Septin Filament Compaction Into Rings Requires the Anillin Mid2 and Contractile Ring Constriction

Septin filaments assemble into high-order molecular structures that associate with membranes, acting as diffusion barriers and scaffold proteins crucial for many cellular processes. However, how septin organize in such is still not well understood. In this study, we used fission yeast to explore filament organization during cell division decipher key factors responsible their regulation. Live-imaging polarization microscopy analysis uncovered are initially recruited a diffuse meshwork surrounding the acto-myosin contractile ring (CR) anaphase, which undergoes compaction two rings when CR constriction initiated. We found evidence anillin-like protein Mid2 necessary promote novel step, possibly bundler filaments. also Mid2-driven requires inputs from Septation Initiation Network (SIN) or β-1-3 glucan synthase Bgs1. This work highlights complex regulations allow coordination between assembly cycle progression.