• To determine any roles that E2F factors may play in a TGF-β-induced growth arrest process, we investigated the effect of TGF-β on the transcription regulation of three promoters that contain E2F binding sites, namely the E2F1 ( 12 ), B-myb ( 6 ), and HsORC1 (human origin recognition complex 1) ( 13 ) promoters. (pnas.org)
  • In vitro , purified ORC-1R [ORC with Orc1R694Ep (Orc1p Arg 694 →Glu mutant)] has decreased ATPase activity in the presence or absence of origin DNA. (biochemj.org)
  • Cdt1), and the Mcm2-Mcm7 complex. (wikipedia.org)
  • New ORC/Cdc6 complexes then recruit Cdt1/Mcm2-7 molecules to the site. (wikipedia.org)
  • Once this massive ORC/Cdc6/Cdt1/Mcm2-7 complex is formed, the ORC/Cdc6/Cdt1 molecules work together to load Mcm2-7 onto the DNA itself by hydrolysis of ATP by Cdc6. (wikipedia.org)
  • This leads to Cdt1 having decreased stability on the DNA and falling off of the complex leading to Mcm2-7 loading on to the DNA. (wikipedia.org)
  • The helicase loaders ORC-Cdc6 function to recruit a single Cdt1-Mcm2-7 heptamer to replication origins prior to Cdt1 release and ORC-Cdc6-Mcm2-7 complex formation, but how the second Mcm2-7 hexamer is recruited to promote double-hexamer formation is not well understood. (osti.gov)
  • However, the mechanisms of origin licensing and helicase activation are poorly understood. (osti.gov)
  • Detailed structural analysis of the loaded Mcm2-7 double-hexamer complex demonstrates that the two hexamers are interlocked and misaligned along the DNA axis and lack ATP hydrolysis activity that is essential for DNA helicase activity. (osti.gov)
  • These data indicate that CDC45 functions in late G 1 phase in concert with CDC7/DBF4 to trigger initiation at replication origins after the assembly of the prereplicative complexes. (pnas.org)
  • Second, mutant cdc45 cells lose plasmids at an elevated frequency in a manner that can be suppressed by the addition of multiple origins to the plasmids ( 29 , 31 , 32 ). (pnas.org)
  • We propose that structural RNA molecules mediate ORC recruitment at some cellular and viral origins, similar to OriP. (embopress.org)
  • First, the ORC and Cdc6 form a complex on origin DNA (marked by ARS type regions). (wikipedia.org)
  • Here, structural evidence for intermediates consisting of an ORC-Cdc6-Mcm2-7 complex and an ORC-Cdc6-Mcm2-7-Mcm2-7 complex are reported, which together provide new insights into DNA licensing. (osti.gov)
  • A highly conserved sequence of 11bp (known as the A element) is thought to be essential for origin function in budding yeast. (wikipedia.org)
  • The A element contains the 11 base pair consensus sequence that is essential for the firing of DNA replication origins. (sanger.ac.uk)
  • Our studies of the H4 ARS and ARS307 have established the requirement for a DNA unwinding element (DUE), a broad easily-unwound sequence 3' to the essential consensus that likely facilitates opening of the origin. (semanticscholar.org)
  • However, in animal cells, replication origins gather into bundles called replicon clusters. (wikipedia.org)
  • We show here that TGF-β treatment of HaCaT cells induced the formation of E2F4-RB and E2F4-p107 complexes, which are capable of binding to E2F sites. (pnas.org)