Activities and Functions of the Basic Pentacysteine DNA-binding Proteins

University Of California-Davis, Davis CA

Investigators

Abstract

Transcription of protein coding genes is a fundamental cellular process that is essential for all aspects of metabolism and development. Understanding of the mechanisms by which DNA-binding transcription factors promote and regulate differential transcription of genes is therefore a major goal of molecular and developmental biologists. The BASIC PENTACYSTEINE (BPC) proteins are a newly described small family of plant-specific DNA-binding proteins that are produced in most plant organs. Phenotypic effects resulting in mutation or overexpression of BPC genes indicate that BPC proteins play roles in expression of a variety of genes. Characterization of the function of the BPC proteins promises to reveal new information on functions of DNA-binding proteins and novel mechanisms for regulation of gene transcription. A multidisciplinary approach will be used to determine the cellular roles of BPC proteins. Direct targets of BPC action will be identified through a "top-down" approach by identifying genes whose expression is altered in bpc mutant plants. Additional screens will make use of conditionally active BPC variants expressed in transgenic plants in combination with comprehensive gene expression profiling. A complementary "bottom-up" approach will identify BPC targets starting from sequences that can be bound by isolated BPC proteins in vitro. The activity of DNA-binding transcription factors commonly results from association with additional protein factors. In vivo systems will be used to determine the nature of proteins bound by BPC proteins to determine the mechanisms through which BPC proteins modulate gene expression. Completion of the project will provide significant new information on the determinants of gene expression in plants. The novel nature of the BPC proteins and the fact that they have a unique DNA-binding domain provides the opportunity to uncover new fundamental information on protein-DNA interactions. Undergraduate, graduate and postdoctoral participants in the research will learn to apply the latest methods of molecular biology and analysis of gene expression in a strong biological context. High school students will also be exposed to this cutting edge research through lab internships and outreach by the principal investigator.