▁an ▁in hib ition ▁of ▁apo pt osis ▁Al ong ▁with ▁being ▁an ▁indu cer ▁of ▁apo pt osis , ▁C AS ▁also ▁plays ▁a ▁role ▁in ▁being ▁a ▁check point ▁for ▁cell ▁cycle . ▁Without ▁the ▁C AS ▁protein , ▁a ▁cell ▁will ▁not ▁be ▁able ▁to ▁go ▁beyond ▁the ▁G 2 ▁phase . ▁It ▁is ▁in ▁the ▁nucle us ▁of ▁the ▁cell , ▁where ▁its ▁export in ▁function ▁comes ▁into ▁play . ▁ ▁The ▁Cas ▁family ▁of ▁prote ins ▁can ▁be ▁divided ▁into ▁ 4 ▁functional ▁domains : ▁expression , ▁inter ference , ▁ad a ption , ▁and ▁anc ill ary . ▁The ▁expression ▁domain ▁help ▁with ▁cr R NA ▁binding ▁and ▁with ▁binding ▁of ▁targets . ▁The ▁inter ference ▁module ▁helps ▁with ▁the ▁cle ave ▁of ▁a ▁target . ▁The ▁ad a ption ▁domain ▁helps ▁with ▁spac er ▁ac quisition . ▁Last ly , ▁the ▁anc ill ary ▁domain ▁helps ▁with ▁reg ulation ▁of ▁the ▁gene ▁and ▁other ▁CR IS PR ▁functions . ▁ ▁The ▁CR IS PR - C as ▁family ▁of ▁protein ▁is ▁also ▁divided ▁into ▁ 3 ▁different ▁types , ▁Type ▁I , ▁Type ▁II , ▁Type ▁III . ▁Each ▁of ▁the ▁ 3 ▁types ▁of ▁CR IS PR - C as ▁are ▁character ized ▁by ▁a ▁specific ▁gene ; ▁Type ▁I : ▁Cas 3 , ▁Type ▁II : ▁Cas ▁ 9 , ▁Type ▁III : ▁Cas ▁ 1 0 . ▁ ▁See ▁also ▁ ▁N uc lear _ p ore # Import _ of _ prote