▁ax in ▁also ▁has ▁the ▁potential ▁to ▁o lig omer ize ▁through ▁its ▁C - term inal ▁D IX ▁domain . ▁The ▁result ▁is ▁a ▁huge , ▁mult imer ic ▁protein ▁assembly ▁dedicated ▁to ▁ β - c aten in ▁ph osph ory lation . ▁This ▁complex ▁is ▁usually ▁called ▁the ▁beta - c aten in ▁destruction ▁complex , ▁although ▁it ▁is ▁distinct ▁from ▁the ▁prote os ome ▁mach in ery ▁actually ▁responsible ▁for ▁ β - c aten in ▁de grad ation . ▁It ▁only ▁marks ▁ β - c aten in ▁mole cules ▁for ▁subsequent ▁destruction . ▁ ▁W nt ▁signal ing ▁and ▁the ▁reg ulation ▁of ▁destruction ▁▁ ▁In ▁rest ing ▁cells , ▁ax in ▁mole cules ▁o lig omer ize ▁with ▁each ▁other ▁through ▁their ▁C - term inal ▁D IX ▁domains , ▁which ▁have ▁two ▁binding ▁interfaces . ▁Thus ▁they ▁can ▁build ▁linear ▁o lig om ers ▁or ▁even ▁polym ers ▁inside ▁the ▁cy top las m ▁of ▁cells . ▁D IX ▁domains ▁are ▁unique : ▁the ▁only ▁other ▁prote ins ▁known ▁to ▁have ▁a ▁D IX ▁domain ▁are ▁Dis he vel led ▁and ▁D IX DC 1 . ▁( The ▁single ▁D sh ▁protein ▁of ▁D ros oph ila ▁corresponds ▁to ▁three ▁par alog ous ▁gen es , ▁D vl 1 , ▁D vl 2 ▁and ▁D vl 3 ▁in ▁m amm als .) ▁D sh ▁associ ates ▁with ▁the ▁cy top las mic ▁regions ▁of ▁Fri zz led ▁re cept ors ▁with ▁its ▁P D Z