In order to study the currently unknown cellular signaling pathways of Cav3.1 T-type Ca2+ channels (Cav3.1 channels), we performed a yeast two-hybrid screening using intracellular domains of Cav3.1 α1 subunit as bait. After screening the human brain cDNA library, several proteins, including RanBPM, were identified as interacting with Cav3.1 channels. RanBPM was found to bind to the cytoplasmic intracellular loop between transmembrane domains I and II of Cav3.1 channels. Using whole-cell patch-clamp techniques, we found that Cav3.1 currents were increased by the expression of RanBPM in HEK293/Cav3.1 cells. We next examined whether RanBPM affected the biophysical properties and plasma membrane expression of Cav3.1 channels. Furthermore, we showed that the PKC activator inhibited Cav3.1 currents, an effect that was abolished by the expression of RanBPM. These results suggest that RanBPM could be a key regulator of Cav3.1 channel-mediated signaling pathways.
|Number of pages||6|
|Journal||Biochemical and Biophysical Research Communications|
|Publication status||Published - 2009 Jan 2|
Bibliographical noteFunding Information:
This work was supported by KIST Vision 21 Program, KIST Core-Competence Program, and Brain Research Center of the 21st Century Frontier Research Program (M103KV010007-08K2201-00710 to H.R.), the Republic of Korea. The authors extend their appreciation to Drs. Nishimoto and Bianchi for providing RanBPM plasmid and to Dr. Perez-Reyes for HEK293/Ca v 3.1 cells.
All Science Journal Classification (ASJC) codes
- Molecular Biology
- Cell Biology