Polycystin-L is a calcium-regulated cation channel permeable to calcium ions

Nature. 1999 Sep 23;401(6751):383-6. doi: 10.1038/43907.


Polycystic kidney diseases are genetic disorders in which the renal parenchyma is progressively replaced by fluid-filled cysts. Two members of the polycystin family (polycystin-1 and -2) are mutated in autosomal dominant polycystic kidney disease (ADPKD), and polycystin-L is deleted in mice with renal and retinal defects. Polycystins are membrane proteins that share significant sequence homology, especially polycystin-2 and -L (50% identity and 71% similarity). The functions of the polycystins remain unknown. Here we show that polycystin-L is a calcium-modulated nonselective cation channel that is permeable to sodium, potassium and calcium ions. Patch-clamp experiments revealed single-channel activity with a unitary conductance of 137 pS. Channel activity was substantially increased when either the extracellular or intracellular calcium-ion concentration was raised, indicating that polycystin-L may act as a transducer of calcium-mediated signalling in vivo. Its large single-channel conductance and regulation by calcium ions distinguish it from other structurally related cation channels.

Publication types

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

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Calcium Channels / genetics
  • Calcium Channels / metabolism*
  • Calcium Signaling
  • Cations, Divalent / metabolism
  • Cell Membrane Permeability
  • Chelating Agents / pharmacology
  • Cloning, Molecular
  • Egtazic Acid / pharmacology
  • Electrophysiology
  • Humans
  • Membrane Glycoproteins / genetics
  • Membrane Glycoproteins / metabolism*
  • Patch-Clamp Techniques
  • Phosphoproteins / genetics
  • Phosphoproteins / metabolism*
  • Polycystic Kidney Diseases / metabolism
  • Receptors, Cell Surface
  • Recombinant Proteins / genetics
  • Recombinant Proteins / metabolism
  • Thapsigargin / pharmacology
  • Xenopus


  • Calcium Channels
  • Cations, Divalent
  • Chelating Agents
  • Membrane Glycoproteins
  • PKD2L1 protein, human
  • Phosphoproteins
  • Receptors, Cell Surface
  • Recombinant Proteins
  • Egtazic Acid
  • Thapsigargin
  • Calcium