Asian Science Citation Index is committed to provide an authoritative, trusted and significant information by the coverage of the most important and influential journals to meet the needs of the global scientific community.  
ASCI Database
308-Lasani Town,
Sargodha Road,
Faisalabad, Pakistan
Fax: +92-41-8815544
Contact Via Web
Suggest a Journal
The American Journal of Physiology - Cell Physiology
Year: 2010  |  Volume: 298  |  Issue: 5  |  Page No.: 1029 - 1037

Inactivation of L-type calcium channel modulated by HCN2 channel

Y. C Lin, J Huang, Q Zhang, J. M Hollander, J. C Frisbee, K. H Martin, C Nestor, R Goodman and H. G. Yu    

Abstract:

Ca2+ entry is delicately controlled by inactivation of L-type calcium channel (LTCC) composed of the pore-forming subunit 1C and the auxiliary subunits β1 and 2. Calmodulin is the key protein that interacts with the COOH-terminal motifs of 1C, leading to the fine control of LTCC inactivation. In this study we show evidence that a hyperpolarization-activated cyclic nucleotide-gated channel, HCN2, can act as a nonchannel regulatory protein to narrow the L-type Ca2+ channel current-voltage curve. In the absence of LTCC auxiliary subunits, HCN2 can induce 1C inactivation. Without 2, HCN2-induced fast inactivation of 1C requires calmodulin. With 2, the 1C/HCN2/2 channel inactivation does not require calmodulin. In contrast, β1-subunit plays a relatively minor role in the interaction of 1C with HCN2. The NH2 terminus of HCN2 and the IQ motif of 1C subunit are required for 1C/HCN2 channel interaction. Ca2+ channel inactivation is significantly slowed in hippocampus neurons (HNs) overexpressing HCN2 mutant lacking NH2 terminus and accelerated in HNs overexpressing the wild-type HCN2 compared with HN controls. Collectively, these results revealed a potentially novel protection mechanism for achieving the LTCC inactivation via interaction with HCN2.

View Fulltext    |   Related Articles   |   Back
   
 
 
 
  Related Articles

No Article Found
 
 
 
Copyright   |   Desclaimer   |    Privacy Policy   |   Browsers   |   Accessibility