Affiliation:
1. Department of Microbiology and Molecular Genetics, UMDNJ—New Jersey Medical School, Newark, New Jersey, USA
2. Department of Biology, Indiana University, Bloomington, Indiana, USA
Abstract
ABSTRACT
Bacillus subtilis
biofilm formation is tightly regulated by elaborate signaling pathways. In contrast to domesticated lab strains of
B. subtilis
which form smooth, essentially featureless colonies, undomesticated strains such as NCIB 3610 form architecturally complex biofilms. NCIB 3610 also contains an 80-kb plasmid absent from laboratory strains, and mutations in a plasmid-encoded homolog of a Rap protein, RapP, caused a hyperrugose biofilm phenotype. Here we explored the role of
rapP phrP
in biofilm formation. We found that RapP is a phosphatase that dephosphorylates the intermediate response regulator Spo0F. RapP appears to employ a catalytic glutamate to dephosphorylate the Spo0F aspartyl phosphate, and the implications of the RapP catalytic glutamate are discussed. In addition to regulating
B. subtilis
biofilm formation, we found that RapP regulates sporulation and genetic competence as a result of its ability to dephosphorylate Spo0F. Interestingly, while
rap phr
gene cassettes routinely form regulatory pairs; i.e., the mature
phr
gene product inhibits the activity of the
rap
gene product, the
phrP
gene product did not inhibit RapP activity in our assays. RapP activity was, however, inhibited by PhrH
in vivo
but not
in vitro
. Additional genetic analysis suggests that RapP is directly inhibited by peptide binding. We speculate that PhrH could be subject to posttranslational modification
in vivo
and directly inhibit RapP activity or, more likely, PhrH upregulates the expression of a peptide that, in turn, directly binds to RapP and inhibits its Spo0F phosphatase activity.
Publisher
American Society for Microbiology
Subject
Molecular Biology,Microbiology
Cited by
67 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献