# SK3 channel trafficking in endothelial cells

> **NIH NIH R01** · UNIVERSITY OF TENNESSEE HEALTH SCI CTR · 2022 · $635,955

## Abstract

Project Summary
Endothelial cells line the wall of all blood vessels and regulate a wide variety of functions, including contractility
and systemic blood pressure. Endothelial cell dysfunction is a hallmark of several cardiovascular diseases, but
pathological mechanisms involved are unclear. Endothelial cells express small-conductance calcium-activated
potassium (SK3) channels, which regulate contractility. Currents (I) generated by SK3 channels in endothelial
cells is the product of the number of channels (N), their open probability (PO) and amplitude (i), such that
I=N.PO.i. Previous studies have focused on identifying mechanisms that regulate the activity of surface SK
channels in endothelial cells. In contrast, mechanisms that control the number (N) of surface SK3 channels in
endothelial cells are poorly understood. Importantly, it is unclear whether physiological stimuli regulate the
abundance of surface SK3 channels to alter arterial contractility. Similarly uncertain is if pathological alterations
in the control of surface SK3 channel abundance occurs during hypertension, leading to attenuated
vasodilation. Using a wide variety of approaches, we provide evidence that vasodilator stimuli activate
trafficking mechanisms that rapidly increase surface SK3 channel abundance in endothelial cells to induce
vasodilation. Preliminary data also suggest that SK3 channel trafficking is dysfunctional during hypertension,
which attenuates this vasodilatory signaling mechanism. In this proposal, we will investigate three specific
aims. Aim 1 will investigate signaling mechanisms by which physiological stimuli alter the surface abundance
of SK3 channels and examine their functional significance. Aim 2 will examine trafficking mechanisms that
control surface SK3 channels in endothelial cells to modify arterial contractility. Aim 3 will study the hypothesis
that hypertension is associated with pathological alterations in SK3 channel trafficking in endothelial cells that
inhibit vasodilation by these proteins. Methods used will include biotinylation, Western blotting, FRET, RNAi,
co-IP, immunofluorescence, super-resolution microscopy, patch-clamp electrophysiology, membrane potential
recording, intracellular Ca2+ imaging, arterial myography, blood pressure telemetry and transgenic mice. This
project will provide significant novel information concerning vasoregulation by SK3 channel trafficking in
endothelial cells.

## Key facts

- **NIH application ID:** 10426319
- **Project number:** 5R01HL158846-02
- **Recipient organization:** UNIVERSITY OF TENNESSEE HEALTH SCI CTR
- **Principal Investigator:** Jonathan H Jaggar
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $635,955
- **Award type:** 5
- **Project period:** 2021-07-01 → 2025-04-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10426319

## Citation

> US National Institutes of Health, RePORTER application 10426319, SK3 channel trafficking in endothelial cells (5R01HL158846-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10426319. Licensed CC0.

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