The phagocytosis-like process of engulfment, a critical step in the sporulation pathway of Bacillus subtilis, provides an ideal system to study how bacterial cells move macromolecules, localize proteins and catalyze membrane fission. During this key step in bacterial endospore formation, one bacterial cell engulfs another mediating a striking reorganization of the sporangium, from two cells that lie side by side, to an endospore, in which one cell lies within the cytoplasm of another. Engulfment offers an ideal system for understanding how cell wall hydrolases are spatially and temporally regulated, and how they contribute to this dynamic process. Current data suggest that the DMP proteins are required for both membrane migration and septal thinning, and demonstrate that SpollD and SpollP hydrolyze peptidoglycan. One of the key goals of this application is to correlate the biochemical activities of these engulfment proteins with their various in vivo activities. Another is to identify and characterize additional engulfment proteins whose involvement in engulfment may be masked by the robust engulfment bestowed by the two identified, DMP and Q-AH, engulfment modules.
The research proposed here will increase our understanding on the mechanisms of development. Developmental biological research, in any organism, can provide important information for uncovering the basis of diseases that result from aberrant gene expression during development in humans. Through this study, we will also increase our understanding of sporulation in, not only, the common soil bacterium B. subtilis but also in other Bacillus species, such as the pathogenic B. anthracis.
|Gutierrez, Jennifer; Smith, Rachelle; Pogliano, Kit (2010) SpoIID-mediated peptidoglycan degradation is required throughout engulfment during Bacillus subtilis sporulation. J Bacteriol 192:3174-86|