Bacillus subtilis Spore Inner Membrane Proteome

The
endospore is the dormant form of Bacillus subtilis and many other Firmicutes. By sporulation, these spore formers can
survive very harsh physical and chemical conditions. Yet, they need
to go through germination to return to their growing form. The spore
inner membrane (IM) has been shown to play an essential role in triggering
the initiation of germination. In this study, we isolated the IM of
bacterial spores, in parallel with the isolation of the membrane of
vegetative cells. With the use of GeLC–MS/MS, over 900 proteins
were identified from the B. subtilis spore IM preparations. By bioinformatics-based membrane protein
predictions, ca. one-third could be predicted to be membrane-localized.
A large number of unique proteins as well as proteins common to the
two membrane proteomes were identified. In addition to previously
known IM proteins, a number of IM proteins were newly identified,
at least some of which are likely to provide new insights into IM
physiology, unveiling proteins putatively involved in spore germination
machinery and hence putative germination inhibition targets.