Intellectual Merit: A central problem in cell biology is to understand how cells build their organelles. To address this problem, this project focuses on using centrioles as a model organelle. Centrioles are tiny organelles that assemble into a centrosome, which produces protein polymers called mircotubules. Microtubules are then used to build numerous protein-based machines within cells that play essential roles in cell motility, sensing the environment, and cell division. Centrioles are also attractive for organellogenesis studies because of their relative simplicity, being composed of only less than 15 different proteins and lacking an enveloping membrane. The goal of this project is to identify basic mechanisms of centriole assembly. Keys to unraveling this process lie in deciphering the roles kinases play as essential regulators of centriole assembly and in identifying their substrates. The master-regulator Polo-like-kinase-4 (Plk4)is such an enzyme, as its kinase activity is required for initiating centriole formation. At present, it is unclear how Plk4 drives centriole assembly, as its substrates at centrioles are only now beginning to emerge. This research involves a multidisciplinary procedure designed to directly identify Plk4 kinase targets specifically required for centriole assembly. This strategy combines high-throughput functional genomic screening, chemical genetics, and focused proteomic screening to identify and characterize key subunits that initiate centriole assembly when phosphorylated by Plk4. Thus, this project is designed to identify the earliest molecular steps in the centriole assembly process. A long-term goal of this research is to uncover fundamental insights into the mechanisms that cells use to build all organelles.
BROADER IMPACTS: This project contains several components designed to promote general education and provide new scientific training. During the course of this research, training will be provided to Ph.D. graduate and undergraduate students who have not yet had the opportunity to learn the scientific process and develop laboratory skills in molecular biology. It is highly encouraged that each of these individual attend national conferences to present his/her findings. Moreover, these participants will attend weekly meetings during which one member of the lab selects a scientific paper for lab members to read and discuss together. This exposes everyone to each others' diverse scientific interests, provides valuable practice in presenting and discussing science, and, for the undergraduates particularly, exposes them to critical discussions of the scientific literature that can give them a view of scientific inquiry that is not often presented in their regular classes. Graduate students will gain experience mentoring undergraduate research students in independent research projects and, for those students who intend to pursue teaching as a primary career, are encouraged to gain experience in teaching undergraduates. Undergraduate researchers will be recruited from the University of Arizona Minority Access to Research Careers (MARC) program, designed to recruit local student researchers from underrepresented groups, as well as the NSF-sponsored Undergraduate Biology Research Program (UBRP). All protocols and reagents developed in this project will be accessible to the scientific community. Results from this work will published in scientific journals. Results that are of especially broad interest will also be disseminated in lay terms, at the time of publication, through the University of Arizona News Service (UANews.org). Furthermore, this project will contribute to both the research and education missions of American universities.
