MiniBAR/KIAA0355 is a dual Rac and Rab effector required for ciliogenesis

Shaughnessy, R.; Serres, M.; Escot, S.; Hammich, H.; Cuvelier, F.; Salles, A.; Rocancourt, M.; Verdon, Q.; Gaffuri, A.-L.; Sourigues, Y.; Malherbe, G.; Velikovsky, L.; Chardon, F.; Tinevez, J.-Y.; Callebaut, I.; Formstecher, E.; Houdusse, A.; David, N.; Pylypenko, O.; Echard, A.

doi:10.1101/2023.07.24.550339

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bioRxiv · 10.1101/2023.07.24.550339

MiniBAR/KIAA0355 is a dual Rac and Rab effector required for ciliogenesis

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Abstract

Cilia protrude from the cell surface and play critical roles in in-tracellular signaling, environmental sensing and development. Actin-dependent contractility and intracellular trafficking are both required for ciliogenesis, but little is known about how these processes are coordinated. Here, we identified a Rac1-and Rab35-binding protein with a truncated BAR domain that we named MiniBAR (aka KIAA0355/GARRE) which plays a key role in ciliogenesis. MiniBAR colocalizes with Rac1 and Rab35 at the plasma membrane and on intracellular vesicles traffick-ing to the ciliary base and exhibits remarkable fast pulses at the ciliary membrane. MiniBAR depletion leads to short cilia resulting from abnormal Rac-GTP/Rho-GTP levels, increased acto-myosin-II-dependent contractility together with defective trafficking of IFT88 and ARL13B into cilia. MiniBAR-depleted zebrafish embryos display dysfunctional short cilia and hall-marks of ciliopathies including left-right asymmetry defects. Thus, MiniBAR is a unique dual Rac and Rab effector that con-trols both actin cytoskeleton and membrane trafficking for cili-ogenesis.

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Shaughnessy, R., Serres, M., Escot, S., Hammich, H., Cuvelier, F., Salles, A., Rocancourt, M., Verdon, Q., Gaffuri, A.-L., Sourigues, Y., Malherbe, G., Velikovsky, L., Chardon, F., Tinevez, J.-Y., Callebaut, I., Formstecher, E., Houdusse, A., David, N., Pylypenko, O., Echard, A.. 2023-07-24. MiniBAR/KIAA0355 is a dual Rac and Rab effector required for ciliogenesis. https://doi.org/10.1101/2023.07.24.550339

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