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bioRxiv · 10.64898/2026.09.03.749286

Cytoskeletal disassembly by optogenetic control of RhoA signaling termination

Berlew, E. E.·Barakat, J.·Camacho Sierra, P.·Boerckel, J. D.
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Abstract

Cellular morphodynamics require adaptive cytoskeletal remodeling, mediated by precisely coordinated activation and termination of RhoA GTPase signaling. RhoA activation is well-studied, but the kinetics and molecular basis of signaling termination remain poorly understood. We engineered an optogenetic toolbox on the single-component BcLOV4 platform for bidirectional control of RhoA activation (opto-GEF11) and termination (opto-DLC1). Prior studies have inferred GTPase inactivation kinetics indirectly, by tracking passive recovery from an activated state, but whether this reflects the kinetics of forward signaling termination remains unclear. Using opto-DLC1, we show that direct RhoA termination is an order of magnitude faster than passive disactivation, despite comparable signaling amplitude. Mechanistically, opto-DLC1 triggered rapid actin disassembly through cofilin disinhibition but drove YAP nuclear efflux at half the rate of opto-GEF11-induced nuclear influx. Together, these findings introduce a platform technology for controlling protein signaling termination, resolve RhoA activation and termination kinetics with sub-second precision, and reveal a mechanistic asymmetry between signaling activation and termination that enables cytoskeletal homeostasis.

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Berlew, E. E., Barakat, J., Camacho Sierra, P., Boerckel, J. D.. 2026-09-07. Cytoskeletal disassembly by optogenetic control of RhoA signaling termination. https://doi.org/10.64898/2026.09.03.749286

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