Abstract
The regulation of L-type Ca2+ channels by protein kinase A (PKA) represents a crucial element within cardiac, skeletal muscle and neurological systems. Although much work has been done to understand this regulation in cardiac Ca V 1.2 Ca2+ channels, relatively little is known about the closely related Ca V 1.4 L-type Ca2+ channels, which feature prominently in the visual system. Here we find that Ca V 1.4 channels are indeed modulated by PKA phosphorylation within the inhibitor of Ca2+-dependent inactivation (ICDI) motif. Phosphorylation of this region promotes the occupancy of calmodulin on the channel, thus increasing channel open probability (P O) and Ca2+-dependent inactivation. Although this interaction seems specific to Ca V1.4 channels, introduction of ICDI 1.4 to CaV 1.3 or CaV1.2 channels endows these channels with a form of PKA modulation, previously unobserved in heterologous systems. Thus, this mechanism may not only play an important role in the visual system but may be generalizable across the L-type channel family.
Original language | English (US) |
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Article number | 12239 |
Journal | Nature communications |
Volume | 7 |
DOIs | |
State | Published - Jul 26 2016 |
ASJC Scopus subject areas
- Chemistry(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Physics and Astronomy(all)