Robert L. Barchi

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We describe the isolation and characterization of a cDNA encoding the alpha subunit of a new voltage-sensitive sodium channel, microI, from rat skeletal muscle. The 1840 amino acid microI peptide is homologous to alpha subunits from rat brain, but, like the protein from eel electroplax, lacks an extended (approximately 200) amino acid segment between(More)
Mutations in the adult human skeletal muscle Na+ channel alpha subunit cause the disease paramyotonia congenita. Two paramyotonia congenita mutations, R1448H and R1448C, substitute histidine and cysteine for arginine in the S4 segment of domain 4. These mutations, expressed in a cell line, have only small effects on the activation of Na+ currents, but(More)
The principal voltage-sensitive sodium channel from human heart has been cloned, sequenced, and functionally expressed. The cDNA, designated hH1, encodes a 2016-amino acid protein that is homologous to other members of the sodium channel multigene family and bears greater than 90% identity to the tetrodotoxin-insensitive sodium channel characteristic of rat(More)
species but encoded by orthologous genes have often Nomenclature of Voltage-Gated been given different names, so that there are multiple Sodium Channels synonyms for many of sodium channel isoforms. To eliminate confusion resulting from the multiplicity of names, we propose a standardized nomenclature for Voltage-gated sodium channels are critical elements(More)
The alpha subunit of a voltage-sensitive sodium channel characteristic of denervated rat skeletal muscle was cloned and characterized. The cDNA encodes a 2018 amino acid protein (SkM2) that is homologous to other recently cloned sodium channels, including a tetrodotoxin (TTX)-sensitive sodium channel from rat skeletal muscle (SkM1). The SkM2 protein is no(More)
  • N Yang, S Ji, +4 authors A L George
  • Proceedings of the National Academy of Sciences…
  • 1994
Mutations in the skeletal muscle voltage-gated Na+ channel alpha-subunit have been found in patients with two distinct hereditary disorders of sarcolemmal excitation: hyperkalemic periodic paralysis (HYPP) and paramyotonia congenita (PC). Six of these mutations have been functionally expressed in a heterologous cell line (tsA201 cells) using the recombinant(More)
1. The characteristics of saxitoxin (STX) binding to the mammalian Na channel have been studied in purified sarcolemma isolated from rat skeletal muscle. 2. STX binds specifically to isolated sarcolemma with a Kd of 1.43 x 10(-9) M and Bmax of 7-8 p-mole STX bound/mg membrane protein at 0 degrees C in the presence of 140 mM-NaCl. In rat muscle homogenate(More)
The periodic paralyses are a group of autosomal dominant muscle diseases sharing a common feature of episodic paralysis. In one form, paramyotonia congenita (PC), the paralysis usually occurs with muscle cooling. Electrophysiologic studies of muscle from PC patients have revealed temperature-dependent alterations in sodium channel (NaCh) function. This(More)
Two isoforms of voltage-dependent Na channels, cloned from rat skeletal muscle, were expressed in Xenopus oocytes. The currents of rSkM1 and rSkM2 differ functionally in 4 properties: (i) tetrodotoxin (TTX) sensitivity, (ii) mu-conotoxin (mu-CTX) sensitivity, (iii) amplitude of single channel currents, and (iv) rate of inactivation. rSkM1 is sensitive to(More)