Degradation by proteases Lon, Clp and HtrA, of Escherichia coli proteins aggregated in vivo by heat shock; HtrA protease action in vivo and in vitro

Molecular Microbiology
E LaskowskaA Taylor

Abstract

Thermally aggregated, endogenous proteins of Escherichia coli form a distinct fraction, denoted S, which is separable by sucrose-density-gradient centrifugation. It was shown earlier that DnaK, DnaJ, IbpA and IbpB heat-shock proteins are associated with the S fraction. Comparison of the rise and decay of the S fraction in mutants defective for heat-shock proteases Lon (La), Clp, HtrA (DegP, Do) and in wild-type strains made studies of proteolysis and the function of the heat-shock response possible in vivo. Different timing and the extent of action of particular proteases was revealed by the initial size and decay kinetics of the S fraction. The proteases Lon, Clp, and HtrA all participated in removal of the aggregated proteins. Mutation in the gene encoding ClpB caused the most prominent effect (47% stabilization of the S fraction). The correlation between the disappearance of the S fraction and proteolytic activity was supported by the result of the in vitro reaction. Approximately one third of the isolated S fraction was converted to trichloroacetic acid-soluble products by the purified HtrA protease. Mg2+ ions stimulated the reaction, in contrast to the reaction of the HtrA protease with casein. The digestion of the aggrega...Continue Reading

Citations

Sep 25, 2007·Archives of Microbiology·Shen LuoRodney L Levine
Apr 22, 2006·Applied Microbiology and Biotechnology·Kirsi SavijokiPekka Varmanen
Jun 28, 2005·Biochemical and Biophysical Research Communications·Jakob HansenPeter Bross
Jul 27, 2002·Journal of Biotechnology·M M Carrió, A Villaverde
Mar 14, 2000·FEMS Microbiology Letters·D Nekolny, J Chaloupka
Sep 24, 2005·Infection and Immunity·Saswati Biswas, Indranil Biswas
Feb 10, 2010·BMC Genomics·Amanjot SinghAnil Grover
Jan 20, 2004·Microbial Cell Factories·Jimena WeibezahnAxel Mogk
Jun 1, 2010·Microbial Cell Factories·Britta JürgenPeter Neubauer
Sep 24, 2011·Gut Pathogens·Kristoffer T BækLone Brøndsted
Nov 13, 2002·Biomedical Papers of the Medical Faculty of the University Palacký, Olomouc, Czechoslovakia·P KopecekE Weigl
Jun 26, 2007·Journal of Molecular Biology·Agnieszka LewandowskaKrzysztof Liberek
Jun 28, 2013·Molecular Microbiology·Annika CimdinsFranz Narberhaus
Sep 26, 2012·Proteomics·A Wilson AruniHansel M Fletcher
Jun 5, 2012·Journal of Structural Biology·Skye HodsonSteven G Burston
Apr 18, 2014·PloS One·Patxi San Martin-UrizJose E Gonzalez-Pastor

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