Regulation of transcription factors by protein-protein interaction

点击翻译按钮获取中文摘要

Activity of many transcription factors are regulated by protein-protein interaction. We have investigated the regulation of transcription factors by protein-protein interaction. Especially, the following transcription factors that are involved in cellular growth control were focused.1. CRE(cAMP response element)-binding protein CRE-BP1.We previously indentified the CRE-binding protein CRE-BP1 by cDNA cloning. CRE-BP1 binds to CRE as a homodimer or heterodimer with c-Jun. We have indentified the CRE-BP1-related protein CRE-BPa by cDNA cloning. CRE-BPa forms a homodimer or a heterodimer with c-Jun or CRE-BP1, and binds to CRE.Interestingly, the trans-activating capacity of CRE-BPa was stimulated by TPA treatment.2. myb proto-oncogene product (Myb)We have found that the activity of Myb is negatively regulated by the leucine zipper motif located in the middle of Myb molecule. This suggests that an inhibitor binds to Myb through this leucien zipper and blocks its activity. We have identified two proteins, 90- and 130kDa proteins, that can bind to the Myb leucien zipper. We have also found that Myb can form a dimer through the leucine zipper and a Myb dimer cannot bind to DNA.This indicates that Myb itself also can function as an inhibitor.