In vivo imaging uncovers an abundant but rarely active pool of plant ARP2/3 and its link to exocytosis and endocytosis
- 1Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic.
Abstract
The ARP2/3 complex generates branched actin networks that regulate membrane dynamics across eukaryotes. In plants, ARP2/3 is activated primarily by the WAVE/SCAR complex and is essential for cell morphogenesis, yet its spatiotemporal behavior in living cells remains poorly understood. Using high-resolution live-cell microscopy, we found that, in addition to their previously reported stable accumulation at three-way cell junctions and peroxisomes, WAVE/SCAR and ARP2/3 subunits also form abundant, highly dynamic, short-lived assemblies in the cortical cytoplasm, with lifetimes of only a few seconds. Genetic and colocalization analyses further revealed that only a minority of observed complexes are fully assembled and active, indicating that plant cells maintain a large pool of partially assembled or inactive ARP2/3 structures. Our data indicate that microtubules influence the abundance of cortical assemblies, whereas actin primarily affects their dynamics. Importantly, our analysis demonstrated a spatial and functional association between dynamic ARP2/3 foci and exocytotic events at the plasma membrane. Together, our findings suggest that the cytoplasm of plant epidermal cells contains a large reservoir of ARP2/3 complexes whose localized activation is tightly regulated and associated with membrane trafficking.
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BibTeX
@misc{jelinkova2026vivo,
title = {{In vivo imaging uncovers an abundant but rarely active pool of plant ARP2/3 and its link to exocytosis and endocytosis}},
author = {B. Jelinkova and M. Voloshina and K. Liebezeit and J. Krtkova and J. Garcia-Gonzalez and S. Vosolsobe and A. Harmanec and K. Malinska and A. Stelate and E. Kollarova and A. Baquero Forero and V. Zarsky and K. Schwarzerova},
howpublished = {bioRxiv},
year = {2026},
month = jul,
doi = {10.64898/2026.07.10.737699},
url = {https://www.biorxiv.org/content/10.64898/2026.07.10.737699v2},
note = {CC BY},
}
RIS
TY - UNPB
TI - In vivo imaging uncovers an abundant but rarely active pool of plant ARP2/3 and its link to exocytosis and endocytosis
AU - B. Jelinkova
AU - M. Voloshina
AU - K. Liebezeit
AU - J. Krtkova
AU - J. Garcia-Gonzalez
AU - S. Vosolsobe
AU - A. Harmanec
AU - K. Malinska
AU - A. Stelate
AU - E. Kollarova
AU - A. Baquero Forero
AU - V. Zarsky
AU - K. Schwarzerova
PY - 2026
DA - 2026/07/10
PB - bioRxiv
DO - 10.64898/2026.07.10.737699
UR - https://www.biorxiv.org/content/10.64898/2026.07.10.737699v2
AB - The ARP2/3 complex generates branched actin networks that regulate membrane dynamics across eukaryotes. In plants, ARP2/3 is activated primarily by the WAVE/SCAR complex and is essential for cell morphogenesis, yet its spatiotemporal behavior in living cells remains poorly understood. Using high-resolution live-cell microscopy, we found that, in addition to their previously reported stable accumulation at three-way cell junctions and peroxisomes, WAVE/SCAR and ARP2/3 subunits also form abundant, highly dynamic, short-lived assemblies in the cortical cytoplasm, with lifetimes of only a few seconds. Genetic and colocalization analyses further revealed that only a minority of observed complexes are fully assembled and active, indicating that plant cells maintain a large pool of partially assembled or inactive ARP2/3 structures. Our data indicate that microtubules influence the abundance of cortical assemblies, whereas actin primarily affects their dynamics. Importantly, our analysis demonstrated a spatial and functional association between dynamic ARP2/3 foci and exocytotic events at the plasma membrane. Together, our findings suggest that the cytoplasm of plant epidermal cells contains a large reservoir of ARP2/3 complexes whose localized activation is tightly regulated and associated with membrane trafficking.
ER -