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Author Notes:

Correspondence: xuemzhang@fudan.edu.cn (XZ); wenpeng@shutcm.edu.cn (WP)

XZ and FL contributed equally to this work.

Conceived and designed the experiments: XZ WP.

Performed the experiments: FL.

Analyzed the data: XZ FL.

Contributed reagents/materials/analysis tools: HC.

Wrote the paper: XZ FL.

Modified the format of the manuscript: LG HH LT.

Submitted the manuscript: LG.

The authors have declared that no competing interests exist.


Research Funding:

This work is supported by the National Science Foundation of China No. 81370979 (X. Zhang), Shanghai science and technology innovation grants 14140903202 and 14431905102 (X. Zhang), and Department of Veteran Affairs MERIT Award 5I01BX000994 (H. Cai).


  • Science & Technology
  • Multidisciplinary Sciences
  • Science & Technology - Other Topics
  • Calcium channel
  • Actins
  • Osteoblasts
  • Cytoskeleton
  • Protein interactions
  • Immunoprecipitation
  • Cell membranes
  • Calcium signaling

Forskolin Regulates L-Type Calcium Channel through Interaction between Actinin 4 and beta(3) Subunit in Osteoblasts


Journal Title:



Volume 10, Number 4


, Pages e0124274-e0124274

Type of Work:

Article | Final Publisher PDF


Voltage-dependent L-type calcium channels that permit cellular calcium influx are essential in calcium-mediated modulation of cellular signaling. Although the regulation of voltage-dependent L-type calcium channels is linked to many factors including cAMP-dependent protein kinase A (PKA) activity and actin cytoskeleton, little is known about the detailed mechanisms underlying the regulation in osteoblasts. Our present study investigated the modulation of L-type calcium channel activities through the effects of forskolin on actin reorganization and on its functional interaction with actin binding protein actinin 4. The results showed that forskolin did not significantly affect the trafficking of pore forming α<inf>1c</inf> subunit and its interaction with actin binding protein actinin 4, whereas it significantly increased the expression of β<inf>3</inf> subunit and its interaction with actinin 4 in osteoblast cells as assessed by co-immunoprecipitation, pull-down assay, and immunostaining. Further mapping showed that the ABD and EF domains of actinin 4 were interaction sites. This interaction is independent of PKA phosphorylation. Knockdown of actinin 4 significantly decreased the activities of L-type calcium channels. Our study revealed a new aspect of the mechanisms by which the forskolin activation of adenylyl cyclase - cAMP cascade regulates the L-type calcium channel in osteoblast cells, besides the PKA mediated phosphorylation of the channel subunits. These data provide insight into the important role of interconnection among adenylyl cyclase, cAMP, PKA, the actin cytoskeleton, and the channel proteins in the regulation of voltage-dependent L-type calcium channels in osteoblast cells.

Copyright information:

© 2015 Zhang et al.

This is an Open Access work distributed under the terms of the Creative Commons Attribution 4.0 International License (https://creativecommons.org/licenses/by/4.0/).
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