Physical and functional interactions between a glioma cation channel and Integrin-β1 require α-actinin

Academic Article

Abstract

  • © 2015 the American Physiological Society. Major plasma membrane components of the tumor cell, ion channels, and integrins play crucial roles in metastasis. Glioma cells express an amiloride-sensitive nonselective cation channel composed of acidsensing ion channel (ASIC)-1 and epithelial Na+ channel (ENaC) β-and α-subunits. Inhibition of this channel is associated with reduced cell migration and proliferation. Using the ASIC-1 subunit as a reporter for the channel complex, we found a physical and functional interaction between this channel and integrin-α1. Short hairpin RNA knockdown of integrin-α1 attenuated the amiloride-sensitive current, which was due to loss of surface expression of ASIC-1. In contrast, upregulation of membrane expression of integrin- α1 increased the surface expression of ASIC-1. The link between the amiloride-sensitive channel and integrin-α1 was mediated by β-actinin. Downregulation of β-actinin-1 or -4 attenuated the amiloride-sensitive current. Mutation of the putative binding site for β-actinin on the COOH terminus of ASIC-1 reduced the membrane localization of ASIC-1 and also resulted in attenuation of the amiloride-sensitive current. Our data suggest a novel interaction between the amiloride-sensitive glioma cation channel and integrin-α1, mediated by β-actinin. This interaction may form a mechanism by which channel activity can regulate glioma cell proliferation and migration.
  • Digital Object Identifier (doi)

    Author List

  • Rooj AK; Liu Z; McNicholas CM; Fuller CM
  • Start Page

  • C308
  • End Page

  • C319
  • Volume

  • 309
  • Issue

  • 5