Membrane pools of LIN-5/GPR-1/2 complexes regulate cleavage furrow formation and abscission. (A) Model demonstrating that enriched pools of LIN-5/GPR-1/2 via membrane binding property of Gα at the polar region and lateral region of the cell cortex confine the timely accumulation of actomyosin and Anillin at the equatorial cortical region for timely cytokinetic furrow formation. Inset highlights the equatorial membrane region where actin, NMY-2, and Anillin accumulate and regulate furrow formation. In contrast, LIN-5/GPR-1/2/Gα complexes accumulate at the polar and lateral membrane surface. (B) Model showing that membrane-enriched pools of LIN-5 and GPR-1/2-based complexes after furrow ingression in the vicinity of the midbody and its membrane regulate the confinement of midbody/midbody membrane–localized proteins, including centralspindlin components—CYK4 and Anillin. Inset highlighting the two juxtaposed equatorial membrane after furrow ingression enriches robust levels of cortical LIN-5/GPR-1/2 pools at the membrane near the midbody and surrounding midbody membrane. The midbody and the surrounding midbody membrane are occupied by microtubules, ECT-2/CYK-4/ZEN-4, Anillin, and other proteins (SPD-1, Aurora B, etc., not shown). Our work indicates that cortical LIN-5/GPR-1/2 after furrow ingression redundantly works microtubule-bundling protein SPD-1 in ensuring the stability of the midbody and thus abscission zone. In the absence of SPD-1, contractile ring proteins are restricted to the midbody and midbody surrounding membrane because of the presence of LIN-5/GPR-1/2 in the proximal region.