TI  - Evidence for physical interaction between the zinc-finger transcription
      factors  <prot>YY1</prot>  and  <prot>Sp1</prot> .
PG  - 6145-9
AB  - Two promoter elements are important for basal-level transcription, the
   TATA motif typically located 30 nucleotides upstream of the transcription
      initiation site and the initiator (Inr) element encompassing the start
      site. The mechanism of how Inr elements work is poorly understood, partly
      because very few proteins that bind to Inr elements have been identified
      and isolated. The recently cloned <prot>YY1</prot> is such an <prot>Inr-binding protein</prot>. <prot>YY1</prot>
      is able to direct transcription upon binding to its recognition sequence
      in vitro. The ability of <prot>YY1</prot> to initiate transcription is augmented by the
      presence of a TATA motif or binding sites for transcription factor <prot>Sp1</prot>. To
      study the mechanism underlying the apparent functional cooperation between
       <prot>YY1</prot>  and  <prot>Sp1</prot> , we explored the possibility of protein-protein interactions
      between these two transcription factors. We found that  <prot>YY1</prot>  and  <prot>Sp1</prot>  can
      form a physical complex. In addition, we identified domains within  <prot>YY1</prot>  and
       <prot>Sp1</prot>  that mediate their interactions with each other. The physical
      interaction between  <prot>YY1</prot>  and  <prot>Sp1</prot>  may thus form the basis for the functional
      interplay observed previously.
AD  - Committee on Virology, Harvard Medical School, Boston, MA 02115.
