Work

Spontaneous Calcium Bursts Organize the Apical Actin Cytoskeleton of Multiciliated Cells

Year: 2025

Type: article

Abstract: Motile cilia perform crucial functions during embryonic development and in adult tissues. They are anchored by an apical actin network that forms microridge-like structures on the surface of multiciliated cells. Using Xenopus as a model system to investigate the mechanisms underlying the formation of these specialized actin structures, we observed stochastic bursts of intracellular calcium concentration in developing multiciliated cells. Through optogenetic manipulation of calcium signaling, we found that individual calcium bursts triggered the fusion and extension of actin structures by activating non-muscle myosin. Repeated cycles of calcium activation promoted assembly and coherence of the maturing apical actin network. Inhibition of the endogenous inositol triphosphate-calcium pathway disrupted the formation of apical actin/microridge-like structures by reducing local centriolar RhoA signaling. This disruption was rescued by transient expression of constitutively active RhoA in multiciliated cells. Our findings identify repetitive calcium bursts as a driving force that promotes the self-organization of the highly specialized actin cytoskeleton of multiciliated cells.

Source: International Journal of Molecular Sciences

DOI: 10.3390/ijms26062507

Authors: Johannes Wiegel, Martin Helmstädter, Gerd Walz, Max D. Bergen

Institutions: University of Freiburg, University Medical Center Freiburg

Language: English

Topic: Genetic and Kidney Cyst Diseases

Subfield: Genetics

Field: Biochemistry, Genetics and Molecular Biology

Domain: Life Sciences

Open Access status: gold

Estimated APC paid: $3,499

Funders: Deutsche Forschungsgemeinschaft, Else Kröner-Fresenius-Stiftung