20.500.12556/RUL-128206 ComX-induced exoproteases degrade ComX in Bacillus subtilis PS-216 Gram-positive bacteria use peptides as auto-inducing (AI) signals to regulate the production of extracellular enzymes (e.g., proteases). ComX is an AI peptide, mostly known for its role in the regulation of bacterial competence and surfactant production in Bacillus subtilis. These two traits are regulated accordingly to the bacterial population size, thus classifying ComX as a quorum sensing signal. ComX also indirectly regulates exoprotease production through the intermediate transcriptional regulator DegQ. We here use this peptide-based AI system (the ComQXPA system) as a model to address exoprotease regulation by ComX in biofilms. We also investigate the potential of ComX regulated proteases to degrade the ComX AI peptide. Results indicate that ComX indeed induces the expression of aprE, the gene for the major serine protease subtilisin, and stimulates overall exoprotease production in biofilms of B. subtilis PS-216 and several other B. subtilis soil isolates. We also provide evidence that these exoproteases can degrade ComX. The ComX biological activity decay is reduced in the spent media of floating biofilms with low proteolytic activity found in the comP and degQ mutants. ComX biological activity decay can be restored by the addition of subtilisin to such media. In contrast, inhibition of metalloproteases by EDTA reduces ComX biological activity decay. This suggests that both serine and metalloproteases, which are induced by ComX, are ultimately capable of degrading this signaling peptide. This work brings novel information on regulation of exoproteases in B. subtilis floating biofilms and reveals that these proteolytic enzymes degrade the AI signaling peptide ComX, which is also a major determinant of their expression in biofilms. cell signaling protease quorum quenching biofilms degradative enzymes quorum sensing auto inducing signal pellicles mikrobne združbe Bacillus subtilis komunikacija med celicami zaznavanje celične gostote zaznavanje kvoruma biofilmi peptidi ComX true false true Angleški jezik Slovenski jezik Članek v reviji 2021-07-06 14:30:22 2021-07-06 14:30:23 2022-09-07 04:13:40 0000-00-00 00:00:00 2018 0 0 11 str. art. 105 Vol. 9 Feb. 2018 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 579.2:547.97 1664-302X 10.3389/fmicb.2018.00105 4876664 RAZ_Spacapan_Mihael_2018.pdf RAZ_Spacapan_Mihael_2018.pdf 1 A7DCC381D84E782167BAAC719576B284 10ecbb1731464d5db35e68f86dfcfe52a139ba37e08f9319fb7d1a5175329dd3 2292a952-de56-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=144869 https://www.frontiersin.org/articles/10.3389/fmicb.2018.00105/full 0 e7505d4b-de55-11eb-a523-00155dcfd717 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=144868 Biotehniška fakulteta 0 0 0