Intercellular communication 101
Oeiras, 04.01.2015
Looking into basic cellular processes in closely related species can shed light into their origin and evolution. Addressing intercellular communication, researchers from the Adriano O. Henriques Lab compared spore formation in two closely related bacteria: Bacillus subtilis and Clostridium difficile. The work, which involves the collaboration of reseachers from the Lab of Mariana Pinho, and from Newcastle University and Imperial College, is published in Molecular Microbiology.
Spore formation in Bacillus subtilis involves the formation of two differently sized cells. The smaller cell will give rise to the future spore, while the larger mother cell will nurture the spore maturation before releasing it to the environment. Soon after cell division, the mother cell engulfs the forespore. This marks the transition to the last stages of spore development, during which forespore and mother cells follow different but coordinated programs of gene expression. Coordination is achieved by cell-cell communication established by the forespore protein SpoIIQ and the mother cell protein SpoIIIAH. Questions were raised if these proteins (which are somewhat different) have similar functions in more ancient sporulating species, like Clostridium difficile.
Analysis of the function of these proteins in Clostridium difficile, shows that SpoIIQ and SpoIIIAH interact during engulfment and form a complex in vitro. By generating C. difficile mutants lacking either SpoIIQ or SpoIIIAH, researchers showed also that these proteins are required for late transcription in the spore and mother cell, suggesting that control of engulfment and a channel-like function are ancestral functions of the SpoIIQ-SpoIIIAH complex.
Results from this study highlight how the ancient Clostridia group of organisms provides new insights into the evolution and mechanism governing endosporulation. Furthermore, the observation that, in the absence of SpoIIQ or SpoIIIAH, proper gene expression is impaired not only in the spore but also in the mother cell expands on the channel model and suggests an unexpected degree of metabolic cooperation between the two cells throughout development. Future work may unable the identification of the compound (or compounds) that are transferred through the channel. On a more applied perspective, and as stated by the authors “the SpoIIQ-SpoIIIAH complex of C. difficile represents a promising target for strategies aiming at interfering with sporulation and therefore with the transmission and environmental persistence of this pathogen”.
Original Article
Molecular Microbiology (2015) Accepted Author Manuscript
The SpoIIQ-SpoIIIAH complex of Clostridium difficile controls forespore engulfment and late stages of gene expression and spore morphogenesis
Serrano, M., Crawshaw, A. D., Dembek, M., Monteiro, J. M., Pereira, F. C., de Pinho, M. G., Fairweather, N. F., Salgado, P. S. and Henriques, A. O.
