# Mechanosensing at Focal Adhesions

> **NIH NIH R01** · GEORGIA INSTITUTE OF TECHNOLOGY · 2022 · $327,349

## Abstract

PROJECT SUMMARY
Integrin-based focal adhesions (FA) function as mechano-active complexes. Despite significant progress in
defining biochemical interactions driving FA assembly and signaling, very little is known about how FAs sense
and transmit force and how these forces are integrated into biochemical signals. The objective of this project is
to elucidate how forces at FAs are converted into biochemical signals. Our central hypothesis is that the local
force balance between ECM-integrin forces and CSK tension at individual FAs regulates FAK phosphorylation
levels via vinculin and these force-dependent signals from individual FAs are spatially integrated within the cell
to trigger YAP nuclear localization. We will test our central hypothesis by addressing 3 key questions:
Q1. Do changes in adhesive force and CSK tension that perturb the local force balance at individual FAs regulate
FAK phosphorylation and YAP nuclear localization? We will analyze traction force, vinculin recruitment, and FAK
phosphorylation at individual FAs and YAP nuclear localization for fibroblasts and human mesenchymal stem
cells cultured on microfabricated post-array-detectors (mPADs). We will evaluate these force-signaling
responses on patterned mPADs with different ECM density and elastic moduli and in the presence of contractility
modulators to perturb the local force balance between ECM-integrin forces and CSK tension in order to examine
how this force balance regulates local FAK phosphorylation and YAP nuclear localization. We will next map
spatiotemporal relationships among force, FAK phosphorylation, and YAP nuclear localization in live cells
expressing a FRET-based FAK biosensor and fluorescent proteins on mPADs presenting caged RGD peptide.
The caged RGD will be activated with UV light to precisely trigger FA assembly in prescribed spatial patterns
while monitoring force, FAK phosphorylation, and YAP nuclear localization.
Q2. Does FAK regulate mechanosensing at individual FAs and YAP nuclear localization? We will use FAK-null
cells expressing wild-type and mutant FAKs to decipher the role of FAK and its Y397 scaffolding and talin- and
paxillin-binding sites on mechanosensing.
Q3. Does vinculin modulate force-dependent FAK phosphorylation and YAP nuclear localization? We will use
vinculin-null cells expressing wild-type and mutant vinculins to analyze how vinculin and its auto-inhibited head-
tail conformation modulate force-FAK phosphorylation coupling at individual FAs and YAP nuclear localization.
This research will generate new insights into how FAs sense force and how these forces are integrated into
biochemical signals. This research will provide a framework to understand cell-ECM mechanotransduction
events as well as fundamental principles to design mechanoresponses in cell-biomaterial interactions.

## Key facts

- **NIH application ID:** 10089442
- **Project number:** 5R01EB024322-04
- **Recipient organization:** GEORGIA INSTITUTE OF TECHNOLOGY
- **Principal Investigator:** Andres J Garcia
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2022
- **Award amount:** $327,349
- **Award type:** 5
- **Project period:** 2018-05-01 → 2024-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10089442

## Citation

> US National Institutes of Health, RePORTER application 10089442, Mechanosensing at Focal Adhesions (5R01EB024322-04). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10089442. Licensed CC0.

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