Time-lapse images show control (top panel) and anillin-depleted HeLa cells (bottom two panels) stably expressing an active form of myosin light chain fused to GFP (GFP:MLC active).
The AHD is essential for anillin's localization and function. This domain shares homology with the RhoA-GTP binding protein Rhotekin, and directly binds to RhoA. It also binds to Ect2 (human cells), RacGAP50C (MgcRacGAP, Drosophila), microtubules, septins (overlaps with the PH domain) and contains an NLS(s) that binds to importins. Anillin is required to maintain active myosin in the equatorial plane during cytokinesis, suggesting that it functions as a scaffold to link RhoA with ring components. We often see two phenotypes after anillin depletion - in one set of cells, furrows can form and ingress, but then oscillate (see figure below), while in the other set of cells, furrows cannot form.
Anillin is a highly conserved 110/124 kDa protein that is highly concentrated in the cleavage furrow of dividing cells in metazoans. Anillin contains N-terminal actin and myosin binding domains, and an Anillin Homology domain (AHD) and Pleckstrin homology domain in the C terminus (see figure below).