Referenced in: none

Automatically associated channels: Cav3.1 , Cav3.2 , Cav3.3

Title: Transforming growth factor-beta1 and bone morphogenetic protein-2 downregulate CaV3.1 channel expression in mouse C2C12 myoblasts.

Authors: Traudy Avila, Arturo Andrade, Ricardo Felix

Journal, date & volume: J. Cell. Physiol., 2006 Nov , 209, 448-56

PubMed link: http://www.ncbi.nlm.nih.gov/pubmed/16883604

Abstract
In the developing skeletal muscle, fusion of myoblasts and myotube formation is a process that involves Ca2+ influx through T-type (CaV3) channels. Treatment of myoblasts with transforming growth factor-beta1 (TGF-beta1) and bone morphogenetic protein-2 (BMP-2) decreases the number of CaV3 channels in the plasma membrane and reduces myotube formation. In the current report, we examined whether the inhibitory actions of TGF-beta1 and BMP-2 involve alterations in CaV3 mRNA expression in the myoblast C2C12 cell line. Using RT-PCR, we found that CaV3.1 but not CaV3.2 and CaV3.3 transcripts are present in either undifferentiated or fusion competent C2C12 myoblasts. Semi-quantitative analysis revealed a significant decrease of CaV3.1 mRNA expression in cells treated with TGF-beta1 and BMP-2. In contrast, patch-clamp recordings on HEK-293 cells stably expressing recombinant CaV3.1 channels showed that T-type currents were not affected by chronic exposure to the growth factors. These results suggest that muscle T-channel downregulation by TGF-beta1 and BMP-2 may be mediated by reduced transcription rather than through post-transcriptional modifications of CaV3.1 channels.