# Characterization of Adenine Nucleotide Translocase (ANT) and Actin-Interacting Protein 1 (AIP1) as Protectors Against Cigarette Smoke

> **NIH NIH F31** · JOHNS HOPKINS UNIVERSITY · 2020 · $45,520

## Abstract

PROJECT SUMMARY
Chronic obstructive pulmonary disease (COPD) is a growing health concern in the United States with no curative
treatments. The development of new therapeutics has been stagnant due to the difficulty of finding new essential
biology and protective pathways in the complex tissue of the human lung. Hence, the Robinson lab was
interested in using a model organism, the social amoeba Dictyostelium discoideum, as a discovery tool to find
new therapeutic targets and pathways that will protect against cigarette smoke (CS), one of the main causes of
COPD. With Dictyostelium, a genetic screen was conducted to find these target genes. Overexpression of two
genes encoding for adenine nucleotide translocase (ANT) and actin-interacting protein 1 (AIP1) offered the most
robust protection in cell growth. Interestingly, we see the same protective effects from these genes in human
bronchial epithelial cells exposed to CS. The focus of this proposal will be to mechanistically understand how
these proteins negate the effects of CS injury. Beginning with ANT, an ATP/ADP transporter in the inner
membrane of the mitochondria, we expected that its overexpression would enhance cellular metabolism.
Interestingly, some preliminary data suggested that ANT was protective through different mechanisms. The
canonical mitochondria protein was surprisingly found at cilia and modulated ciliary function, which is known to
be altered by CS. In ciliated primary human bronchial epithelial cells (NHBEs), ANT2 (one of the paralogs of
ANT) enhanced ciliary function by increasing airway hydration and maintaining normal ciliary beat frequency in
the presence of CS. Based on this preliminary data and the idea that extracellular ATP is released to increase
airway hydration, we hypothesize that ANT is one of the elusive cell surface transporters of extracellular ATP.
This idea will be tested in aim 1 of this proposal through immunofluorescence and super-resolution imaging,
surface biotinylation assays, and the measurement of extracellular ATP on ANT gain- or loss- of function NHBEs.
Since protective phenotypes of ANT were found, a preliminary drug screen will also be conducted to find
activators of ANT. In aim 2, we will focus on AIP1. We will similarly find how its overexpression protects against
CS. CS was found to affect actin dynamics and cellular mechanics, which caused increased airway barrier
permeability. Considering its role as a regulator of actin depolymerization, we expect that AIP1 will negate the
effects of CS on actin dynamics, which will tighten cell-cell interactions and fortify airway barrier function.
Experiments to study this will include cytoskeletal fractionation to evaluate actin assembly via F/G-actin ratios
and confocal imaging to assess whether AIP1 changes the expression and localization of cell junction proteins.
Trans-epithelial resistance (TEER) measurements and a FITC-dextran permeability assay will be used to assess
epithelial barrier tightness. ...

## Key facts

- **NIH application ID:** 9917578
- **Project number:** 5F31HL145910-02
- **Recipient organization:** JOHNS HOPKINS UNIVERSITY
- **Principal Investigator:** Jennifer Nguyen
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $45,520
- **Award type:** 5
- **Project period:** 2019-02-16 → 2022-02-15

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9917578

## Citation

> US National Institutes of Health, RePORTER application 9917578, Characterization of Adenine Nucleotide Translocase (ANT) and Actin-Interacting Protein 1 (AIP1) as Protectors Against Cigarette Smoke (5F31HL145910-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/9917578. Licensed CC0.

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