DAAM1 formin and Ena/VASP proteins assemble functionally distinct actin filaments for focal adhesions
Abstract
SUMMARY Eukaryotic cells contain multiple biochemically distinct actin filament networks, which enable versatile functions of actin in a range of cellular processes. Yet, the mechanisms by which specific actin filament networks are assembled in a common cytoplasm remain elusive. Here, we investigated how functionally distinct actin nanoscale layers, specified by α-actinin and tropomyosin isoforms, Tpm1.6 and Tpm3.2, are assembled at focal adhesions. By combining genetic perturbations with mitochondrial-targeting of actin polymerases, we discovered that DAAM1 formin assembles Tpm3.2-actin filaments, whereas Ena/VASP family proteins polymerize α-actinin cross-linked actin filament bundles at focal adhesions. Consequently, loss of DAAM1 dampened Tpm3.2 protein levels and impaired focal adhesion disassembly, thus phenocopying Tpm3.2-deficient cells. In contrast, Ena/VASP depletion led to defective focal adhesion maturation and loss of α-actinin from focal adhesions. More broadly, our study highlights specific roles for formin and Ena/VASP family proteins in assembling biochemically and functionally distinct linear actin filament arrays in cells.
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BibTeX
@misc{chua2026daam1,
title = {{DAAM1 formin and Ena/VASP proteins assemble functionally distinct actin filaments for focal adhesions}},
author = {Xiang Le Chua and Parijat Biswas and Hugo Wioland and Pekka Lappalainen},
howpublished = {HAL},
year = {2026},
month = aug,
doi = {10.64898/2026.08.19.745742},
url = {https://hal.science/hal-05770766v1},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - DAAM1 formin and Ena/VASP proteins assemble functionally distinct actin filaments for focal adhesions
AU - Xiang Le Chua
AU - Parijat Biswas
AU - Hugo Wioland
AU - Pekka Lappalainen
PY - 2026
DA - 2026/08/20
PB - HAL
DO - 10.64898/2026.08.19.745742
UR - https://hal.science/hal-05770766v1
AB - SUMMARY Eukaryotic cells contain multiple biochemically distinct actin filament networks, which enable versatile functions of actin in a range of cellular processes. Yet, the mechanisms by which specific actin filament networks are assembled in a common cytoplasm remain elusive. Here, we investigated how functionally distinct actin nanoscale layers, specified by α-actinin and tropomyosin isoforms, Tpm1.6 and Tpm3.2, are assembled at focal adhesions. By combining genetic perturbations with mitochondrial-targeting of actin polymerases, we discovered that DAAM1 formin assembles Tpm3.2-actin filaments, whereas Ena/VASP family proteins polymerize α-actinin cross-linked actin filament bundles at focal adhesions. Consequently, loss of DAAM1 dampened Tpm3.2 protein levels and impaired focal adhesion disassembly, thus phenocopying Tpm3.2-deficient cells. In contrast, Ena/VASP depletion led to defective focal adhesion maturation and loss of α-actinin from focal adhesions. More broadly, our study highlights specific roles for formin and Ena/VASP family proteins in assembling biochemically and functionally distinct linear actin filament arrays in cells.
ER -