# 14-3-3 regulation of cardiac L-type calcium channels and EC-coupling

> **NIH NIH F31** · UNIVERSITY OF CALIFORNIA AT DAVIS · 2022 · $39,101

## Abstract

Project Summary: The voltage-gated L-type calcium channel (CaV1.2) is essential for cardiac excitation-
contraction (EC)-coupling and dysregulation of the channel is implicated in many forms of heart disease. 14-3-3
is a ubiquitous protein that interacts with numerous cellular proteins to affect multiple physiological processes
including cell growth, apoptosis, and ion channel trafficking. It preferentially binds phospho-serine/threonine
residues on target proteins to regulate their trafficking, cooperativity, phosphorylation state, and/or activity. In
HEK293 cells, 14-3-3 enhances trafficking of another voltage gated Ca2+ channel (CaV2.2) and has been shown
to indirectly alter CaV1.2 trafficking via interactions with CaVβ subunits, however direct evidence and information
about the extent and phosphorylation-dependence of this regulation is still needed. In addition, there have been
no investigations into the role of 14-3-3 in CaV1.2 channel trafficking/regulation in cardiomyocytes. We address
these gaps in knowledge in the current application. Since 14-3-3 has been reported to facilitate cooperative
gating of the voltage-dependent cardiac Na+ channel, NaV1.5, we will also investigate the role of 14-3-3 in
cooperative interactions of CaV1.2. This gating modality of CaV1.2 occurs when allosteric interactions form
between C-terminal tails of adjacent channels in a cluster such that the opening of one channel can be
communicated to other attached channels to enhance their open probability and amplify whole-cell Ca2+ influx.
Our group has previously shown that PKA-mediated phosphorylation of CaV1.2 channels triggers enhanced
trafficking of these channels into the sarcolemma of ventricular myocytes, producing larger channel clusters that
facilitate enhanced cooperative gating behavior and augmented whole-cell Ca2+ currents. This helps tune cardiac
EC-coupling to meet the enhanced demand during fight-or-flight. However, the molecular details of this enhanced
trafficking are unclear. Here we propose that 14-3-3 plays a role in this response. We have identified several
putative binding sites for 14-3-3 on the C-tail of CaV1.2 and other critical regulatory sites, including consensus
PKA phosphorylation sites. This project aims to test the hypothesis that 14-3-3 regulates CaV1.2 trafficking,
resulting in enhanced channel clustering on the sarcolemma that facilitates cooperative interactions and
amplifies Ca2+ influx. We further propose that these interactions are strengthened by channel
phosphorylation providing a means to tune CaV1.2 channel activity and EC-coupling to meet demand. In
this two-year predoctoral project, we will rigorously test this hypothesis in three Specific Aims. Aim 1 tests the
hypothesis that 14-3-3 interacts with CaV1.2 in a phosphorylation-dependent manner. Aim 2 tests the hypothesis
that CaV1.2 channel trafficking, sarcolemmal clustering, and cooperative interactions are enhanced by 14-3-3.
Aim 3 focuses on the functional effects o...

## Key facts

- **NIH application ID:** 10536570
- **Project number:** 1F31HL165815-01
- **Recipient organization:** UNIVERSITY OF CALIFORNIA AT DAVIS
- **Principal Investigator:** Heather Spooner
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $39,101
- **Award type:** 1
- **Project period:** 2022-09-01 → 2024-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10536570

## Citation

> US National Institutes of Health, RePORTER application 10536570, 14-3-3 regulation of cardiac L-type calcium channels and EC-coupling (1F31HL165815-01). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10536570. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*