CAREER: GTPase Control of Ribosome Biogenesis

Michigan State University, East Lansing MI

Investigators

Abstract

The assembly of the ribosome, a complex macromolecular machine consisting of at least 54 proteins and 3 RNA molecules in bacteria, is a poorly understood process in all cells. GTPases have critical roles in ribosome biogenesis in organisms ranging from bacteria to humans, yet their molecular functions are not well characterized. The overall objective of the research project outlined in the career development plan is to elucidate how an essential GTPase, RbgA, participates in the biogenesis of the large ribosomal subunit in Bacillus subtilis. RbgA is widely conserved in most bacteria and eukaryotes and therefore the results obtained regarding RbgA function will be applicable to ribosome biogenesis in many systems. The plethora of genetic tools, the ability to reconstitute bacterial ribosome biogenesis in vitro, and the fact that Gram positive bacteria utilize alternative pathways in the synthesis and biogenesis of the ribosome make B. subtilis an ideal system to study RbgA function. A model in which RbgA facilitates the final maturation of a 45S intermediate into a mature 50S subunit by regulating the insertion of ribosomal protein L16 has been developed. To test this working model and the hypothesis that RbgA serves as a factor with dual functions in ribosome assembly and subunit coupling the following specific aims will be pursued: 1. Structural and functional characterization of a novel large ribosomal subunit intermediate. 2. In vitro and in vivo analysis of the function of RbgA in ribosome biogenesis. The intellectual merit of this research is a better understanding of how non-ribosomal factors influence ribosome biogenesis in vivo. As part of the educational component of the career development plan a hands-on undergraduate laboratory course highlighting the use of various genomic technologies is being developed. This course will supplement an existing undergraduate lecture and bioinformatics course already being taught by Dr. Britton. The broader impacts of this research project are: 1. The preparation of undergraduates for graduate school or jobs in biotechnology by giving them a solid foundation in genomics, 2. The integration of current research projects into the undergraduate laboratory course, 3. The training of undergraduates and graduate students in the laboratory, and 4. Elucidating how ribosomes are formed in vivo, a process important for bacteria, archaea, and eukaryotic cells.