Modulation of Ca(v)3.1 T-type Ca2+ channels by the ran binding protein RanBPM

Biochem Biophys Res Commun. 2009 Jan 2;378(1):15-20. doi: 10.1016/j.bbrc.2008.09.034. Epub 2008 Sep 16.


In order to study the currently unknown cellular signaling pathways of Ca(v)3.1 T-type Ca(2+) channels (Ca(v)3.1 channels), we performed a yeast two-hybrid screening using intracellular domains of Ca(v)3.1 alpha1 subunit as bait. After screening the human brain cDNA library, several proteins, including RanBPM, were identified as interacting with Ca(v)3.1 channels. RanBPM was found to bind to the cytoplasmic intracellular loop between transmembrane domains I and II of Ca(v)3.1 channels. Using whole-cell patch-clamp techniques, we found that Ca(v)3.1 currents were increased by the expression of RanBPM in HEK293/Ca(v)3.1 cells. We next examined whether RanBPM affected the biophysical properties and plasma membrane expression of Ca(v)3.1 channels. Furthermore, we showed that the PKC activator inhibited Ca(v)3.1 currents, an effect that was abolished by the expression of RanBPM. These results suggest that RanBPM could be a key regulator of Ca(v)3.1 channel-mediated signaling pathways.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / genetics
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Animals
  • Calcium Channels, T-Type / genetics
  • Calcium Channels, T-Type / metabolism*
  • Cell Line
  • Cell Membrane / metabolism
  • Cytoskeletal Proteins / genetics
  • Cytoskeletal Proteins / metabolism*
  • Electrophysiological Phenomena
  • Humans
  • Membrane Potentials
  • Nuclear Proteins / genetics
  • Nuclear Proteins / metabolism*
  • Patch-Clamp Techniques
  • Protein Kinase C / metabolism
  • Rats
  • Two-Hybrid System Techniques


  • Adaptor Proteins, Signal Transducing
  • CACNA1G protein, human
  • Calcium Channels, T-Type
  • Cytoskeletal Proteins
  • Nuclear Proteins
  • Ran binding protein 9
  • Protein Kinase C