@article{2528,
  abstract     = {We previously reported a novel rat membrane protein that exhibits a voltage-dependent potassium channel activity on the basis of molecular cloning combined with an electrophysiological assay. This protein, termed I(sK) protein, is small and different from the conventional potassium channel proteins but induces selective permeation of potassium ions on its expression in Xenopus oocytes. In this investigation, we examined cellular localization of rat I(sK) protein by preparing three different types of antibody that specifically reacts with a distinct part of rat I(sK) protein. Immunohistochemical analysis using these antibody preparations demonstrated that rat I(sK) protein is confined to the apical membrane portion of epithelial cells in the proximal tubule of the kidney, the submandibular duct and the uterine endometrium. The observed tissue distribution of rat I(sK) protein was consistent with that of the I(sK) protein mRNA determined by blot hybridization analysis. In epithelial cells, the sodium, potassium-ATPase pump in the basolateral membrane generates a sodium gradient across the epithelial cell and allows sodium ions to enter the cell through the apical membrane. Thus, taking into account the cellular localization of the I(sK) protein, together with its electrophysiological properties, we discussed a possible function of the I(sK) protein, namely that this protein is involved in potassium permeation in the apical membrane of epithelial cells through the depolarizing effect of sodium entry.},
  author       = {Sugimoto, Tetsuo and Tanabe, Yasuto and Shigemoto, Ryuichi and Iwai, Masazumi and Takumi, Toru and Ohkubo, Hiroaki and Nakanishi, Shigetada},
  issn         = {1432-1424},
  journal      = {Journal of Membrane Biology},
  number       = {1},
  pages        = {39 -- 47},
  publisher    = {Springer},
  title        = {{Immunohistochemical study of a rat membrane protein which induces a selective potassium permeation: Its localization in the apical membrane portion of epithelial cells}},
  doi          = {10.1007/BF01869604},
  volume       = {113},
  year         = {1990},
}

@article{3465,
  abstract     = {Asymmetrical displacement currents and Na currents of single myelinated nerve fibers of Xenopus laevis were studied in the temperature range from 5 to 24 degrees C. The time constant of the on-response at E = 4 mV, tau on, was strongly temperature dependent, whereas the amount of displaced charge at E = 39 mV, Qon, was only slightly temperature dependent. The mean Q10 for tau on-1 was 2.54, the mean Q10 for Qon was 1.07. The time constant of charge immobilization, tau i, at E = 4 mV varied significantly (alpha = 0.001) with temperature. The mean Q10 for tau i-1 was 2.71 +/- 0.38. The time constants of immobilization of gating charge and of fast inactivation of Na permeability were similar in the temperature range from 6 to 22 degrees C. The Qoff/Qon ratio for E = 4 mV pulses of 0.5 msec duration decreased with increasing temperature. The temperature dependence of the time constant of the off-response could not be described by a single Q10 value, since the Q10 depended on the duration of the test pulse. Increasing temperature shifted Qon (E) curves to more negative potentials by 0.51 mV K-1, but shifted PNa (E) curves and h infinity (E) curves to more positive potentials by 0.43 and 0.57 mV K-1, respectively. h infinity (E = -70 mV) increased monotonously with increasing temperature. The present data indicate that considerable entropy changes may occur when the Na channel molecule passes from closed through open to inactivated states.},
  author       = {Jonas, Peter M},
  issn         = {1432-1424},
  journal      = {Journal of Membrane Biology},
  number       = {3},
  pages        = {277 -- 289},
  publisher    = {Springer},
  title        = {{Temperature dependence of gating current in myelinated nerve fibers}},
  doi          = {10.1007/BF01870958},
  volume       = {112},
  year         = {1989},
}