TI  - Nuclear protein  <prot>CBP</prot>  is a coactivator for the transcription factor  <prot>CREB</prot> .
PG  - 223-6
AB  - The transcription factor <prot>CREB</prot> binds to a DNA element known as the
      cAMP-regulated enhancer (CRE).  <prot>CREB</prot>  is activated through phosphorylation
      by  <prot>protein kinase A</prot> (<prot>PKA</prot>) , but precisely how phosphorylation stimulates
      <prot>CREB</prot> function is unknown. One model is that phosphorylation may allow the
      recruitment of coactivators which then interact with basal transcription
      factors. We have previously identified a nuclear protein of M(r)265K,  <prot>CBP</prot> ,
      that binds specifically to the <prot>PKA</prot>-phosphorylated form of  <prot>CREB</prot> . We have
      used fluorescence anisotropy measurements to define the equilibrium
      binding parameters of the  <prot>phosphoCREB</prot> : <prot>CBP</prot>  interaction and report here that
      <prot>CBP</prot> can activate transcription through a region in its carboxy terminus.
      The activation domain of  <prot>CBP</prot>  interacts with the basal transcription factor
       <prot>TFIIB</prot>  through a domain that is conserved in the yeast coactivator <prot>ADA-1</prot>
      (ref. 8). Consistent with its role as a coactivator, <prot>CBP</prot> augments the
      activity of phosphorylated <prot>CREB</prot> to activate transcription of
      cAMP-responsive genes.
AD  - Vollum Institute, Oregon Health Sciences University, Portland 97201.
