9724000 McCarty This proposal continues our investigation of the molecular mechanisms that underlie VP1 mediated gene activation and repression. The VP1 factor of maize plays a central role in integration of the maturation and germination pathways in the developing seed. The VP1/AB13 family of regulatory proteins is unique to the plant kingdom. Recent studies indicate that related proteins function in other phases of plant development. Dr. McCarty has shown that VP1 functions as an activator or repressor depending upon the target promoter and he has recently been able to demonstrate a cooperative sequence specific DNA binding activity. He will address three key issues: 1) The unique properties and regulation of the B3 DNA binding domain of VP1. 2) The mechanism by which promoter context is interpreted to determine whether VP1 activates or represses transcription. 3) The identification of partner proteins that provide the context information and mediate repression.
