Myosin-X sorts actin filaments into parallel bundles and tunes barbed-end dynamics
Abstract
Whether a molecular motor can spontaneously organize actin filaments into bundles has remained an open question despite decades of in vitro investigation. Here, we show that the dimeric myosin-X, essential for filopodia initiation and extension in cells, is capable of sorting actin filaments into parallel bundles, gathering barbed ends within 1-2 micrometers. We observe that myosin-X processivity is comparable on single filaments and on bundles induced by myosin-X or fascin. Upon reaching barbed ends, myosin-X slows down the addition or removal of actin subunits, in a myosin density-dependent manner. Furthermore, the funneling of myosin-X towards the remaining filaments at the bundle tip increases motor density and triggers dynamic clustering. Together, we propose that the motor activity of myosin-X is sufficient to initiate filopodia, independently of passive crosslinkers such as fascin or fimbrin.
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BibTeX
@misc{kools2026myosinx,
title = {{Myosin-X sorts actin filaments into parallel bundles and tunes barbed-end dynamics}},
author = {Wouter Kools and Sara Faour and Aliette Carlier and Trayana Hristova and Maria Elena Sirkia and Ludivine Chaix and Antony Lee and Pascal Martin and Anne Houdusse and Guillaume Romet-Lemonne and Antoine Jégou},
howpublished = {HAL},
year = {2026},
month = sep,
doi = {10.64898/2026.09.08.749704},
url = {https://hal.science/hal-05761015v1},
note = {CC BY-NC},
}
RIS
TY - UNPB
TI - Myosin-X sorts actin filaments into parallel bundles and tunes barbed-end dynamics
AU - Wouter Kools
AU - Sara Faour
AU - Aliette Carlier
AU - Trayana Hristova
AU - Maria Elena Sirkia
AU - Ludivine Chaix
AU - Antony Lee
AU - Pascal Martin
AU - Anne Houdusse
AU - Guillaume Romet-Lemonne
AU - Antoine Jégou
PY - 2026
DA - 2026/09/08
PB - HAL
DO - 10.64898/2026.09.08.749704
UR - https://hal.science/hal-05761015v1
AB - Whether a molecular motor can spontaneously organize actin filaments into bundles has remained an open question despite decades of in vitro investigation. Here, we show that the dimeric myosin-X, essential for filopodia initiation and extension in cells, is capable of sorting actin filaments into parallel bundles, gathering barbed ends within 1-2 micrometers. We observe that myosin-X processivity is comparable on single filaments and on bundles induced by myosin-X or fascin. Upon reaching barbed ends, myosin-X slows down the addition or removal of actin subunits, in a myosin density-dependent manner. Furthermore, the funneling of myosin-X towards the remaining filaments at the bundle tip increases motor density and triggers dynamic clustering. Together, we propose that the motor activity of myosin-X is sufficient to initiate filopodia, independently of passive crosslinkers such as fascin or fimbrin.
ER -