actindriven

Actindriven, often written actin-driven, is a descriptive term used to characterize processes whose dynamics are powered primarily by actin filament polymerization and network remodeling. It denotes cellular and molecular phenomena in which force generation and movement arise from actin dynamics rather than direct motor protein activity alone. Actindriven processes are central to cell morphology, motility, and shape changes, as well as intracellular transport and endocytic or exocytic events that depend on rapid actin reorganization.

The underlying mechanisms involve regulated assembly and disassembly of actin filaments. Nucleation factors such as the Arp2/3 complex promote branched networks, while formins generate or stabilize linear filaments. Capping proteins, cofilin, profilin, and crosslinkers modulate filament length and network stiffness. Signaling pathways, particularly Rho family GTPases (Rac, Cdc42, RhoA), coordinate actin dynamics with membrane protrusions like lamellipodia and filopodia, enabling directional movement. Actin-driven propulsion also underlies specialized systems such as actin comet tails that drive movement of intracellular pathogens like Listeria monocytogenes.

Examples and significance include cell migration during development, wound healing, and immune responses; endocytosis and vesicular trafficking; and intracellular positioning of organelles. Dysregulation of actindriven processes is linked to cancer metastasis, inflammatory disorders, and developmental defects. Research on actindriven mechanisms uses a range of methods, from live-cell imaging of actin dynamics to in vitro reconstitution of actin networks, enabling a deeper understanding of how cells convert polymerization energy into mechanical work.