# Identification of an FMNL2 Interactome by Quantitative Mass Spectrometry

## TL;DR

This paper identifies proteins that interact with FMNL2, a cytoskeletal regulator, revealing new connections to extracellular vesicle assembly.

## Contribution

The study discovers a novel link between FMNL2 and extracellular vesicle assembly through proteomic analysis.

## Key findings

- FMNL2 interacts with proteins involved in filopodia, junctions, and adhesions.
- FMNL2 is associated with extracellular vesicle assembly and is present in exosomes.

## Abstract

Formin Homology Proteins (Formins) are a highly conserved family of cytoskeletal regulatory proteins that participate in a diverse range of cellular processes. FMNL2 is a member of the Diaphanous-Related Formin sub-group, and previous reports suggest FMNL2’s role in filopodia assembly, force generation at lamellipodia, subcellular trafficking, cell–cell junction assembly, and focal adhesion formation. How FMNL2 is recruited to these sites of action is not well understood. To shed light on how FMNL2 activity is partitioned between subcellular locations, we used biotin proximity labeling and proteomic analysis to identify an FMNL2 interactome. The interactome identified known and new FMNL2 interacting proteins with functions related to previously described FMNL2 activities. In addition, our interactome predicts a novel connection between FMNL2 and extracellular vesicle assembly. We show directly that FMNL2 protein is present in exosomes.