphorin-3A (Sema3A), but the NP-1/Plex 1 complex has a higher affinity for Sema3A than does NP-1 alone. While Sema3A binding to NP-1 does not alter nonneuronal cell morphology, Sema3A interaction with NP-1/Plex 1 complexes induces adherent cells to round up. Expression of a dominant-negative Plex 1 in sensory neurons blocks Sema3A-induced growth cone collapse. Sema3A treatment leads to the redistribution of growth cone NP-1 and plexin into clusters. Thus, physiologic Sema3A receptors consist of NP-1/plexin complexes.
Publication types
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Research Support, Non-U.S. Gov't
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Research Support, U.S. Gov't, Non-P.H.S.
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Research Support, U.S. Gov't, P.H.S.
MeSH terms
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Animals
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COS Cells
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Ganglia, Spinal / cytology
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Gene Expression / physiology
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Growth Cones / chemistry
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Growth Cones / metabolism
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Humans
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Kidney / cytology
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Multigene Family
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Nerve Tissue Proteins / chemistry
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Nerve Tissue Proteins / genetics
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Nerve Tissue Proteins / metabolism*
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Neurons / chemistry
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Neurons / cytology
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Neurons / ultrastructure
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Neuropilin-1
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Protein Binding / physiology
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Protein Structure, Tertiary
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Receptors, Cell Surface / chemistry
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Receptors, Cell Surface / genetics
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Receptors, Cell Surface / metabolism*
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Signal Transduction / physiology
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Solubility
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Transfection
Substances
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Nerve Tissue Proteins
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PLXNA1 protein, human
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Receptors, Cell Surface
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Neuropilin-1