Project summary: The focus of this proposal is to identify and characterize factors controlling cell division in the model organism Bacillus subtilis. The first established event in prokaryotic cell division is assembly of the tubulin homolog FtsZ into a ring-like structure at the future division site. The spatial and temporal regulation of cell division is achieved through a network of regulatory factors that modulate FtsZ assembly dynamics and coordinate FtsZ-ring formation with chromosome replication, segregation and cell growth. Although some factors that inhibit or potentiate bacterial cell division have been characterized, the complete suite of factors and signals governing this process has yet to be identified. Genetic approaches will be utilized to identify proteins that modulate cell division in response to cell cycle signals. Promising candidates will be characterized genetically and biochemical to determine the mechanism by which they affect FtsZ-ring formation, ultimately providing a clearer picture of the spatial and temporal regulation of cytokinesis. Relevance: Given the fundamental and highly conserved nature of cell division across evolutionary boundaries, identifying and characterizing the suite of factors involved in bacterial cell division will add to our understanding of the general principles that govern and coordinate cell division, and will provide insights into cell cycle regulation in all cells, both prokaryotes and eukaryotes. From an applied perspective, as components of an essential biological process, factors involved in bacterial cell division make attractive targets for novel antibiotic and antimicrobial drug development. [unreadable] [unreadable] [unreadable]