Dr. Craig Ellermeier
Participation year
Project title

  Identification of regulators of the ECF sigma factor, SigV, in Bacillus subtilis


It was recently found that one ECF sigma factor, SigV, in Bacillus subtilis is induced by lysozyme stress. Activity of SigV is inhibited by a membrane bound anti-sigma factor RsiV. Many ECF sigma factors are activated by two successive proteolytic events known as site 1 and site 2 cleavage of the anti-sigma factor in response to antimicrobial peptides and other agents that damage the cell envelope. These two sites are cleaved by specific proteases that function to destroy the anti-sigma factor. Site 2 cleavage of the anti-sigma factor, RsiV , is achieved by a protease called rasP/YluC , but the protease responsible for site 1 cleavage remains unknown. We presume that there is a site 1 where regulation occurs because generally site 2 cleavage occurs as a passive consequence of the first cleavage event. In order to find out about this site 1 protease we have performed transposon mutagenesis to look for mutants that don't turn on sigV in response to lysozyme stress and find genes that are required for activation of sigV.

University of Puerto Rico at Aguadilla