RUI: Analysis of the Role of CHD1 in Chromatin Structure and Transcription

Claremont Mckenna College, Claremont CA

Investigators

Abstract

Chromatin remodeling factors use the energy of ATP to modulate the structure of chromatin, thereby regulating processes such as transcription, replication, and repair. While significant advances have been made in regards to the mechanism of action of these ATPases in vitro, much remains unknown regarding their activities in vivo. The PI's long-term goal is to understand how the CHD1 chromatin remodeling and assembly factor is regulated and targeted in vivo. Drosophila melanogaster is an ideal model system in which to study the actions of this unusual protein. Intellectual merit: The goal of this research is to use the powerful tools of Drosophila genetics to investigate the in vivo activities of CHD1, a chromodomain, helicase, and DNA-binding domain protein. CHD1 is an unusual ATPase in that it possesses both nucleosome remodeling and nucleosome assembly activities in vitro. These experiments address the specific hypothesis that CHD1 functions globally to reassemble chromatin on active genes, an activity that results in the inhibition of transcription. This hypothesis will be addressed by pursuing three specific aims (1) Investigate the in vivo function of CHD1 by examining phenotypes of both gain of function and loss of function chd1 mutants. (2) Determine the relative contributions of each of the conserved protein domains. (3) Examine the consequences of both gain and loss of CHD1 ATPase activity on chromosome structure and RNA Polymerase II. The PI will employ a combination of genetic and cell biological approaches to analyze mutant phenotypes, chromosome morphology, and transcription. These well-established techniques are amenable to undergraduate research, and have been extensively used by the PI in her studies of related chromatin remodeling factors Brahma and ISWI. The PI's preliminary result and expertise place her in a unique position to accomplish these specific aims, the results of which should provide significant insights into the function and regulation of CHD1, a highly conserved yet poorly understood ATPase. Broader impacts: The research will be carried out primarily by undergraduate science students from Claremont McKenna, Scripps, and Pitzer Colleges. During her first three years in the Joint Science Department, the PI personally trained 15 undergraduates in the laboratory (13 women and two men), including two Latina first-generation college students. Students spend an average of two years in the research laboratory. Of the PIs research students who have graduated, 100% are continuing their science education in graduate or medical schools. Over the three years of this study, the PI will personally train an additional 12-15 undergraduates in the research laboratory, providing them with skills to help them succeed in their careers in science. The PI is in a unique department (The Joint Science Department) that is shared by three top-tier liberal arts institutions. Scripps is an all-women college, while Claremont McKenna and Pitzer College are the 5th and 7th most ethnically diverse liberal arts colleges in the top tier. This diverse student body allows the PI to encourage science students from historically underrepresented groups. In addition to providing research opportunities for undergraduates, this research will allow undergraduates to attend the Annual Drosophila Research Conference in addition to the Southern California Conference for Undergraduate Research. One of the PI's undergraduate research students is a co-author on the lab's most recent publication in Genetics. This RUI research will provide resources for the PI and her students to continue their current, competitive research into chromatin remodeling proteins using modern molecular genetic techniques.