MassIVE MSV000087154 - High resolution time-lapse proteomic analysis of sporulation

Bacillus subtilis vegetative cells switch to sporulation upon nutrient limitation. To investigate the proteome changeover during sporulation, a time-lapse proteomic analysis was performed in a cell population that was induced to sporulate synchronously. Here, we are the first to comprehensively investigate the changeover of sporulation regulatory proteins, coat proteins and other proteins involved in sporulation and spore biogenesis. Protein co-expression analysis revealed four co-expressed modules. Modules brown and green are upregulated during sporulation and are annotated as associated with sporulation. Module blue, which is negatively correlated with modules brown and green, comprised ribosomal and metabolic proteins, and module yellow is co-expressed with module blue and modules brown & green. Notably, several proteins not belonging to any of the known transcription regulons were identified as co-expressed with modules brown and green. We speculate that they may also play roles during sporulation. Finally, amounts of some coat proteins, for example morphogenetic coat proteins, decreased late in sporulation. While we speculate on their possible role in guiding or helping assembly of other coat proteins, after which they can be disposed of, such a hypothesis remains to be experimentally addressed.