Seeonlineversionforlegendandreferences.974Cell135,November28,2008©2008ElsevierInc.DOI10.1016/j.cell.2008.10.040SnapShot:Cell-CycleRegulatorsIIDavidO.MorganUniversityofCalifornia,SanFrancisco,CA94143,USAfunctionS.cerevisiae(BuddingYeast)S.pombe(fissionYeast)D.melanogaster(fruitfly)X.laevis(clawedToad)H.sapiens(Human)Cdk-inhibitorykinasesPhosphorylateCdkinactivesite,blockingactivityswe1Wee1,Mik1Dwee1,Dmyt1Wee1,Myt1Wee1,Myt1Cdk-activatingphosphatasesDephosphorylateinhibitoryphosphorylationofCdksubunitMih1cdc25string,Twinecdc25A,B,ccdc25A,B,cCdkinhibitorproteins(CKIs)(selected)Sic1class:inhibitsSandMphaseCdkssic1Rum1Roughex(Rux)Cip/Kipclass:inhibitsG1,S,MphaseCdksandactivatesG1CdksDacapo(Dap)Xic1(Kix1)p21(Cip1,Waf1),p27(Kip1),p57(Kip2)INK4class:inhibitsG1Cdksp15Ink4b,p16Ink4a,p18Ink4c,p19Ink4dAPCinhibitors(selected)Bindactivatingsubunit,oftenaspseudosubstratesAcm1bindsCdh1Mes1bindsCdc20inmeiosisRca1bindsCdh1Xerp1(Emi2)bindsCdc20inmeiosisemi1bindsCdc20andCdh1SCF(Skp1-Cullin-Fbox)ubiquitinligaseF-boxsubunits(selected)RecruitindicatedsubstratestoSCFligaseforubiquitinationcdc4recruitsSic1,Far1,Cdc6fbw7(Cdc4,Ago)recruitscyclinEβ-TrcP1recruitsCdc25A,Wee1,Emi1Grr1recruitsCln1,2skp2recruitsE2F-1,p27G1/SgenecontrolTranscriptionfactors:Sequence-specificDNA-bindingproteinsatG1/SgenepromoterssBf(Swi6+Swi4):activatorde2f1:activatore2f-1,2,3:activatorsMBf(Swi6+Mbp1):regulatorde2f2:repressore2f4,5:repressorsCdk-dependentinhibitors:Inhibitactivatorsorassistrepressors;inhibitedbyG1-CdkWhi5dRBf1,dRBf2pRB,p107,p130974.e1Cell135,November28,2008©2008ElsevierInc.DOI10.1016/j.cell.2008.10.040SnapShot:Cell-CycleRegulatorsIIDavidO.MorganUniversityofCalifornia,SanFrancisco,CA94143,USAThecorecomponentsofthecell-cyclecontrolsystemaregovernedbynumerousadditionalregulators,whichensurethatcyclin-dependentkinase(Cdk)andanaphase-promotingcomplex(APC)activitiesarerobustlyandrapidlyactivatedinthecorrectorderandattheappropriatecell-cyclestage.Cyclin-Cdkactivitiesarecontrolledbyphosphorylationatinhib...
