G-protein activation modulates pseudo-periodic oscillation of Na channel.
We have shown before that the duration and amplitude of both prolonged (1-160 s) and short (100-1000 ms) depolarizing prepulse altered all the steady-state and kinetic parameters of rNav1.2a voltage-gated sodium channel in a pseudo-oscillatory fashion with variable time period and amplitude, often superimposed on a linear trend. In this study, we have examined the effect of G-protein activation on pseudo-oscillatory properties of the rNav1.2a sodium channel alpha subunit, heterologously expressed in Chinese hamster ovary cells. G-protein modification caused insignificant changes in the slow pseudo-periodic oscillation of the activation properties of sodium channel; only the time period of the oscillation was altered from approximately 30 to 21s. In contrast, G-protein activation abolished the faster component of pseudo-periodic oscillation in steady-state inactivation properties of sodium channel; the conditioning duration dependence of steady-state inactivation becomes monotonic in nature.
Majumdar
Sriparna
S
Molecular Biophysics Unit, Indian Institute of Science, Bangalore 560012, India.
Sikdar
Sujit K
SK
D000465:Algorithms; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D004558:Electric Stimulation; D019204:GTP-Binding Proteins / Q000378:metabolism*; D015870:Gene Expression; D006160:Guanosine Triphosphate / Q000494:pharmacology; D008564:Membrane Potentials / Q000187:drug effects; D062551:NAV1.2 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000502:physiology; D018408:Patch-Clamp Techniques; D051381:Rats; D015222:Sodium Channels / Q000235:genetics / Q000502:physiology*; D013997:Time Factors
D062551:NAV1.2 Voltage-Gated Sodium Channel; D009419:Nerve Tissue Proteins; C568253:Scn2A protein, rat; D015222:Sodium Channels; D006160:Guanosine Triphosphate; D019204:GTP-Binding Proteins