TY - JOUR
T1 - Palmitoylation of the pore-forming subunit of Ca(v)1.2 controls channel voltage sensitivity and calcium transients in cardiac myocytes
AU - Kuo, Chien-Wen S.
AU - Dobi, Sara
AU - Gök, Caglar
AU - Da Silva Costa, Ana
AU - Main, Alice
AU - Robertson-Gray, Olivia
AU - Baptista-Hon, Daniel
AU - Wypijewski, Krzysztof J.
AU - Costello, Hannah
AU - Hales, Tim G.
AU - MacQuaide, Niall
AU - Smith, Godfrey L.
AU - Fuller, William
A2 - Catterall, William
PY - 2023/2/6
Y1 - 2023/2/6
N2 - Mammalian voltage-activated L-type Ca2+ channels, such as Ca(v)1.2, control transmembrane Ca2+ fluxes in numerous excitable tissues. Here, we report that the pore-forming α1C subunit of Ca(v)1.2 is reversibly palmitoylated in rat, rabbit, and human ventricular myocytes. We map the palmitoylation sites to two regions of the channel: The N terminus and the linker between domains I and II. Whole-cell voltage clamping revealed a rightward shift of the Ca(v)1.2 current-voltage relationship when α1C was not palmitoylated. To examine function, we expressed dihydropyridine-resistant α1C in human induced pluripotent stem cell-derived cardiomyocytes and measured Ca2+ transients in the presence of nifedipine to block the endogenous channels. The transients generated by unpalmitoylatable channels displayed a similar activation time course but significantly reduced amplitude compared to those generated by wild-type channels. We thus conclude that palmitoylation controls the voltage sensitivity of Ca(v)1.2. Given that the identified Ca(v)1.2 palmitoylation sites are also conserved in most Ca(v)1 isoforms, we propose that palmitoylation of the pore-forming α1C subunit provides a means to regulate the voltage sensitivity of voltage-activated Ca2+ channels in excitable cells.
AB - Mammalian voltage-activated L-type Ca2+ channels, such as Ca(v)1.2, control transmembrane Ca2+ fluxes in numerous excitable tissues. Here, we report that the pore-forming α1C subunit of Ca(v)1.2 is reversibly palmitoylated in rat, rabbit, and human ventricular myocytes. We map the palmitoylation sites to two regions of the channel: The N terminus and the linker between domains I and II. Whole-cell voltage clamping revealed a rightward shift of the Ca(v)1.2 current-voltage relationship when α1C was not palmitoylated. To examine function, we expressed dihydropyridine-resistant α1C in human induced pluripotent stem cell-derived cardiomyocytes and measured Ca2+ transients in the presence of nifedipine to block the endogenous channels. The transients generated by unpalmitoylatable channels displayed a similar activation time course but significantly reduced amplitude compared to those generated by wild-type channels. We thus conclude that palmitoylation controls the voltage sensitivity of Ca(v)1.2. Given that the identified Ca(v)1.2 palmitoylation sites are also conserved in most Ca(v)1 isoforms, we propose that palmitoylation of the pore-forming α1C subunit provides a means to regulate the voltage sensitivity of voltage-activated Ca2+ channels in excitable cells.
KW - heart
KW - ion transport
KW - acylation
KW - excitation–contraction coupling
U2 - 10.1073/pnas.2207887120
DO - 10.1073/pnas.2207887120
M3 - Article
C2 - 36745790
AN - SCOPUS:85147461165
SN - 1091-6490
VL - 120
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 7
M1 - e2207887120
ER -