# Nanobodies for Dissecting the Structure and Function of Oligomeric BAX

> **NIH NIH F30** · HARVARD MEDICAL SCHOOL · 2024 · $35,118

## Abstract

PROJECT SUMMARY
BCL-2 family proteins are critical regulators of apoptosis and deregulation of their protein interaction network
drives oncogenesis and chemoresistance. BAX is a pro-apoptotic BCL-2 protein that serves as a cardinal
executioner of the death pathway. During homeostasis, BAX resides as a latent monomer in the cytosol until
triggered by cellular stress to undergo a major conformational change, leading to its translocation to the
mitochondria and self-assembly into oligomeric species that permeabilize the mitochondrial outer membrane.
Cancer cells usurp the survival arm of the pathway, overexpressing anti-apoptotic members such as BCL-2 and
MCL-1, which can trap activated monomers of BAX, prevent oligomeric assembly, and thereby preserve
mitochondrial integrity. A critical missing link in our understanding of BAX-mediated apoptosis during
homeostasis and cancer is the structure of oligomeric BAX, referred to as the “holy grail” of apoptosis research.
The Walensky laboratory has recently generated the first stable and homogeneous oligomeric species of full-
length BAX amenable to structure-function analyses. Having characterized this BAX oligomer, termed BAXo, by
small-angle X-ray scattering, negative stain electron microscopy (EM) of BAX-porated liposomes, and
comparative functional studies of wild-type and BAX mutants in liposomes, mitochondria, and cells, a critical next
step is to deploy BAXo to solve a definitive structure and interrogate its functional interfaces. I hypothesize that
by generating diverse nanobodies against BAXo, I will be able to obtain high-resolution structures of this elusive
“death channel” and generate fresh insight into the mechanism of BAX-mediated mitochondrial apoptosis.
Specifically, I aim to (1) develop and characterize nanobodies that bind to oligomeric BAX and (2) harness BAXo-
binding nanobodies to determine the structure of oligomeric BAX and the interfaces critical to membrane-
permeabilizing function. To accomplish my goals, I will pursue a multidisciplinary workflow that incorporates a
yeast display nanobody discovery platform, protein engineering, biochemical assays in model membranes and
mitochondria, hydrogen-deuterium exchange mass spectrometry, X-ray crystallography, cryo- EM microscopy,
and mechanistic analyses of apoptosis in cancer cells. Thus, by developing and deploying BAXo-binding
nanobodies in comprehensive structure-function studies with built-in alternative approaches, I aim to both
characterize the execution-phase of BAX-mediated apoptosis and uncover novel and potentially druggable
surfaces for therapeutic benefit in cancer. I am excited to be pursuing a rigorous graduate training program in
the laboratory of Dr. Loren Walensky at the Dana-Farber Cancer Institute and Harvard Medical School, and look
forward to developing as an independent and innovative physician-scientist at the interface of biochemistry,
structural biology, cancer biology, and clinical oncology.

## Key facts

- **NIH application ID:** 10849662
- **Project number:** 5F30CA275293-02
- **Recipient organization:** HARVARD MEDICAL SCHOOL
- **Principal Investigator:** Ellen Yu
- **Activity code:** F30 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $35,118
- **Award type:** 5
- **Project period:** 2023-07-01 → 2027-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10849662

## Citation

> US National Institutes of Health, RePORTER application 10849662, Nanobodies for Dissecting the Structure and Function of Oligomeric BAX (5F30CA275293-02). Retrieved via AI Analytics 2026-05-28 from https://api.ai-analytics.org/grant/nih/10849662. Licensed CC0.

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