Involvement of actin cytoskeleton in modulation of apical K channel activity in rat collecting duct

W. H. Wang, A. Cassola, G. Giebisch

Research output: Contribution to journalArticlepeer-review

66 Scopus citations

Abstract

We have employed the patch-clamp technique to investigate the role of the actin cytoskeleton in the modulation of the low-conductance K+ channel in the apical membrane of the rat cortical collecting duct (CCD). This K+ channel is inactivated by application of cytochalasin B or D, both compounds known to disrupt actin filaments. The effect of both cytochalasins, B and D, was fully reversible in cell-attached patches, but channel activity could not be fully restored in excised membrane patches. The effect of cytochalasins on channel activity was specific and resulted from depolymerization of the actin cytoskeleton, since application of 10 μM chaetoglobosin C, a cytochalasin analogue that does not depolymerize the actin filaments, had no effect on channel activity in inside-out patches. Addition of either actin monomers or of the polymerizing actin filaments in inside-out patches to the cytosolic medium had no effect on channel activity. This suggests that cytochalasin B- or D-induced inactivation of apical K+ channels is not caused by obstruction of the channel pore by actin. We also observed that channel inhibition by cytochalasin B or D could be blocked by pretreatment with 5 μM phalloidin, a compound that stabilizes actin filaments. We conclude that apical K+ channel activity depends critically on the integrity of the actin cytoskeleton.

Original languageEnglish
Pages (from-to)F592-F598
JournalAmerican Journal of Physiology - Renal Fluid and Electrolyte Physiology
Volume267
Issue number4 36-4
DOIs
StatePublished - 1994
Externally publishedYes

Keywords

  • actin
  • cytochalasin B
  • cytochalasin D
  • phalloidin
  • potassium secretion
  • principal cell
  • renal tubule

Fingerprint

Dive into the research topics of 'Involvement of actin cytoskeleton in modulation of apical K channel activity in rat collecting duct'. Together they form a unique fingerprint.

Cite this