# Regulation of nutrient transporters

> **NIH NIH R01** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2020 · $363,469

## Abstract

Project Summary
The surface expression of nutrient transporters is acutely regulated by the concentration of the
nutrient they pump and the metabolic state of the cell. The presence of high nutrient
concentrations causes rapid endocytosis and degradation of the corresponding transporter. This
negative-feedback system ensures that cytoplasmic nutrient concentration remains in a
physiological range. On the other hand, metabolic stress such as glucose or amino acid
starvation also triggers rapid turnover of transporters, in this case to safe energy and recover
amino acids by protein degradation. This project focuses on a regulatory system that in part
determines the turnover rate of yeast transporters: eisosomes and the proton pump Pma1. The
majority of proton-driven nutrient transporters localize to plasma membrane structures called
eisosomes. Our data suggest that eisosomes function as storage compartments in which
transporters are kept in an inactive state. The storage capacity of eisosomes seems to be
regulated by the activity of Pma1, a proton pump that uses ATP to maintain the proton gradient
across the plasma membrane. High Pma1 activity causes the release of proton-driven
transporters from eisosomes, which in turn results in rapid turnover of these proteins. This
regulatory system ensures a balance between the proton influx by transporters and proton
export by Pma1. Our studies will focus on the mechanism of this eisosome regulation and how
the metabolic state of the cell can modulate this system.

## Key facts

- **NIH application ID:** 9978900
- **Project number:** 5R01GM123147-04
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **Principal Investigator:** MARKUS BABST
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $363,469
- **Award type:** 5
- **Project period:** 2017-07-01 → 2021-12-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9978900

## Citation

> US National Institutes of Health, RePORTER application 9978900, Regulation of nutrient transporters (5R01GM123147-04). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/9978900. Licensed CC0.

---

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