Roles of α_1 and α_1/β Subunits Derived from Cardiac L-Type Ca^<2+> Channels on Voltage-Dependent Facilitation Mechanisms

Access this Article

Author(s)

Abstract

Strong depolarization pulses facilitate L-type Ca<sup>2+</sup> channels in various cell types including cardiac myocytes. The mechanisms underlying prepulse facilitation are controversial with respect to the requirements for channel subunits, cAMP-dependent protein kinase, and additional anchor proteins. The properties of voltage-dependent facilitation of the L-type Ca<sup>2+</sup> channel was studied in recombinant cardiac α<sub>1</sub> subunits with or without cardiac β subunit, expressed in Chinese hamster fibroblast cells. The magnitude of voltage-dependent I<sub>Ba</sub> facilitation in the α<sub>1</sub> subunit channel is dependent on the duration of the prepulse as well as on the interval duration between prepulse and test pulse. The characteristics of this facilitation were not affected by coexpression of the β subunit. These results indicate that cardiac α<sub>1</sub> subunits exhibit voltage-dependent facilitation because of their own intrinsic structure, independent of any other accessory subunit or additional regulatory proteins, and that cardiac β subunits have no essential regulatory role at the onset or continuance of the voltage-dependent facilitation.<br>

Journal

  • The Japanese Journal of Physiology

    The Japanese Journal of Physiology 51(3), 337-344, 2001-06

    THE PHYSIOLOGICAL SOCIETY OF JAPAN

References:  35

Cited by:  1

Codes

  • NII Article ID (NAID)
    10008293784
  • NII NACSIS-CAT ID (NCID)
    AA00691224
  • Text Lang
    ENG
  • Article Type
    Journal Article
  • ISSN
    0021521X
  • NDL Article ID
    5840287
  • NDL Source Classification
    ZS8(科学技術--医学--解剖学・生理学・生化学)
  • NDL Call No.
    Z53-D40
  • Data Source
    CJP  CJPref  NDL  J-STAGE 
Page Top