Tracking Focal Adhesion Turnover: A Novel Reporter for FA-Phagy Flux

TL;DR

This paper introduces a new tool to track how focal adhesions are broken down by autophagy, offering insights into cell adhesion and disease processes.

Contribution

A novel fluorescence reporter system is developed to visualize and study focal adhesion autophagy flux in real time.

Findings

The reporter system effectively tracks FA-phagy from autophagosome formation to lysosomal degradation.

The tool reveals dynamic FA-phagy responses under starvation and autophagy regulation by mTOR and ATG genes.

Abstract

Focal adhesions (FAs) are critical multi-protein complexes regulating cell adhesion, migration, and survival, and their dysregulation contributes to cancer metastasis and vascular diseases. Despite extensive research on FA formation, little is known about FA turnover, particularly its regulation by autophagy. This study introduces a novel tandem fluorescence reporter capable of tracking the entire FA-phagy flux, from autophagosome formation to lysosomal degradation. The reporter, based on a red–green fluorescence system with a lysosome-specific cleavage site, integrates seamlessly into endogenous focal adhesion complexes, demonstrating sensitivity and specificity to autophagy stimuli. Validated in multiple cell lines, the tool revealed dynamic FA-phagy responses to starvation-induced autophagy and the involvement of autophagy regulators such as mTOR and ATG genes. This versatile reporter provides a powerful tool for investigating FA-phagy mechanisms, with significant implications for cancer biology and vascular research.

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