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Link to original content: https://pubmed.ncbi.nlm.nih.gov/9861042
Interaction of voltage-gated sodium channels with the extracellular matrix molecules tenascin-C and tenascin-R - PubMed Skip to main page content
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. 1998 Dec 22;95(26):15753-7.
doi: 10.1073/pnas.95.26.15753.

Interaction of voltage-gated sodium channels with the extracellular matrix molecules tenascin-C and tenascin-R

J Srinivasan  1 , M Schachner, W A Catterall
Affiliations

Interaction of voltage-gated sodium channels with the extracellular matrix molecules tenascin-C and tenascin-R

J Srinivasan et al. Proc Natl Acad Sci U S A. .

Abstract

The type IIA rat brain sodium channel is composed of three subunits: a large pore-forming alpha subunit and two smaller auxiliary subunits, beta1 and beta2. The beta subunits are single membrane-spanning glycoproteins with one Ig-like motif in their extracellular domains. The Ig motif of the beta2 subunit has close structural similarity to one of the six Ig motifs in the extracellular domain of the cell adhesion molecule contactin (also called F3 or F11), which binds to the extracellular matrix molecules tenascin-C and tenascin-R. We investigated the binding of the purified sodium channel and the extracellular domain of the beta2 subunit to tenascin-C and tenascin-R in vitro. Incubation of purified sodium channels on microtiter plates coated with tenascin-C revealed saturable and specific binding with an apparent Kd of approximately 15 nM. Glutathione S-transferase-tagged fusion proteins containing various segments of tenascin-C and tenascin-R were purified, digested with thrombin to remove the epitope tag, immobilized on microtiter dishes, and tested for their ability to bind purified sodium channel or the epitope-tagged extracellular domain of beta2 subunits. Both purified sodium channels and the extracellular domain of the beta2 subunit bound specifically to fibronectin type III repeats 1-2, A, B, and 6-8 of tenascin-C and fibronectin type III repeats 1-2 and 6-8 of tenascin-R but not to the epidermal growth factor-like domain or the fibrinogen-like domain of these molecules. The binding of neuronal sodium channels to extracellular matrix molecules such as tenascin-C and tenascin-R may play a crucial role in localizing sodium channels in high density at axon initial segments and nodes of Ranvier or in regulating the activity of immobilized sodium channels in these locations.

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Figures

Figure 1
Figure 1
Specific binding of sodium channels to tenascin-C. Microtiter plates were coated with increasing concentrations of tenascin-C or laminin as indicated on the abscissa. After washing, purified sodium channels were added at a concentration of 40 nM and incubated as described under Experimental Procedures. The bound sodium channels were washed and quantitated by labeling with anti-SP1 antibody in an ELISA as described under Experimental Procedures. The results of a single experiment representative of eight similar experiments are shown.
Figure 2
Figure 2
High affinity binding of sodium channels to tenascin-C. Microtiter plates were coated with a fixed 100 nM concentration of tenascin-C or laminin. After washing, the indicated concentrations of sodium channels were added, incubated, washed, and quantitated by ELISA as described under Experimental Procedures. Half maximal binding of sodium channels was observed at 15 nM.
Figure 3
Figure 3
Domain structure of tenascin-C and tenascin-R. The domain structures of tenascin-C and tenascin-R are illustrated. EGF-like domains, open ovals; fibronectin-like domains, squares; fibrinogen-like domains, solid ovals. The fibronectin domains indicated as A, B, C, and R1 are alternatively spliced. In the text, the fusion protein containing fibronectin domains A1 to A4 is labeled FN-A. Adapted from ref. .
Figure 4
Figure 4
Binding of sodium channels to the domains of tenascin-C and tenascin-R. (A) Microtiter plates were coated with 100 nM solutions of the indicated bacterially expressed domains of tenascin-C. After washing, purified sodium channels were added at 40 nM, incubated, washed and quantitated by ELISA as described under Experimental Procedures. The results of a single experiment representative of five separate experiments are illustrated. Binding to TNC FN1–2, TNC FN-A, TNC FN-B, and TNC FN6–8 were consistently greater than background binding in these experiments. (B) A similar experiment was carried out with the indicated domains of tenascin-R.
Figure 5
Figure 5
Binding of GST-β2 to the domains of tenascin-C and tenascin-R. (A) Microtiter plates were coated with 100 nM solutions of the indicated domains of tenascin-C expressed and purified from E. coli. After washing, GST-β2 was added at 40 nM, incubated, washed and quantitated by ELISA as described under Experimental Procedures. The results of a single experiment representative of three separate experiments are illustrated. Binding to TNC FN1–2, TNC FN-A, TNC FN-B, and TNC FN6–8 were consistently greater than background binding in these experiments. (B) A similar experiment was carried out with the indicated domains of tenascin-R.
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References

    1. Eccles J C. Prog Brain Res. 1964;12:1–31. - PubMed
    1. Stuart G, Sakmann B. Neuron. 1995;15:1065–1076. - PubMed
    1. Catterall W A. J Neurosci. 1981;1:777–783. - PMC - PubMed
    1. Wollner D A, Catterall W A. Proc Natl Acad Sci USA. 1986;83:8424–8428. - PMC - PubMed
    1. Ritchie J M, Rogart R B. Rev Physiol Biochem Pharmacol. 1977;79:1–49. - PubMed

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