Sculpting Shape: How the Cytoskeleton, Molecular Motors and Mechanical Forces Control Morphogenesis

Abstract:

After a brief introduction to the cytoskeleton (actin and microtubules), their molecular motors (myosins and kinesins), and their roles in intracellular processes, I will present two stories illustrating how actin and microtubules control symmetry breaking and shape formation. The first explores how actomyosin generates chiral patterns across multiple organizational scales—from the molecular level to tissue and organ morphology in Drosophila. The second focuses on plant morphogenesis, where microtubules are known to direct cellulose synthase orientation and show cortical arrangements that correlate with mechanical stress patterns in tissues. A fundamental question has thus far remained unanswered: do microtubules function as passive geometric elements or active mechanosensors? I demonstrate that microtubules are indeed mechanosensors: mechanical tension within the microtubule lattice regulates interactions with microtubule-associated proteins (MAPs). Using kinesin-1 as a proof of principle, I show how tensile forces modulate MAP binding to microtubules, establishing that force-dependent regulation of MAP-MT interactions is a general mechanosensing mechanism.

References:

Membrane-BoundMyo1c Powers Asymmetric Motility of Actin Filaments: Current Biology (link is external)

Molecularto organismal chirality is induced by the conserved myosin 1D | Science (link is external)

Aremicrotubules tension sensors? | Nature Communications (link is external)

Mechanical tension expands the microtubulelattice stepwise and modulates kinesin-1 binding in an isoform-dependent manner| bioRxiv (link is external)