▁a ▁protein ▁that ▁in ▁humans ▁is ▁encoded ▁by ▁the ▁W I PI 2 ▁gene . ▁ ▁Function ▁▁ ▁W D 4 0 ▁repeat ▁prote ins ▁are ▁key ▁components ▁of ▁many ▁essential ▁bi olog ic ▁functions . ▁They ▁reg ulate ▁the ▁assembly ▁of ▁multip rote in ▁complex es ▁by ▁present ing ▁a ▁beta - prop eller ▁platform ▁for ▁simultane ous ▁and ▁revers ible ▁protein - prote in ▁interactions . ▁M embers ▁of ▁the ▁W I PI ▁sub family ▁of ▁W D 4 0 ▁repeat ▁prote ins , ▁such ▁as ▁W I PI 2 , ▁have ▁a ▁ 7 - bl aded ▁prop eller ▁structure ▁and ▁contain ▁a ▁conser ved ▁mot if ▁for ▁interaction ▁with ▁ph osph ol ip ids . ▁ ▁W I PI 2 ▁is ▁the ▁m amm al ian ▁hom olog ▁of ▁At g 1 8 , ▁not ▁At g 2 1 , ▁along ▁with ▁the ▁closely ▁related ▁protein , ▁W I PI 1 . ▁W I PI 2 ▁m R NA ▁is ▁readily ▁detect able ▁in ▁several ▁commonly ▁used ▁labor atory ▁cell ▁lines ▁( HE K 2 9 3 A , ▁He La , ▁A 4 3 1 ) ▁and ▁several ▁cancer ▁cell ▁lines , ▁while ▁W I PI 1 ▁expression ▁is ▁limited ▁to ▁cancer ▁cells . ▁ ▁The ▁At g ▁prote ins ▁reg ulate ▁aut oph agy , ▁which ▁is ▁a ▁l ys os om al ▁de grad ation ▁path way ▁required ▁for ▁maintain ing ▁cell ▁health , ▁surv iving ▁periods ▁of ▁nut ri ent ▁dep riv ation ▁and ▁also