Model of actin/actin regulatory factors position and ER MCS just before fission. The WASH complex recruits and activates ARP2/3 to form a stabilizing actin structure on the endosome bud. COR1C is recruited to these actin structures to bind and counter act ARP2/3 actin nucleation via its CC. This results in an actin structure large enough to stabilize the bud, allowing cargo to sort, but small enough to allow ER recruitment and bud fission.