# Regulation and Cellular Functions of V-ATPases

> **NIH NIH R35** · UPSTATE MEDICAL UNIVERSITY · 2024 · $53,211

## Abstract

PROJECT SUMMARY
V-ATPases are versatile, highly conserved, multi-subunit proton pumps responsible for
organelle acidification in virtually all eukaryotic cells. Under the parent proposal, we are seeking
to understand the regulation of V- ATPases, including the roles of subunit isoforms and enzyme
subpopulations, in order to distinguish, and eventually target, V-ATPases in specific locations.
V-ATPases are regulated by reversible disassembly of the peripheral V1 subcomplex from the
integral membrane Vo subcomplex, and RAVE/Rabconnectin-3 complexes play a critical role in
this process. Visualizing the localization of V-ATPase subunits and regulators by wide-field and
fluorescence microscopy is a critical component of this work. We have been able to visualize
reversible release of V1 subunits from Vo in membranes as extracellular conditions vary.
Recently, we have found that the V-ATPases become more disassembled as yeast cells age;
this disassembly results in vacuole alkalinization but can be reversed by caloric restriction, an
established mechanism for prolonging lifespan in multiple organisms. This result is exciting as
mammalian cells show declines in lysosomal acidification in age that are poorly understood.
We also observe glucose-dependent changes in association of the RAVE complex with the
vacuolar membrane and have shown that loss of RAVE function shortens lifespan, consistent
with its role in V-ATPase assembly. Much of our work continues to be in the yeast model
system, and in addition to the inherent challenges of imaging in small cells, some of the proteins
that signal and drive V-ATPase assembly changes are present at low levels in cells. We are
requesting an administrative supplement for purchase of an improved camera, along with an
updated workstation and software for its operation. These additions to an existing wide-field
microscope will allow us to better detect and localize the proteins involved in V-ATPase
regulation as cells respond to diverse conditions.

## Key facts

- **NIH application ID:** 11098823
- **Project number:** 3R35GM145256-03S1
- **Recipient organization:** UPSTATE MEDICAL UNIVERSITY
- **Principal Investigator:** PATRICIA M KANE
- **Activity code:** R35 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $53,211
- **Award type:** 3
- **Project period:** 2022-04-01 → 2027-03-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/11098823

## Citation

> US National Institutes of Health, RePORTER application 11098823, Regulation and Cellular Functions of V-ATPases (3R35GM145256-03S1). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/11098823. Licensed CC0.

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