... described However, Xenopus egg extract MCMs dissociate from the chromatin as S- phase progresses (Kubota et al., 1997; Thommes et al., 1997) In humans, MCMs also seem to dissociate during S- phase, ... cells, Orc1 seems to be mono- and di-ubiquitinated, which causes its release from chromatin in S- phase until M-G1 (Li and DePamphilis, 2002) Regulation of S Phase 37 In humans, several studies show ... inhibitory of Cdt1, increases in S- phase, further preventing MCM2-7 loading Regulation of S Phase 43 wise assembly of factors is regulated at each stage, mostly through changes in protein levels, chromatin...