Mechanism by which Liddle's syndrome mutations increase activity of a human epithelial Na+ channel

Cell. 1995 Dec 15;83(6):969-78. doi: 10.1016/0092-8674(95)90212-0.


Liddle's syndrome is an inherited form of hypertension caused by mutations that truncate the C-terminus of human epithelial Na+ channel (hENaC) subunits. Expression of truncated beta and gamma hENaC subunits increased Na+ current. However, truncation did not alter single-channel conductance or open state probability, suggesting there were more channels in the plasma membrane. Moreover, truncation of the C-terminus of the beta subunit increased apical cell-surface expression of hENaC in a renal epithelium. We identified a conserved motif in the C-terminus of all three subunits that, when mutated, reproduced the effect of Liddle's truncations. Further, both truncation of the C-terminus and mutation of the conserved C-terminal motif increased surface expression of chimeric proteins containing the C-terminus of beta hENaC. Thus, by deleting a conserved motif, Liddle's mutations increase the number of Na+ channels in the apical membrane, which increases renal Na+ absorption and creates a predisposition to hypertension.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Amiloride / pharmacology
  • Amino Acid Sequence
  • Animals
  • Cell Line
  • Consensus Sequence
  • Dogs
  • Electric Conductivity
  • Epithelial Sodium Channels
  • Epithelium
  • Frameshift Mutation
  • Humans
  • Hypertension / genetics*
  • Hypertension / metabolism*
  • Hypertension / physiopathology
  • Ion Channel Gating / drug effects
  • Kidney / cytology
  • Kidney / metabolism
  • Kidney / physiopathology
  • Molecular Sequence Data
  • Oocytes
  • Patch-Clamp Techniques
  • Sequence Deletion / genetics*
  • Sodium Channels / biosynthesis
  • Sodium Channels / genetics
  • Sodium Channels / metabolism*
  • Syndrome
  • Xenopus


  • Epithelial Sodium Channels
  • Sodium Channels
  • Amiloride