Dataset Information

Clp-mediated proteolysis in Gram-positive bacteria is autoregulated by the stability of a repressor.

ABSTRACT: The heat shock proteins ClpC and ClpP are subunits of an ATP-dependent protease of Bacillus subtilis. Under non-stressed conditions, transcription of the clpC and clpP genes is negatively regulated by CtsR, the global repressor of clp gene expression. Here, CtsR was proven to be a specific substrate of the ClpCP protease under stress conditions. Two proteins of former unknown function, McsA and McsB, which are also encoded by the clpC operon, act as modulators of CtsR repression. McsA containing zinc finger motifs stabilizes CtsR under non-stressed conditions. McsB, a putative kinase, can inactivate CtsR by modification to remove the repressor from the DNA and to target CtsR for degradation by the ClpCP protease during stress. Thus, clp gene expression in Gram-positive bacteria is autoregulated by a novel mechanism of controlled proteolysis, a circuit of down-regulation by stabilization and protection of a transcription repressor, and induction by presenting the repressor to the protease. Thereby, the ClpC ATPase, a member of the Hsp100 family, was identified as a positive regulator of the heat shock response.

SUBMITTER: Kruger E

PROVIDER: S-EPMC145420 | biostudies-literature | 2001 Feb

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Clp-mediated proteolysis in Gram-positive bacteria is autoregulated by the stability of a repressor.

Krüger E E Zühlke D D Witt E E Ludwig H H Hecker M M

The EMBO journal 20010201 4

The heat shock proteins ClpC and ClpP are subunits of an ATP-dependent protease of Bacillus subtilis. Under non-stressed conditions, transcription of the clpC and clpP genes is negatively regulated by CtsR, the global repressor of clp gene expression. Here, CtsR was proven to be a specific substrate of the ClpCP protease under stress conditions. Two proteins of former unknown function, McsA and McsB, which are also encoded by the clpC operon, act as modulators of CtsR repression. McsA containing ...[more]

PMID: 11179229

Similar Datasets

Project description:Myxococcus xanthus kills other species to use their biomass as energy source. Its predation mechanisms allow feeding on a broad spectrum of bacteria, but the identity of predation effectors and their mode of action remains largely unknown. We initially focused on the role of hydrolytic enzymes for prey killing and compared the activity of secreted M. xanthus proteins against four prey strains. 72 secreted proteins were identified by mass spectrometry, and among them a family 19 glycoside hydrolase that displayed bacteriolytic activity in vivo and in vitro This enzyme, which we name LlpM (lectin/lysozyme-like protein of M. xanthus), was not essential for predation, indicating that additional secreted components are required to disintegrate prey. Furthermore, secreted proteins lysed only Gram-positive, but not Gram-negative species. We thus compared the killing of different preys by cell-associated mechanisms: Individual M. xanthus cells killed all four test strains in a cell-contact dependent manner, but were only able to disintegrate Gram-negative, not Gram-positive cell envelopes. Thus, our data indicate that M. xanthus uses different, multifactorial mechanisms for killing and degrading different preys. Besides secreted enzymes, cell-associated mechanisms that have not been characterized so far, appear to play a major role for prey killing.IMPORTANCEPredation is an important survival strategy of the widespread myxobacteria, but it remains poorly understood on the mechanistic level. Without a basic understanding of how prey cell killing and consumption is achieved, it also remains difficult to investigate the role of predation for the complex myxobacterial lifestyle, reciprocal predator-prey relationships or the impact of predation on complex bacterial soil communities.We study predation in the established model organism Myxococcus xanthus, aiming to dissect the molecular mechanisms of prey cell lysis. In this study, we addressed the role of secreted bacteriolytic proteins, as well as potential mechanistic differences in the predation of Gram-positive and Gram-negative bacteria. Our observation shows that secreted enzymes are sufficient for killing and degrading Gram-positive species, but that cell-associated mechanisms may play a major role for killing Gram-negative and Gram-positive prey on fast timescales.

Dataset Information

Clp-mediated proteolysis in Gram-positive bacteria is autoregulated by the stability of a repressor.

Publications

Clp-mediated proteolysis in Gram-positive bacteria is autoregulated by the stability of a repressor.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets