ia , ▁Ukraine ) ▁ ▁Tem perate ▁con ifer ous ▁for ests ▁ ▁Car path ian ▁mont ane ▁con ifer ▁for ests ▁( U k raine ) ▁ ▁Tem perate ▁grass lands , ▁sav ann as ▁and ▁shr ub lands ▁ ▁Pont ic ▁ste ppe ▁( M old ova , ▁Roman ia , ▁Russia , ▁Ukraine ) ▁ ▁Category : Environment ▁of ▁Ukraine ▁Ukraine ▁* ▁* ▁Category : P ale ar ctic ▁e cor eg ions <0x0A> </s> ▁SV 4 0 ▁large ▁T ▁ant igen ▁( Sim ian ▁V acu ol ating ▁Vir us ▁ 4 0 ▁T Ag ) ▁is ▁a ▁hex amer ▁protein ▁that ▁is ▁a ▁dominant - act ing ▁on cop rote in ▁derived ▁from ▁the ▁poly om av irus ▁SV 4 0 . ▁▁ ▁T Ag ▁is ▁capable ▁of ▁indu cing ▁m align ant ▁transformation ▁of ▁a ▁variety ▁of ▁cell ▁types . ▁The ▁transform ing ▁activity ▁of ▁T Ag ▁is ▁due ▁in ▁large ▁part ▁to ▁its ▁perturb ation ▁of ▁the ▁ret in ob last oma ▁( p R b ) ▁and ▁p 5 3 ▁tum or ▁suppress or ▁prote ins . ▁In ▁addition , ▁T Ag ▁bind s ▁to ▁several ▁other ▁cell ular ▁factors , ▁including ▁the ▁trans cription al ▁co - activ ators ▁p 3 0 0 ▁and ▁C B P , ▁which ▁may ▁contribute ▁to ▁its ▁transformation ▁function . ▁ ▁T Ag ▁is ▁a ▁product ▁of ▁an ▁early ▁gene ▁trans cribed ▁during ▁vir al ▁in fection ▁by ▁SV 4 0 , ▁and ▁is ▁involved ▁in ▁vir al