Abstract
The voltage-gated sodium channel (Nav1) plays an important role in initiating and propagating action potentials in neuronal cells. We and others have recently found that the Alzheimer’s disease-related secretases BACE1 and presenilin (PS)/γ-secretase regulate Nav1 function by cleaving auxiliary subunits of the channel complex. We have also shown that elevated BACE1 activity significantly decreases sodium current densities in neuroblastoma cells and acutely dissociated adult hippocampal neurons. For detailed molecular studies of sodium channel regulation, biochemical methods are now complementing classical electrophysiology. To understand how BACE1 regulates sodium current densities in our studies, we setup conditions to analyze surface levels of the pore-forming Nav1 α-subunits. By using a cell surface biotinylation protocol, we found that elevated BACE1 activity significantly decreases surface Nav1 α-subunit levels in both neuroblastoma cells and acutely prepared hippocampal slices. This finding would explain the decreased sodium currents shown by standard electrophysiological methods. The biochemical methods used in our studies would be applicable to analyses of surface expression levels of other ion channels as well as Nav1 in cells and adult hippocampal neurons.
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References
Lai, H., and Jan, L. (2006) The distribution and targeting of neuronal voltage-gated ion channels. Nat Rev Neurosci. 7, 548–562.
Catterall, W. (2000) From ionic currents to molecular mechanisms: the structure and function of voltage-gated sodium channels. Neuron. 26, 13–25.
Isom, L., De Jongh, K., and Catterall, W. (1994) Auxiliary subunits of voltage-gated ion channels. Neuron. 12, 1183–1194.
Isom, L., and Catterall, W. (1996) Na+ channel subunits and Ig domains. Nature. 383, 307–308.
Brackenbury, W. J., Djamgoz, M. B. A., and Isom, L. L. (2008) An emerging role for voltage-gated Na+ channels in cellular migration: regulation of central nervous system development and potentiation of invasive cancers. Neuroscientist. 14, 571–583.
Schmidt, J., and Catterall, W. (1986) Biosynthesis and processing of the alpha subunit of the voltage-sensitive sodium channel in rat brain neurons. Cell. 46, 437–444.
Isom, L. (2001) Sodium channel beta subunits: anything but auxiliary. Neuroscientist. 7, 42–54.
Catterall, W. (2002) Molecular mechanisms of gating and drug block of sodium channels. Novartis Found Symp. 241, 206–218; discussion 218–232.
Isom, L., Ragsdale, D., De Jongh, K., Westenbroek, R., Reber, B., Scheuer, T., and Catterall, W. (1995) Structure and function of the beta 2 subunit of brain sodium channels, a transmembrane glycoprotein with a CAM motif. Cell. 83, 433–442.
Chen, C., Bharucha, V., Chen, Y., Westenbroek, R., Brown, A., Malhotra, J., Jones, D., Avery, C., Gillespie, P., Kazen-Gillespie, K., Kazarinova-Noyes, K., Shrager, P., Saunders, T., Macdonald, R., Ransom, B., Scheuer, T., Catterall, W., and Isom, L. (2002) Reduced sodium channel density, altered voltage dependence of inactivation, and increased susceptibility to seizures in mice lacking sodium channel beta 2-subunits. Proc Natl Acad Sci USA. 99, 17072–17077.
Lopez-Santiago, L., Pertin, M., Morisod, X., Chen, C., Hong, S., Wiley, J., Decosterd, I., and Isom, L. (2006) Sodium channel beta2 subunits regulate tetrodotoxin-sensitive sodium channels in small dorsal root ganglion neurons and modulate the response to pain. J Neurosci. 26, 7984–7994.
Schmidt, J., Rossie, S., and Catterall, W. (1985) A large intracellular pool of inactive Na channel alpha subunits in developing rat brain. Proc Natl Acad Sci USA. 82, 4847–4851.
Wong, H., Sakurai, T., Oyama, F., Kaneko, K., Wada, K., Miyazaki, H., Kurosawa, M., De Strooper, B., Saftig, P., and Nukina, N. (2005) {beta} Subunits of Voltage-gated Sodium Channels Are Novel Substrates of {beta}-Site Amyloid Precursor Protein-cleaving Enzyme (BACE1) and {gamma}-Secretase. J Biol Chem. 280, 23009–23017.
Kim, D., Ingano, L., Carey, B., Pettingell, W., and Kovacs, D. (2005) Presenilin/{gamma}-Secretase-mediated Cleavage of the Voltage-gated Sodium Channel {beta}2-Subunit Regulates Cell Adhesion and Migration. J Biol Chem. 280, 23251–23261.
Kim, D., Carey, B., Wang, H., Ingano, L., Binshtok, A., Wertz, M., Pettingell, W., He, P., Lee, V., Woolf, C., and Kovacs, D. (2007) BACE1 regulates voltage-gated sodium channels and neuronal activity. Nat Cell Biol. 9, 755–764.
Vassar, R., Kovacs, D. M., Yan, R., and Wong, P. C. (2009) The beta-secretase enzyme BACE in health and Alzheimer’s disease: regulation, cell biology, function, and therapeutic potential. J Neurosci. 29, 12787–12794.
Fukumoto, H., Cheung, B., Hyman, B., and Irizarry, M. (2002) beta-Secretase Protein and Activity Are Increased in the Neocortex in Alzheimer Disease. Arch Neurol. 59, 1381–1389.
Tyler, S., Dawbarn, D., Wilcock, G., and Allen, S. (2002) alpha- and beta-secretase: profound changes in Alzheimer’s disease. Biochem Biophys Res Commun. 299, 373–376.
Yang, L., Lindholm, K., Yan, R., Citron, M., Xia, W., Yang, X., Beach, T., Sue, L., Wong, P., Price, D., Li, R., and Shen, Y. (2003) Elevated beta-secretase expression and enzymatic activity detected in sporadic Alzheimer disease. Nat Med. 9, 3–4.
Li, R., Lindholm, K., Yang, L., Yue, X., Citron, M., Yan, R., Beach, T., Sue, L., Sabbagh, M., Cai, H., Wong, P., Price, D., and Shen, Y. (2004) Amyloid beta peptide load is correlated with increased beta-secretase activity in sporadic Alzheimer’s disease patients. Proc Natl Acad Sci USA. 101, 3632–3637.
Zhao, J., Fu, Y., Yasvoina, M., Shao, P., Hitt, B., O’Connor, T., Logan, S., Maus, E., Citron, M., Berry, R., Binder, L., and Vassar, R. (2007) Beta-site amyloid precursor protein cleaving enzyme 1 levels become elevated in neurons around amyloid plaques: implications for Alzheimer’s disease pathogenesis. J Neurosci. 27, 3639–3649.
Thomas-Crusells, J., Vieira, A., Saarma, M., and Rivera, C. (2003) A novel method for monitoring surface membrane trafficking on hippocampal acute slice preparation. J Neurosci Methods. 125, 159–166.
Acknowledgments
We would like to thank Mr. Manuel T. Gersbacher and Ms. Ateka Ahmed for their technical help. This work is supported by grants from the Cure Alzheimer’s Fund and the NIH/NIA to DMK and DYK.
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Kim, D.Y., Kovacs, D.M. (2011). Surface Trafficking of Sodium Channels in Cells and in Hippocampal Slices. In: Manfredi, G., Kawamata, H. (eds) Neurodegeneration. Methods in Molecular Biology, vol 793. Humana Press, Totowa, NJ. https://doi.org/10.1007/978-1-61779-328-8_23
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DOI: https://doi.org/10.1007/978-1-61779-328-8_23
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