TI  - In vivo association of <prot>E2F</prot> and DP family proteins.
PG  - 2536-46
AB  - The mammalian transcription factor    <prot>E2F</prot>    plays an important role in
      regulating the expression of genes that are required for passage through
      the cell cycle. This transcriptional activity is inhibited by association
      with the <prot>retinoblastoma tumor suppressor protein</prot> ( <prot>pRB</prot> ) or its relatives
       <prot>p107</prot>  and  <prot>p103</prot> . The first cDNA from the <prot>E2F</prot> family to be cloned was
      designated <prot>E2F-1</prot>, and multiple <prot>E2F</prot> family members have now been
      identified. They bind to DNA as heterodimers, interacting with proteins
      known as DP. Here we demonstrate that DP is also a family of polypeptides
      with at least two members (<prot>hDP-1</prot> and <prot>hDP-2</prot>). Both  <prot>hDP-1</prot>  and  <prot>hDP-2</prot>   bind to
      all    <prot>E2F</prot>    family members in vivo, and each complex is capable of activating
      transcription. However, the various    <prot>E2F</prot> / DP    complexes display strong
      differences in the ability to bind to either  <prot>pRB</prot>  or  <prot>p107</prot>  in vivo, and the
      specificity of <prot>pRB</prot> or <prot>p107</prot> binding is mediated by the <prot>E2F</prot> subunit.
AD  - Massachusetts General Hospital Cancer Center, Charlestown 02129, USA.
